Introduction to Textile Fabric Part 2: Plain Knit Dr. Jimmy Lam Institute of Textiles & Clothing The 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 knitting (weft knitting)

Basic Loops The single knit fabrics can be made of: All Knit loops Knit & miss loops Knit & tuck loops 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 Knit General 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 Knit End 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 Knit Shirting 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 Knit Underwear 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 fabrics with Knit + Tuck loop

Plain Knit with Knit + 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 Invisible from the face side of fabric Will increase fabric width Will reduce fabric length Better Ladder resistance Thicker and heavier fabric Open work effect

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

Fabric Length Which fabric (A, B or C) is shortest?

Open Work effect (See through) with tuck loops

Common single knit tuck structures

Miss Loop Knit + 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 Invisible from the face of fabric Will reduce the fabric width Will reduce the fabric height Will reduce the fabric elasticity 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?