11004660-R01-0001-01 Rev.0

ERNEST HENRY MINING PTY LTD Underground Expansion Project

Conveyor Belt, Splice Kits and Sensor Guard Rip Detection

Conveyor Belts

Contract No.

1100 4660

Installation, Operation and

Maintenance Manual

2

TABLE OF CONTENTS

1.0 Veyance Belting Pty Ltd Contacts ........................................Page 4 2.0 GENERAL INFORMATION ...................................................Page 5

2.1 Purpose……………………………………………………………………………..Page 5 2.2 Statutory Requirement…………………………………………………….Page 6

2.3 Belt Specification ……………………………………………………………….Page 6 2.4 Belt Construction ……………………………………………………………….Page 7 2.5 Rubber Compound………………………………………………………………Page 7 3.0 SPLICING

3.1 Splice Specification ……………………………………………………..Pages 8 - 9 3.2. Splice Kits …………………………………………………………………..Page 10 3.3 Splice Drawings …………………………………………………………Pages 11-14

4.0 MAINTENANCE INSTRUCTIONS AND PROCEDURES

Section A Belt Installation ................................................. Pages 15-19 Section B Flexsteel Belt Splicing ........................................ Pages 20-38 Section C Repairing Steel Cable Conveyor Belting............... Pages 39-41 Section D Fabric Splice Preparation.................................... Pages 42-46 Section E Fabric Belt Vulcanising....................................... Pages 47-50 Section F Fabric Belt Bias Splice........................................ Pages 51-56 Section G Training The Belt................................................Page 57 Section H Factors Affecting The Training Of The Belt .......... Pages 58-60 Section I Sequence Of Training Operations ....................... Pages 61-62 Section J Cleaning ........................................................... Pages 63-64 Section K Loading ............................................................ Pages 65-67 Section L Pulley Lagging................................................... Pages 67-69 Section M Trouble Shooting............................................... Pages 70-71

5.0 SENSOR GUARD RIP PROTECTION……….Separate Section Pages 1-58

Addendum…………………………………………………………… Pages 59-60 6.0 REPAIRING FABRIC CONVEYOR BELTS…Separate Section Pages 1-11

7.0 MATERIAL SAFETY DATA SHEETS…………Separate Section Pages 1-30

8.0 LIFTING POINTS AND HANDLING ………..Separate Section Pages 1-5

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9. RECOMMENDED SPARE PARTS LIST………………Separate Section 1 Page

10. CERTIFIED DRAWINGS …….…….…………..Separate Section Pages 1-11

4

1.0 Veyance Belting Pty Ltd Contacts Sydney Contact : Bob Patman / Con Michaels Address : Level 3, 470 Church Street NORTH PARRAMATTA NSW 2151 Telephone: (02)8839 9602 / (02) 8839 9601 Fax: (02) 9890 8973 Email: robert_patman@veyance.com con_michaels@veyance.com Melbourne Contact: Gus McLennan

Address: 7 Dunlop Court BAYSWATER VIC 3153 Telephone: (03) 9721 0604 Fax: (03) 9720 5520 Email: gus_mclennan@veyance.com

Mackay Contact: Michael Anastasi Address: PO Box 1634 MACKAY QLD 4740 Telephone: 0432 640 649 Email: Michael_anastasi@veyance.com

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2.0 GENERAL INFORMATION

2.1 Purpose: Bulk Materials Handling

The ST1800 steel cord belting was manufactured by Veyance Belting Pty Ltd

in the plant located at Bayswater, Melbourne, Australia. The PN1000/5 fabric belting was manufactured by Shandong Aneng

Conveyor Belt & Rubber Co.Ltd. Joint Venture in Yanzhou City, Shandong Province, China.

The conveyor belt details are as follows:

Conveyor Number/ name

Belt Specification Supply Quantity (metres)

No. of Reels

(metres)

Identifier/ Job No.

E752CV001 Crusher Collector Conveyor

2000mm PN1000/5 with 15x5mm ARMA II covers

80 1x80 VB18846

E752CV002 Trunk Conveyor

1050mm ST1800 15x5mm ARMA II covers.

1390 3x463.40 JO32065

E755CV003 Loading Collection Conveyor

2000mm PN1000/5 with 15x5mm ARMA II covers

95 1x95 VB18846

E756CV004 Loading Conveyor

2400mm PN1000/5 with 15x5mm ARMA II covers.

110 1x110 VB18847

E771CV005 Overland Conveyor

1050mm ST1800 15x5mm ARMA II covers.

1245 3x415 JO32065

6

Supply Lengths Conveyor Supply

Quantity No. of Reels Gross Weight

(kgs) Reel Height /Length (m)

Reel Width (m)

E752CV001

80 1x80 7600 1.9x1.9 2.1

E752CV002

1390 3x463.4 19011 3.9x3.9 1.35

E755CV003

95 1x95 8700 2.0x2.0 2.1

E756CV004

110 1x110 11800 2.7x2.7 2.24

E771CV005

1245 3x415 17109 3.7x3.7 1.35

2.2 Statutory Requirements: Not applicable 2.3 Belt Specifications

Conveyor: E752CV001 E755CV003

E752CV002 E771CV005

E756CV004

Width: 2000mm 1050mm 2400mm Rating: PN1000/5 ST1800 PN1000/5 Top Cover 15mm 15mm 15mm Bottom Cover: 6mm 5mm 5mm Cover Grade: ARMA II ARMA II ARMA II Sensor Loops: None 45 metre None

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2.4 Belt Construction FABRIC BELT E752CV001 E755CV003 E756CV004 Width 2000mm 2000mm 2400mm Rating: PN1000/5 PN1000/5 PN1000/5 Top cover 15.0mm 15.0mm 15.0mm Bottom cover 5.0mm 5.0mm 5.0mm Cover grade ARMA II ARMA II ARMA II Number of cords: 5 5 5 Cord diameter: 0.5mm 0.5mm 0.5mm Ply strength: 200 kN 200 kN 200 kN Ply construction: Polyester/Nylon Polyester/Nylon Polyester/Nylon Belt breaking strength: 1000kN/m 1000kN/m 1000N/m Belt rated tension: 100.0 kN/m 100.0 kN/m 100.0 kN/m

STEEL CORD BELT E752CV002 E771CV005 Width 1050mm 1050mm Rating: ST1800 ST1800 Top cover 15.0mm 15.0mm Bottom cover 5.0mm 5.0mm Cover grade ARMA II ARMA II Number of cords: 84 84 Cord diameter: 4.6mm 4.6mm Cord strength: 23.0kN 23.0kN Cord construction: 7x7 7X7 Cord pitch: 12mm 12mm Belt breaking strength: 1800kN/m 1800kN/m Belt rated tension: 270.0kN/m 270.kN/m Sensor Loops Yes@45m

spacing Yes@45m

spacing

2.5 Rubber Compound

All belt types Top Cover Grade ARMA II Minimum Tensile Strength: 16.0 MPa Elongation Min: 450% Abrasion Value Max: 120mm³ Bottom Cover Grade ARMA II Minimum Tensile Strength: 16.0 MPa Elongation Min: 450% Abrasion Value Max: 120mm³

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3.0 SPLICING 3.1 Splice Specification 3.1.1 Conveyors E752CV001,E755CV003

2000mm PN1000/5 with 15mmx5mm ARMA II covers Type: Hot vulcanised Step: 4 Splice details

Cover Saddle Step length Splice type

100mm/75mm 250mm 4 step hot vulcanised Curing Splice Cure time: 50 minutes Cure temperature 143ºC ± 3ºC Cure pressure: 700 kPa Humidity: <75% Thermocouple all Platens Record all Temperatures 3.1.2 Conveyor E756CV004

2400mm PN1000/5 with 15mmx5mm Grade ARMA II covers Type: Hot vulcanised Step: 4 Splice details

Cover Saddle Step length Splice Type

100mm/75mm 250mm 4 step hot vulcanised Curing Splice Cure time: 55 minutes Cure temperature 143ºC ± 3ºC Cure pressure: 700 kPa Humidity: <75% Thermocouple all Platens Record all Temperatures

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3.1.3 Conveyors E752CV002 and E771CV005

1050mm ST1800 15mmx5mm Grade ARMA II Type: Hot vulcanised Stage: Two Stage Cord splice details

Belt Splice

Cord diameter 4.6mm 4.6mm

No of cords 84 140

Cord spacing 7.4mm 2.5mm

Cord pitch 12.0mm 7.1mm Splice Dimensions: Cover Skive: 15.0mm Transition Zone: 110mm Step length 509mm Splice length 1286mm Curing Splice Cure time: 57 minutes Cure temperature 145ºC ± 3ºC Cure pressure: 1030-1240 kPa Humidity: <75% Thermocouple all Platens Record all Temperatures

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3.2 Splice Kits

When a splice kit is required we strongly recommend it be sourced from Veyance. This will ensure the materials are compatible, fresh and are prepared to suit the belt construction.

Veyance splice kits are supplied in a sealed box containing all materials necessary to carry out one splice.

Splice Kit Contents – 2000mm PN1000/5 15mmx5mm grad e ARMA II and 2400mm PN1000/5 15mmx5mm grade ARMA II

Veyance Reference 1. Top and Bottom Covers fill in strips (Saddles) ZX5066 2. Fill in strips (Saddles) breaker fabric 1498/19722 3. Inside gum (Tie gum) ZX 5032 4. Cover cement Nylobond 5. Inside gum (Tie gum) cement M920C 6. Solvent M 714C 7. Light weight nylon BW1585 8. Polyethylene Plain XA665 9. Cellophane M604

Splice Kit Contents – 1050mm ST18000 15mmx5mm Grade ARMA II

Veyance Reference 1. Top and Bottom Covers ZX5066 2. Insulation gum ZX 5032 3. Cover cement Nylobond 4. End fill in gum ZX 5032 5. Edge fill in gum ZX 5032 6. Cable cement M893C 7. Solvent M 714C 8. Light weight nylon BW1585 9. Polyethylene Plain XA665

10. Cellophane M604 Splice Kit Shelf Life Splice Kit contains uncured rubber and cements.

Therefore the shelf life for the splice kits is 6 months refrigerated at 7ºC

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3.3 Splice Drawings

See next five pages:

i. Drawing No. VB-13202-00041 2000mm PN1000/5 15mmx5mm grade ARMA II ii. Drawing No. VB-13202-00042 2400mm PN1000/5 15mmx5mm grade ARMA II iii. Drawing No. VB-13201-00081 1050mm ST1800 15mmx5mm grade ARMA II

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15

SECTION A BELT INSTALLATION

1.1 STORAGE AND INSTALLATION The methods of storing and handling Conveyor Belting and the procedures for tensioning it prior to making the final splice are just as important as actually making the splice. New conveyor belting should be stored upright in the factory package until used. A cool dry room, free from sunlight, steam pipes, oil and corrosive fumes is best. Under no circumstances should a roll of belting be stored on its side, even if on a concrete floor. Moisture will shrink any exposed fabric which gets damp from such storage and the belt may “bow” on one edge. Storage of rolls in an upright position on a dry wooden floor is recommended. If long term outside storage is necessary, the lay down area should be prepared by placing matting or other material to protect the belt from sharp objects. If long term, storage outside is necessary, (more than one year) the belt should be covered with a suitable material such as a tarpaulin or heavy pigmented plastic sheeting. This will protect the belt from the effects of weathering. 1.2 HANDLING THE ROLL OF CONVEYOR BELT Conveyor belts should never be dropped while unloading from a freight car, truck, or other means of transportation. Due to their weight, dropping rolls can break the packaging and may damage the belt. Belts should never be rolled or skidded. Provisions should be made to use proper moving equipment. Care must be taken when hoisting a conveyor belt to prevent damaging the edges. Insert a bar through the centre of the roll and lift with cords or chains attached to a spreader. (Fig.1-1)

Fig. 1-1

Once the roll of belting has been transported to the installation area it should be mounted on a suitable shaft for unrolling and stringing onto the conveyor system. Conveyor belting is normally rolled at the factory with the carrying side out. Consequently, in mounting the roll, the belt must lead off the top of the roll if it is being pulled onto the troughing or carrying idlers but off the bottom of the roll if it is being pulled onto the return idlers. Fig. 1-2 illustrates a suitable method of mounting as well as leading off the top of the roll for pulling onto the troughing idlers.

Note: Temporary flat roll at bend point, as roll is pulled onto troughing idlers.

Fig. 1-2

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To prevent the belt roll from over-running at the let-off a braking device is often needed. (Fig. 1-3)

Fig. 1-3

1.3 STRINGING THE BELT Textile belts such as Plylon, Wingfoot, Pathfinder, etc. that have been slit from a full width slab at the factory, should be spliced with the factory cut edges on the same side of the conveyor. (Goodyear identifies these edges with blue paint applied at the factory after slitting.) To minimise side travel on steel cord belt rolls, it is recommended that rolls be strung onto the conveyor in the exact sequence they were manufactured. For new installations and major replacements, the following procedure is recommended for Flexsteel Belting. Each roll of belting will be clearly identified with a roll number. • The 1st end cured at the factory will be attached

to the shell. • The last end cured in the factory will be the outer

wrap. • The top cover will face “outside”. All rolls of belting are to be spliced onto the conveyor in the following sequence starting with the last manufactured roll. (e.g. Roll #8 of a total of 8). • The inside wrap of roll #8 will be spliced to the

outside wrap of roll #7. • The inside wrap of roll #7 will be spliced to the

outside wrap of roll #6 and so on. After the belt has been positioned, the means of threading it on the conveyor system must be considered. If the new belt is a replacement, the old belt can be used to pull it on. The old belt is clamped off, cut and the new belt then spliced to the end of the old belt using plate type fasteners (fabric belts) or pulling plates as illustrated in Fig. 1-4 for fabric belts and Fig. 1-5 for Flexsteel belts. The trailing end of the old belt is connected to a suitable power device to pull the belt through the system. The conveyor drive motor can be used to pull on the new belt.

