Issue 2/2004 demagpress - Jusuco Oy · Injection moulding in a clean environ-ment: Smart solutions for clean-room production Injection moulding medical com-ponents: Sovrin relies

Precision as a competitive advantage:Why Europe needs all-electric machines

Accuracy and constancy: The IntElectproves its practical excellence

The IntElect at PKT: Producing microparts with maximum precision

Successful Production Strategies:How to prevent charring

From Smarts to Maybachs:Wafa with a focus on radiator grilles

Injection moulding in a clean environ-ment: Smart solutions for clean-roomproduction

Injection moulding medical com-ponents: Sovrin relies on IntElectmachines

IntElect machines for Elster Metering:More precision for water meters

demagpress

Issue 2/2004

N e w s f r o m D e m a g P l a s t i c s G r o u p

demagpress II.04 gb. 06.09.2004 10:32 Uhr Seite 1

News

Extra upgraded

Demag Plastics Group has upgraded its Extra range ofinjection moulding machines with additional and impro-ved functional features. The machines’ improved standardequipment includes the tried-and-tested injection unitsfrom Demag’s modular system and automatic screw reco-gnition.

The parallel movement of the ejector in synchronous mo-tion to mould opening reduces cycle time and boosts themachine’s output range. It can now be pre-selected com-fortably via the operator terminal. The Extra machines arefitted with a non-contact, high-resolution ultrasound stro-ke measuring system. Accelerated signal processing in-creases the precision of the injection process, makes theproduction process more transparent for the operator andensures an operation free of wear.

The individual Extra models are nowavailable with clamping forces of 1,200kN (formerly 1,100), 1,300 kN (formerly1,250 kN) and 1,600 kN (formerly 1,500kN). The distance between tie bars andplaten dimensions remain unchanged.

Plastpol award for IntElect machines

Demag Plastics Group was awarded the goldmedal in the injection moulding machinescategory at the Plastpol exhibition in Kiel-ce/Poland. At the Plastpol, which takes placeevery year, a jury selects interesting exhibits,assesses current developments and awardsprizes to products in different categories witha focus on technology and marketing.

The jury, a group of technical engineers, workers wit hands-on experience and several professors, rated the technicalequipment of the all-electric IntElect injection mouldingmachine as particularly innovative. They were pleasedwith the technical solution, which involves a high-torqueelectric direct drive on the clamping unit, the machine’keen price/performance ratio and the efficient energyconsumption. The jury was also impressed by the elegantand maintenance-friendly machine construction, whichoperates with a minimum of mechanical transfer ele-ments. Tomasz Tybura, head of Dematech the Polish Demagsubsidiary, received the award from the technical jury atthe Plastpol exhibition.

In May 2004 more than 500 ex-hibitors were registered at Plast-pol, one of the most importantevents for the central Europe-an plastics industry. In additionto Polish plastics processors, theexhibition grounds at Kielce at-tracted visitors from Germany,the Ukraine and White Russia.

2

Imprint

Published byDemag Ergotech GmbH, Altdorfer Str. 15, D-90571 SchwaigTel.: ++49(0)911/5061-232, Fax: ++49(0)911/5061-750

Editors:Gerd Liebig (Editor-in-chief), Martin Bichler, Armin Distler,Dr. Bettina Laube, Stefanie Lauterbach, Jens Löwe,Markus Lüling, Dr.-Ing. Sabine Pahlke, Thomas Schwachulla,Johannes Strassner, Ronald Wanski

Designed, set and printed byPLASTICS PEPPER Lüling & Troche GbR, Lauf an der PegnitzFahner Druck, Lauf an der Pegnitz

Printed on 100% chorine-free bleached paper

Gerd LiebigChief Strategic

Marketing Officer

Prof. h.c. Helmar FranzExecutive Managing Director

Editorial

Production at short notice

More and more often, tight customer deadlines demanda heightened flexibility in capacity planning. Does thissound familiar to you? We have the same problem. Whenscheduling our production we often have to act at shortnotice to supply your new machine within a few weeks.Flexible machine manufacturers are in demand – especial-ly now that the economy seems to be picking up.

Over the past few years Demag Plastics Group has a-chieved a significant reduction in its machine deliverytimes. At present, the minimum delivery period for stand-ard machines from our Wiehe facility is only two weeks,and medium-size machines from Schwaig can be deliver-ed within three weeks.

The product policy for our basic machines is deeply rootedin Demag’s platform strategy. The global Demag PlasticsGroup production pool offers close-to-market manufactu-ring facilities in Germany, the US, India and China. Pro-duction close to the market not only demands extremelyshort delivery times, it also means machine technologywith a close eye on local market requirements.

Only Demag Plastics Group has this competitive edge overall other international injection moulding machinery ma-nufacturers. This strategy works to your advantage andhelps to meet your increasingly exacting flexibility require-ments.

Yours

The gold medal forthe IntElect machine

Upgraded Extra 130-430 injection moulding machinewith a 1,300 kN toggle clamp unit

The IntElect 100/420-310 was shownat the Plastpol in Kielce/Poland


With 75%, all-electric injection moul-ding machines hold a major share in theJapanese market. Showing first signs ofsaturation, the Japanese market for all-electric injection has only limited potentialin the area of replacement machine supply.Boosted by the strong penetration by Japa-nese suppliers, all-electric machines nowalso represent 30% of the US market.

Since all-electric machines have beenestablished in the US for a long time, thepotential of this market lies in the replace-ment of hydraulic machines with all-elec-tric machines and the supply of spare ma-chines. The demand for all-electric machi-nes is expected to rise over the next fewyears.

In Europe, however, all-electric machi-nes have only been established in a fewareas of application. Hence, their share inthe market remains within the single-digitrange (6% in 2003). With its insignificantmarket penetration and the intractabledemand for replacement machines, Euro-pe promises the highest growth potentialand dynamics for all-electric machines,China not included.

More exacting precision and qualityrequirements

Customers are demanding higher quali-ty and more precision in injection mouldedcomponents across all technological sta-ges, areas of application and productionlocations. As part of this development,manufacturers of injection moulding ma-chines have identified three major trendsamong their customers, which are listedbelow:

1. Plastics processors with a focus on theglobal market will analyse injectionmoulded components in terms of theirmachine technology requirements. Thenecessary production equipment is of-ten categorised according to technolo-gy, outfit and performance levels and istherefore defined in relation to themoulded component. The focus of ma-chine acquisition is shifting towards amore product-oriented approach which,among other trends, displays a clear,specific demand for precision injectionmoulding machines.

2. Moreover, processors are more prone torelocating their small-machinery pro-duction capacities to low-wage coun-tries rather than moving their large ma-chinery capacity. Formerly, this trendalmost exclusively involved relocationfrom western Europe to eastern Euro-pe. Now, both western and easternEuropean producers are shiftingtheir production to low-wageand as yet undeveloped mar-kets (China and South-EastAsia).

3. As a result, plastics proces-sors, whose objective it is tomaintain their production focusin western Europe, are callingfor economically efficient pro-duction equipment, almost reject-free production and maximum pro-duct quality. They are driven by the aimof becoming the technological leader intheir market segment and claim to de-ploy the entire range of relevant process

company report

3

Johannes Strassner, Demag Plastics Group’sGeneral Sales Manager

technologies. More stringent quality re-quirements and the aggravated econo-mic situation increase the importanceof precision and efficiency as a competi-tive edge.

