Knitted Fabrics, Difference between woven and knitted fabrics, Single Knit Fabric, Uses of Knitted Fabric

Knitted Fabrics, Difference between Knitted Fabrics, Difference between woven and knitted fabrics, Single Knit woven and knitted fabrics, Single Knit

Fabric, Uses of Knitted FabricFabric, Uses of Knitted Fabric

Knitted Fabrics, Difference between Knitted Fabrics, Difference between woven and knitted fabrics, Single Knit woven and knitted fabrics, Single Knit

Fabric, Uses of Knitted FabricFabric, Uses of Knitted Fabric

Hafeezullah MemonHafeezullah MemonZSTU, Hangzhou, ChinaZSTU, Hangzhou, China

Content• Knitted Fabrics

– Weft Knitting– Warp Knitting

• Difference between woven and knitted fabric

• Single Knit Fabric– General Charachteristic of Single Knit Fabric

• Uses of Knitted Fabric

Knitted fabricsKnitted fabricsKnitted fabricsKnitted fabrics

Knitted Fabrics• Knitted fabrics are made from interlocking

loops of yarn.There are two main types of knitting:

•WEFT KNITS WARP KNITS

In weft knitting the loops of yarn are linked across the width of the fabric.

In warp knitting the loops are linked in a vertical direction.

Warp knitting machine

Weft KnittingWeft knitting is made using a single yarn. It can be

made by hand knitting or by machines.

Characteristics of weft knits:

• The fabric has high elasticity and stretch.

• The loops of yarn trap air which retains body heat to keep us warm.

• The right and wrong sides of the fabric look different.

• The fabrics can lose shape easily.

• Creases fall out easily.

• The fabric can unravel and ladder easily.

• Weft knitted fabrics curl up at the edges when they are cut.

Weft KnittingWeft knitting machines being used in industry:http://www.youtube.com/watch?v=B4qzdAdhKIoWhat this looks like in slow motion:http://www.youtube.com/watch?v=SUXk-EHKD_c&feature=relatedHow to knit by hand:http://www.youtube.com/watch?v=4ViZRI6oPPg&feature=related

Warp Knitted FabricsIn warp knitting the yarn loops vertically up the fabric and the process uses many yarns rather than one. The fabric does not unravel or ladder. It is an industrial process only.

Characteristics of warp knits:

• The production system is fast so the fabrics are quick to make.

• The fabric is elastic but it can keep its shape.

• It can be cut and sewn easily as it lies flat when cut.

• It is mainly used with synthetic filament yarns.

Warp KnittingA warp knitting machinehttp://www.youtube.com/watch?v=xrSU2XfkAdg&feature=relatedMaking a narrow lace

trimhttp://www.youtube.com/watch?v=Wpx5Cubq7oo&feature=related

Difference between Difference between woven and knitted woven and knitted

fabricsfabrics

Difference between Difference between woven and knitted woven and knitted

fabricsfabrics

Difference between woven and knitted fabrics

• 1) Fabric Construction– Woven fabric is at least

made up of two separate groups of yarns (warp and weft) and knitted fabric can be made up of one yarn only.

– Weaving is interlacing of 2 set of yarn to form a fabric.

– Knitting is a process of converting yarn to fabric by forming a series of loops dependent on each other.

Difference between woven and knitted fabrics• 2) Elasticity

– Elasticity is the ability of the fabric to extend and recover to its original shape and length.

– Knitted fabric has higher extensibility and instant recovery ability than woven fabric. up of one yarn only.


• 3) Fabric Density and Cover

– In general, woven fabric can be produced in extremely tight and higher coverage when compared with knitted fabric.

– Range of density variation is much higher than knitted fabric.

– Knitted fabric in general, is looser in structure.


• 4) Thickness and Handle

– Knitted fabric is much thicker and softer than woven fabric as it has a complicated 3-dimensional structure.