Other suitable pulling devices such as cord winches, belt winders and bulldozers, can also be used. Fig. 1-6. NOTE: SEE CAUTION STATEMENT REGARDING TURNOVERS- FIG. 1-8

Fig. 1-4

Fig. 1-5

Fig. 1-6

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For a new conveyor installation having little or no slope, a rope or cord of suitable strength should be attached to steel pulling plates. The rope or cord is then threaded around the conveyor system and attached to a suitable power device to pull the belt into place. A belt being installed on a system with a relatively high degree of slope (12° or more) must be handled with more precaution to guard against run-away. The belt roll is set up as previously mentioned, usually at or near the head pulley. This is generally the most accessible Assuming the conveyor is sufficiently long so as to require more than one splice, the carrying side and the return side may be threaded on separately. Care must be taken to see that the heavier cover is up on the carrying side and down on the return run. NOTE: If belts are to be strung on both the carrying and return side of the system, then rerolling of the belts for one of the sides is necessary before stringing to ensure the correct sequence in splicing. For major installations, rolls can be shipped in this configuration by prearrangement. As the belt is fed on the system, tension at the roll tends to build up due to the weight of the belt on the slope. For this reason some method of braking is required such as using a belt clamp mounted on the conveyor structure, through which the belt is threaded. Where the slope is very long, additional clamps should be used, spaced approximately 1000 feet (305m) apart. Mechanical, air and hydraulic clamps are recommended. Wooden clamping devices are not recommended. To estimate the pull required to hold a belt on a slope, multiply belt weight (Ib/ft) times the vertical lift of the slope and add 10%. For example, assume a 40 Ib/ft belt and a 300 ft high slope. The approximate pull is (40 X 300) X 1.1 = 13,200 lb. If calculating in S.l. units, multiply the belt weight (kg/m) times the vertical lift and add 10%. For example, assume a 60 kg/m belt and a 100m high slope. The approximate pull is (60 x 100) x 1.1 = 6600 kg. If the conveying side and the return side have been fed on separately the final splice can be made at the bottom of the slope where the ends of the belt meet. In some situations it is advisable to utilise a suitable temporary splice to index the belt and complete the final splice at the original location. Making the final splice at the top of the slope is possible but a greater force will be required to remove the sag and lift the counterweight. Belt clamps must be used on the final pull. The system illustrated in Fig. 1-7 will avoid dismantling the work area by allowing a suitable length of belt to lay back over the clamp.

1.4 TENSIONING Once the belt has been pulled onto the conveyor system it must be tensioned prior to splicing to facilitate correct positioning of the take-up and to eliminate sag. The tensioning operation takes place at the location where the last splice will be made. After final tensioning, clamps are placed on each end of the belt. These are made of steel and have a clamping surface as indicated in Fig. 1-7. Tension is applied by means of a power device which is used to pretension the belt before “clamping off” When tension measuring load cells or scales are used, they are rigged to measure the pull on the take-up pulley. The belt is pulled until the load cell or scales register a tension equal to or slightly greater than the recommended take-up force. Make allowance for an amount of belt necessary to correctly position the counterweight from this point. Certain basic statements and recommendations can be made about tensioning for splicing: a) Belts which are tensioned by pulling in only one

direction require more splicing tension than those pulled in both directions.

b) Slope belts spliced at the top of the slope require

more splicing tension than those spliced at the bottom.

c) Slope belts having an anti-rollback device which

cannot be released must be tensioned by pulling in the direction of belt travel only.

d) Check the belt frequently during tensioning to

ensure that the belt is free and not binding at any place.

e) During the final tensioning pull be sure the ends

of the belt are lined up properly. Conveyor installations having limited take-up travel should be spliced to a tension based on the loaded running tension. This tension should be specified by Goodyear and measured by suitable load cells or

18

dynamometers. Where it is practical, fabric belts should be run for several weeks with mechanical fasteners before making the final vulcanised splice. Obtaining the required tension depends heavily on the experience of the individual making the splice. It is possible for a gravity type take-up to severely damage the conveyor structure if it is positioned too close to the forward or upward stop. Too much tension applied to a relatively short belt may thus have a harmful effect on the pulley shafts and bearings as well as the belt. Fabric belting (eg. Plylon, Wingfoot, Glide, Pathfinder, etc.) is usually installed so that most of the take-up travel is available for subsequent increase in belt length. Flexsteel belting is usually installed with most of the take-up filled with belt. The belt may be tensioned with a suitable take-up device as follows: a) When the Counterweight is on: Tie the take- up

off 6” to 8” (150mm to 200mm) above the desired running position. (Consideration may have to be

made for excessive sag.) Next, pull the belt until the take-up starts to lift and the tie-off ropes become slack. Make the final splice allowing a minimum of belt slack.

b) When the counterweight is not on: Splicing

without the counterweight installed is undesirable, however the following procedure should be employed if necessary. Use suitable belt clamps to hold the take-up pulley 6” to 8” (150mm to 200mm) above the desired running position. (Consideration may have to be made for excessive sag.) Pull the belt to its running tension which can only be estimated in this situation. Judgement in estimating this tension will improve with the experience of the splicer.

1.5 TAKE-UP TRAVEL AND INITIAL POSITION Tables 1-1 and 1-2 show the recommended minimum take-up travel and initial take-up position respectively.

TABLE 1-1

RECOMMENDED MINIMUM TAKE-UP TRAVEL IN PERCENT OF CENTER DISTANCED

TYPE OF TAKE-UP AND PERCENT OF RATED TENSION

CARCASS MATERIAL (WARP) 100% 75% 50% or LESS

MANUAL TAKE-UP**

NYLON 4.0% 3.0% 2.0% POLYESTER 2.5% 2.0% 1.5% ARAMID 2.0% 1.5% 1.0% FIBREGLASS 1.0% 0.75% 0.5%

AUTOMATIC TAKE-UP

NYLON 3.0% 2.50% 1.50% POLYESTER 1.7% 1.25% 0.75% ARAMID 1.5% 1.00% 0.75% FIBREGLASS 0.5% 0.40% 0.25% STEEL 0.30% 0.23% 0.15% *For [1] belts installed at average empty running tension [2] take-up position per Table 1 -2, and [3] Drive location at or near the high tension end of the conveyor. **Only short endless feeder belts and the like would normally be Vulcanised on conveyors with a manual take-up.

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TABLE 1-2 RECOMMENDED INITIAL TAKE-UP POSITION

CARCASS MATERIAL (WARP)

PERCENT AVAILABLE FOR LENGTH INCREASE

PERCENT AVAILABLE FOR LENGTH DECREASE

STEEL 25% 75% NYLON, POLYESTER, ARAMID, FIBREGLASS

90%

10%

+Take-up conditions and travel amounts as shown in Table 1-1. 1.6 CUTTING BELT TO LENGTH a) When splicing a belt to a specified length or a net

endless length (NEL), the following total length of belt will be required: The specified NEL length plus one splice length plus a minimum of 2” (50mm) trim allowance. If two or more belt rolls are to be spliced NEL add a splice length plus a minimum of 2” (50mm) trim for each roll or splice.

b) When replacing a damaged section of belt the

required length of new belt will be: The length of the damaged section plus 2 splice lengths, plus a minimum of 4” (100mm) trim allowance. Cut the ends square. NOTE: Whenever a section of new belt is to be spliced into an old belt the length of old belt to be removed should include as many of the old splices as is reasonably possible on very short conveyors it is sometimes necessary to remove the tail pulley in order to have adequate slack for splicing after cutting to length.

d) When a splice has to be done on the return run,

precaution must be used in measuring the belt length. The splice area may be located on the ground requiring an adjustment in belt length, if the conveyor is elevated above ground level.

e) In most cases it is not possible to pull up and utilise

all of the belt that appears to be available in a take-up. About 4 ft (1.2m) of belt will be needed for slack in splicing. In other words, for a re-splice the take-up should have at least a splice length plus 4 ft (1.2m) available for removal.

f) If a fabric splice is to be remade and there is very

little belt in the take-up, the old splice can be cut parallel to the bias and

near the centre. The old splice area is then re-stepped and re-spliced and the take-up is only raised 1/2 the total length of the steps on one end of the splice.

g) Belts running on 45° idlers on a system with a

minimum take-up should be clamped off at or near the head pulley. Tension the belt with a centre pulling plate so the belt will conform to the idlers when pulled and then mark master line on each end. Leave minimum slack for the vulcaniser.

CAUTION: TURNOVERS: THE CONVEYOR PROFILE MUST BE CONSIDERED WHEN STRINGING THE BELT TO PREVENT THE FINAL ORIENTATION FROM BEING UPSIDE DOWN. FOR EXAMPLE, TURNOVERS ADD A TWIST TO THE BELT THAT MUST BE ANTICIPATED. GOODYEAR RECOMMENDS TURNING THE BELT 180° AT THE HEAD AND REVERSED 180° AT THE TAIL. SEE FIG 1-8 FOR A TYPICAL TURNOVER DESIGN.

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SECTION B FLEXSTEEL BELT SPLICING

The quality of the finished splice is highly dependent upon the cleanliness of the work area during all stages of splice preparation. Good work practices and cleanliness go hand in hand and are essential in achieving this goal. A STEEL CORD SPLICE MUST BE VULCANISED IN ONE CONTINUOUS LENGTH. THE VULCANISING PRESS MUST CONTAIN THE ENTIRE SPLICE LENGTH PLUS THE MINIMUM RECOMMENDED LENGTH OF BOTH BELT ENDS. 7.1 WORK AREA AND CREW a) LOCATION OF WORK AREA If a permanent building is not available then a

temporary shelter must be built to protect the exposed belt ends from weather, dust, etc.

The temperature in the work area must be

maintained at approximately 68°F (20°C) or greater. This is to insure that the thick rubber materials that must be handled will be both tacky and flexible. Open flame torpedo style kerosene heaters are not recommended due to explosive hazards and the potential contamination by residual kerosene in the splice area.

b) DIMENSIONS OF WORK AREA The work area should extend at least 3 feet (1m)

beyond each edge of the belt (more if possible). The roof of the shelter should be at least 8 feet (2.5m) above the top of the splice work table.

Fig. 7-1

The length of the work area should be 4.5 times the total splice length (including the bias) c) THE WORK TABLE All idlers must be removed from the work area and

a flat smooth surface provided which extends approximately 3” (75mm) beyond each edge of the belt. This is usually accomplished using 5/8” (15mm) or heavier plywood solidly supported by timbers and firmly anchored so that it will not slip and misalign the belt ends.

The bottom half of the vulcaniser is used as the

centre section of the work table. d) WORK CREW A work crew of 4 to 6 men is usually adequate on

steel cord belt splices depending on belt width and splice length.

7.2 TOOLS AND MATERIALS a) TOOLS The tools necessary for preparing a steel cord belt

splice are listed in Fig. 7-1. 1. Rubber & fabric pulling device 2. Thermocouple unit & wires 3. Steel cable cut off saw 4. Buffer 5. Sharpening stone 6. Foxtail brush 7. Chalk line 8. Cotton sampler knives 9. Square 10. Awl 11. Ply & rubber lifting clamp 12. Tape 13. Pricker roll 14. Hook knife 15. Small T square 16. Stanley knife 17. 4” roller 18. V knife 19. Flexible skiver 20. Cable cutters 21. Silver pencil 22. 1 /16” stitcher 23. Scissors 24. Folding rule

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FLEXSTEEL SPLICE FLOW CHART

7.1

WORK AREA AND CREW

7.2

TOOLS AND MATERIALS

7.3

SPLICE DIMENSIONS

(CONTACT GOODYEAR)

7.4

MASTERLINE

7.4.1

SQUARE AND STRAIGHT EDGE

WHAT TYPE

7.4.3

SWINGING ARC

7.4.2

TRIANGULATION

7.5

MARKING AND PREPARING FIRST END

7.5.1

HOOKING CORD REMOVAL

7.5.2

PIANO METHOD

1

22

FLEXSTEEL SPLICE FLOW CHART

1

7.6

CORD AND SKIVE PREPARATION

7.7

ALIGNMENT, CORD WASHING AND CEMENTING

7.7.4

PULLEY COVER PREPARATION COMPONENTS

No PULLEY COVER SUPPLIED PRE-

ASSEMBLED

Yes

7.7.3

PULLEY COVER PREPARATION

PRE-ASSEMBLED

7.7.5

PULLEY COVER INSTALLATION

7.8

CORD LAY-UP AND EDGE GUM INSTALLATION

7.9.2

PULLEY COVER PREPARATION COMPONENTS

No TOP COVER

SUPPLED PRE-ASSEMBLED?

