POWER LOOMSWell come to the presentation on

Presented byMd. Rasel RanaDUET Gazipur

INTRODUCTION

Woven fabrics are produced by interlacing warp and weft yarn –the process known weaving. The apparatus used for weaving is termed a loom. A loom cannot be said a machine but it is a device which is used to produce woven fabric. Three operations are necessary –shedding, picking, beating up, to complete this operation various loom parts are used.

DIFFERENT PARTS OF LOOMA. weaver’s beam or loom beamB. warp threads (ends, sheet form)C. back rest or bearerD. lease rodsE. “shed”F. healdsG. reedH. fell of cloth or beat-up pointJ. shuttleK. breast beamL. cloth take-up rollerM. tug barN. cloth rollerO. tappets

P. tappet treadles, with anti-friction bowlsR. treadle fulcrumS. roller-top, heald reversing motionT. rocking rail, or shaftU. sley swordV. crank armW. sleyX. top shaftY. bottom shaft

A :warp beam: (1)This is also known as the weaver’s beam. It is fixed at the back of the loom. The warp sheet is wound on to this beam. The length of warp in the beam may be more than a thousand metres.

C : Back Beam / back rest. (2.3)This is also known as the back rest. It is placed above the weaver’s beam. It may be of the fixed or floating type. In the first case the back rest merely acts as a guide to the warp sheet coming from the weaver’s beam. In the second case it acts both as a guide and as a sensor for sensing the warp tension.

B : Warp yarn: the warp yarn are wound on the weavers beam. The length of warp in the beam may be more than a thousand meters.

D : Lease rod: An arrangement of warp to maintain the same relative position during handling. This is done generally by criss- crossing the yarns alternatively, keeping them in position by two rods called lease rod.

E : Shed: The path across the warp in the loom formed when some warp yarns are lifted by their harness while others are left down or depressed. The shuttle or other picking mechanism passes through the shed to insert the filling.

F : Healds: Every warp thread passes through a heddle/healds. Heddles keep warp threads separate and allow for passage of weft threads. Heddles are made of wire or cord and are attached to the shaft of the loom.

G : Reed: The reed is the steel comb that spaces warp threads evenly and pushes weft into cloth.

H : Fell of the cloth or beat up point: the point where the lay or batten beats the last loose pick in the shed back against preceding picks to make a compact cloth.

J : Shuttle: It is basically a weft carrier and helpsin interlacement of the weft with the warp threads to form cloth. The shuttle which is made of wood passes from one end of the loom to the other. It travels along the wooden sley race and passes between the top and bottom layers of the warp sheet. The shuttle enters a shuttle box fitted at either ends of the loom, after passing through the warp shed. A shuttle normally weighs about 0.45 kgs.

K : Breast or Front Beam: Cloth passes over the breast beam on its way to the cloth beam. It is placed above the cloth roller at the front of the loom and acts as a guide for the cloth being wound on to the cloth roller. The front rest maintain proper tension to facilitate weaving.L . Cloth take- up R/r:The fabric is passed over a take up roller before being wound over the cloth roller.The cloth R/r is driven through friction between it and the take up r/r. It is a negative motion of cloth winding.

N : Cloth roller/ Cloth Beam: It is also known as the cloth roller. The woven cloth is wound on to this roller. This roller is placed below the front rest.

Shuttle box: It is the housing for the shuttle and is made of wood. It has a spindle and a picker. It may also accommodate the picker without spindle. The top and side of the box towards the sley race are open. The shuttle dwells inside the box for the intermediate period between two successive picks.

Picker: The picker is a piece made either of leather or synthetic material. It may be placed on a spindle or grooves in the shuttle box. It is used to drive the shuttle from one box to another. It also sustains the force of the shuttle while entering the box.

O : Tappet: The main shaft is connected by means of gearing or other tooted drive to a second shaft called a cam shaft . This cam shaft drives the shedding motion is known tappet.

Buffer : Buffer is used to control the beater speed when beating arm is push shuttle from the shuttle box.

P : Tappet treadles :The treadle is a paddle or lever under a loom with which a thread is connected by means of cords.

R : Treadle fulcrum:Treadle fulcrum with anti –friction bowl. For this it can move easily.

S : Roller top:It is present on the top of the loom, which joined with heald shaft . For this heald shaft can move easily and help to shedding.

T : Rocking rail or shaft:The sley must reciprocate for the reed to push the weft into the fell cloth, and the two sley swords therefore extend down from the raceboard to a fulcrum point known as the rocking shaft or rail.

U :Sley sword:The supports which connect the sley to the rocking shaft about which the sley oscillates.V : Crank arm:The crank arm is connected to the back of each of the two sley swords by a pin just below the level of the raceboard, and its other end fastens round the dend in the crankshaft.

W : Sley: It is made of wood and consists of the sley race or race board, reed cap and metal swords carried at either ends. The sley mechanism swings to and fro. It is responsible for pushing the last pick of weft to the fell of the cloth by means of the beat up motion. The sley moves faster when moving towards the fell of the cloth and moves slower when moving backwards. This unequal movement is known as ‘eccentricity of the sley’. It is needed in order to perform the beat up and also to give sufficient time for passage of shuttle to pass through the,arp shed. The beat up of the lastly laid pick of weft is accomplished through a metal reed attached to the sley.X : Top shaft or crank shaft :A device in which an eccentric pin drives a connecting rod and causes a member to oscillate. It connected with crank arm and bottom shaft.Y : Bottom shaft:The shaft in a loom which carries the picking cams and which is normally situated below the crank shaft.Conclusion: Loom is the basic part of weaving section, to properly operate a loom for produce fabric we have to acquire concept about variable parts of loom and function of different parts. For improve our weaving section the study on loom will very helpful in our practical life.

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