Demag Plastics Group’s corporate phi-losophy demands that every injectionmoulding machine be equipped with dri-ves which yield maximum benefit in relati-on to the specific requirements of thecustomer. Over the past decade, this phi-losophy and its implementation in cost-efficient machine technology has raisedDemag to the rank of global trend-setterfor modular drive technology.

Demag’s all-electric injectionmoulding machine range

In applications with high requirementsin terms of precise reproducibility, con-stancy of shot weights, part weight andmelt cushion, direct electric drives are thebest option for all main machine move-ments. Due to the use of direct electric dri-ves and the general abandonment ofreduction gears in the shape of mechanicaltransmission elements, the price of mo-dern all-electric high-precision injectionmoulding machines is only slightly higherthan that

Precision as a competitive edgeAll-electric injection moulding machines have been dominating the Japanese market formany years and have been enjoying increasing popularity in the US market. In co-operationwith several partners, Demag Plastics Group has developed direct high-torque drives for lar-ge-scale production processes. A property profile featuring the combination of maximumprecision and economic efficiency has long been awaited by European producers of industralcomponents. Author: Johannes Strassner


company report

4

of hydraulic or hydromechanical machinesof the same size. IntElect machines combi-ne the tradition, competence, continuityand reliability of Demag Plastics Group as along-standing market partner with theinnovative force of a global player in thelarge-scale machine engineering segment.

Precision as a competitive edgeIn the two decades since the extensive

establishment of micro-processors in con-trol systems for injection moulding machi-nes in the 1980s, new trends in injectionmoulding technology have mainly evolvedwithin the area of special injection moul-ding techniques. The most recent develop-ments involved the combination of severalspecial techniques. Since these innovati-ons boosted the technological evolution ofniche applications they had a minor impacton the injection moulding segment as awhole. In order to open up new marketsand new areas of application for polymermaterials and injection moulding techni-ques, the main focus should now shift tothe improvement of machine precision.The following list confirms this demand:

1. In many applications, easy-flow materi-als facilitate the production of morecomplex and more filigree componentswith better functional integration andprovide the potential for higher addedvalue. In most cases, production ofmoulded components with the objec-tive of meeting maximum quality requi-rements calls for a more exact processcontrol, which demands heightenedoverall mould and machine precision.

2. In many cases, the established hydraulicmachine technology

is not sufficient to meet the increasinglystringent part quality requirements. Of-ten, the latest developments in mouldtechnology will push machine techno-logy to its limits.

3. The advancement of the injection moul-ding segment demands high-precisionmachine technology to make processesmore transparent, to allow a more sen-sitive process control, and to deliver amore precise repeatability. A competiti-ve edge can be attained by the use ofprecision machinery in the early stagesof production, an insight into all relatedprocesses and the collective expertise ofall involved personnel.

Efficiency as a competitive edgeThe improved precision of all-electric

machines over hydraulic machines offersa whole range of advantages. A more reli-able adherence to critical process parame-ters and higher quality help reduce thereject quota and keep quality assurancemeasures to a minimum. This in turnincreases the machine’s productivity. TheIntElect supports the free definition ofcomplex production processes with decen-tralised drives. Therefore, all parallel or syn-chronous movements can be finely tunedto save cycle times while boosting the out-put rate and productivity and reducingpart costs.

The IntElect consists of fewer moveablecomponents than conventional all-electricmachines with low-torque yet high-revolu-tion, high-noise motors. The abandon-ment of reduction gears or belt drives for-merly used for reducing the number ofrevolutions means fewer mechanical ele-ments, less wear and lower maintenancerequirements for the entire system. Impro-

ved reliability as well as lower mainten-ance and service requirements also

lead to a better utilisation of theentire system and correspon-

dingly lower costs.During the production of

moulded components withaverage performance requi-rements – this applies toabout 90% of mouldedcomponents – the IntElect

uses less energy than compa-rable machines with hydraulic

drives. The IntElect saves anaverage of 60% over hydraulic

standard machines and 50% overhydraulic machines with variable deli-

very pumps. In the wake of a heightenedfocus on resource protection and rising

energy costs, energy efficient productionwill become an even more important assetin the future.

Image promotion and innovation asa competitive edge

In addition to maximised precision andimproved efficiency, IntElect machinesprovide a significant advantage for all pla-stics processors in terms of a speedy upta-ke, utilisation and implementation of themost recent market trends and technolo-gical developments. If precision is concei-ved as a challenge for all production tech-niques, direct drives are established as sta-te-of-the art technology, and cost-efficient

production is promoted as a crucial aspectof protecting the production location,then IntElect machines can be perceived assetting a new trend in injection moulding.With the decision to opt for an IntElectmachine, injection moulding companiescan offer their customers an unexpectedadded value with potential for the futureand justify their claim to technological lea-dership in the plastics processing segment.Processors deciding for an IntElect todaycan be sure to produce on the leading edgeof the market even five years from now.

Protecting the production locationthrough technological leadership

With IntElect machines, plastics proces-sors have the right production equipmentto boost their product quality, improve therepeatability of their processes and increa-se the efficiency of their production. IntEl-ect all-electric injection moulding machi-nes offer a technological and economicaledge over low-wage countries in the lessdeveloped market of eastern Europe andAsia.

A global manufacturer of plastic plugconnectors has been maintaining a large-scale production on an IntElect for severalmonths. Following major production suc-cess, the leading manufacturer in this mar-ket segment has now placed a large orderfor more IntElect machines.


5

Selection of technical componentswhich prove the IntElect’s highprecision

IntElect machines for moreprecision and efficiencyDemag’s fully electric injection moulding machines have beenestablished in the market for a year. High-torque, water-cool-ed direct drives for all main machine movements deliver highprecision, low energy consumption and outstanding efficien-cy. IntElect machines have become established among manu-facturers of industrial components. The machine’s high preci-sion technology, high process constancy and clean-room pro-perties have been tried and tested many times over. More-over, the machine saves energy: compared with hydraulicmachines, fully electric machines can save up to 60%.Authors: Dipl.-Ing. (FH) Jens Löwe, Dr.-Ing. Sabine Pahlke and Ronald Wanski

Since their introduction to the market inthe summer of 2003, IntElect machineshave quickly become established in indu-stries with exacting quality and precisionrequirements such as the electric and elec-tronics industry, medical engineering andmicro technology. The most importantarea of application for IntElect machines isin processing engineering thermoplasticsfor the production of high-precision com-ponents. With their extensive standardequipment, IntElect machines are particu-larly suitable for the production of thesehigh-precision components. Standard fea-tures include a temperature-controlledmetering section, melt-pressure relatedswitch-over to holding pressure, and ex-tensive process monitoring options provi-ding a choice of statistics, graphical displayor accept/reject separation.

Full marks for large-scale productionperformance

As part of numerous machine accep-tance procedures, mould trials and custo-mer tests, IntElect machines have passedextensive testing and proved their highprecision as well as their high efficiency. Aglobal player in the production of E+E poly-butylene terephtalate (PBT) and polyamide6.6 connectors with production facilities inSwitzerland has accumulated the extensi-ve experience of 5,000 operating hours onan IntElect 100 used for large-scale pro-duction. The company has reported nomachine downtimes to date. The verdict ofthe company’s production hall supervisor:“We have never operated a better injec-tion moulding machine than the IntElect”.

With its direct drives, IntElect machinesare widely independent of reduction and

mechanical transmission gears. The lownumber of moving components is subjec-ted to a minimum of wear, thus significant-ly reducing maintenance requirements tofar less than conventional fully electricinjection moulding machines. Due to itslow servicing costs and high reliability IntEl-ect machines operate with impressive effi-ciency.