Yes

7.9.1

TOP COVER PREPARATION

PRE-ASSEMBLED

7.9.3

TOP COVER INSTALLATION

2

23

FLEXSTEEL SPLICE FLOW CHART

2

7.10

FINAL PRESS ASSEMBLY

7.12

SPLICE VULCANISATION

711

MONITORING TEMP. AND PRES.

7.12.2

PRESS REMOVAL

No PRESS PLATEN COOLING TO BE

USED?

Yes

7.12.1

PRESS COOLING AND REMOVAL

13.0

SPLICE COMPLETION

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NOTE: AC power supply will be required for buffers or other power tools. b) MATERIALS A splice drawing must be obtained from Goodyear

for each belt to be spliced. Each of these drawings will list the materials required for one splice. THE INSULATION GUMS AND CEMENTS USED ON AND AROUND THE CORDS OF THESE BELTS ARE VERY CRITICAL AND NO SUBSTITUTIONS SHOULD BE MADE. Otherwise, proper cord adhesion in the splice may not be achieved.

IMPORTANT: CHLORINATED SOLVENTS MUST NOT BE

USED FOR WASHING THE STRIPPED CORDS NOR FOR THINNING CEMENTS APPLIED TO CORDS. RESIDUAL CHLORINATED SOLVENTS REACT WITH THE ZINC COATING ON THE CORDS DURING VULCANISATION AND CAUSE SEVERE LOSS OF ADHESION.

URETHANE OR CELLULOSE SPONGES, NEW

CLEAN WHITE COTTON RAGS, AND/OR PAINT BRUSHES ARE PREFERRED FOR WASHING AND CEMENTING CORDS AND SHOULD BE PROPERLY DISPOSED OF AFTER USE. RAGS THAT HAVE BEEN RECYCLED AND COMMERCIALLY CLEANED HAVE BEEN KNOWN TO CONTAMINATE CORD SURFACES FROM MATERIALS EXTRACTED DURING CORD CLEANING. PAPER TOWELS SHOULD NOT BE USED.

7.3 SPLICE DIMENSIONS Individual splice drawings for each Goodyear

Flexsteel splice will be furnished specifying the proper dimensions for assembly.

7.4 MASTER LINE This is normally the first line to be made on the belt

on each of the two ends. The master line is a line drawn straight across the belt width at a distance from the belt end equal to the splice length plus the bias length plus a 2” (50mm) tab length. Three methods of locating and squaring the master line are as follows:

Fig . 7-2

7.4.1 SQUARE AND STRAIGHT EDGE - FIGURE 7-2 a) From the end of belt, measure the length of splice

plus trim allowance. b) Use a square and straight edge to draw master

line. c) Check the master line by laying the square along

the opposite edge. Repeat the procedure on the other belt end.

7.4.2 TRIANGULATION - FIGURE 7-3

Fig. 7-3

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a) From the end of the belt, measure along one edge to a point equal to the splice length plus trim allowance. Mark the edge. This mark is then the centre point of a line exactly 4 ft (1200mm) long drawn along this edge.

b) From each end of the 4 ft (1200mm) line measure

equal diagonal lengths to the opposite edge and mark (Fig. 7-6). Draw the master line.

c) This method is common on belts 72” (1800mm)

and wider. 7.4.3 SWINGING ARC - FIGURE 7-4

Fig. 7-4

a) Carefully mark a point at the exact centre of the belt width. Measure from this centre point and make a mark at each edge near the end. These two diagonal measurements must be exactly equal.

b) From each of the two edge marks measure back

the total splice length plus trim allowance. Mark the edges and draw the master line.

Fig. 7-5 7.5 MARKING & PREPARING FIRST END - FIGURE 7-5 a) Measure the bias length on the correct edge and

mark Point B. The bias length is selected so that the bias angle will match the vulcaniser angle.

b) Draw the bias line A,B and mark the edges with a

vertical line at these points for opposite cover marking. As in (Fig. 7-6).

Fig . 7-6

c) From A, measure the splice length and mark point C.

d) From B. measure the splice length and mark point

C. Join C and D. e) From C, measure 2” (50mm) and mark point D. f) From C, measure 2” (50mm) and mark point D.

Join D & D. g) Remove a strip of cover rubber about 1/2” (12mm)

wide down to the cords by cutting at approximately 45° on either side of line D-D.

26

h) Place a suitable piece of lumber underneath the belt to facilitate cutting and prevent the cut off saw from damaging the underlying belt or splice press platen.

i) Cut the belt along line D-D. j) Starting at point A, remove the edge rubber (to the

first cord) to a point 1” (25mm) from point A (Fig. 7-7).

Fig. 7-7

k) Repeat the procedure on the other edge from point C to 1” (25mm) from point B.

I) Make a cut along line A,B at 45° angle down to t he

cords (Fig. 7-8).

Fig. 7-8

m) Make a vertical cut along line C,C down to the cords.

n) The belt over can be divided into widths of 16” to

24” (400mm - 600mm) to facilitate stripping.

To do this, mark the appropriate number of lines on the surface, parallel to the belt edge and make a vertical cut through the cover to the cord layer on each line starting at line C,C and ending about 3” (75mm) from line A,B.

o) Remove cover strips by starting at point A (Fig. 7-

9). Lift the corner of the cover and start skiving cover and insulation gum from the cords. An air tugger or electric winch is usually used to keep tension on the cover and facilitate removal. Skive sufficient cover into the adjacent strip before cutting the balance of the strip separation line. This will provide a point for gripping for the start of the subsequent strip.

Fig . 7-9

p) Continue this process until all cover has been removed.

q) Turn the belt end back and draw line A,B on the

pulley cover by joining the vertical lines previously marked on the edge of the belt.

r) Draw line C,C on the pulley cover by repeating the

process used on the top cover (see Fig. 7-5). s) Make a cut along line A,B at a 45° angle down to

the cords. t) Make a vertical cut along line C,C down to the

cords.

27

u) For cord diameters up to 7/32” (5.4mm) proceed to 7.5.1. Cord Removal by Hooking. For larger cord diameters proceed to 7.5.2 Piano Wire Cord Removal.

7.5.1 CORD REMOVAL BY HOOKING a) Turn the belt end back onto the table with the

pulley cover down. Mark a line across the belt 1/2” (13mm) from and parallel to line A,B towards the belt end.

b) Using a Hyde angle knife (Fig. 7-10) with 3/8”

(9.5mm) hook blades, begin hooking cords from the chalk line to the end of the belt. Run the hook blade on an angle on either side of each cord. Repeat the process until all cords have been cut away from the pulley cover rubber.

Fig. 7-10 c) Attach grips to the pulley cover at point A (Fig. 7-

11) and using the winch or tugger remove the pulley cover.

Fig. 7-11

d) Proceed to cord preparation.

28

7.5.2 CORD REMOVAL BY PIANO WIRE METHOD (Fig. 7-12)

Use of Piano Wire Loops to Strip out Cables

Fig. 7-12

29

7.5.2 CORD REMOVAL BY PIANO WIRE METHOD a) Mark a line 4” (l00mm) from and parallel to A,B

towards the end of the belt. b) Make a vertical cut along this line down to the

cords. c) Using a skive knife and tugger remove the 4”

(100mm) strip of pulley cover between the skive on line A,B and the newly cut line.

d) Using a sharp knife, remove the web of rubber

between each cord. e) Install piano wires by bending the wire 180° aro und

the centre and inserting one looped end on either side of the cord. Install wires on all cords before next step.

f) Turn the belt end back on to the table with the

pulley cover down. g) Attach four to six wires to the pull plate by crossing

each wire and affixing to the lug on the opposite corner of plate.

h) Using a winch, pull the plate and wire assembly

towards the end of the belt to separate the cords from the pulley cover rubber. Pull the wires the length of the splice, stopping at the tab.

i) Repeat the process until all cords have been

separated from the pulley cover rubber. j) Attach grips to the pulley cover at point A and

using the winch or tugger remove the pulley cover. k) Proceed to 7.6 Cord Preparation. 7.6 CORD AND SKIVE PREPARATION a) Use a V-knife (Fig. 7-13) to trim the ribs of rubber

remaining on cords removed with the hook knife or the loose rubber created during piano wire removal of cords. All excess rubber must be removed so that cords have a round cross section.

Fig . 7-13

NOTE: IF THE CORDS HAVE BEEN CORRODED THROUGH EXPOSURE TO THE ELEMENTS OR OTHER CAUSTIC MATERIALS ADDITIONAL PRECAUTIONS MUST BE TAKEN. THE GALVANISED COATING AND/OR RUST MUST BE COMPLETELY REMOVED BY BUFFING WITH A WIRE BUFFER UNTIL THE BARE STEEL IS EXPOSED. CONTINUE WITH NORMAL SPLICING PROCEDURE

b) Using a wire wheel or wire brush, (Fig. 7-14)

buff the bias skive across the full width of the belt. Buff the top cover and both edges about 2” (50mm) from the skive.

Fig. 7-14

30

c) Turn the belt back and repeat the process on the back cover skive and pulley cover:

d) Using a brush or broom, clean off buffing dust from all areas.

e) Wrap the cords and prepared buffed areas in clean

poly film and fold the belt end back out of the work area.

f) Repeat procedures in sub section 4 through 6 to

prepare the other belt end for splicing. 7.7 ALIGNMENT, CORD WASHING AND

CEMENTING 7.7.1 LOCATING AND ALIGNING ENDS a) Place the belt ends on the bottom platen so that

the distance between the top of the skives equals the splice length. (Fig. 7-15) The centre of the splice should be located on the centre of the press (both length and width). THE TOP OF THE SKIVE MUST BE A MINIMUM OF 6” (150mm) FROM END OF THE VULCANISING PRESS.

Fig.. 7-15

b) On each end of the belt mark four equally spaced

centre locations from the skive to the end of the work table.

c) Run a string line from the centre mark at the

outside ends of each work table, supported by a suitable block to keep line free from interference by the belt surface.

d) Use a square to align these end marks to the

string. Check remaining centre marks and adjust belt as necessary until all marks are aligned.

e) Recheck the splice length distance between the skives. IF THE MEASUREMENTS ARE OUTSIDE A TOLERANCE OF -0 +1” (25mm) IT IS NECESSARY TO REPEAT THE ABOVE STEPS.

f) Secure the belt ends in this position. It is common to C-clamp the belt to the work table and nail blocks of wood to the table flush with the belt edges to prevent lateral movement.

7.7.2 CORD WASHING AND CEMENTING From this point on, CLEANLINESS IS MUCH

MORE CRITICAL. It is imperative that no foreign material such as dust, dirt, sand etc. be allowed to contact the cords and other uncured components. CONTAMINATION WILL CAUSE LACK OF CURED ADHESION AND CAN RESULT IN SPLICE FAILURE. All exposed rubber surfaces should be covered with poly film protection when not actively being worked on.

Should an area of the splice become

contaminated, in spite of precautions, it can be cleaned by swabbing with a clean cloth or sponge soaked in the solvent provided with the kit. DO NOT USE ANY CHLORINATED SOLVENT. Ensure that dirt or other contamination is removed and not merely spread around.

If massive contamination is encountered, the splice

will have to be cut out and restarted. a) Depending upon individual circumstances and

splice lengths, belt ends are either suspended or turned back onto the belt for washing and cementing. Cover all areas under the washing and cementing locations with poly film.

b) Brush off any loose dirt or rubber dust. c) Wash cords with the appropriate solvent and allow

sufficient time to dry. d) Apply two coats of cement to the cords and to the

skived cover cuts. (Fig. 7-16) Allow each coat to dry thoroughly.

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Fig. 7-16

IMPORTANT: BE SURE TO CHECK INDIVIDUAL SPLICE MATERIAL INSTRUCTIONS TO ENSURE CORRECT CEMENTS ARE APPLIED IN THESE AREAS.

e) After the final coat of cement on the cords has

dried thoroughly, cut all the cords at the end tab and discard the tab. When cutting be sure clean poly film is under the work area. After all cords have been cut, wrap the cords in poly film to keep clean (Fig. 7-17).

Fig. 7-17

Typically, the cords from each end of the belt are wrapped in two separate bundles divided at the centre line. These bundles are then folded back over the poly film on the belt surface.

f) Top and bottom cover panels may be supplied

either in separate components or in a factory assembled composite. If the splice covers are pre assembled proceed to 7.3. If individual components are being used proceed to 7.4.

