WEAVING & KNITTING

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Department of Textiles

WEAVING

TEXTILES PRODUCTION FLOW

TEXTILE RAW MATERIAL (NATURAL/MAN-MADE) YARN MANUFACTURING (SPINNING) FABRIC MANUFACTURING (WEAVING/KNITTING)

TEXTILES PROCESSING

GARMENT MANUFACTURING

FABRIC MANUFACTURINGFabric construction involves the conversion of yarns, and sometimes fibres, into a fabric having characteristics determined by the materials and methods employed .

Flow chart of fabric productionFabric production techniques

Interlaced

Non- Interlaced

Felting

Bonding

Laminating

Woven

knitted

Net

Lace

Braid

Weft type

warp type raschel tricot

Basic weaves Pile Jacquard

Fancy Weaves Dobby Gauze

Plain

Twill

Satin

Non Interlaced Fabrics Are Produced By

Felting Bonding laminating

Interlaced Fabrics Include

Woven fabrics Knitted fabrics Net Lace Braid

KnittingIt is a method of fabric construction which employees a continuous yarn or set of yarns to form a series of interlocking loops.

Types of knitted fabricsKnitted fabrics include: Weft types Warp types Raschel Tricot etc.

WEAVINGProduction of fabrics by interlacing two sets of yarns ( the warp & the weft yarns) so that they cross each other, normally at right angles, usually accomplished with a hand- or power-operated loom. hand- powerloom.

HISTORYExamples of prehistoric textiles are extremely rare because of the perish ability of fabrics. The earliest evidence of weaving, closely related to basketry, weaving, dates from Neolithic cultures of about 5000 BC. Cotton was used in India by 3000 BC.

General Theory Of WeavingWoven cloth is normally much longer in one direction than the other. The lengthwise threads are called the warp; the other threads, warp; which are combined with the warp and lie widthwise, are called the weft (synonyms are "filling," "woof," and "shoot," or "shute"). An filling," "woof," "shoot," "shute"). individual thread from the warp, of indefinite length, is called an end; each individual length end; of weft, extending from one edge of the cloth to the other, is called a pick, or shot. pick, shot.

Grey Cotton Fabric The grey yarn obtained from spinning without any wet process of prior dyeing and then woven into a fabric is called a grey cotton fabric.

Flow chart of weaving for grey cotton fabricWarp PreparationHigh Speed Warping SizingDrawing- in (knotting-in)

Weft Preparation

Looming-in Pirn Winding Weaving

WARPING PROCESS Function of this process is to assemble a group of warp threads onto a beam in sheet form. In this process, yarn is wound onto a warpers beam.

SizingFunction of this process is to apply size to the warp threads. At the end of this process weavers beam is produced. This process increases the weaveablity of the warp threads.Objectives of sizing:

Smoothness of yarn Elasticity of yarn Pliability of yarn

DrawingDrawing-in Function of this process is to pass the warp threads through the heald wires and reed according to the design. Knotting-in KnottingFunction of this process is to tie or twist the threads of exhausted beam to the threads of fresh beam.

LoomingLooming-in Function of this process is to load and fix the drawn-in weavers beam onto the drawnloam and thread the warp sheet in such a way that the loom becomes ready for weaving. Pirn winding Function of this process is to wind weft yarns on a Pirn. Pirn is a bobbin which fits into a shuttle and supplies the weft yarn.

Shuttles

PIRN WINDING

Passage of yarns through different parts of a loom

SIZING MACHINE

Basic weaves Basic weaves include:

Plain weave Twill weave Satin weave

Plain weaveIn the plain weave, each filling yarn passes over and under the warp yarns, with the order reversed in alternating rows. Fabrics made in the plain weave include percale, muslin, percale, muslin, and taffeta

Twill weaveTwill weaves are made by interlacing the yarns in a manner producing diagonal ribs, ridges, or Wales on the fabric. Twill fabrics include; denim, gabardine, flan and the herringbone.

Satin weaveSatin weaves have a sheen produced by exposing more warps than fillings on the face of the fabric. The exposed warps are called floats. floats. The amount of twist in the yarns and the length of the floats produce variations. Fabrics made in these weaves include slipper satin, satin crepe, and various sateen types.

The Three Basic Weaves

LoomsThese are the machines used for weaving cloths. Looms are frames or machines made of wood, metal or plastic. There are many different kinds of looms but all looms perform the same function of holding the warp threads under tension in an orderly manner and weaving the cloth.

MOTIONS OF A LOOMThere are three types of motions for the weaving process in a loom.

Primary Motions Secondary Motions Auxiliary Motions

PRIMARY MOTIONS MOTIONS Primary motions are those which are compulsory for the weaving process. Without these weaving is impossible. The order of primary motion is also essential.

TYPES OF PRIMARY MOTIONS Primary Motions include:

Shedding Picking Beating -up

SHEDDINGThis motion separates the warp sheet into two groups so as to make a gap known as the shed for the insertion of pick. pick.

PICKINGThis motion propels a weft thread (a pick) through the shed.

BeatingBeating-upThis motion pushes a newly inserted pick to the fell of the cloth.

SECONDARY MOTIONS The basic purpose of these motions is to enable the weaving process to be continuous. continuous.

TYPES OF SECONDARY MOTIONSThe secondary motions include:

Let -off motion Take -up motionLet off motion The basic function of this motion is to unwind warp threads from weavers beam in such a way that fresh warp is presented to the weaving area under controlled tension & at the required rate. Take up motion The basic function of this motion is to wind the woven cloth on to the cloth roller at a specified speed.

AUXILIARY MOTIONSThe function of these motions is to increase the quality and the production of the fabric. Auxiliary motions include: Warp break stop motion. Warp protector motion. Weft break stop motion. Weft replenishing motion. Multiple shuttle box motion.

CLASSIFICATION OF LOOMS

According to shedding motion Tappet SheddingIn this motion 2-8 heald shafts can be used. 2 Dobby Shedding In this motion 2-24 heald shafts can be used. 2 Jacquard Shedding In this motion 2-2600 heald shafts can be used. 2-

Classification of looms depending on picking motion

Shuttle looms

Hand looms Power looms

ShuttleShuttle-less loomsAir jet loom Water jet loom Rapier loom Projectile loom

OLD HAND LOOMS

POWER LOOMS

The Dobby Mechanism