High-precision mould movement The mould opening and closing move-

ments of IntElect machines are driven by ahigh-torque motor located at the end pla-te. The motor transmits the rotation to thetoggle clamp system via a screw drive foraxial motion of the moving platen. The tog-gle clamp system with direct electric drivehas the advantage of highly dynamic, fastas well as highly precise mould movementpromoted by the precision and short reac-tion time of the motor. Tests and practicalapplication has shown that IntElect machi-nes reach the required position of themould with a maximum deviation of 0.1mm. This is useful for processing steps suchas the defined transfer of moulded compo-nents to handling devices or robots. IntEl-ect machines require very short machinetimes to achieve Euromap opening strokes.The mould height has been increased by100 mm to offer optimum flexibility forusing more complex and higher moulds.

Active mould protection The machines are equipped with the

innovative, active mould protection sys-tem that has been tried-and-tested onEL-EXIS S high-speed machines. A piezo-electronic sensor on the toggle clamp gau-ges and records the clamping force requi-

machinery & data


6

red during the production process. Duringevery clamping cycle, this profile is compa-red with the master profile stored duringmachine optimisation. If the current profileshows deviations from the stored masterprofile of more than the set mould protec-tion force, mould closure is actively stalled.Compared with hydraulic systems, activestalling shortens the machine’s reactiontime. Mould protection can be activeacross the entire closing movement. Theset speed remains unaffected.

Maximum precision for the long term The injection unit is equipped with two

combined direct high-torque drives in axialconfiguration. This arrangement promoteshigh metering and injection precision.Ergocontrol supports input of the injectionand holding pressure phases by means ofgraded or polygon entry with up to 10 sup-port points for the injection phase and up

to 10 support points for the holding-pres-sure phase. Compared with velocity profi-les often encountered in conventional fullyelectric machines, a profile consisting of asequence of speed ramps is more benefici-al, particularly for ensuring an even flowfront velocity in applications featuring ex-tensive wall-thickness variations within onecomponent or different flow distances.This system prevents flow marks and mattareas on the component surface.

IntElect machines have also proved theirhigh precision during large-scale produc-tion. One feature of particular interest interms of process-related properties is themachine’s part weight. IntElect machinesdeliver an outstanding constancy with onlyminute deviations from cycle to cycle. Thisprocess constancy is illustrated by the pro-cess parameters which are analysed by themachine after every shot. The melt cush-ion, the pressure during the change-over

The all-electric IntElect

from the injection to the holding-pressurephase, the metering time as well as the scr-ew disposition display a high repeatability.

Large-scale production up to 10,000class clean-room conditions

Tests conducted by clean-room specia-list Max Petek Reinraumtechnik of Radolf-zell/Germany with an IntElect 100/420-310 proved the suitability of IntElect ma-chines for clean-room conditions up toclass 10,000 (ISO category 7) without theneed for modification of enhancements tothe machine’s standard equipment. This ismainly due to the machine’s belt-less directdrives for all main movements, water-cool-ed motors and frequency converters with-out fans, which avoids swirling and turbu-lences.

Energy savings of up to 60%With their electric drives, IntElect ma-

chines use significantly less energy forplasticisation and injection – the mainenergy consumers – than hydraulic injec-tion moulding machines. Depending oncomponent and cycle, these machines useup to 60% less specific energy than hy-draulic machines.

machinery & data

Part weight Melt cushion

Part

wei

gh

t [g

]

0,2%

∆=

0,0

20 g

Mel

t cu

shio

n [

mm

]

Cycle Cycle

∆ = 0,008 g∆ = 0,04 mm

∆=

0,2

mm

During the production of technical components,the IntElect displays an extraordinary constancyof important process parameters

Based on the specific product requirements, thered lines mark the quality limits for high-precisiontechnical parts


7

Part weight Change-over pressure

Part

wei

gh

t [g

]

0,2%

∆=

0,0

23 g

Ch

ang

e-o

ver

pre

ssu

re [

bar]

Cycle Cycle

∆ = 0,006 g ∆ = 7 bar

Part weight Melt cushion

Part

wei

gh

t [g

]

0,2%

∆=

0,0

49 g

Mel

t cu

shio

n [

mm

]

Cycle Cycle

∆ = 0,018 g ∆ = 0,08 mm

∆=

0,2

mm

3%

∆

= 1

7 b

ar

Part weight Metering time

Part

wei

gh

t [g

]

∆=

0,0

2 g

Met

erin

g t

ime

[s]

Cycle Cycle

∆ = 0,011 g

∆ = 0,04 s

∆=

0,0

8 s

machinery & data


8

industries & markets

While injection moulded componentson a miniature scale are still one of thegreat challenges of plastics processing, theyare also among the products that currentlyenjoy a stable sales situation. PKT speciali-ses in this market segment and has beenmanufacturing components for the watchand clock making industry, the precisionmechanics industry, the electronics seg-ment and medical engineering industriessince 1969. Every production step demandsmaximum precision to reliably meet theexacting requirements.

The production yields part weights ofbetween 0.002 g and 30 g, but every-dayproduction mostly deals with parts with aweight of up to about 1.0 g. Rainer Gillesmiles and explains: “We rarely produceparts near the 30 g limit. That wouldalmost be considered an aberration”. Hestresses that a high precision in the µm ran-ge is standard at PKT. Only the highest

standard ensures that the company achie-ves and maintains its unique selling propo-sition in the market.

About one third of PKT’s machines aremade by Demag. A series of System ma-chines is responsible for encapsulatingparts such as metal blanks in a reel-to-reelproduction of components for the electro-nics industry. In his ongoing quest for ad-vanced high-precision production techno-logies, Walter Spielmann, managing part-ner at PKT, discovered the new IntElectat Fakuma 2003. Walter Spielmann wasquickly convinced of the advantages of theIntElect and decided there and then toorder an IntElect 50 with a clamping forceof 500 kN.

The IntElect outperforms Demag’spromises

Jörg Sprenger, head of PKT’s plasticsprocessing division, had high expectationsbecause it was clear from the start that themachine was earmarked for the state-of-the-art injection moulding of a polypheny-lene sulphide main plate for clockworks inan 8-cavity mould. For the watch and clockmaking industry, the implementation ofplastic components is a viable alternativeto the costly and time-consuming manu-facture of metal parts. However, the plasticcomponents still have to meet very exac-ting precision requirements. Completelydevoid of ridges, the parts must meet to-lerances in the 0.001 mm range in highbatch quantities. Before its operation onthe new machine, the mould for the pro-

IntElect delivers top-notchprecision plastic componentsfor PKTPKT Präzisions-Kunststoff-Teile GmbH is a manufacturer of amultitude of components. The filigree structures of the do-minant geometries in the shape of ducts, pins, apertures,cogs and watch gears are hidden from the naked eye andthey become visible only when seen through the microsco-pe. Since the spring, the injection moulding specialist fromTiefenbronn near Pforzheim/Germany has been operatingan IntElect 50/330-100 to manufacture high-precision compo-nents for the watch and clock making industry. For RainerGille, the company’s managing director, after just a fewmonths of large-scale production this all-electric machine hasbecome an asset he would not like to have to do without.Authors: Dr. Bettina Laube and Markus Lüling

Fast removal system with side-entryat the rear of the IntElect

Main plates for clockworks are collectedaccording to cavity

Mechanical precision parts for the watchand clock making industry

Electronic components, encapsulated inreel-to-reel production

Ball bearing cages and other mechanicalengineering parts

Rainer Gille (on the right) with Demagsales engineer Herbert Gegenheimer



9

duction main plates had been running on ahydraulic machine. Therefore, PKT is ableto draw a direct comparison between bothmachines. Having compiled all requireddata, Jörg Sprenger is entirely justified inhis claim that “Every single statement madein the IntElect brochure was confirmedduring our production.”