7.7.3 PULLEY COVER PREPARATION - PRE

ASSEMBLED NOTE: WHEN SPLICING ON A SLOPE, SET THE

UPPER SKIVE FIRST. a) THE INSULATION GUM SIDE OF THE COVER

ASSEMBLY IS IDENTIFIED WITH A WHITE STRIPE AND GOES NEXT TO THE CORDS.

b) INSTALL THERMOCOUPLE WIRES ON THE

BOTTOM PLATEN PER THE CURING INSTRUCTIONS IN SUB SECTION 11.1. ROUTE THE WIRES OUT ONE END OF THE VULCANISER AND TAPE IN POSITION ON THE PLATEN. IT IS RECOMMENDED THAT THE WIRES BE CONNECTED TO THE MEASURING DEVICE AND CHECKED FOR FUNCTIONALITY BEFORE PROCEEDING FURTHER.

c) Lay down the release material on platen over the

thermocouple wires. d) Place the pulley cover composite (with the white

stripe side up) on the platen extending past the skive cuts on both belt ends. Remove the poly film from the platen side of the rubber only.

e) Proceed to 7.7.5. 7.7.4 PULLEY COVER PREPARATION - COMPONENTS NOTE: WHEN SPLICING ON A SLOPE BELT SET

THE UPPER SKIVE FIRST. a) Identify the pulley cover panel and the insulation

gum rolls by referring to the materials list provided with the kit.

b) INSTALL THERMOCOUPLE WIRES ON THE

BOTTOM PLATEN PER THE CURING INSTRUCTIONS IN SUB SECTION 11.1. Route the wires out one end of the vulcaniser and tape in position on the platen. It is recommended that the wires be connected to the measuring device and checked for functionality before proceeding further.

32

c) Lay down the release material on platen over the thermocouple wires.

d) PLACE THE PULLEY COVER PANEL ON THE

PLATEN EXTENDING PAST THE SKIVE CUTS ON BOTH BELT ENDS. PLACE THE BARE SIDE AGAINST THE PLATEN. THE POLY FILM IS ON THE TOP SIDE.

e) Remove the poly film and wash the surface with

the solvent included in the list. Allow to dry thoroughly.

f) Apply 18” (450mm) strip of .100 [2.4mm] insulation

gum, slightly overlapping the joints at 1/8” (3mm). (Fig. 7-18). Cover the entire surface of the pulley cover.

Fig . 7-18

IMPORTANT: LEAVE THE POLY FILM ATTACHED TO THE UPPER SURFACE OF THE INSULATION GUM. IT WILL BE NECESSARY TO REMOVE A 1/2” (12.7mm) STRIP FROM THE EDGE OF THE PREVIOUSLY LAID GUM IN THE OVERLAP AREA. THE FILM ON THE OVERLAPPED STRIP IS LEFT INTACT TO PROTECT THE JOINT.

g) Proceed to 7.7.5. 7.7.5 PULLEY COVER INSTALLATION a) Turn back one of the belt ends onto the pulley

cover composite. Using a straight edge and pen or a chalk line mark the bias line on the poly covering insulation gum of the cover composite to locate starting points for this line.

b) Cut the skive along this line to match the bias angle of the belt. Lay a straight edge under the material being cut.

CAUTION: BE SURE NOT TO CUT THROUGH THE

THERMOCOUPLE WIRES IF THEY ARE AT THIS END.

c) Apply one coat of the appropriate cement on the

freshly cut skive. d) Refer to the splice diagram included in the kit to

determine location of the first step line. Using a straight edge and pen or a chalk line mark this line on the poly film.

e) Using sharp knife cut through the film along the

line, using just enough pressure to cut the film. f) Remove the short piece of film from the surface,

making sure that no small pieces are left on the splice area.

g) Scribe a line on the rubber surface at the edge of

the film using a 1/16” (1.5mm) stitcher, using sufficient pressure to make a visible line.

h) CAREFULLY LOWER THE BELT END INTO

POSITION MAKING SURE A TIGHT FITTING PULLEY COVER JOINT. USE A MALLET TO SECURE THE JOINT BY POUNDING ON THE UPPER SURFACE OF THE BELT.

i) Repeat this procedure on the other end of the belt. j) Proceed to subsection 7.8. 7.8 CORD LAY UP a) Refer to the splice diagram supplied with the kit to

determine the location of step line for two-step and higher splices.

b) Using the methods described in sub section 7.5

scribe the appropriate step lines. Do not remove poly film at this time. The film will be removed as cords are laid.

33

c) Make a full length longitudinal cut through the polyfilm near the belt centre. Then fold the film back 4” to 5" (100-125mm) on each side of the cut to expose 8" to 10" (200 - 250mm) of insulation gum for the full splice length.

d) Stretch an UNCHALKED string down the centre line

of the splice using the previously marked centre positions.

e) Each cord is cut to length immediately before being

laid down in the pattern in multiple stage splices. To do this, use the reference lines previously marked on the bottom cover to locate the step line. For unbutted cords, cut the cord at the reference line. For butted cords, cut the cord at a point 1/2 the specified gap distance (shorter) from the reference line.

f) Lay the matching centre cords from each end of the

belt parallel to the string line. If a butt is called for in the splice diagram, make the gap dimension as specified.

g) Lay a full length strip of noodle gum along the cords

so that each cord is separated by one strip of gum. (Fig. 7-19)

Fig. 7-19

h) From this point continue laying cords following the

prescribed splice diagram and gum strips alternately working from centre towards each edge. A clean hammer is usually used to lightly tap cords into place. STRAIGHTNESS MUST BE MAINTAINED. Poly film is turned back as cords are laid. Frequent light swabbing with solvent keeps the exposed insulation gum clean and tacky.

i) Check cord straightness with an UNCHALKED

string line every 4 to 5 cords and make adjustments as needed.

a1) If cords are bowing in towards the belt centre, add

additional noodle strips. b1) If cords are bowing out towards the belt edges,

stretch the noodle strip slightly to reduce its thickness. Cords may also be shifted with additional tapping of the hammer.

DO NOT CUT OUT CORDS TO CORRECT BOW. j) After all cords have been laid, build up the edges to

the level of the cord tops with available gum. (Fig. 7-20) Pulley cover gum, 1/16" (1.5mm) cover build up gum or 0.050" insulation gum can be used. In some cases a special strip of the appropriate width and thickness is supplied for this purpose.

Fig. 7-20

k) Using insulation gum, fill all gaps at cord ends, cord

butt gaps and all voids between cords. Insulation gum strips are typically used for this purpose and in some cases a larger strip of insulation is provided for plugging voids. (Fig. 7-21)

34

Fig. 7-21

An air operated extruder can greatly facilitate the

void filling process. 7.9 TOP COVER PREPARATION AND

INSTALLATION For a pre-assembled cover composite proceed to sub-section 7.9.1. For individual cover components proceed to subsection 7.9.2. 7.9.1 TOP COVER PREPARATION - PRE-ASSEMBLED a) Clean the skived top cover cuts at each end of the

splice with solvent and apply a coat of cover cement.

b) Place a sheet of clean poly film over the entire

splice area. c) Roll out the top cover composite with the insulation

gum side next to the cords. The insulation gum side is identified with a white stripe.

d) Proceed to step 7.9.3 Top Cover Installation. 7.9.2 TOP COVER PREPARATION - COMPONENTS a) Clean the skived top cover cuts at each end of the

splice with solvent and apply a coat of cover cement.

b) Place a clean sheet of poly film over an area the

size of the splice on the worktable in an area away from the splice.

c) Roll the top cover with poly film side down. d) Wash the rubber surface lightly with solvent.

e) Apply .100" (2.4mm) strips of insulation to cover the

entire surface using the same procedures as was done for the pulley cover (see subsection 7.4.6). Be sure to leave the film on the insulation side.

Fig. 7 22

f) Place a sheet of clean poly film over the entire

splice area. g) Place this assembled panel, insulation side down

over the splice area. h) Insulation gum may be placed over the cables in 18"

sheets. See Fig. 7-22. i) Proceed to step 7.9.3 Top Cover Installation. 7.9.3 TOP COVER INSTALLATION a) Fold back the top cover about half way and remove

the film liner on insulation side of the cover. Cut the film at the bend of the roll, remove and discard. Carefully roll up the film laid on the splice. ROLL FROM SPLICE END TOWARDS THE CENTRE TO ENSURE THAT ANY DIRT WHICH MAY HAVE BEEN TRANSFERRED FROM THE OUTSIDE OF THE COVER ROLL IS CONTAINED IN THE FILM.

b) Lay the top cover back in position and repeat the

process at the other end of the splice. After the underlying film has been rolled to the centre from this end, carefully remove the entire roll piece (both ends at once) and discard. (Fig. 7-23) ENSURE THAT NO FILM IS LEFT IN THE SPLICE.

35

Fig. 7-23

c) Remove the poly film from the outside of the top

cover. d) Trim off the excess width of the top cover only at

the skive area to assist in locating the cut mark. (both edges).

e) Mark a point on each edge 1/16" (1.5mm) longer

than the splice cover insert length. f) Use a chalk line to draw a line between these two

points. g) Place a clean piece of flat 2" (50m) wide steel

under the cover panel in the area to be cut. h) Put the top cover matching the angle of the belt

end skive. i) Tip the flat bar on its edge to raise the cover panel

and apply a light coat of the proper cover cement. LET IT DRY THOROUGHLY.

j) Remove the flat steel and fit the skive into place. k) Repeat the process from step g for the other end

of the belt. I) Using a chalk line straight edge on the original belt

edges, mark & remove excess rubber from the splice edges. (Fig. 7-24)

Fig. 7 -24

m) With an awl, thoroughly prick the top cover over

the entire splice area down to the cable level. n) Install thermocouple wires on the top cover as

outlined in the curing instructions in sub section 11.1. Route the wires along with surface and out the same end of the press as the bottom platen wires. (Fig. 7-25)

Fig. 7.25 o) Lay down the release material over the top of the

splice. 7.10 FINAL PRESS ASSEMBLY a) To obtain edge pressure use steel guides along

each edge of the press. Select guides that are 1/32" to 1/16" (0.8mm to 1.0mm) less than the belt thickness. The recommended width for the guides is 4" (100mm).

The area between the steel guides and the edge of

the vulcaniser should be filled to avoid possible distortion and damage to the vulcaniser. Pieces of

36

the belt being spliced are usually used for this purpose. Plywood of the same thickness or slightly thinner than the guides can also be used.

b) Following the press manufacturer’s instructions,

assemble the top platen of the press on the splice area. (Fig. 7-26).

Fig. 7-26 c) Draw the guides together against the edges as

uniformly as possible using a ratchet-type or cord-type come-a- longs. DO NOT OVERTIGHTEN AT THIS TIME.

d) Tighten all bolts joining top and bottom of the

splice press as recommended by the press manufacturer.

e) Using the come-a-longs, draw in the guides until

they contact the cured belt edges at both ends of the press.

f) Place wedges between the guide iron and the edge

bolts at sufficient locations to reduce bowing of the guides. For splices up to 8’ (2.4m) the use of one wedge is usually satisfactory. Additional wedges will also be necessary if guide irons are less than the recommended 4” (100mm) width.

g) Make the necessary electrical and hydraulic

connections. h) Connect the thermocouple wires transducer to the

recording unit and ensure that they are operating properly.

7.11 GENERAL VULCANISING NOTES a) TIME AND TEMPERATURE THE VULCANISATION OF RUBBER

COMPOUNDS NEEDS TO BE CAREFULLY CONTROLLED AND MONITORED TO ENSURE OPTIMUM PHYSICAL PROPERTIES FOR MAXIMUM SPLICE LIFE.

VULCANISATION, AS A RULE OF THUMB,

DOUBLES IN CURE RATE FOR EVERY 18°F (10°C) CHANGE IN TEMPERATURE. OVERCURING A SPLICE CAN BE AS DETRIMENTAL AS UNDERCURING.

TEMPERATURE CONTROLLERS AND

MEASURING DEVICES ON VULCANISING EQUIPMENT SHOULD NOT BE RELIED UPON TO PROVIDE A DEPENDABLE ASSESSMENT OF THE ACTUAL PLATEN TEMPERATURES. FOR THIS REASON EACH INDIVIDUAL HEATING ELEMENT IN A PLATEN MUST BE MONITORED WITH A THERMOCOUPLE PLACED ON THE SURFACE OF A BELT. A PROPERLY CALIBRATED THERMOCOUPLE UNIT CONNECTED TO A CHART RECORDER OR OTHER SUITABLE DATA ACQUISITION UNIT IS REQUIRED.

DURING A CURE, IT IS THE RESPONSIBILITY

OF THE SPLICE OPERATOR TO OBSERVE THE TEMPERATURES OF EACH THERMOCOUPLE AND USE THE INFORMATION TO CONTINUALLY ADJUST THE PRESS CONTROL UNITS TO MAINTAIN TEMPERATURES WITHIN + 5°F (3°C).

It is recommended that all field vulcaniser

temperature controlling and measuring equipment be regularly maintained and calibrated to minimise the amount of manual adjustment required during a cure cycle.

Cure times and temperatures are shown on Table

3-1. 7.11.2 PRESSURE The use of a field vulcaniser with a bladder(s) to

apply pressure to the entire platen surface is preferred because of its uniform pressure distribution. If multiple bladders are used they must be connected to a common manifold to ensure equal pressure in bladders.

37

Other types of pressure systems on field vulcanisers are acceptable provided that they are capable of meeting a tolerance of + 5% over the curing area of the platen.

DURING THE CURE CYCLE ON BLADDER

PRESSES, PRESSURE SHOULD BE MONITORED THROUGH THE USE OF A TRANSDUCER CONNECTED TO A SUITABLE RECORDING DEVICE.

7.11.3 POWER AND PRESSURE FAILURES a) In case of a power failure while curing, do not

release the pressure, but hold it until power is restored and then bring the vulcaniser back up to cure temperature. At that time:

IF THE SPLICE HAD LESS THAN HALF ITS

SPECIFIED CURE TIME BEFORE POWER FAILURE-REPEAT THE ENTIRE SPECIFIED CURE TIME.

