KNITTING by M.Amsaveni, Assistant Professor, Dept. Costume Design and Fashion, Kongunadu Arts and Science College, Coimbatore. Finger knitting Peg knitting Warp knitting machine Hand knitting needles Rib knitting machine Circular knitting machine Weft knitting: In this type of knitting, the direction of loop formation is at right angles to the direction of fabric formation. Normally the fabric is formed vertically and the loops are formed horizontally. It is the most common fabric formation technique for knitted fabric. It is usually knitted with one piece of yarn, and can be made either by hand or using a knitting machine. Weft knitting is the most common form of knitting as it is simpler than warp knitting, the other form of knitting. There are four basic weft knitted fabric structures: interlock, purl, plain, and rib. The action of the needle during loop formation produces all these distinct weft knitted structures. On the basis of the type of weft knitting machine, the weft knitted fabric can be classified as single jersey or double jersey. Warp knitting: The second knitting method is termed warp knitting, though its share in the production of knitted fabric is low compared to weft knitting but it is used in technical areas. In warp knitting, the yarn runs zigzag along the length of the fabric. It requires the preparation of a warp sheet for further use on machine. The most common warp knitted designs or structures are raschel and tricot. COMPARISON OF WARP AND WEFT KNITTING S/No Weft Knitting Warp Knitting 1 Plain, rib, interlock, purl Tricot, raschel, milanese, crochet etc. 2 Loops are produced along the width of fabric Loops are produced along the length of fabric 3 Less production speed More production speed 4 Not necessarily each needle has its own thread Each needle has its own thread 5 Yarn is supplied from a cone held on creel Yarn is supplied from a beam 6 Knitting process can be done from a single yarn Large number of yarns are required for knitting a fabric 7 Staple yarn is preferable but filament is also used Filament yarns are preferable but staple yarns are also used 8 Less preparatory processes are required More preparatory processes are required 9 Latch needle are used in all machines Bearded needle is mostly used but latch needle can also use in some cases 10 Less variety of structure can be made Wide variety of structure can be made 11 Fabric has less aesthetic value Fabric has more aesthetic value 12 Fabric has good stretch ability in both directions, higher in Fabric has low stretch ability in both directions, higher width direction in width direction 13 Dimension stability of fabrics is lower Dimension stability of fabrics is higher 14 Machines may be flat or circular Warp knitting machines are generally flat 15 Width wise more elastic Length wise more elastic 16 More shrinkage Less shrinkage 17 Easy snagging Less snagging 18 It may ravel from edges Does not ravel from edges Course & Wales Course : The series of loops those are connected horizontally, continuously are called as course. The horizontal row of loops that are made by adjacent needles in the same knitting cycle. Wales : The series of loops that intermeshes vertically are known as Wales. Vertical column of loops that are made from same needle in successive knitting cycle GENERAL TERMS IN KNITTING Parts of a loop Each knit stitch (knit loop) is a basic unit for the knitted goods H: Head or Crown or top arc L: Side limbs or Legs S: Bottom arc or Sinker loop →Needle loop=H+2L →A complete loop=Needle loop+Sinker loop Needle loop: Needle loop is the upper part of the loop produced by the needle drawing the yarn. Sinker loop: The lower part of the knitted loop is technically referred as sinker loop. It is the connection of two legs belonging to neighboring stitches lying laterally. Open loop: The open loop is one in which the loop forming yarns do not cross at the bottom of the loop. Closed loop: In closed loop the legs cross at the bottom, so that the loop closing takes place. Face loop and technical face Face loop: During loop formation, when the new loop emerges through the old loop from back to the face side then it is termed as face loop or weft knitted loop. Technical face: The side of the fabric which contains all face loops or weft knit loops is known as technical face. Back loop and Technical Back Back loop: During loop formation, when the new loop passes from the face side to the back of the previous loop then it is termed as back loop or purl loop. Technical back: The side of the fabric which contains all back