3 Warp knit productsPopular products: swimwear, lingeries, curtains, football jersey, lace fabric etc.
4 KNITTING TERMINOLOGYA Stitch is the basic unit of a knitted fabric which is commonly called ‘loop’If the feet (c) are below the binding points and the legs (b) are above, then the TECHNICAL FACE of the loop is being viewed.If, on the other hand, the feet (c) of a loop lie above the binding points at the base, and the arms (b) lie below then the loop is being viewed from the TECHNICAL BACK side.
8 Course There are two distinguished loops: WALE & COURSE Wale - vertical column of loops formed by a single needle. Wales run lengthwise through out the fabric and in that sense as similar to the warp in a woven fabric.Coursehorizontal rows of loops.Courses run widthwise from side to side of the cloth, and in that sense as similar to the weft in a woven fabric.
9 Unit for Wale: The number of wales per cm or wales per inch Unit for Wale: The number of wales per cm or wales per inch. This depends on upon the closeness of the needles and their thickness. The use of thinner needles can result in higher wales per unit length. Unit for Course: The number of course per cm or course per inch. It is dependent upon the height of the stitch loop.
10 Stitch density = wpcm x cpcm The stitch density is actually a total number of stitches (loops) per unit area of the fabriceg: stitches/2cm.The higher the stitch density the thinner the fabric and vice-versa.
11 Cut and Gaugeare expressions of fineness and coarseness of stitches in knitted material.The number of needles in the slot of the machine per unit length is called CUT.GAUGE is referred to the closeness of the needles in the machine. The higher the gauge number, the finer the fabric.
20 Types of knitting stitches i. KNIT STITCHIt is produced whenever a new loop is intermeshed as a single loop through an old loop.ii.TUCKIt is produced when a needle holding its loop also receives the new loop which becomes a tuck loop. Used mainly for design effect. iii. MISSThe miss yarn floating freely on the reverse side of the held loop.
21 Single Knit FabricThe fabric is produced from one set of needles. They can be produced from flat or circular machine.The fabric is unstable and thinner.Types of single knit fabric:i. Plain Jersey or Stockinetteii. Purl
22 STRUCTURE OF SINGLE KNIT FABRIC PLAIN JERSEYPURL
23 Single knit fabrics 1. Plain Jersey or stockinette. Products: The jersey knit is unbalanced and have the tendency to curl at the edges. It stretches approximately equally in both the length and width direction.Products:- T-shirts,- underwear,- panty-hose,- knit terry,etc.Limitation: if one yarn breaks, it causes an unraveling of adjoining stitches called run.
25 Technical Face and Technical Back Fabric Properties:ExtensibleCurls
26 Fabric CurlingThe top and bottom curl in towards the face of the fabric and the sides towards the back of the fabric.
27 Fabric UnravelingThe constituent loops of plain fabric can readily be disconnected from the structure, course by course, by merely pulling at the most exposed thread. This can take place either from the end first knitted or the end last knitted.
28 Purl FabricProduced by knitting alternate courses in opposite directions using double-ended latch needle.Because of the double hooked needle, the purl machine has the capability of producing a knit and a purl stitch in the same wale.Made on link-link knitting machinewhich use double headed latch needle.Purl fabric lie flat and do not curl.Famous for infants and children’swear.
29 Technical front Technical back Purl FabricPurl or “links-links” fabrics differ from plain knitted fabrics in that the loops are not all meshed in the same direction. In the simplest purl fabric alternate courses are meshed in opposite directions so that the appearance of the fabric is the same from front or back.Technical front Technical back
34 DOUBLE KNIT FABRIC ii. Interlock Types of double knit fabrics: Produced from two sets of needles and can be produced on rib and interlock machines. These fabrics are close stitch, which provides good stability, and thicker, heavier than jersey.Types of double knit fabrics:i. Rib knit fabricii. Interlock
35 Double knit fabric Rib Knit Fabrics Produced from two sets of needle positioned at right angles to each other.Rib-knit fabrics have a very distinct lengthwise rib effect on both sides of fabric.Rib knit lie flat and do not curl at edges. It has greater elasticity in their width than their length.Products: sweater, waistbands, knit cuffs, knit hats, men’s hosiery etc.
37 Interlock fabric Columns of wales are directly behind each other. It is a variation of rib knits made on the interlock machine.Columns of wales are directly behind each other.Interlock is smoother, more stable, better insulators and more expensive.It does not tend to stretch easily.Fabrics are popular for blouses, dresses, and dress T-shirt.
44 Ribs do not curlWhen the fabric is relaxed and under no strain in the direction of the courses, it collapses to a situation of alternate wale touching one another. The face loop wale tend to move over and in front of the reverse loop wale.
45 Ribs are thickerHence a rib is theoretically twice as thick and half the width of an equivalent plain fabric, but it has twice as much width-wise recoverable stretch.
47 The interlock fabric is a variation of the rib fabric, resembling two separate 1 x 1 rib fabrics inter-knitted. The fabric is relatively firm and smooth. Interlock has the technical face of plain fabric on both sides but its smooth surface cannot be stretched out to reveal the reverse meshed loop wales because the wales on each side are exactly opposite to each other and are locked together
51 Loop Configuration Technical front Technical back Single Jersey InterlockThe fabric has technical face of plain fabric on both sides
52 Each interlock pattern row requires two feeder courses each with a separate yarn which knits on separate alternate needles producing two half-gauge 1x1 rib courses whose sinker loop cross over each other, thus odd feeders will produce alternate wale of loops on each side and even feeders will produce the other wale.
53 Interlock fabric properties The positioning of one set of ribs between the other gives a smooth surface and prevents the relaxed fabric from contracting in width like a 1x1 rib so that thickness is obtained without widthwise contraction.It is obvious that the fabric will have these additional properties:Surface smoothDoes not curl; fabric lies flatHeavier and narrower than rib