IF THE SPLICE HAD CURED HALF OR MORE

OF THE SPECIFIED CURE TIME THEN FINISH CURING THE REMAINING TIME.

b) In case of a pressure failure the splice may have to

be remade depending upon what point in the cure cycle the failure occurred. If the rubber has not cured beyond the blow point, porosity will be evident around the cords.

7.12 VULCANISING THE SPLICE a) If a bladder type press is being used, pressurise

the press to 200 psi (1380 kPa) and hold for approximately 2 min. to check for any possible leaks, then release pressure.

b) Turn on the power to the platen heaters. c) Apply 100 psi (690 kPa) pressure and hold until the

thermocouple readings all reach 203°F (95°C). d) Increase pressure to 150 psi minimum (1035 kPa)

and hold throughout the balance of the cure cycle. Monitor the pressure carefully during the splice cycle and adjust as necessary to maintain 200 psi (1380 kPa).

PRESSURE NORMALLY WILL INCREASE AS

THE TEMPERATURE RISES AND WILL HAVE TO BE BLED OFF.

e) START TIMING THE CURE WHEN ALL THERMOCOUPLE READINGS HAVE REACHED THE SPECIFIED CURING TEMPERATURE. f) THROUGHOUT THE CURE IT IS NECESSARY TO MONITOR AND ADJUST THE PLATEN TEMPERATURES TO WITHIN A TOLERANCE OF 5°F (3°C) AFTER THE SPECIFIED CURE TEMPERATURE HAS BEEN REACHED. (SEE SUB SECTION 11.1)

g) If the press has cooling capabilities which will be

used proceed to 7.12.1. If cooling is not available or cannot be used, proceed to 7.12.2.

7.12.1 PRESS PLATEN COOLING a) At the completion of the specified cure time, leave

the pressure on, turn off the heating elements and start the flow of cooling fluid through the press.

b) Continue to monitor the temperature readings

using the embedded thermocouples. c) Continue cooling until all zones have been reduced

to 130°F (55°C). on “quick cool” vulcanisers continue cooling for 10 additional minutes.

d) Release the pressure on the press and remove the

top platen. e) Proceed to 7.13.0. 7.12.2 WITHOUT PLATEN COOLING a) It is Goodyear’s policy to water cool all vulcanised

splices to prevent over-cure. This section is included only to address those rare instances where the Vulcaniser is not fitted with water cooling ports.

b) At the completion of the specified cure time, TURN

OFF HEATING ELEMENTS, RELEASE THE PRESSURE AND REMOVE THE TOP PLATEN IMMEDIATELY. This procedure is necessary to avoid overcuring the splice.

c) DO NOT LET THE BELT SIT ON A HOT PLATEN.

Either remove the bottom of the press or carefully elevate the belt to provide an air space for cooling. Lift the belt off the press using a support bar at each end of the splice.

d) Proceed to 7.13. 7.13 SPLICE COMPLETION a) Inspect the splice and trim flash off the edges. Buff

flash on the top and bottom covers at the skive joints so that the belt surface is level in these areas.

NOTE: DO NOT PUT A BELT INTO SERVICE OR

DROP THE COUNTERWEIGHT UNTIL THE SPLICE HAS COOLED TO AMBIENT TEMPERATURE.

38

THE 10 MOST COMMON MISTAKES MADE IN BELT SPLICING THAT LEAD TO PREMATURE SPLICE

FAILURE.

1. Not using thermocouples to control cure temperatures can result in overcure or undercure of compounds.

2. Nicking the fabric plies with knives can damage the warp and fill cords. 3. Overbuffing the fabric destroys warp and fill cord strength and reduces adhesion. 4. Curing with wet cement in splice area can cause ply blows or cover blows. 5. Over prodding the fabric when lifting the plies can damage warp and fill cords. 6. Reducing step lengths to fit a splice into a shorter Vulcaniser can reduce the Vulcanised splice

strength. 7. Assembling a splice with contamination can reduce adhesions. 8. Using overage compound and cements can reduce cover and ply adhesions. 9. Use of incorrect compounds and cements can reduce adhesions and cause ply/cover blows. 10. Improper splice alignment can cause splice section to track off centre.

39

SECTION C

REPAIRING STEEL CABLE CONVEYOR BELTING

CLASSIFICATION OF MAJOR REPAIRS A DAMAGE TO THE COVER WHICH

DOES NOT EXTEND DOWN TO THE CABLES

B EDGE DAMAGE WHICH DOES NOT

EXTEND TO THE CABLES C EDGE OR COVER DAMAGE WHICH

DOES EXTEND TO THE CABLES D DAMAGE COMPLETELY THROUGH

BELT, E.G., LONGITUDINAL TEAR WHERE CABLES ARE NOT DAMAGED

E DAMAGE WHICH RESULTS IN

CABLES BEING DAMAGED OR BROKEN

A Damage to the cover which does not extend to the cables. Cut out damaged section, taking care to keep the depth of the cut at least 3mm from the steel cables. Roughen the cut out section well including approximately 25mm of the cover surface around the repair. Apply 2 coats of cover cement and fill in with regular repair materials, and vulcanise. B Edge damage which does not extend to the cables. Cut out damaged edge section. Roughen cut surface of the repair and about 25mm of cover surface all around the repair. Apply 2 coats of cover cement to the roughened surfaces. Fill in with regular repair materials, and vulcanise.

Fig. 49

C Edge or cover damage which does extend to the cables. Cut or damaged section down to the cables similar to the method used to remove cover at splicing. Roughen or buff all cut out section of repair and about 25 mm of cover surface all around the repair. Clean off all dust and wash with solvent. Apply 2 coats of cable cement to the skinned cable surface. Apply 2 coats of cover cement to the buffed skived cover surface. Fill in with combination cover stock.

40

D Damage completely through belt, e.g. a longitudinal tear where cables are not damage. (Fig 51).

Remove cover from damaged area on both sides of the belt. Skin the covers down to the cables similar to the method used to remove the cover at splicing. Off-set the dimension of cut out on opposite covers by at least 25mm. Remove the damaged gum from between the cables, flush with the Cable edges(Fig.52)

Roughen or butt all cut out sections of the repair and about 25 mm of cover surface all around the repair. Clean off all dust and wash with solvent. Apply 2 coats of cable cement to the bottom of repair, i.e., the skinned cable surface. Apply 2 coats of cover cement to the buffed skived cover surfaces. Fill in pulley side of repair with combination cover stock. Cut a piece of wire fill-in gum stock – gauge = cable diameter, width= wire spacing, length= repair length. Wash with solvent and fill in gap between the cables. Fill in conveyor side with combination cover stock. On a long repair use a Vulcaniser wider than the belt and use guides, sash clamps and wedges (if necessary) so that the repair will not spread under vulcaniser pressure. Again on long repairs it would be an advantage to use a Vulcaniser with cold

ends to eliminate porosity that can occur at the ends of a conventional vulcaniser where both temperature and pressure are low. This problem may be eliminated by using a steel or aluminium plate approximately 150 mm longer than the press between each platen and the belt. The use of channel iron clamps over these protruding plates will be of further aid to eliminate porosity. If this method fails it will be necessary to re-do repair at press end after each cure.

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E Damage which results in cables being damaged or broken (Fig.No.53) Remove cover from damaged area on both sides of the belt. Skin covers down to the cables similar to the method used to remove covers at splicing. Off-se the dimension of cut out on opposite covers by at least 25 mm. Strip the rubber from between the damaged cables and cut out damaged section of cables using bolt cutters (Fig.No.54) New lengths of steel cable are to be placed between the damaged cable or cables and the inserts will overlap the break at each end (Fig.No.55). Buff or roughen all cut out sections of the repair and about 25mm of cover surfaces all around the repair. Clean off all dust and wash with solvent. Apply 2 coats of cable cement to the bottom of the repair, i.e. the skinned cable surface and cables. Apply 2 coats of cover cement to the buffed skived cover surfaces. Fill in pulley side or repair with combination cover stock. Wash cable

inserts thoroughly in solvent and place in position. Apply a strip of wire fill-in gum each side of the inserts. Fill gaps between ends of cut cables with wire fill-in gum. Fill in conveyor side with combination cover stock. It may be necessary to displace unbroken wire slightly to maintain minimum 1.5mm gum gauge between inserts and original wires.

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SECTION D FABRIC SPLICE PREPARATION

2.1 PREPARATION OF WORK AREA

2.1.1 LOCATION FOR SPLICE WORK

On incline or decline belts, it is desirable to work at the lower end if possible. Splices can be made at the upper end but high belt tensions can cause difficulties in restraining the belt with clamping devices. At the upper end, there is a risk of the belt breaking away from the clamps and running loose down the slope.

Level belts may be spliced at any location where power is available and it is convenient to set up the equipment. The location must have facilities for hoisting the vulcanizer or other heavy equipment and placing them in the desired positions.

The locations must be long enough and wide enough to accommodate the necessary work area and shelter. One must be accounted for the weight of splicing, personnel, and ancillary equipment if the splicing is to be completed on the conveyor structure.

2.1.2. SHELTER FOR WORK AREA

a) A shelter must be provided to keep the belt ends clean and dry at all times. In hot weather, the cemented belt ends must never be exposed to direct sunrays. In cold weather, the shelter must be heated to 60F-(15C) minimum.

b)The size of the shelter depends on the width and construction of the belt to be spliced. Generally it should be 4 to 6 ft (1.2m to 2.0m) wider than the belt, 12 to 18 ft (3.6m to 5.5m) longer than the splice and have 8 ft (2.4m) or more between roof and the work table. As a rule of thumb, 4.5 times the splice length is a good starting point.

2.1.3 THE WORK TABLE

Laying out the splice and cutting of the plies must be done on a flat, smooth surface. This surface should be 6" (150mm) wider than the belt being spliced and at least 4' (1.2m) longer than the splice. The surface should be one piece or smoothly joined and firmly held in position. Plywood with a thickness of 5/8"-3/4" (15mm-19mm) is usually sufficient. The table must be elevated to provide clearance for clamps used to hold the belt ends in alignment.

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2.2. SPLICE TOOLS

2.2.1 IDENTIFICATION

The tools used for preparing a belt for a vulcanized splice are shown in Fig. 2-1.

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2.2.2 MISCELLANEOUS ITEMS

a) A tugger will greatly reduce the time spent stripping the belt ends. Power is a prerequisite when tearing down high-tension belts. An air or electric winch should be available.

b) Water - for cooling the vulcanizer.

c) Appropriate power supply to operate electric buffers, tuggers, etc.

d) Thermocouple unit and pressure transducer with chart recorder.

e) Required personal Safety equipment.

2.2.3 THE ONE PLY KNIFE

The one ply knife as the name implies is intended to cut only one ply. Therefore, certain points should be carefully observed.

a. The depth of the cutting edge should be sharp and approximately 75% of the thickness of one ply of the fabric being cut. Various weights and types of fabric require different depths of the cutting edge. (Figure 2-2)

b. The cutting edge should be sharp.

c. The knife should be held at approx. 45° from the belt surface so that the land of the knife will be flat on the ply below the one being cut.

d. Practice sessions with its use are recommended.

e. Never cut deeper than intended or cut into or destroy any fabric, which is to remain a part of the splice. CAUTION: A HIGH PERCENTAGE OF FABRIC SPLICE FAILURES ARE CAUSED

BY THE ONE PLY KNIFE-NICKING, CUTTING OR GOUGING THE ADJACENT PLY.

f. Inspect one-ply knives frequently and see that the hook or cutting edge is not too deep. Regardless of the condition of the knife, it is possible to cut through more than one ply and the operator should always watch this closely. Keeping knives in proper condition is important.

2.2.4 THE PLY LIFTER

The care and handling of the ply lifter is important.

a) The corners should be rounded. Approx. 1/8" (3mm) radius is recommended. Sharp corners will injure the ply beneath the one Being loosened. (Fig.2-3)

b) The edge at the end or tip, after considerable use, will become worn and sharp. This should be kept dull, rounded and free from burrs.

c) Use the ply lifter so that it is parallel to the cut and held at an approximate 30ø angle from the belt. The flat end or tip of the ply lifter should also be at about a 30° angle from the belt. In this manner, it will loosen the edge of the fabric without "digging into" or injuring the next ply. (Fig. 2-4)

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CAUTION: IMPROPER CARE AND USE OF THE PLY LIFTER CAN ALSO DAMAGE THE ADJACENT PLY AND CAN CONTRIBUTE TO SPLICE FAILURE.

2.3 DIRECTION OF SPLICE AND BIAS

a)In most level or inclined (power requiring) belts, it is recommended that the belt ends be stepped down so that the pulley side joint leads and the top side joint trails the direction of belt travel. (Fig 2-5 and Fig 2-6)

b) In most decline (regenerative) belts the splice is prepared according to Fig. 2-7 so that the pulley side joint trails and the top side joint leads the direction of belt travel.

c) An exception to the above splice directions sometimes occurs when splicing a new belt into an old one. If the old belt covers are badly worn then both ends of the new section should be stepped from the pulley side. This leaves new unworn top cover on both splices and will provide more uniform vulcanizer pressure. In doing this, one splice will run in reverse to the usual recommendation.

d) Be sure that the bias direction will conform to that of the vulcanizer and that the entire cover insert can fit within one setting of the vulcanizer. Slight adjustments of 1" to 3" (25mm to 75mm) of the bias angle are permissible if necessary.