First and foremost, the observation ofall process parameters is the cornerstonefor the entire production. Jörg Sprengerstresses that “Particularly during operator-free production we cannot afford machinedowntimes”, and explains that the appli-cations require very narrow tolerances, asmajor deviations would cause an immedia-te machine stop. Since its launch in April2002, the 500 kN IntElect has producedabout five million parts and has thereforeachieved the targeted level.

The machine quickly finds its thermalequilibrium. For Jörg Sprenger, this meansthat the machine quickly reaches produc-tion levels after start-up and therefore pro-duces less waste material for disposal.Sprenger is also entirely satisfied with themachine’s dynamics during injection. Com-

pared to the hydraulic machine, the injec-tion speed is almost 25% faster and achie-ves an output rate of 150mm/s at a reliablyconstant part weight. The componentweight of 2.4 g does not deviate more than0.008 g from the required value. This highrepeatability promotes a smooth and relia-ble production process.

For safe production, PKT relies on theIntElect’s integrated mould protection me-chanism. Originally developed for theEL-EXIS S, this system is based on a piezo-electric sensor located on the toggleclamp, which continuously measures theclamping force required for mould closure.The data of each closing cycle is comparedto the required data with the help of amaster curve. Deviations can thus bedetected quickly and in emergencies theclosing movement can be slowed down tobraking point. The sensitive mould protec-tion mechanism will detect not only jam-med components but also tight slide barsor angled bolts.

PKT uses a fast side-entry robot by theGerman company Waldorf Technik GmbH& Co for the automated removal of finis-hed clockwork plates. The robot approa-ches the machine from opposite the con-trol panel, picks up the parts and placesthem in collecting bins by cavity content.Long-term comparisons between the esta-blished hydraulic and the new all-electricmachines in terms of wear, maintenanceand energy consumption will have to wait.The operation period has not been longenough to allow definitive assessment butboth Gille and Sprenger are convinced thatthey will not be disappointed. On the con-trary, they are tentatively expecting a re-

The IntElect 50/330-100 has been in operation at PKT since April 2004

Jörg Sprenger, head of PKT’s plasticsprocessing division

PKT in profileThe family-owned company PKT Prä-

zisions-Kunststoff-Teile GmbH in Tiefen-bronn/Germany employs 75 people. Its60 injection moulding machines withclamping forces between 150 kN and1,000 kN can process all types of engi-neering plastics. The production proces-ses are organised in a fully automatedthree-shift operation. PKT supplies andsupports its customers across the entireprocess chain from part construction andmould engineering to large-scale pro-duction. The process-linked quality assu-rance system has been certified to DINISO 9001. A DIN ISO TS 16949 certificati-on will be awarded shortly.

At present, PKT is extending its pro-duction area by adding a 3,000 m2 buil-ding to expand its capacity for mouldengineering, injection moulding and sto-rage. The new building will be completedby January 2005. www.pkt-gmbh.de

duction in wear and the correspondingmaintenance benefit. “In total, the machi-ne just has less moving components suchas reduction gears in the electro-motors.Moreover, wear on Demag machines hasalways been low.” PKT has already madenew plans involving the IntElect. The firststep is to test several moulds to generatedata which allows a comparison with hy-draulic machines. At PKT, the IntElect’s ISOclass 7 clean-room capacity is already ear-marked for producing applications for themedical engineering segment.


Grey or black charring streaks can ap-pear in virtually all areas of an injectionmoulded part, be it near the sprue, half-way along the flow path or away from thesprue. While it is always visible in crystal-clear parts, it is only sometimes discernablein coloured components and occurs mostfrequently in mouldings made from PMMA,PC or PS.

A premature plasticising process canentrap the air between the pellets in thefeed section of the screw (Fig.1). The air isenclosed by the melt and the pressure nearthe feed section is not sufficiently high toforce the air back. The entrapped air in themelt inside the screw cylinder turns intoblack streaks in the injection moulded part(Figs. 2 to 4).

Derived from the auto-ignition engine,an invention by Rudolf Diesel, the flawscaused by entrapped air in the screw cylin-der are referred to as the “diesel effect”.

The charring described above occurs alongthe edges of the compressed air bubbleswhere compression has increased the tem-perature of the material and the higherlevel of oxygen has accelerated the degra-dation of the plasticised polymer. A poten-tial remedy would target the timing of theplasticisation process, which preferablyshould start in the middle of the feed sec-tion where the melt pressure is higher andair between the pellets can be forced to-wards the feed opening.

Grey or black streaks near the sprueSilver or black streaks spread centrically

directly from the sprue or from the areanear the sprue. In polymers with a low-vis-cosity (easy-flow materials) which are pro-cessed at a high temperature, these streaksare often black while melt with a high vis-cosity (poor flowing materials) will showsilver streaks upon charring. These streaks

How to prevent charringCharring in injection moulded parts frequently manifests itself in black charring streaks or inthe so-called “diesel effect”. Charring in both melt and cavity can be detected and remediedeasily. Author: Martin Bichler

are caused by compressed gas bubbles wit-hin the plasticised polymer material. Exces-sive melt decompression (screw retraction)at a high decompression speed can releasetoo much of the pressure on the melt infront of the screw tip too quickly and leavea vacuum in its wake. High melt tempera-tures can then cause gas bubbles in theplasticised material (Fig. 5).

During the subsequent injection phase,these gas bubbles are compressed andbecome very hot. The ensuing local over-heating of the melt brings about its degra-dation and causes black streaks on theinjection moulded part.

In parts produced by means of directgating, the streaks will spread directly fromthe sprue while hot-runner injection ofaffected melt will produce streaks whichstart at some distance along the flow path(Fig.6) because the material inside the hotrunner is devoid of gas bubbles and thecorresponding effects of charring. Only thematerial inside the runner head will showevidence of charring.

Plasticised material with a low viscositywill display darker and larger streaks thanmaterial with a high viscosity as the screwdecompression is more likely to cause avacuum and gas bubbles when low-visco-sity polymers are processed. With the helpof a proportionate screw decompressionand/or a reduced melt temperature, theproblem of streaks can be easily avoided.

Diesel effect away from the sprueBlack colouring on the surface of a

moulded part at some distance from the

metering-zone4D

airplasticisedmaterial

pellets

compressionzone6D

feed zone

10D

Plasticisation process in the cylinder

plasticisedmaterial

air pellets plasticisedmaterial

air

1

2 3 4 5 6

10

machinery & data


sprue, or along the flow lines, and incom-plete filling of the part itself are the hall-marks of the so-called diesel effect.

As a result of the high injection speed,the air entrapped in the mould undergoesexcessive compression and heating. Thiscauses charring of the melt along the flowlines (Fig.7) and weld lines, behind flangesor blind holes. These high temperatureslead to local burning.

Because modern mould cavities consistof just a few constituents and are mainlymanufactured by means of electric dis-charge machining, ventilation of the trap-ped air is difficult. Previously, cavities weremade from several inserts which wouldhave allowed the air to escape through thesmall gaps between them.

A transfer of the flow line to the mouldparting line (Fig. 8), changing the gate(Fig. 9) or the introduction of additional airvents can help remedy the diesel effect.