loops or purl loops is known as technical back. Knitted stitch The knitted stitch is the basic unit of intermeshing. It usually consists of three or more intermeshed needle loops. The centre loop has been drawn through the head of the lower previously-formed loop and is, in turn, intermeshed through its head by the loop above it. Notations Knitting notation is a simple, easily-understood, symbolic representation of a knitting repeat sequence. Its resultant fabric structure that eliminates the need for time-consuming and possibly confusing sketches and written descriptions. Notations are used to express the knitted fabric structure and design. Notations are of four types: 1.Verbal notation. 2.Line diagram/ Looping diagram 3.Diagrammatic notation/ Chain notation 4.Symbolic notation Stitch length The length of yarn required to produce a complete knitted loop (i.e Needle loop and sinker loop) is known as stitch length or loop length. A course length The length of yarn required to produce a complete knitted course is known as course length. Course length= No. of loops per course X Stitch length Course length= No. of needles X Stitch length Stitch density Stitch density refers to the total number of loops in a measured area of fabric. It is the total number of needle loops in a given area (such as a square inch Stitch density= Wales density x Courses density =Wales per inch X Courses per inch = WPI X CPI Unit: number of loops per square inch Or, SD= CPC x WPC (cm scale) Single jersey & Double jersey Single jersey or plain fabric: The weft knitted fabric (Tubular/flat) which is produced by one set of needles. Double jersey: The weft knitted fabric (Tubular/flat) which is produced by two sets of needles. Needle bed or needle carrier Needle bed or needle carrier is the place where the needles are located or mounted in a knitting machine. Needle moves up and down in the trick of a needle carrier. Two types of needle carrier: Cylindrical or circular Flat Cylinder and Dial Cylinder: Cylinder is a circular steel bed having grooves / tricks /cuts on it’s outer periphery into which the needles are mounted. With reference to the tricks, the needles move vertically up and down by their butt being in contact with the cam track. The diameter of the cylinder also varied based on the type and width of the fabric. Maximum diameter of the cylinder: 46 inches. Dial: Dial is the upper steel bed used in double knit circular machines. Into the grooves of the dial, the needles are mounted horizontally and are allowed to move radically in and out by their dial cams. Machine gauge or Needle gauge The number of needles present in one inch of a needle bed is called machine gauge. It is denoted by G or E. Needle pitch: The distance between two neighboring needles Space required for each needle. Feeder Feeders are the yarn guides placed close to the needles to the full circumference of the knitting zone. The feeders feed the yarn into the needle hooks and control the needle latches in their open position while the needle attain their clearing position. Cut edge fabric Cut edge fabric usually produced by slitting open a tube of fabric produced on a circular machine. A slit tube of fabric from a 30” diameter machine will have an open width of 94”(πd) at knitting & before relaxation. Tubular Fabric This may be produced in double faced or single faced structures on circular machine, or in a single faced from on a straight machines with two sets of needles provided each needle set only knits at alternate cycles and that the yarn only passed across from one needle bed to other Important Parts of Circular Knitting Machine: Creel: Creel is a part of a knitting machine. Hear yarn package are store and ready to feed in the machine. VDQ Pulley: It is a very important part of the machine. It controls the quality of the product. Altering the position of the tension pulley changes the G.S.M. of the fabric. If pulley moves towards the positive directive then the G.S.M. is decrease. And in the reverse direction G.S.M will increase. Pulley Belt: It controls the rotation of the MPF Brush: Its clean the pulley belt. wheel. Tension Disk: It confronts the tension of Inlet and Outlet Stop Motion: It is an the supply yarn. important part of the machine. It stops the machine instantly when a yarn is break. Yarn Guide: Its help the yarn to feed MPF Wheel: Its control the speed of the MPF. in the feeder. Pulley belt gives motion to the wheel. MPF: It is Mamenger positive feed. It is also an Feeder Ring: It is a ring. Where all feeders important part of the machine.