– Knitted fabric seems to be softer because the knitted loops are more easily compress and extensible than straight yarn (warp and weft in woven fabric)


• 5) Production Cost

– Weaving requires expensive preparation processes like warping, sizing, draw-in; while knitting only requires yarn waxing.

– The production rate of circular knitting is roughly FIVE times faster than modern weaving loom. and weft in woven fabric)


• 6) Fabric Application

– The popularity of sportswear, hosiery, underwear and high fashion knitwear make a strong demand on knitted fabric every year which cannot be replaced by woven fabric.

– However, if fabric requires good dimensional stability, high tenacity like trousers, jackets, canvas, woven fabric is the right choice

Single Knit FabricSingle Knit FabricSingle Knit FabricSingle Knit Fabric

What is single knit fabric

• Single knit fabric or single jersey is a general term for knitted fabrics produced by the knitting machines using one set of needles only.

• The fabrics could be composed of different patterns, stitches, materials and different weight and thickness.

General Characteristics of Single Knit Fabric

1) Fabric Elasticity• The single knit fabrics are composed of loops linking

with each other on the two sides as well as on the two ends.

• The shape of a loop can easily be changed by stretching the fabric in all directions.

• The elasticity of knitted fabrics makes them favorable for sports’ wear, casual wear and hosiery.

• This elasticity, however, will be deterioriate due to over stretching, washing or ageing and eventually, the loops cannot recover to its original shape.

• This change of shape is called distortion or poor dimensional stability


1) Fabric Elasticity

• A loop is a very short length of yarn bent into a OMEGA shape as shown on the black area


1) Fabric ElasticityThe dimensional stability of single knitted fabrics can be improved by:

• Increase the fabric density, by using smaller loop length to give the fabric higher cover factor.

• Warp and weft insertion, by inserting straight yarns to the fabric and bind the loops together to reduce their freedom of movement

• Apply resin finishing, a resin chemical can set the fibres and loops on fabric.

• Use the thermal plastic yarns, man-made fiber like polyester or nylon can be set at high temperature and maintain the loop shape on knitted fabrics.


2) Edge Curling

– Almost all single knit fabrics will curl on the edges when cut.

– It is the unbalanced loop structure and the yarn torque inside the fabric which tends to recover the original shape of the yarn.

– It is the edges of a piece of fabric that is free for movement, therefore, the edges curl.

• .


2) Edge Curling

The curling on the fabrics edges is one of the disadvantages of single knit fabircs.

– It gives problems to the cutting, sewing and linking processes.

– Edge curling can be reduced by the following:• Wet finishing, high temperature treatment like

sourcing, bleaching and dyeing can remove the torque in the yarn and fabric.

• Stentering or steam pressing, stentering is used on open width piece goods, and steam pressing for knitwear panel and garment.

• .


3) LadderingWhen a loop in the fabric is broken, the loop directly underneath it will slip off and become a short length of horizontal line instead of maintaining the OMEGA shape.If a vertical row of loops slip off from the fabric, it looks like ladder.


3) LadderingLaddering is a fabric fault which affects the fabric appearance. Laddering will easily occur when:

• The fabric is loosely knitted;• The yarn frictional index is low;• The fabric is plain knit;• There is a big knot in yarn during knitting;• The needle head is broken.


4) Fabric AppearanceAll single jersey fabrics have different appearance on two sides

Looking on the face side, the fabric seems to be composed by thousands of “V” loops; while on the back side, the loops appear to be semi-circles.

Uses of Knitted FabricUses of Knitted FabricUses of Knitted FabricUses of Knitted Fabric

Uses of Knitted FabricsWeft Knits

• T-shirts• Jumpers• Cardigans• Sweatshirt fabrics

Warp Knits• Net curtains• Swimwear• Terry towelling fabrics• Patterned tights• Lace fabrics

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Knitted Fabrics, Difference between woven and knitted fabrics, Single Knit Fabric, Uses of Knitted Fabric