2.4 MASTER LINE

This is normally the first mark to be made on the belt on each of the two ends. The mark is drawn straight across the belt width at a distance from the belt end and equal to the total splice length plus trim allowance. Three methods of locating and squaring the master line are as follows:

2.4.1 SQUARE AND STRAIGHT EDGE

a) From the end of the belt, measure back the length of splice plus trim allowance.

b) Use a square and straight edge to the draw master line.

c) Check the master line by laying the square along the opposite edge. As a final check, mark off the bias lengths on each edge and check that the two diagonal lengths are equal.

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To prepare the second (opposite) end fold the belt back and repeat the procedure. Make sure that the bias is on the opposite edge on the other end.

2.4.2 TRIANGULATION

(Fig 2.9) Draw the master line.

a) From the end of the belt, measure back along one edge the splice length plus trim allowance. Mark the edge. This mark is then the center point of a line exactly 4 ft (1200mm) long drawn along this edge.

b) From each end of the 4 ft (1200mm) line measure equal diagonal lengths to the opposite edge and mark.

Fig. 2-9: Triangulation method of obtaining a “master line”.

c) This method is common on belts 72" (1800mm) and wider.

2.4.3 SWINGING ARC

a. Carefully mark a point at the exact center of the belt width. Measure from this center point and make a mark at each edge near the end. These two diagonal measurements must be exactly equal.

b. From each of the two-edge marks measure back the total splice length plus trim allowance. Mark the edges and draw the master line.

2.5 BELTS WITH DAMAGED EDGE (S)

When belt edges are damaged it is necessary to establish a master line on one end only by one of the above methods and proceed to step that end down. Then lay the ends together, align by eye as well as possible, and transfer all marks to the second end.

2.6. BELTS WITH UNEQUAL END WIDTHS

If the two belt ends are not the same width, the wide end is to have bias and step points marked along the edges in the normal manner. Then measure in from these marks at right angles to the edge a distance 1/2 the width difference and make marks. Connect these new marks for correct bias and step lines.

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SECTION E FABRIC BELT VULCANISING

3.1 TIME AND TEMPERATURE

The vulcanization of rubber compounds needs to be carefully controlled and monitored to ensure optimum rubber properties for maximum splice life. Vulcanization, as a rule of thumb, doubles in the rate of cure for every 18°F (10°C) change in temperature. Over curing, a splice can be as detrimental as under curing. Temperature controllers and measuring devices on vulcanizing equipment should not be relied upon to provide a dependable assessment of the actual platen temperatures. For this reason, each individual heating element in a platen must be monitored with a thermocouple placed on the surface of the belt. A properly calibrated thermocouple unit connected to a chart recorder or other suitable data acquisition unit is required.

During a cure, it is the responsibility of the splice operator to observe the temperatures of each thermocouple and continually adjust the press control units to maintain temperatures within +/- 5°F (3°C).

It is recommended that all field vulcanizer temperature controlling and measuring equipment be regularly maintained and calibrated to minimize the amount of manual adjustment required during a cure cycle.

a) Cure times and temperatures are shown on Table 3-1 , (next page)

b) THE TIMING OF A SPLICE CURE IS NOT TO START UNTIL ALL THERMOCOUPLE READINGS HAVE REACHED THE SPECIFIED TEMPERATURE.

c) In windy and cool conditions, the use of tarpaulins or similar cover over the vulcanizer to minimize heat loss and promote uniform heating is recommended.

d) The temperature in the work area must be maintained between 60ºF - 90 ºF (15 ºC - 32 ºC)and less than 75% relative humidity. This is to insure that the thick rubber materials that must be handled will be tacky and flexible. In hot, humid conditions this will also prevent condensation. Open flame

torpedo style kerosene heaters are not recommended due to explosive hazards and the potential contamination by residual kerosene in the splice area.

e) Due to heat radiation, about 2" (50mm) of the edge of most vulcanizers will not rise to cure temperature and should not contain belt.

f) THE SPLICE MUST NOT BE PUT INTO SERVICE UNTIL THE SPLICE HAS COOLED TO AMBIENT TEMPERATURE.

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TABLE 3-1

CURE TIME AND TEMPERATURES

For double platen vulcanizers only. Single platen v ulcanizers are not recommended.

BELT THICKNESS FABRIC BELT CURE TIME

STEEL CORD BELT CURE TIME

mm Inches Time (in minutes)

Up to 3.1 Up to 1/8 20

3.1 6.3 1/8 1/4 25

6.3 9.5 1/4 3/8 25

9.5 12.7 3/8 1/2 30

12.7 15.8 1/2 5/8 35

15.8 19 5/8 3/4 35

19 22.2 3/4 7/8 40

22.2 25.4 7/8 1 45

Add 5 min. for Neoprene belts over 1" gauge (25.4mm )

25.4 28.5 1 1 1/8 50

28.5 31.7 1 1/8 1 1/4 50

31.7 34.9 1 1/4 1 3/8 55

34.9 38.1 1 3/8 1 1/2 60

38.1 41.2 1 1/2 1 5/8 60

41.2 44.4 1 5/8 1 3/4 65

CURE TEMPERATURES

Cure Temperatures Fahrenheit Celsius

Super Thermo-Flo and Thermo-Chem 310 154

Solarshield 325 162

All other belts / compounds 290 143

Control all cures ±5º ±2.5º

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3.2 PRESSURE

The use of a field vulcanizer with a bladder(s) to apply pressure to the entire platen surface is preferred because of its uniform pressure distribution. (Fig 3-1) If multiple bladders are used, they must be connected to a common manifold to ensure equal pressure in all bladders.

Other types of pressure systems on field vulcanizers are acceptable if they are capable of meeting a tolerance of +/- 5% over the curing area of the platen.

During the cure cycle on bladder presses, pressure should be monitored using a transducer connected to a suitable recording device.

a) Follow operating and safety procedures recommended by the vulcanizer manufacturer.

b) Use care if pressure is applied while the vulcanizer is still cold. Platens can expand when heated causing extreme pressures, which may damage the vulcanizer.

c) To obtain edge pressure use steel guides along each edge which are approximately 1/32"~1/16" (0.8mm - 1.6mm) less than belt thickness. The guides should be drawn together against the edges as uniformly as possible with ratchet chain type or cord type come-along. These come-along should be only drawn up snug initially. Then, after the vulcanizer pressure is applied, they should be drawn tight.

USE OF WEDGES AGAINST THE EDGE IRONS IN THE SPLICE AREA WILL LIMIT BOWING.

d) The recommended vulcanizer pressure for fabric belts is 100 PSI, however precautions should be taken NOT to exceed the manufactures maximum pressure.

3.3 GENERAL CURING NOTES

a) The area between the steel guides and the outside edge of the vulcanizer should be filled to avoid possible vulcanizer distortion and damage. Pieces of the belt being spliced are usually used for this purpose.

b) To help release steam on an obviously wet belt, an awl should be used to perforate the belt every 2"~4" (50-100mm) along the vulcanizer ends.

c) Though not recommended there are instances when the vulcanizer dimensions are such that a splice will be cured in two or more heats. IN THESE CASES EACH OF THE COVER (FILL-IN) STRIPS SHOULD BE COMPLETELY CURED IN A SINGLE HEAT.

The bias length is sometimes adjusted a few inches to insure that this can be done. Note that the one end of the vulcanizer should extend at least 2" (50mm) beyond the fill-in strip and onto original belt to insure adequate cure temperature. The other end should extend at least 4" (100mm) beyond the fill-in and onto splice area to prevent possible slippage and buckling. Always start curing at one end of the splice and never in the center.

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d) In case of a power failure while curing, do not release the pressure, but hold it until power is restored and then bring the vulcanizer back up to cure temperature. At that time:

If the splice had less than half of its specified cure time before power failure, repeat the entire specified cure time.

If the splice had cured 1/2 or more of the specified time, then finish curing the remaining time after all thermocouples again register the specified temperature.

e) If vulcanizing pressure is lost on the surface of the splice, it must be remade.

f) To prevent blistering, the vulcanizer should be cooled to 130°F (55°C), or less, before releasing pressure. This is a good practice at all times since unexpected blisters are undesirable and requires repair or sometimes a complete remake of the splice.

g) After the splice is cured, remove release material. If Holland cloth is used a water soak may be necessary. Trim and/or buff the overflow at the edges.

h) Do not leave the belt on a hot vulcanizer.

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SECTION F FABRIC BELT BIAS SPLICE

4.2 PROCEDURE

The technique for splicing fabric belts is essentially the same for any number of plies. A 3-ply construction is illustrated in the sketches and instructions that follow.

a. Measure the splice length; in addition, 1" (25mm) trim starting from the end of the belt. (Fig 4-1) Draw the master line. A square and straight edge is generally used to mark the master line on the belt as described in section 2. In checking both edges if there is a difference, it can be halved and the result will usually give an accurate line

b. .Measure off the bias length and draw the bias line to the end of the master line on the opposite edge. (Fig. 4-2) This line marks the location of the top ply cut after the cover gum is removed.

c. Extend the end of the bias line down over the belt edge.

d. From the bias line measure toward the end of the belt a distance equal to the total number of steps plus 1" (25mm) trim for Example:

A 2-ply fabric belt requiring 8" steps would equal 9" (230mm)

3 ply = 17" (430mm)Mark the cut off line, which is parallel to the bias line. Fig 4-1.

e. Lay out the cover strip for removal. Draw one line parallel to and approximately 1/2" (13mm) from the bias line and on the splice side. Draw a second line on the belt side of the bias line but at a distance of 2" (50mm). (Fig 4-3)

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f. Cut along the two covers cut lines just made. The line on the belt side of the bias line should be skived per Fig. 4-3. The other cut may be vertical. Do not cut too deep. IF YOU FEEL FABRIC, YOU HAVE DAMAGED THE BELT.

g. Cut off the belt at the cutoff line. (Fig 4-1)

h. Remove the cover strip. Note the one skived cut and one vertical cut in the cover. (Fig 4-4)

i. From marks made down the edges, redraw the bias line where the cover was removed. Then cut the top ply along this line. (Fig 4-5)

j. Prod the top ply loose along the bias line where the cut was just made. BE VERY CAREFUL AS YOU CAN EASILY DAMAGE THE FABRIC. (Fig 4-6)

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k. Turn the belt end over and mark the cover strip for removal. (Fig 4-7) Cut and remove this cover strip. (Fig 4-8)

l. Turn the belt end back down and remove the cover and top ply. (Fig 4-9) This is a very difficult pull. If a winch or equivalent is not available, use a come-along and very carefully cut the inside gum with a ply knife. NOTE: DO NOT KNICK THE FABRIC. DAMAGE TO THE UNDERNEATH PLY WILL CAUSE PREMATURE SPLICE FAILURE.

m. The other end of the belt is torn down from the opposite side using the same system. Note the bias length on this end must be measured from the opposite edge that was used on the first end.

n. Use a light weight, low-speed buffer with a wire wheel brush and remove most of the gum from the fabric. (Fig 4-10) Do not contact the fabric. Buffing the fabric not only reduces its strength but removes the chemical treatment from the fabric which reduces adhesions.

Roughen up the cover cut edges on top and pulley sides as well as an inch or so of cover surface adjacent to the cuts. Blow or brush away all rubber dust.

o. Mark a center line on each end of the belt by connecting three center marks, the furthest being a minimum of three times the splice length

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distance from the master line. Align the belt using the center marks and dry fit the ends to ensure the steps fit together properly. Do not allow any steps to overlap; trim to fit as necessary. After completing adjustments, secure the belt ends in this position. It is common to C-clamp the belt to the work table and nail blocks of wood to the table flush with the belt edges to prevent lateral movement.

p. Clean all rubber areas with the appropriate solvent and allow to dry thoroughly. (Fig 4-11)

q. Apply 2 coats of the proper cement over the entire fabric step area starting at the first ply fabric cut. (Fig 4-12)

ALLOW FIRST COAT TO DRY THOROUGHLY BEFORE APPLYING SECOND COAT.

r. After cement is dry, apply inside gum to the fabric step area starting at the first ply cut and proceeding to the end of the splice area. (Fig 4-13) Be sure the correct gauge gum and the

proper number of layers are used. Roll gum thoroughly with a 2" (50mm) roller. The gum is applied to only one of the stepped ends. Do not remove film from the gum at this time.

s. On the end, which now has the splice gum, mark a ply cut-off line as follows. Measure both edges from the master line. On one edge measure the total step length plus bias length. On the other edge measure only the total step length. Then draw the cutoff line.

t. Cut film, gum and the one ply with a smooth straight cut across the line just marked.

u. About 2"~ 3" (50-75mm) from the cut just made, make a cut through the film only. Remove the 2" ~ 3" (50-75mm) strip of film.

v. Assemble breaker, fill-in gum, and release material on the pulley side using the same system except the pulley gum is to overlap the original cover 1/16" to 3/32" (1 to 2 mm).

w. With the belt edges properly aligned, carefully lay the ends together making a tight uniform joint at the bottom ply. MAKE SURE FABRIC IS NOT OVERLAPPED. (Fig 4-14)

x. Remove the remaining film and lower the remainder of the splice into place. Keep edges aligned.