Fig. 1. An optimal plasticisation process inthe screw cylinder (top) allows the air trap-ped between the pellets to escape in the di-rection of the feed opening. Premature pla-sticisation of the pellets (bottom) blocks theairflow towards the feed opening. The air en-trapped in the melt is compressed and leadsto local damage of the plasticised materialwhich manifests itself as grey or black streaks

Fig. 2. PVC container with black streaks

Fig. 3. Two-colour injection moulded lampcover: Air is entrapped and compressed during plasticisation of yellow PMMA andcauses clearly visible black streaks in themoulded part

Fig. 4. Thick-wall PMMA lens with greystreaks on the inside

Fig. 5. Compressed plasticised material infront of the screw tip at the end of the metering process (top). Correct setting ofthe screw decompression (screw retraction)will lift the pressure from the melt in thisarea (centre). Excessive or hastened screwdecompression/retraction (bottom) will cau-se gas bubbles in the hot melt

Relatedliterature

Martin Bichler, the author of this report,provides in-depth information and dealswith exceptional cases in his book “Guideto Flawless Injection Mouldings” publishedby Hüthig Verlag, Heidelberg/Germany(ISBN 3-7785-30097).

Error

Grey orblack clouds

Design-related

Parameter-related

Dynamic screw pressure too low

Cylinder temperature in the feed sectiontoo high

Screw speed too high

Unsuitable screw geometry

Excessive screw decompression

Screw decompression speed too high

Excessive melt temperature

Injection speed too high

Melt temperature too high

Clamping force too high

No air vents

Unsuitable part geometry

Increase dynamic screw pressure

Reduce temperature in the feed section

Reduce screw speed

Use screw with longer feed section and deeper flightdepth in the feed section

Decrease screw decompression

Slow down screw decompression

Reduce cylinder temperature; reduce dynamicscrew pressure; reduce screw speed

Reduce injection speed, alternating injection speed,fast – slow

Reduce cylinder temperature

Reduce clamping force

Introduce air vents, use ventilation to suit the mate-rial (ABS: depth 0.02 mm, PA: depth 0.01 mm), intro-duce venting pins; transfer ejectors to critical areas

Change part geometry to allow a better part filling;change the gate

Parameter-related

Design-related

Grey or blackclouds nearthe sprue

Diesel effect inareas awayfrom the sprue

Parameter-related

Characteri-sation Cause Remedy

Fig. 6. Diesel effect at the bottom ofa thin-wall bucket made from PP witha low viscosity. The material in the vici-nity of the sprue left the hot runner inimmaculate condition. The followingmaterial emerged from the front sectionof the nozzle section, where excessivedecompression caused gas bubbles andcharring

Fig. 7. Diesel effect along the flow line ofa transparent PMMA part

Fig. 8. The affected flow line in this partmade from PA-GF30 may be transferredto the mould parting line by changingthe injection speed or the mould fillingprocess. The entrapped air can then esca-pe through the parting line, thus preven-ting the diesel effect

Fig. 9. The diesel effect in this moulded-on component can only be remedied bychanging the position of the gate. Whilethe diesel effect had not yet manifesteditself in the half-filled part, the comple-tely filled component showed signs ofcharring

Constructive and process-related measures to prevent charring

7 8 9

11

machinery & data


12


sed its capacity to a daily output of 1,200m2. Now the rest of the production equip-ment is earmarked for restructuring.

“We will change the layout of the com-pany and the material flow to accommo-date the production of radiator grilles,”Müller explains. His objective: leadership inthe market for automotive radiator grilles.In addition to grilles, the specialist will fo-cus on decorative exterior and interior trimand exclusive fresh air nozzles for luxurycars as the cornerstones of his business.

In this company radiator grilles are acommon sight inside almost every produc-tion hall.. Grilles are being processed in theinjection moulding shop, at the galvani-sing line, in the coating hall and at the carlogo assembly point. The image-bearingradiator grille of the luxury Maybach car is aprime example of ultimate achievementand therefore Wolfgang Müller’s pride andjoy. In addition to Daimler-Chrysler’s topmodel, Wafa also supplies decorated coo-ler grilles for top-range Opel/VauxhallCorsa, MCC Smart, Ford Fiesta and FordMondeo models. The latest major projectsinvolve the production of radiator grillesfor car models of BMW’s 1 and 6 seriesmodels and the next A-class Mercedes-Benz.

Rushing from hall to hall, Wafa’s ownerWolfgang Müller displays his dynamic per-sonality. A visit to the production halls ofhis 37,000 m2 facility is not for slow wal-kers. With every step, Müller oozes theenergy that drives him. No matter who hemeets or where he stops, the energeticmanager will greet every single one of hisemployees by name.

Six years ago when Müller, a businessgraduate, took over Wafa Kunststofftech-nik, his first achievements were the con-solidation of customer relations and anextension of the company’s portfolio. Threeyears ago he acquired a new galvanisingsystem – the centrepiece of the companywhich was founded in 1943 – and increa-

Wafa’s product range covers almost theentire range of known car logos – from thefamous Mercedes star, BMW’s blue-and-white logo to the Ford oval. At Wafa’s pro-duction facility thousands of car emblemsare being injection moulded, decoratedand mounted to the radiator grilles andwheel boss caps on wheel shields for May-bachs, Fords, Mercedes SLs and BMWminis every day.

It is only a small step from the produc-tion of galvanised radiator grilles to that ofother decorative car components, and soWafa plans to produce under-the-bonnetair baffles, door handle coverings and airscoops for the mudguard of the new Mer-cedes SL. Decorative exterior trim fromAugsburg is also an attractive feature ofthe new BMW Z8.

Wafa also caters for other under-the-bonnet applications such as engine coversfor the 6-cylinder VW Passat. This injectionmoulded component has a glossy surfaceand is finished with a high-gloss PA insert,chrome-plated letters and an emblem.

As a result of chrome-plating also beco-ming a popular finish for car interior trim,Wafa has extended its range from May-bach interior door decoration to centralfresh air nozzles for Mercedes SLs and thenew Porsche models.

Wafa has developed particular experti-se in injection moulding transparent com-ponents. Tachometer covers, dashboardinserts and other interior car componentsmust be free of contamination, even if they

Multi-injection moulding machines for car components with a sealing effect

From Smarts to MaybachsSurface finishing for plastic components such as galvanising, coating, metal-plating, prin-ting, laminating, hot-embossing – you name it, Wafa Kunststofftechnik in Augsburg will doit. Particularly when it comes to car components, the long established company will apply itsexpertise to a whole range of different car models, as varied as the two-seater Smart andthe luxury Maybach car. In his endeavour to become the top supplier of automobile grilles,Wafa’s owner Wolfgang K. Müller is currently changing his entire production concept.Author: Markus Lüling

Production of sanitary products withsmaller Demag machines

Wolfgang Müller with a Maybachradiator grille



13

The production of transparent PMMA components

are not visible to the naked eye. In co-ope-ration with Demag Plastics Group, Wafahas optimised the plasticisation system ofDemag machines and added several speci-al features for PMMA processing to themachines’ control system. Important pro-ducts in this market segment are dashbo-ard inserts for Audi TT and Porsche Boxstermodels as well as housings for the navigati-on system of the latest BMW 7 series.

Wafa’s own mould engineering depart-ment is responsible for the maintenance,servicing and repair of its 2,000+ moulds.New moulds are being designed on-siteand then engineered by experiencedmould makers. About 70 injection moul-ding machines with clamping forces of upto 7,500 kN are already in operation inWafa’s production halls. Production peak

times are supported by sub-contractingto galvanising, injection moulding and as-sembly companies.

