Folded yarn calculation Indirect system 1 / R = 1 / R1 + 1 / R2 + 1/ R3 +………where, R is the resultant count in indirect systemR1, R2, R3 are the count of single yarn in indirect systeme.gWhen two cotton yarns are of 24 and 36 Ne are folded, 1/R = 1/24 +1/36 R = 14.4 Ne so the resultant count of 24 and 36 Ne folded cotton yarn is 14.4 Ne
Direct system R = R1 + R2 + R3 +……..Where R is the resultant count in direct system,And R1, R2, R3 are the count of single yarn in direct systeme.gWhen two polyester filament yarns of 40 and 76 denier are plied together, their resultant count, R = 40 + 76 = 116 Denier
Formation of Fabrics Weaving Knitting Braiding Nonwovens
WEAVINGInterlacement of Warpyarns Weft Plain Weave
Different Types of WeavesDifferent arrangement of Plain threads……… Plain Twill Satin Sateen Diamond Honeycomb And many more…………… Satin Twill
AIM……… Quality Production Minimum loss of energyand material
To achieve these aims…….. Good quality of yarns Proper maintenance of machinery Skilled worker
Material flow Winding Warping Sizing Drawing in Weaving
WindingObjective To produce a good package that contains long length of yarn and unwound well during warping. To remove objectionable yarn faults
Requirement of winding The fault level in the yarn must be reduced to an acceptable level. The yarn must not be damaged in any way in the winding process. Unwinding in the following process with minimum difficulty. Package size, shape, and built must be most technologically suitable
Requirement of knotting Be easy to tie, Have good resistance to slippage, and Be of a size and shape that gives it little chance of catching or jamming in narrow openings
A high degree of yarn quality is impossible throughknot…..as the knot itself is objectionable due to itsphysical dimension, appearance and problems duringdownstream processes.The knots are responsible for 30 to 60% of stoppagesin weaving.
SplicingJoining two yarn ends by intermingling the constituent fibres
WarpingObjective-To arrange a convenient number numbers of warpyarns so that they can be collected on a singlewarper’s beam.An operation where yarn is transferred from singlepackages of yam to an even sheet of yam representinghundreds of ends and then wound onto a warp beam
Producing An Even and Uniform Sheet Of Yarn The packages in the warper creel must be uniform in density, size, and wind configuration. Tension applied in warping must be uniform throughout. Contact surfaces which the yarn passes must be smooth and must not impede the progress of the yam.
SizingObjective To improve the abrasion resistance, and incidentally, the tensile strength of the yarn1. Strengthen the yarn2. Make outer surface of yarn smoother3. Lubricate the yarnIt causes fibers mutually to adhere in such a way as to make the warp yarn stronger, smother and better lubricatedAdhesives : Starch and gumLubricants : Fatty and Oily substance
During slashing the exact no. of warp yarnsrequired in the fabric is wound onto theweavers beam .The warp ends are then passed through thedrop wires of the warp stop motion, thehealds of the harness frames and the dentsof the reed.
Drawing-in This is the process of drawing every warp end through its drop wire, heald eye and reed dents.
Take upTo pull the cloth forward after the beat-up ofweft, maintaining the same pick density andspacing throughout weaving of a cloth andwinding the woven cloth on to a roller
Let off To allow the warp to unwind from the warp beam during weaving of a cloth and also to maintain an average constant tension of warp as it weaves downTypes:- Negative let off- Positive let off
Warp StopTo stop the loom when a warp thread breaksor get loose.
Weft stopTo stop the loom when a weft breaks or theweft runs out of the package
Weaving MachinesClassification on basis of Weft Insertion Conventional Loom (shuttle loom) Unconventional Loom ( shuttleless loom) Projectile loom Rapier loom Air Jet loom Water Jet loom
Weft insertion device in conventional loomsIn conventional loomsa shuttle weighingaround half a Kg isinserted through warpshed to insert a lengthof weft weighing only afew grams. Shuttle For weft insertion in conventional looms
Limitations of Conventional Looms1. Small weft package size, requiring frequent replenishment2. Heavy consumption of spare parts, particularly of picking and checking motions3. Limited scope for increase in the speed and performance4. Complicated mechanism for multi colour weft5. High noise level.
Unconventional LoomsShuttleless loomsCertain features of unconventional looms:- Large weft package supply, mostly in forms of cheese/cone- Improved weft insertion system- Unconventional selvedge formation
Different methods of weft insertion Projectile Rapier Air Water
Projectile loom Projectile weaving machines use projectile equipped with a gripper to insert the weft yarn across the shed It allows use of any yarn cotton, wool, mono or multifilament and even hard fibers like jute and linen. Projectile weaving m/c are available in two or four color with working width of 190-540 cm.
Features of rapier loom The rapier loom can weave very light fabric of 20 gsm to heavy 850 gsm The gripper head can take a wide range of yarn count ranging from 5 to 1000 tex. Upto 16 different weft yarn can be inserted
Air Jet loom High speed weaving machines Insertion of weft yarn into the warp shed with compressed air.
Earlier air jet wet insertion Buckling of weft yarnMaximum width 110 cm
Relay nozzles• With relay nozzles it is possible to propel the weft thread across the greater width• Machine upto 400 cm width are available
Water jet loomWeft is inserted into shed with highly pressurizedwater.Hydrophobic warp and weft. The range of jet and the width of water jet loomdepends on the water pressure and the diameter ofthe jet.………..Modern looms have speed of 1500 ppm
Demerits of water jet loomsLeast flexible as compared to other shuttlelessloomsMaximum width of 3 m.
Making of Terry TowelRequired properties of yarns which are used in towel are:1. High absorbency2. High wet strength3. Ability to dye well4. Good colour fastness5. Wash-ability6. Soft hand7. Hypoallergenic
Why cotton……..??HydrophilicHigh wet strengthHypoallergenicEasy availabilityMost economical fiber among other natural fibers
Four group of yarn are used in terry towel Pile warp Ground warp Weft Border weft
Pile warp 100% cotton yarns 16 and 20 Ne When high quality of towel is needed……two or more ply yarn are used Rotor spun yarns are also used.Ground warp 100% cotton Carded yarn 20/2 or 24/2 are generally used Two ply yarns are preferred Sometimes cotton/polyester blend is used for greater strength
Weft 100% cotton Carded 16s and 20s Ne Rotor spun yarns are also usedBorder Decorative, shinny and bulky yarns of rayon, viscose, polyester, and mercerized cotton are used with different yarn sizes
Construction of Terry Towel Pile warpGround Warp Weft
Fabric weightWEIGHT OF WARP IN LB.warp length in yds* Ends per inch * Reed width (“) 840 * Count of warpWEIGHT OF WEFT IN LB.Cloth length in yds.* Picks per inch * Reed width (“) 840 * Count of weftWEIGHT OF FABRIC IN LB. Warp weight in lbs . + Weft weight in lbs.
Theoretical Loom Production Loom production in yards per hour Loom Speed (or picks per min) 60 Pick density (or picks per inch) 36Production in square yards per hourLoom Speed (or picks per min) 60 loom width (inch) Pick density (or picks per inch) 36 36