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y. Trim the top ply step making a tight joint with no gap. (Fig 4-15)

z. Apply a second coat of the proper cement after the first coat of cement is dry) to the fill-in area on the topside. (Fig 4-16) Lay in the breaker. (Fig 4-17) The breaker is 1/4" (6mm) narrower than the exposed fabric.

aa. Cement a strip of top cover, roll it into place, and trim.

bb. Use a small straight edge to check for the proper gauge of fill-in gum. The straight edge should make imprints on the gum. (Fig 4-18) ANY LOW SPOTS SHOULD BE BUILT UP.

cc. Prick the fill-in gum with an awl to release trapped air. Cover with a cemented strip of release material 2" (50mm) wider than the gum strip. (Fig 4-19)

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dd. To insure solid edges, guides of the proper gauge must be used. The guides must contact the belt edges for the full length of the splice and extend 6" (150mm) on both ends of the press. (Fig 4-20)

NOTE: An exception to the above splice directions sometimes occurs when splicing a new belt into an old one. If the old belt covers are badly worn then both ends of the new section should be stepped from the pulley side. This leaves new unworn top cover on both splices and will provide more uniform vulcanizer pressure. In doing this, one splice will run in reverse to the usual recommendation.

ee. After cure, trim the edges of the splice. It is normal for the fabric joints to be spaced 1/4"(6mm) or so during cure due to shrinkage.

ff. Refer to Section 3 of this manual for vulcanizing instructions.

gg. The splice must not be put into service until the splice has cooled to ambient temperature.

hh. Buff inserts and overflows down to original belt gauge to prevent damage from scrapers.

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SECTION G TRAINING THE BELT

Training the belt is a process of adjusting idlers, pulleys and loading conditions in a manner which will correct any tendency of the belt to run other than centrally. When all portions of a belt run off through a part of the conveyor length the cause is probably in the alignment or levelling of the conveyor structures, idlers or pulleys in that area. If one or more portions of the belt run off at all points along the conveyor the cause is more likely in the belt itself, in the splices or in the loading of the belt. When the belt is loaded off-center the center of gravity of the load

tends to-find the center of the troughing idlers, thus leading the belt off on its lightly loaded edge. (See Fig. 4) These are the basic rules for diagnosis of belt running ills. Combinations of these things sometimes produce cases that do not appear clear cut as to cause but if a sufficient number of belt revolutions is observed the running pattern will become clear and the cause disclosed. The usual cases when a pattern does not emerge are those of erratic running which may be found on an unloaded belt that does not trough well or a loaded belt which is not receiving its load uniformly centred.

Fig. 3

Reefing the Belt

Fig. 4 Effects of Off-Centre Loading

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SECTION H FACTORS AFFECTING THE

TRAINING OF THE BELT 1. Pulleys and Snubs Relatively little steering effect is obtained from the crown of conveyor pulleys. Crown is most effective when there is a long unsupported span of belting, (approximately four times belt width) approaching the pulley. As this is not possible on the conveyor carrying side, head pulley crowning is relatively ineffective and is not worth the lateral mal-distribution of tension it produces in the belt. Tail pulleys may have such an unsupported span of belt approaching them and crowning may help except when they are at points of high belt tension. The greatest advantage here is that the crown, in some degree, assists in centring the belt as it passes beneath the loading point which is necessary for good loading. Take-up pulleys are sometimes crowned to take care of any slight mis-alignment which occurs in the take-up carriage as it shifts position. Consult the Goodyear “Handbook of Belting” for a more detailed discussion of pulley crown. All pulleys should be level and with their axis at 90º to the intended path of the belt. They should be kept that way and not shifted as a means of training with the exception that snub pulleys may have their axis shifted when other means of training have provided insufficient correction. Pulleys with their axis at other than 90º to the belt path will lead the belt in the direction of the edge of the belt which first contacts the mis-aligned pulley. When pulleys are not level the belt tends to run to the low side. This is contrary to the old “rule of thumb” statement that a belt runs to the “high” side of the pulley. When combinations of these two occur, the one having the stronger influence will become evident in the belt performance. 2. Carrying Idlers Training the belt with the troughing idlers is accomplished in two ways. Shifting the idler axis with respect to the path of the belt, commonly known as “knocking idlers” is effective where the entire belt runs to one side along some portion of the conveyor. The belt can be centred by “knocking” ahead (in the

direction of belt travel) the end of the idler to which the belt runs. (See Fig. 5). Shifting idlers in this way should be spread over some length of the conveyor preceding the region of the trouble. It will be recognised that a belt might be made to run straight with half the idlers “knocked” one way and half the other, but this would be at the expense of increased rolling friction between belt and idlers. For this reason all idlers should initially be squared with the path of the belt and only the minimum shifting of idlers used as a training means. If the belt is over-corrected by shifting idlers it should be restored by moving back the same idlers, not by shifting additional idlers in the other direction. 3. Return Idlers Return idlers, being flat, provide no self-aligning influence as in the case of tilted troughing idlers. However, by shifting their axis (knocking), with respect to the path of the belt, the return roll can be used to provide a constant corrective effect in one direction. As in the case of troughing rolls, the end of the roll toward which the belt is shifting should be moved longitudinally in the direction of return belt travel to provide correction (Fig. 5). Self aligning return rolls should also be used. These are pivoted about a central pin. Pivoting of the roll about this pin results from an off-centre belt and the idler roll axis becomes shifted with respect to the path of the belt in a self correcting action (Fig. 8). Some return idlers are made with two rolls forming a 10º to 20º V-trough which is effective in helping to train the return run. A further aid to centring the belt as it approaches the tail pulley may be had by slightly advancing and raising the alternate ends of the return rolls nearest the tail pulley (Fig. 9).

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4. Assuring Effectiveness of Training Rolls Normally, extra pressure is desired on self aligning idlers and, in some cases, on standard idlers where strong training influence is required. One way to accomplish this is to raise such idlers above the line of adjacent idlers. Idlers or bend pulleys on convex (hump) curves along the return side have extra pressure due to component of the belt tension and are therefore effective training locations. Carrying side self aligners should not be located on a convex curve since their elevated positions can promote idler juncture failure of the carcass. 5. Side Guide Rollers Guides of this type are not recommended for use in making belts run straight (Fig. 10). They may be used to assist in training the belt initially to prevent it from running off the pulleys and damaging itself against the structure of the conveyor system. They may also be used to afford the same sort of protection to the belt as an emergency measure, provided that they do not touch the belt edge when it is running normally. If they bear on the belt continually, even though free to roll, they tend to wear off the belt edge and eventually cause ply separation along the edge. Side guide rollers should not be located so as to bear against the belt edge once the belt is actually on the pulley. At this point no edge pressure can move the belt laterally.

Obviously such idler shifting is effective for only one direction of belt travel. If the belt is reversed, a shifted idler, corrective in one direction, is mis-directive in the other. Hence reversing belts should have all idlers squared up and left that way. Any correction required can be provided with self-aligning idlers designed for reversing operation. Not all self-aligners are of this type, as some work in one direction only. Tilting the troughing idler forward (not over two degrees) in the direction of belt travel produces a self aligning effect. The idlers may be tilted in this manner by shimming the rear leg of the idler stand. Here again this method is not satisfactory where belts may be reversing. This method is illustrated in Fig. 6. This method has an advantage over “knocking idlers” in that it will correct for movement of the belt to either side of the idler, hence is useful for training erratic belts. It has the disadvantage of encouraging accelerated pulley cover wear due to increased friction on the troughing rolls. It should therefore be used as sparingly as possible - especially on the higher angle troughing idlers. Special, self aligning troughing idlers are available to assist in training the belt (Fig. 7). For a more complete discussion of these idlers refer to the Goodyear “Handbook of Belting”.

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6. The Belt Itself A belt having extreme lateral stiffness relative to its width, will be more difficult to train due to its lack of contact with the centre roll of the carrying idler. Recognition of this fact enables the user to take extra precaution and, if necessary, load the belt during training to improve its steerability. Observation of

troughability design limitations will normally avoid this trouble (Fig. 11). Some new belts may tend to run off to one side, in a certain portion or portions of their length, because of temporary lateral mal-distributions of tension. Operation of the belt under tension corrects this condition in practically all cases. Use of self-aligning idlers will aid in making the correction.

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SECTION I SEQUENCE OF TRAINING OPERATIONS

Initial installation of conveyor equipment should ensure good alignment of all pulleys, troughing and return idlers, i.e., they should be placed at right angles to the direction of belt travel, leveled and centred on a straight line. First movement of the belt should be slow and intermittent so that any tendency of the belt to run off may be quickly observed and the belt stopped before damage occurs. When the conveyor is a long centre installation, men should be stationed at frequent intervals to observe the action of the belt. They should be provided with an effective method of communication so as to report their observations and, if necessary, cause the belt to be stopped. Initial movement of the belt will provide indication of where corrections of the types described are required. The first corrections must be those at points where the belt is in danger of being damaged. Once the belt is clear of all danger points, a sequence of training operations can be followed. The best procedure to use in starting the training sequence is probably to start with the return run and work toward the tail pulley. This assures early centring of the belt on the tail pulley so that it can be centrally loaded. If the empty belt troughs readily, so that its running tendencies are not erratic, the training can and should be completed. Should the belt tend toward stiffness and erratic running, getting some load onto the belt as soon as the return run has been straightened up and the belt centred on the tail pulley will help hold the top run. Normally, the belt can be trained properly onto the tail pulley by manipulation of return idlers and with the assistance of self-aligning return rolls. Seldom is any adjustment of snub or tail pulley necessary but the snub can be used as a supplementary training means. Training of the top run, with the belt empty, is usually no problem if the belt troughs readily. In this case self-aligners on top are not required except as insurance against damage in the region approaching the head pulley. There, two self-aligners, placed approximately 12 and 24 metres preceding the pulley, will

help re-centre the belt if it is ever forced off due to some temporary disturbance. It should not be necessary to use the head pulley for training purposes if it has been aligned properly. Likewise, the snub following the head pulley should not be required as a training means. It is relatively ineffective as a training device due to the strong influence of the head pulley. The take-up carriage has a strong influence on the running of the belt at that point and, due to its movement as belt length changes, is subject to mis-alignment. A vertical take-up carriage, hanging in a festoon of belt, must be guided in its travel so that the pulley shaft remains horizontal. The belt cannot be depended upon to centre itself on the pulley and, once it moves off centre, the pulley will tip out of horizontal if not guided closely on its posts. A horizontal takeup carriage is subject to mis-alignment due to loose track gauge, fouled rails or even jumping off the track. V-shaped rails will hold the gauge tight and, with the apex upward, are self-cleaning. Hold-down rails above the wheels with sufficient clearance so that they do not touch under normal operation will help prevent jumping off the track. (Fig.12) With the empty belt trained satisfactorily, good operation with load is usually assured. Disturbances which appear with load are usually due to off-center loading or to accumulation of material from the load on snub pulleys and return idlers. When equipment is known to be properly aligned, training action should be taken slowly and in small steps because the belt requires some time to respond to corrective measures. It should begin at some point preceding that where run-off occurs and the gradually proceed forward, in the direction of belt travel, until the run-off condition has been corrected. Under some conditions of operation where the conveyor is not level, is extremely short or too wide to be affected by permissible crowning, belts with a special guide strip have been used. This V-guide strip runs loosely in grooved pulley and idler rolls. Guide strips are not recommended or necessary for the long conveyors normally encountered in industrial use.

62

63

SECTION J CLEANING

Special care must be exercised to keep the return rolls and snub pulleys clean. Buildup of material on this equipment has a destructive effect upon training with the result that the belt may run against the structure and damage itself. It is advisable wherever possible that return idlers be suspended far enough below the structure so that any mis-alignment or dirty idlers can be easily seen. Keeping the return rolls and snubs clean requires that the belt be clean when it enters the return run. Scraping is the most common method of doing this. Rubber scrapers can be made by clamping rubber slabs 13 mm to 25 mm thick (not old belting) between two metal or wooden bars. Extend the rubber about twice its thickness beyond the bars and suspend the mechanism with a counter-weight to provide pressure against the belt (Fig. 13). Replace the rubber when it wears down near the bars. Two or three such scrapers can be used in succession. The most common steel scraper is a series of diagonally set blades mounted on the end of a leaf spring to maintain pressure against the belt. These will scrape sticky materials which rubber scrapers may ride over (Fig. 14). Washing the belt with a water spray before wiping with a rubber scraper will do a good

cleaning job on almost any material, including iron ores and mixed concrete. Dry materials can be cleaned off the belt with rotating bristle or rubber vane brushes, driven at fairly high surface speed, usually three to five times the belt speed (Fig. 15). They wear rapidly, require considerable maintenance and are likely to fill up solid if used with wet and sticky materials. It is preferable to clean just after the head pulley and before the snub. An exception to this is that sticky material often requires scraping on the head pulley. This is because a large part of the fine material sticks to the belt and must be scraped into the chute. In some cases the best possible cleaning is insufficient and steps must be taken to compensate for the effect of a dirty belt. Snub pulleys can be kept from building up by the use of soft rubber lagging or by scraping directly against the pulley. Diagonal grooving will distort and discharge accumulations on these pulleys. Rubber disc or spiral type return rolls prevent build up on themselves and thus save a training problem (Fig. 16 & 17). The only cleaning required on the pulley side is removal of material, principally lumps, which may fall or bounce onto the return run, and be carried between the belt and tail pulley if not removed (Fig. 20). Rubber faced plows immediately in front of the tail pulley are used for this purpose (Fig. 18 & 19). They are usually held against the belt by gravity and set at an angle to the direction of belt travel.