Mid-term plans envisage the extensionof machine capacity by means of largerinjection moulding machines with clam-

ping forces of up to 13,000 kN. WolfgangMüller is already in discussion with Demagsales engineer Günter Jank. “As marketleader, we must be able to produce alldimensions on site,” says Müller and castsa glance at some shiny large radiator gril-les. There is no doubt that he sees thisdevelopment as the next step on his way tobecoming “a specialist for niche markets”.

Galvanising toilet flush buttons Wafa Kunststoff-technik in profile

Wafa Kunststofftechnik GmbH of Augs-burg/Germany specialises in the deve-lopment, production and surface finishingof injection moulding components forcustomers from the automotive industrysuch as Mercedes-Benz, BMW, Audi, Por-sche as well as Tier-1 suppliers such as VDOor Faurecia. All established decorationprocesses are carried out on-site. With aproduct range of car exterior, interior andunder-the-bonnet plastic components, thecompany’s core business focuses on radia-tor grilles, decorative trim, fresh air nozz-les, cladding and covers. In addition to allknown decoration techniques, Wafa alsooffers a range of techniques for joining,assembly and insertion. For many years,the supplier to the automotive industryhas also been delivering galvanised fittingsto the sanitary industry. Wafa has 500employees and posted sales of about EUR60m.


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Smart solutions for clean-room injectionmouldingClean-room technology which meets all process and economic requirements needs extensiveexpertise and strong system partners. In co-operation with Max Petek Reinraumtechnik ofRadolfzell, Demag Plastics Group has proved the clean-room capability of its Concept andIntElect machines and found solutions for various applications.Authors: Armin Distler and Thomas Schwachulla

Clean-room technology has long cea-sed to be associated with the production ofmedial engineering components, semi-conductors or microchips. An ever-increa-sing number of technical applications suchas moulded components with a sophistica-ted surface finish in packaging or automo-tive applications or sensitive structural mic-ro-components have a demand for a clea-ner production environment. For theseproducts as for many others, just a fewdust particles make the difference bet-ween acceptance and rejection.

Irrespective of this aspect, many plasticsprocessors have recognised the benefit of aclean, mainly dust-free production envi-ronment for the quality of the producedcomponents, and the resulting efficiencyof the entire production. In order to profitfrom this, however, the economic effect ofevery single one of these implementedmeasures must always be proportionate totheir initial purpose, or in other words, theproduct determines the production envi-ronment.

Focus on protecting moulded partsDemag Plastics Group is co-operation

partner for Max Petek Reinraumtechnik ofRadolfzell/Germany in their endeavour tointegrate injection moulding machinesinto a clean-room environment. At an earlystage, Petek realised that the installation ofa complete injection moulding machine ina clean-room is not an economically viablemeans to an end. Therefore, he concentra-ted all his efforts on trying to protect pro-duct, i.e. the moulded parts, from conta-mination. In practical applications, this

means that the focus lies on protecting thepassage of the moulded parts from mouldto packaging or secondary finishing. Pro-cessors are to be equipped with a clean-room area, which provides maximum pro-tection from contamination to suit the in-dividual application with a minimum tech-nical effort.

In short, clean-rooms have the purposeof protecting the parts to be producedfrom air-borne particles such as dust,germs or bacteria. The area of application

of the finished parts determines the tech-nical effort required. Medical engineeringapplications for instance, require a germ-free production while micro-electroniccomponents demand a completely dust-free environment.

The requirements:ISO and GMP standards

The classification into clean-room cate-gories is carried out in accordance withthe range of ISO 14644 standards (clean-rooms and corresponding clean-room

areas). The production of medical engi-neering components must also complywith international cGMP guidelines (cur-rent Good Manufacturing Practice). It isobvious that the technical effort to providea clean-room environment for medicalengineering parts or micro-components issignificantly higher and more cost-consu-ming than that required for the averagetechnical application. The main causes ofair-borne contamination are humanbeings, generating about 40%, followed

Classification of clean-room categories according to ISO and GMP with measurement data for Demag Concept andIntElect machines (data for Concept only in the mould space)


by machines and equipment with 30%.Contamination caused by operating per-sonnel can be avoided simply by introdu-cing specific rules of conduct and specialclothing.

Machines call for other measures. Inorder to minimise the risk of particle conta-mination for moulded parts, the environ-ment – for injection moulding machines,this is the mould area – must display suffi-cient purity when the system is in operati-on. In order to ensure this, this area mustbe designed to ensure a certain degree ofair purity even when the system is at rest.“At rest” refers to a condition when theentire technical system is installed and rea-dy for operation without the presence ofthe attending personnel. A system is inoperation if it is working in its designatedway and is being attended to by a determi-ned number of personnel.

Clean-room production with IntElectand Concept

Demag instructed Max Petek to measu-re the particle concentration in the mouldarea of an all-hydraulic Concept 110 andan all-electric IntElect 100. The initial mea-surements were taken from standard ma-

chines and another set of data were acqui-red after minor modifications.

For practical applications, the resultsproved that only minor modifications tostandard machines in combination with acareful part removal or enclosed conveyor

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belts are sufficient to create clean-roomconditions. This result is based on the in-sight that the majority of installed clean-rooms are used for the production of indu-strial components. A high number of opti-cal parts as well as medical engineering

Areas of application for clean-room technology

The IntElect 100/420-310 underwent extensive tests at Demag’s main facility in Schwaig/Germany to proveits suitability for clean-room production


16

machinery & data

products, pharmaceutical applications orcomponents with a special surface finishare being produced in ISO 7 or ISO 8 clean-rooms. To complete the picture, it is impor-tant to point out that most medical pro-ducts or food packaging must be sterilisedbefore use.

Tailor-made clean-room solutionsDepending on product-specific require-

ments, Demag co-operates with partnerssuch as Max Petek to provide tailored mo-dular clean-room solutions ranging fromenclosed mould spaces to stationary clean-room cells. This equipment operates with acombination of various measures to pro-tect moulded parts from contamination.These measures, however, are only effec-tive when combined as instructed. At theheart of this equipment is a constant lami-nar air flow to ensure that any particles areremoved from the vicinity of the mouldedparts. The purified air required for this pro-cess is created by filter fan units (FFU). The-se ventilation systems are equipped with atwo-stage filter for coarse and fine suspen-ded particles. They create a slight pressuri-sation of the area inside the machine’s pro-tective cover to prevent the penetration ofdust particles.

The easiest and most inexpensive soluti-on is an enclosed mould space with an FFUmounted directly above the mould. TheFFU can easily be moved to the side to allowmould changes, is equipped with an inte-grated lighting system and different fansdepending on the model. The part deliverychute is also enclosed. The finished parts

are released into a funnel onto an enclosedconveyor belt to a collection station or anadjacent clean-room. The major benefit ofthis solution lies in the strict separation ofthe machine from the clean-room. Sincemachine movements stir up the air, theyare a constant source of potential contami-nation. The separation between machineand clean-room ensures that waste heatemitted from the machine stays outsidethe clean-room, thus facilitating air condi-tioning within the clean-room.

Smart Solution #1:Mobile clean-room cabin with sealinglip attached to the fixed platen

A mobile clean-room cabin above theinjection unit is a viable alternative to theenclosed mould space with FFU. Modularcabins are designed in a profile-based tem-plate system and can be modified to suitindividual space requirements. The mobileclean-room cabin mentioned above can beequipped with one or more FFUs which are

mounted on the cabin roof. A sealing lipattached to the fixed mould platen acts abarrier from the immediate environment.This solution was successfully implemen-ted with a Demag System 25/280-80 for aproducer of optical parts. The clean-roomcan be accessed through a second clean-room tent which acts as a pass through forpersonnel.

