Calculate The Twist Per Inch & Twist Multiplier Of Single Yarn By Contraction Method.

OBJECT:

            Calculate the twist per inch & twist multiplier of single yarn by contraction method.

INSTRUMENT/TOOLS:

            Single yarn twist tester etc.

WORKING PRINCIPLE:

            Twisting  of a  strand of yarn, causes contraction in length of yarn. Suppose, a yarn is twisted in z direction and has length H, on untwisting the strand the length increases  to H+C.

            If this untwisting is continued in the same direction, the contraction in length becomes equal to original length  can give twice the turns in the strand of yarn.

PROCEDURE:

•        Take a sample of yarn and find tex count .

•        Fix the length of 10 inch as gauge length .

•        Put the tex count/2  gms as tension on pendulum.

•        Clamp the yarn between fixed jaw and rotating jaw with the pendulum on the reference point.

•        Now rotate the rotating jaw till the pendulum on fixed jaw again comes to reference point.

•        Note the reading on counter and repeat the same process for 20 samples.

FORMULA:

Twist per inch    =        total revolutions

                                        Length of yarn x 2

RESULT:

            TWIST PER INCH ……………………………………………………

            TWIST MULTIPLIER ……………………………………………….

            STANDARD DEVIATION …………………………………………

            COEFFICIENT OF VARIATION……………………………………….

PRECAUTIONS:

•        Maintain proper tension on yarn clamped.

•        Set the counter to zero error before use.

•        Check that yarn is properly clamped between fixed jaw and rotating jaw.