64

65

SECTION K LOADING

Receiving material off centre will cause the belt to move sideways after loading as the centre of the load seeks the lowest point in the troughing idlers. This can be corrected by proper chute arrangement provided, of course, that the belt is centred as it enters the loading point (Fig. 4, Section D). The loading point of any conveyor is nearly always the critical point, the life determining point of the belt. Here the conveyor receives its major abrasion, and practically all of its impact. The “ideal condition” is to have the material pass from chute to belt at the same speed and direction of travel as the belt with a minimum amount of impact. The subject of chute design and arrangement is too broad to be discussed in detail here. In lieu of such discussion, the following suggestions are offered:

The width of the receiving end of the loading chute should be great enough to accept material lying on the extreme edge of the preceding belt or feeder, and its position determined by the trajectory of the material coming into it. At no place should the chute be less than twice the size of the largest lumps, if fines are present, and 3-1/2 times the size of lumps, if uniform. The discharge width of the chute thus determined should not exceed about 2/3 of the receiving belts width (Fig. 21). The slope of the chute is determined by the nature of the material, its entering velocity and length of the chute. This value varies with each particular installation, but about 35° has been found satisfac tory for most dry industrial materials such as coal and rock

.

66

An attempt to approach the above “ideal condition” should be made continually by adjusting the chute arrangement. Optimum loading and transferring through chutes still requires considerable experimental adjustment in the field. Skirt boards should be used to further center and settle the load as it leaves the loading point. The steel structure of the chute and skirts never should be placed closer to the surface of the belt than 25 mm, this distance to be made increasing the direction of belt travel to free any material trapped between the belt surface and the skirt. (Fig 22) Skirt boards are usually 4 to 5 times the belt width in length, but may vary considerably due to belt speed, type of material and lump size. Sample skirt board arrangements are shown in Fig.23.

67

Impact of material being loaded on the belt is often the cause of sever cuts and gouges. The degree of impact can be lessened to some extent by providing a cushion in the form of rubber covered disc type or semi-pneumatic idlers which also tend to prevent material from crowding under the skirt boards at the instant of impact. (Fig.24) The use of a “Grizzly”, a slightly fanned row of bars, at the bottom of the transfer chute reduces wear on the

belt. It distributes the impact of large lumps by allowing the fines to fall onto the belt first which act as a cushion. The fan shape of the “Grizzly” in the direction of travel prevents jamming of the lumps. (Fig. 25) A “V-slot” cut in the bottom of the chute is another very satisfactory method of allowing fines to fall on the belt before the lumps and thereby reduce belt wear at this point. (Fig.26)

SECTION L PULLEY LAGGING

Lagging is recommended for drive pulleys for the following reasons: 1. Improved co-efficient of friction. This permits

a belt to be driven by lower slack side tension and sometimes results in lower total tension.

2. Reduction of slippage due to wet conditions if grooved lagging is used.

3. Increased life for pulley and pulley cover of belt. Other pulleys in the system, especially those contacting the carrying side of the belt, are often lagged to prevent build-up of material. Grooving improves cleaning action on the lagging and the belt.

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Fig. 25

Grizzly Chute

Fig. 26 V-Slot Chute

Types of Lagging: 1. Bolted lagging is usually fabric reinforced, the

fabric being necessary to give proper bolt-holding. This type has no inner or pulley cover; where no grooving is intended, 3mm top cover is the proper minimum, but if the lagging is to be grooved a minimum of 6mm top cover must be used.

Bolted lagging is usually applied in two or

more circumferential strips, applied under tension with the points in the different strips staggered around the pulley. (On flat-faced pulleys one strip the width of the pulley may be used.)

For open end pulleys 8mm or 10mm diameter

flat head elevator bolts with nuts may be used. Alternate methods include slotted bolts with tapped holes or self tapping screws for use in welded steel pulleys. It is necessary that the bolt heads be sunk below the level of the surrounding lagging to prevent damage to the belt as it passes over the pulley. This may be accomplished by counter-sinking the holes in the pulley or, where the lagging cover is greater than about 3mm, it is possible to sink the heads merely by tightening the bolts.

Ends of the strips should be bolted in a

dovetail joint as shown in Fig. 27. In addition, bolts should be used in rows running across the face and around the circumference of the pulleys no further than 254mm apart in either direction. Edges of all strips should be bolted down and it is recommended that all exposed fabric edges be cemented to keep out moisture.

2. Vulcanised lagging is a sheet of rubber,

usually 13mm thick, bonded directly to the metal. No fabric is used because no bolt-holding reinforcement is needed. It is much

longer wearing, has better and more uniform adhesion to the pulley and eliminates the hazard of serious belt damage due to a loose bolt.

This type of lagging can be applied in two

different ways: Spiral method - generally used for lower

tension applications. A 100mm wide strip is recommended for ease of handling (Fig. 28). The length of the strip may be calculated by the formula:

C x W L =

4 + C

In application by the sheet wrap method, a

bevelled lateral splice is recommended (Fig. 29). The tie gum side should contact the bevelled leading edge for maximum adhesion at the splice.

3. Grooved lagging should be used on drive

pulleys if they are liable to be wet. The grooves break the film of moisture between the belt and lagging thereby eliminating slippage. Either bolted or vulcanised lagging can be furnished with grooves. Either type can be grooved in the field with a tire-groover if there is sufficient rubber to prevent cutting into the fabric carcass or metal pulley. Herringbone grooving 5mm deep and wide spaced 25mm apart is recommended (Fig. 30).

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4. A modified type of bolted pulley lagging is also

available which features replaceable rubber

pads that slip into metal guides bolted or welded to the pulley.(Fig.31)

70

SECTION M TROUBLE SHOOTING

The previous portions of this manual have described some methods for training and maintaining your conveyor system. The section which follows will allow you to trouble shoot your belt system and apply recommended corrective actions.

PROBLEM /Cause ..In Order of Probable Occurrence PROBLEM /Cause ..In Order of Probable Occurrence A. Conveyor runs to one

side at given point on structure.

5

4

1

2

3

44

M. Covers harden or

crack.

23

37

-

-

-

-

B. Particular section of

the belt runs to one side at all points on conveyor.

6

7

-

-

-

-

N. Cover swells in spots

or streaks.

21

-

-

-

-

-

C. Belt runs to one side

for long distance or entire length of conveyor.

39

8

5

1

2

3

O. Belt breaks at or

behind fasteners; fasteners pull out.

24

22

12

23

-

-

D. Belt runs off at tail

pulley.

39

10

1

-

-

-

P. Vulcanised splice

separation.

38

30

12

17

25

-

E. Belt runs off at head

pulley.

33

10

1

3

-

-

Q. Excessive edge

wear, broken edges.

8

10

40

7

-

-

F. Belt slip.

34

33

31

10

4

-

R. Transverse breaks at

belt edge.

18

25

26

-

-

-

G. Belt slip on starting.

34

31

33

-

-

-

S. Short breaks in

carcass parallel to belt edge, star breaks in carcass.

16

17

-

-

-

-

H. Excessive belt

stretch.

41

42

43

12

32

35

T. Ply separation.

29

30

23

-

-

-

I. Grooving, gouging or

stripping of top cover.

13

14

15

16

-

-

U. Carcass fatigue at

idler junction.

25

26

27

28

29

36

J. Excessive top cover

wear, uniform around belt.

19

20

10

8

36

-

V. Cover blisters or

sand blisters.

45

21

-

-

-

-

K. Severe pulley cover

wear.

4

9

10

17

11

27

W. Belt Cupping - New belt.

46

-

-

-

-

-

L. Longitudinal grooving

or cracking of bottom cover.

4

10

9

33

-

-

X. Belt Cupping - Old belt. (Was

OK when new.)

21

23

-

-

-

-

The idler junction is the gap between the functioning surfaces of the centre rolls and one of the side rolls of the idler (see Fig. 32). This gap poses a potential hazard for the belt by providing a narrow space in which the belt can settle, experiencing highly detrimental flex and possible exposure to oil or grease from the idler bearings (see Fig. 33). When slipping of the belt into the idler junction is the cause of belt damage, it is called idler junction failure.

Fig. 32

Fig. 33

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CAUSES AND THEIR SOLUTIONS

1. Idlers or pulleys out-of-square with centre line of belt: readjust idlers in affected area.

2. Conveyor frame or structure crooked: straighten in affected area. 3. Idler stands not centred on belt: readjust idlers in affected area. 4. Sticking idlers: free idlers and improve maintenance and

lubrication. 5. Buildup of material on Idlers: remove accumulation; improve

maintenance; install scrapers or other cleaning devices. 6. Belt not joined squarely: remove affected splice and resplice. 7. Bowed belt: for new belt this condition should disappear during

break-in; in rare instances belt must be straightened or replaced; check storage and handling of belt rolls.

8 Off-centre loading or poor loading: adjust chute to place load on

centre of belt; discharge material in direction of belt travel at or near belt speed.

9. Slippage on drive pulley: increase tension through screw takeup or

add counterweight; lag drive pulley; increase arc of contact. 10. Material spillage and buildup: improve loading and transfer

conditions; install cleaning devices; improve maintenance. 11. Bolts heads protruding above lagging: tighten bolts; replace

lagging; use vulcanised-on lagging. 12. Tension too high: increase speed, same tonnage; reduce tonnage,

same speed; reduce friction with better maintenance and replacement of damaged idlers; decrease tension by increasing arc of contact or go to lagged pulley; reduce CWT to minimum amount.

13. Skirt boards improperly adjusted or of wrong material: adjust skirt

board supports to minimum 25mm between metal and belt with gap increasing in direction of belt travel use skirt board rubber (not old belt).

14. Belt spanking down under load impact: install cushion idlers. 15. Material hanging up in or under chute: improve loading to reduce

spillage: install baffles widen chute. 16. Impact of material on belt: reduce impact by improving chute

design install impact idlers 17. Material trapped between belt and pulley: install plows or scrapers

on return run ahead of tail pulley 18. Belt edges folding up on structure: same corrections as for 1 2 3;

install limit switches; provide more clearance. 19. Dirty stuck or misaligned return rolls:remove accumulations; install

cleaning devices; use self-cleaning return rolls; improve maintenance and lubrication

20 Cover quality too low: replace with belt of heavier cover gauge or

higher quality rubber. 21. Spilled oil or grease over-lubrication of idlers: improve

housekeeping reduce quantity of grease used check grease seals. 22. Wrong type of fastener, fasteners too tight or too loose: use proper

fasteners and splice technique: set up schedule for regular fastener inspection.

23. Heat or chemical damage: use belt designed for specific condition.

24. Fastener plates too long for pulley size: replace with smaller

fasteners; increase pulley size. 25. Improper transition between troughed belt and terminal pulleys:

adjust transition in accordance with Goodyear Handbook of Belting

26. Severe convex {hump) vertical curve: decrease idler spacing in

curve; increase curve radius; consult Goodyear Handbook of Belting for assistance.

27. Excessive forward tilt of trough rolls: reduce forward tilt of idlers to

no more than 2° from vertical. 28. Excess gap between idler rolls: replace with heavier belt 29. Insufficient transverse stiffness: replace with the proper belt. 30. Pulleys too small: use larger diameter pulleys. 31. Counterweight too light: add counterweight or increase screw

take-up tension to value determined from calculations. 32. Counterweight too heavy: lighten counterweight to value

determined by calculations. 33. Pulley lagging worn: replace pulley lagging. 34. Insufficient traction between belt and pulley: lag drive pulley;

increase belt wrap; install belt cleaning devices. 35. System underbelted: recalculate belt tensions and select proper

belt 36. Excessive sag between idlers causing load to work and shuffle on

belt as it passes over idlers: increase tension if unnecessarily low; reduce idler spacing.

37. Improper storage or handling: refer to Goodyear for proper

storage and handling instructions 38. Belt improperly spliced: resplice using proper method as

recommended by Goodyear 39. Belt running off-centre around the tail pulley and through the

loading area: install training idlers on the return run prior to tail pulley

40. Belt hitting structure: install training idlers on carrying and return

run. 41. Improper belt installation causing apparent excessive belt stretch:

pull belt through counterweight with a tension equal to at least empty running tension; run belt in with mechanical fasteners.

42. Improper initial positioning of counterweight in its carriage causing

apparent excessive belt stretch: check Goodyear Handbook of Belting for recommended initial position.

43. Insufficient counterweight travel: consult Goodyear Conveyor and

Elevator Belt Selection Manual for recommended minimum distances.

44. Structure not level: level structure in affected area 45. Cover cuts or very small cover punctures allow fines to work

under cover and cut cover away from carcass: make spot repair with Vulcaniser or self-curing repair material.

46. Excessive cover gauge ratio: use a belt with a lower gauge and/or

a thicker carcass.