Smart solution #2:Enclosed conveyor belt

The combination of a production sys-tem with a clean-room cabin and an enclo-sed conveyor belt is also a cost-efficientsolution. Therefore, whr Hossinger Kunst-stofftechnik GmbH, Roding/Germany deci-ded to use a protected production unitnext to a Demag System 25/280-120 forthe production of small medical compo-nents. The clean-room cabin is fitted withone FFU and protects the area next to theinjection moulding machine where thecollection bins are emptied. The housing ofthe collection bin is also equipped with afilter fan module and is connected to anenclosed conveyor belt running along thelongitudinal machine axis. Purified air fromthe bottom flows counter to the conveyingdirection into the mould space.

Smart solution #3:Docking station between clean-roomand injection moulding machine

A slightly more sophisticated solution,this option operates with GMP compliantwall panels instead of a profile-based cle-an-room cabin. These can be equippedwith a material pass through to preventunauthorised access to the clean-roomenvironment. If the dimensions are suita-ble, the cabin can also be used for secon-dary finishing tasks.

In co-operation with Demag and otherpartners, Petek also developed a conceptfor applications that require active partremoval from the machine. This conceptwas shown at Fakuma 2003 for the firsttime. The ISO 5 compatible clean-roommodule is placed at the rear of a DemagSystem 35/320-120 injection mouldingmachine with enclosed mould space. A ro-bot operating in the clean-room uses thedocking station, a tunnel system locatedbetween the machine and the clean-room,which is supported by the cabin wall andthe protective cover, to remove the finishedparts from the machine. The sprue wastesseparated by the robot inside the tunnelare taken away by means of a revolvinggate. Quality control and magazining of the

System 110/470-600 injection moulding machine with FFU above the mould spaceat Demag’s Wiehe facility for small machines


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accepted nasal spray tops takes place wit-hin the clean-room. The six-axis robot, inthis example a K16 by Kuka Roboter GmbHof Augsburg/Germany, transfers the partsto an optical quality control station andthen places them in a transport container.

Sectional clean-room concepts withcomplete machine integration

Naturally, there are applications whichrequire the complete integration of a ma-chine into the clean-room. For these cases,it is recommended to draw up a so-calledsectional concept, i.e. the division of a pro-duction hall and the installed productionlines into different clean-room sections.According to this concept, a production

hall can be equipped to ISO 8 clean-roomstandard while the installed clean-roommodules comply with ISO 5 categories.Sectional concepts similar to those knownfrom industrial-scale clean-room plants areparticularly beneficial in terms of economicefficiency. In addition to investment costsfor air conditioning, it may be useful toconsider the operational costs of large-sca-le industrial clean-room plants.

Clean-room equipmentfor Demag machinesThe IntElect and other machines made by Demag Plastics Group can be equippedwith a range of additional features to facilitate clean-room production.

These include the following:

• Enclosed ejector system

• Enclosed mould space

• Machine bed elevated by between 100 mm and 200 mm to allow optimum cleaning

• Slide-action FFU above the mould space

• Air baffles for controlled laminar air flow

• Closures for unused mould attachment holes

• Reject gate for quality control

• Pipe inlets coated with PVS

• Antistatic coating

• Use of smooth stainless steel sheet metal for optimum cleaning

• Use of approved lubricants

A GMP-approved ISO 5 clean-room cellinstalled opposite the operator's side ofa Demag System 35/320-120 injectionmoulding machine with an enclosedmould space as presented at Fakuma2003. A six-axis robot with a protectivehood uses a docking station for gripping,removing and transferring the finisednasal spray tops to the the quality con-trol and magazining station.

System 25/280-120 injection moulding machine during clean-room production at whr Hossinger’s production facility. The collectionbin is equipped with an FFU. From there the purified air flows along the enclosed conveyor belt into the mould space. The collectionbin is located inside a mobile clean-room cabin. The walk-in cabin is equipped with a disinfection station for personnel.



18

Sovrin Plastics on the IntElect: “Cleaner,quieter, more efficient and cost effective”In 1976, Sovrin Plastics, manufacturer of technical, medical and pharmaceutical componentsbased in Slough/UK, was the first British plastics processor to use digitally controlled injec-tion moulding machines. Today, twenty-eight years later, the company will be among thefirst to use IntElect all-electric injection moulding machines. In his decision, managing direc-tor Peter Joiner was influenced not only by criteria such as improved precision and efficiency,but by the positive effect the machine will have on his company’s image as an innovativeand modern supplier. Author: Markus Lüling

As the manufacturer of a wide array oftechnical and medical components andpharmaceutical applicators, Sovrin Plasticsprocesses almost all types of thermopla-stics except PVC. Some of the materialsused by Sovrin are biodegradable poly-mers. A special type of material for sutureclips, available at a price of USD 1,600/kg,requires particularly gentle processing.Surgical appliances and surgical instru-ments are important growth generatorsfor the company’s medical moulding seg-ment.

Sovrin has its own integrated mouldengineering facilities and its core businessis medical and technical moulding. There-

fore, the business is largely unaffected byeconomic fluctuations.

Focus on applications and materials Sovrin Plastics operates two facilities in

Slough. At its main plant, the companyproduces technical components and partof its medical moulding range. The secondfacility, opened a few years ago, is fullyequipped for the production and assemblyof medical and pharmaceutical articlessuch as containers for mixing bone ce-ment, inhalers, dispensers and compo-nents for needle-less injection systems.

After injection moulding of the indivi-dual components, most parts are manually

assembled and decorated in clean-rooms.Large-scale products undergo automa-ted assembly and are then decorated bymeans of pad-printing, involving up to fivecolours.

Demag machines are part of Sovrin’stradition

As a customer since the days of Anker-werk Gebr. Goller, now Demag, Peter Joi-ner has never had reason to abandonAnker or Demag machines for fear of apotential failure to meet technical require-ments. Operations director Andrew Rankinrelies on personal experience: “A properlyserviced Demag machine will run as smoo-

The machine’s injection unit is located outside of the clean-rooms to provide easy access


thly as a new one.” Over the past ten years,as managing director and owner of Sovrin,Peter Joiner has been enjoying the com-pany’s significant growth. At the begin-ning of the 1990s, he ordered his thir-teenth injection moulding machine, a 350kN machine, from Demag’s manufacturingsite for small machinery in Wiehe/Ger-many.

Very happy with his small Demag, Joinerdecided to gradually expand his produc-tion with an almost exclusive range ofDemag machines. „We buy Demag machi-nes for their technical capability and wewould have stopped buying them long agoif we weren’t happy with them,” explainsJoiner. Today, Sovrin Plastics runs forty-ninemachines with clamping forces of between50 and 2,500 kN, thirty of which are in ser-vice in technical moulding and almosttwenty producing medical moulding com-ponents. Now the company is planning toacquire its 50th injection moulding machi-ne. This “jubilee machine“, an IntElectfrom Demag Plastics Group, will be the firstall-electric machine Sovrin Plastics has everoperated.

Clean-room technologyAt its two production facilities in Slough,

Sovrin Plastics is currently operating sevenclean-rooms with an overall floor space of11,000 m2. Two clean-rooms (representing

half of the total floor space) are equippedwith injection moulding machines, whilefive others (representing the other half ofthe total floor space) are designed forassembly, secondary finishing and finis-hing of the injection moulded compo-nents. The clean-room for medical moul-ding complies with ISO class 7 (10,000class clean-room), while the clean-roomfor technical moulding is valid for ISO class8 (100,000 class clean-room).

