Introduction to Textile Introduction to Textile FabricFabric

Part 2: Plain KnitPart 2: Plain Knit

Introduction to Textile Introduction to Textile FabricFabric

Part 2: Plain KnitPart 2: Plain KnitDr. Jimmy LamDr. Jimmy Lam

Institute of Textiles & ClothingInstitute of Textiles & ClothingThe Hong Kong Polytechnic UniversityThe Hong Kong Polytechnic University

Content• Basic Knit, tuck and miss loop in single

knit fabrics.• Characteristics of all knit loops (plain)

fabric.• Characteristics of knit + tuck single knit

fabric• Characteristics of knit + miss single knit

fabric• Accordian fabric (knit + tuck + miss

loops)

Basic Loops for Basic Loops for knitting (weft knitting (weft

knitting)knitting)

Basic Loops for Basic Loops for knitting (weft knitting (weft

knitting)knitting)

Basic Loops• The single knit fabrics can be

made of:1. All Knit loops2. Knit & miss loops3. Knit & tuck loops4. Knit & tuck & miss loops

Plain knit(All Knit loops)

• If a single knit fabric is composed entirely by knit loops, the fabric is called plain knit or jersey knit.

Plain Knit(Notation)

• The above loop diagrams indicate the face and back side of a plain knit.

• It consists of many loops of the same shape and is not easy to draw by hand; therefore, knitters use simple notation to represent different type of loops.

• X= technical face loop; O=technical back loop

Plain KnitGeneral Features

• Plain knit fabrics are quite good in cover and elasticity and can be knitted by following machines:– V-bed machines– Circular machines and– Fully fashion machines.

• The suitable gauges of knitting are from 2.5 to 36 needles per inch; that means the plain fabrics can be cover the whole range of fabric thickness, in which the fabric weights include 80 g/m2 for fine shirting to 600 g/m2 for heavy weight outwear.

• The yarn for plain knit fabrics can be unroved from both ends.

Plain KnitEnd Uses

• The end uses of fabric mainly depend on the following:– Material used;– Yarn linear density or count;– Machine gauge;– Fabric thickness and weight; and – Type of finishing

Plain KnitShirting

• Produced on the finer gauge circular sinker top machine.

• Example: 28 gauge machine knitting 30Ne cotton or 150 Denier texturised polyester. Fabric weight is 100 g/m2

• The most common materials for shirting fabrics are:– 100% cotton;– 65/35 polyester/cotton blend; and– 100% texturised polyester filament

• Most plain fabrics are piece dye. Yarn dyeing is only used for fabric with colour striping.

Plain KnitUnderwear

• The machine gauge for underwear fabrics may be slightly coarser than those for shirting; this is 20-24 gauge and yarn used are mainly cotton.

• All wool underwear fabrics are knitted on 14-16 gauge machines which will give thicker fabrics for winter underwears

Plain knit fabricsPlain knit fabricswithwith

Knit + Tuck loopKnit + Tuck loop

Plain knit fabricsPlain knit fabricswithwith

Knit + Tuck loopKnit + Tuck loop

Plain Knit withKnit + tuck loop

• All knitted fabrics are formed by knit loop. Tuck loops alone can never be formed into a fabric.

• However, tuck loops are used for the following purposes:– To produce colour patterns;– To give open work or see through effect,– To make raise effect– To make fabric ladder resist

Plain knit with tuck loop

Characteristics of tuck loops

1. Invisible from the face side of fabric

2. Will increase fabric width3. Will reduce fabric length4. Better Ladder resistance5. Thicker and heavier fabric6. Open work effect

Fabric Width

Fabric A is wider than fabric B as it has more tuck stitches on each course

Fabric LengthWhich fabric (A, B or C) is

shortest?

Open Work effect (See through) with tuck

loops

Common single knit tuck structures

Miss LoopMiss LoopKnit + Miss fabricsKnit + Miss fabrics

Miss LoopMiss LoopKnit + Miss fabricsKnit + Miss fabrics

Miss Loop• Miss loop is called float or welt, is

rather similar to tuck loop as it cannot be seen from the face side of fabric.

• The miss loop appears as short length of horizontal yarn at the back of single knit fabric

Characteristics of Miss Loop

1. Invisible from the face of fabric2. Will reduce the fabric width3. Will reduce the fabric height4. Will reduce the fabric elasticity5. Will increase the fabric density

Application of Miss loop

• Miss loop is used for jacquard (colour design) single knit jersey knitting/

• It is used to hide the unwanted colours at the back of the fabric.

• Example: shirting fabrics for casual wear

• Example: sweater fabrics

Accordian fabric• This is single knit jacquard fabric with

knit, tuck and miss loops on the same course.

• The knit and miss loops are for colour pattern knitting, while the tuck loops are used to tie-in the long floats at the back of the fabric and make the float lengths shorter.

Discussion• Why fabric is narrower with

insertion of float loop?• Why fabric is wider with insertion

of tuck loop?• Why knit + tuck loops will never

be used for underwear fabric?