The second most important fabric construction method after weaving is knitting. Knitting is the process of making loops and throwing the yarns through loops to form a fabric. In the earlier days knitting was con-sidered as a unique technique of making fabric using wool fibres. The oldest knitted products are socks found in Egypt tombs. Knitting is done using long stick like nee-dles. The first knitting machine was invented in 1589, by Reverend William Lee. It slowly developed and today the market is filled with complex knitting machine to produce a huge range of knitted fabric.
Knitting is divided into two main groups as warp and weft knitting. Warp knitted fab-rics are produced by a series of yarn forming loops in the lengthwise direction of the fab-ric. Weft knitted fabrics is produced when one continuous yarn forms the loops in the crosswise directions. The most common types of warp knitt fabrics are Tricot knit, Raschel, Milanese and Simples knit. The different kinds of weft knits are plain, purl and rib. Both weft and warp knitting can be incorporated in the jacquard mechanism to produce fancy knitted fabrics.
Knitted fabric is constructed by forming the yarns into loops. The vertical rows of loops stitches in knit fabric are known as wales and the horizontal rows of loops are called courses. The loops are formed by a group of needles or shafts, which are arranged one after the other in the knit-ting machine on the needle plate. The needles are evenly placed. Sinker is used to pull the needles down, which pulls the yarn into the previous loop. The knitted fabric is pulled down and rolled at the base of the machine and collected for fur-ther use.
Knitted fabrics are used for (Figure 5.15)
· Clothing (Underwear, Sweaters)
· Home furnishing (Curtains, Towels)
· Medical textiles (Grip Bandages)
· Industrial textiles (Wipes, Absorbent Pads)