Demag machines at Sovrin Plastics areequipped with a sealing lip on the statio-nary mould platen to close off the clean-room wall. The plasticising and injectionunit operates outside the clean-room andis connected to the material supply, allo-wing easy access. The machine’s clampingunit and the operator panel are within thesealed-off clean-room boundaries.

Twice a year, the clean-room equipmentand technology are subjected to inspectionand validation by an independent controlauthority. Most customers of Sovrin Pla-stics expect compliance with the strict FDAcriteria. Two customers also demand a par-ticularly high degree of microbiological pu-rity and take samples at regular intervals.As a consequence, Sovrin Plastics is com-pelled to rely on a minimum of staff forcomponent handling.

In 1986, Sovrin Plastics built its firstclean-room with the intense support of a


19

Peter Joiner, managing director,founder and owner of Sovrin Plastics

Andrew Rankin, operation directorof Sovrin Plastics

View of the clean-rooms with Demag injection moulding machines

service provider. Over the years, PeterJoiner and his team have made an ongoingeffort to acquire their own expertise inclean-room technology. Today, Sovrin Plas-tics will engineer new clean-rooms forinjection moulding and assembly itself,leaving only their implementation and con-struction to specialised suppliers.

IntElect machine as an imagepromoter

Sovrin Plastics’ 50th injection moul-ding machine is intended to become thecompany’s first all-electric machine. In-tense testing of the IntElect at DemagPlastics Group’s Wiehe facility has convin-ced Sovrin’s team of engineers. But Sovrin’sdecision was not just influenced by thehigh precision of IntElect machines or themachine’s particular suitability for theproduction of technical components. “TheIntElect delivers high precision. What’smore, the running costs of all-electric tech-nology are lower,” Peter Joiner explains.

Operation Director Andrew Rankinknows: “The IntElect will improve the fide-lity of reproduction while reducing ourenergy costs. Hydraulic machines operatedin clean-rooms have higher cooling requi-rements. In this area, electric machinesprovide clear advantages. We expect thereduction in both heat and noise emissionfrom these machines to have a positiveeffect on the clean-room environment.”

Joiner is certain of the positive effect ofhis latest acquisition. “The machine withits all-electric technology promotes a posi-tive image”. For Joiner, the ability to pre-sent state-of-the-art production technolo-gy to customers is one way of imparting hiscompany’s potential: “Our customers maynot understand the technical details of all-electric injection moulding machines butthey can see for themselves that we areusing state-of-the-art technology to meettheir requirements.”

www.sovrin.com


together on a fully automated assemblyline. This line can handle different compo-nent sizes and designs in any required or-der, add and mount inserts, drill holes andinsert seals or screens. Maximum precisionof the individual components is prerequisi-te not just for the precision of the meteringsystems but also to ensure a smooth opera-tion of the assembly line.

After the metering system has beenequipped with external counters and inser-ted into a plastic housing, it is ready forinstallation. The meters are then placed inconventional metal water meter housingsto assess their performance in large-scaletesting lines. Each individual water meter istested for accuracy within the statutorytolerances for minimum and maximumwater volumes across a specified period oftime. After passing the test, the meters arelabelled with a cut serial number.

The IntElect allows Elster Metering toproduce plastics components with tighttolerances and reduce its machining requi-rements while increasing the safety of itsassembly process.

Elster Metering Holdings Ltd. with head-quarters in Luton/UK manufactures, cali-brates and sells water meters, electricitymeters and energy meters for a whole ran-ge of applications used by public suppliers,in municipal and industrial applications aswell as for residential volumetric metering.The company’s service and product rangeinclude standard as well as customised pro-ducts, system solutions and services suchas counter installation and removal, datamanagement, remote meter reading and

meter management. Elster Metering is aglobal metering group created by the con-solidation of ABB’s electricity and watermetering business and the global gas mete-ring businesses of Ruhrgas. The enterpriseforms a new group of companies headedby Ruhrgas Industries, a subsidiary of E.ONAG, a German energy supplier. With 3,500employees and 33 production facilities aswell as sales outlets in 32 countries all overthe world, Elster Metering posts sales ofUSD 1bn. www.elstermetering.com

Elster Metering in profile

More precision for Water MetersElster Metering Holdings Ltd. with headquarters in Luton/UK, is a manufacturer of water me-ters for different areas of application. The company’s latest acquisition, an all-electric IntElectinjection moulding machine from Demag Plastics Group, will introduce more precision to itsproduction of plastic metering chambers with narrow tolerance levels. Author: Markus Lüling

For a long time, water meters were madeexclusively from metal components. Howe-ver, injection moulded components for wa-ter meters have been in use for forty years.Over the years, polymer material has slowlysuperseded metal in measuring chambersand the latter material is now restricted to asmall number of axes and shafts. Water me-ter axes and shafts are inserted into the in-jection moulds and encapsulated by injec-tion moulding. The accurate registration ofthe measurement data, which is acquired onthe velocity principle, requires maximum-precision measuring chambers.

The measuring chambers consist of seve-ral, high-precision technical componentswith mechanical functions. Inserted intothe meters, the measuring chamber trans-mits the velocity of the rotor to an outputregister for reading directly by means of ashaft or inductively by means of a co-rota-ting magnet.

Injection moulding and machiningfor minimum tolerances

The core components of the measuringchambers are injection moulded on machi-nes of different sizes in moulds with up toeight cavities. The tolerances achieved du-ring this process are dependent on bothmachine and mould. In order to compen-sate for the different production toleran-ces, all main plastic constituents must besubjected to a multi-stage machining pro-cess which involves turning on a lathe andmilling. At its headquarters in Luton/UK,Elster operates about 30 injection moul-ding machines for the production of mea-suring chambers and a number of CNC-controlled machining stations. „Our custo-

mers have come to expect a superior per-formance of our systems. This is why narrowtolerances are of the utmost importance forour products “, Clint Sharp, head of produc-tion, explains. „We already employ highly-qualified personnel, use top-of-the-rangematerials and world-class moulds. All weneed now is an injection moulding machinewith minimum shot tolerances.”

IntElect machine saves machining costsDuring his quest for an injection moul-

ding machine with the ultimate precision,Sharp discovered the IntElect all-electricinjection moulding machine from DemagPlastics Group, represented in the UK byDemag Hamilton Ltd. with headquarters inAylesbury.

In February 2004 an IntElect 100/420-150 with a clamping force of 1,000 kN wasinstalled on site and has been tested withseveral different moulds. The machine’s pre-cision is superior to all hydraulic machines.For many components the machine deli-vers tolerance levels which are narrower bysome µm. These products require far less ma-chining than before. The IntElect machinedelivers particularly impressive shot tole-rances which exceed those of all other in-jection moulding machines operated byElster. The IntElect machine proved superiorin precision and repeatability during theproduction of both sensitive metering sys-tem components with narrow tolerances andstandard parts such as water meter covers.

Every week, around 100,000 meteringsystems are shipped from the company’sLuton facility. The metering systems are put

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Water meters made by Elster Metering

Simon Morris, Senior Process Engineerwith Elster Metering in Luton


Documents

Issue 2/2004 demagpress - Jusuco Oy · Injection moulding in a clean environ-ment: Smart solutions for clean-room production Injection moulding medical com-ponents: Sovrin relies