yarn count yarn twist
Post on 21-Apr-2017
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Yarn count&YARN TWIST
Topic : Yarn count & YARN TWIST
Md. Shahanaz Pervez 162-23-4763Md. Mohidul Hassan162-23-4780Md. Tofayel Ahamed...162-23-4765
Yarn CountCount is an numerical expression which denotes the fineness or coarseness the yarn or fibre.According to the definition of textile institute of UK count means weight per unit lengthor length per unit weight of yarn.There are two system of yarn count1. Direct system2. Indirect system
According to this system, yarn length is fixed and weight is variable.However the following general formula can used to find count in all direct system. W X lN = L X wWhere,N = The yarn in direct system.W = The weight of the sample.w=The weight units of yarnL = The length of the sample.l = The units of length of the system
According to this system, weight is fixed yarn and length is variable.However the following general formula can used to find count in all indirect system. L X w N = l X W Where,N = The yarn count in indirect system.W = The weight of the sample.w = The units of weight of the systemL = The length of the sample.l = The units of length of the system
Methods of beesley balance:1. This instrument consists of a simple beam is initially leveled to bring the poiter opposite adatum line. 2. A standrd weight is hung in a notch on the beam arm on the pointer side of the pivot. 3. A template is used to cut short length of yarn,the length depending upon the count system required. 4. These short lengths are added to the hook until the pointer is opposite the datum line. 5. the count is the number of the short lengths required to balance the beam. 6. When used in the analysis of small samples of fabric,a rough estimate of the crimp should be made and the count corrected.
YARN TWISTYarn twist means no of spiral turns per unit length of yarns the main function of twist is to increase strength of the yarn up to a certain point.
TYPES OF TWISTReal twist:: To insert a real twist into a length of yarn, one end of the yarn should be rotated relative to the other end,Spun yarns usually have real twist, which holds the fibres together in the yarn. as indicated in figure (a)
False twist: When inserting false twist into a length of yarn, both ends of the yarn are clamped, usually by rollers, and twist is inserted with a false twister between the clamping points, as indicated in figure (b)
Types of twist
Expression of twistAmount of twist expressed in
Twist Per Inch(TPI)Twist Per Meter(TPM)Twist Per Centemeter(TPC)
S twist When a twisted yarn is held vertically, the individual filaments are appearing in this case as the diagonal in the letter "S". The same can apply if several yarns have been twisted together: their combined twist can again appear as the diagonal of the letter "S".
Fig: Direction of S twist
TWIST DIRECTION Z twist When a twisted yarn is held vertically, the individual filaments are appearing in this case as the diagonal in the letter "Z". The same can apply if several yarns have been twisted together: their combined twist can again appear as the diagonal of the letter "Z".
Fig: Direction of Z twist