The variation of the yarn count (CV count) is the variation from one bobbin to the other. If this variation is more than 2% the difference in the fabric is visible with bare eyes. … In general the lower the C.V.% the better is the measured value of the yarn.
What is CV in yarn?
Coefficient of mass Variation (CV%):
The coefficient of mass variation CV % is the ratio of standard deviation of mass variation divided by average mass variation. The higher the CV value is the more irregular the yarn.
What is CV percentage in textile?
The Coefficient of Variation (CV) is the standard Deviation (SD) expressed as a percentage of the mean CV % = (SD ÷ mean) x 100 • Each process in a spinning mill contributes a part to the evenness. 7. … Fig shows a comparison between two fabrics with a low (CV = 11.48%) and a high coefficient of variation (CV = 17.76%).
How do you control yarn count on a CV?
So control of with in CV should be focus at (a) D/F U % (b) stretch at S/F Control of sliver U% , U% Check by 10 mm layer cut. Depending upon draft yarn spun is 40 mtrs- 160 mm. so directly affect CV within U % of 2nd passage D/F is 3-5% & first – 5-7% Less U% is 3 passage but hooks at R/F is not favourable.
How do I calculate yarn count?
The indirect system uses the formula: N = (L/w) / (W/l). In these formulas, N is the yarn count, W is the weight of a sample of yarn, l is the unit of length, L is the length of the sample, and w is the unit of weight.
How do you calculate CV?
The formula for the coefficient of variation is: Coefficient of Variation = (Standard Deviation / Mean) * 100.
What is CV% of count?
1.1 Definition of the relative count – Count C.V. The relative count gives the mass deviation in % of the whole test length of each test sample as compared to the average mass of all samples. This value is an indication of relative count deviation (CV). The lower the value the better.
What is unevenness of yarn?
unevenness is a measure of variation in weight per unit length of the yarn or the variation in thickness of the yarn. Uster measures the yarn unevenness by a capacitive method.
What is limit irregularity?
For a particular fiber and count of yarn, there is a basic or limit irregularity which cannot be improved by the spinning machinery. The CV of the most regular/uniform strand of material in which the ﬁber ends are laid in a random order in the sliver, roving, or yarn is called limit irregularity.
How do you calculate CSP of yarn?
Theory: C.S.P is the product of English count and strength of yarn in pound. i.e. C.S.P = Strength of yarn in pound x Count in English system.
How do you calculate the number of Fibres in cross section of yarn?
5. What is the formula to calculate the number of fibres in a yarn cross section? Ans: N = (5315/fibre denier)/ yarn count (Ne) 6.
What is cotton mixing?
Mixing and blending of different varities of cotton:
In mixing process, Two or more different varieties of cotton are mixed together. Some times two or more types of fibres such as cotton and polyester are mixed together in this process.
What is Count strength product?
Theory: C.S.P is the product of English count and strength of yarn in pound. i.e. C.S.P = Strength of yarn in pound x Count in English system. Again, english count is the no. of hanks in 840 yards length per 1 pound weight of yarn.
What is the count of yarn?
Yarn count refers to the thickness of a yarn and is determined by its mass per unit length. It is usually measured by the number of grams per one kilometer of yarn, a unit of measure called “Tex”. … In this system, the larger the number the finer the yarn and vice versa.
How can you tell the quality of yarn?
Skein strength or Lea strength: The skein breaking strength was the most widely used measure of yarn quality in the cotton textile industry. for determination of the linar density of the yarn as well.
- yarn twist.
- linear density.
- yarn strength.
- yarn elongation.
- yarn evenness.
- yarn hairiness etc.
Which yarn count is finer?
The count of yarn expresses the number of length units in one weight unit. Thus higher the count, finer the yarn. The system is generally used for cotton, worsted, linen (wet spun), etc. Where, W = The weight of the sample.