Twisted strand method

The friction of yam to yam is measured by moving yam at known speed in contact with itselfThe input and output tensions are measured and the coefficients of friction are calculated. Two methods of determination are used. In the Capstan method, the coefficient of friction is calculated from equation [3.3]. In the twisted strand method, the equation is modified to account for twist characteristics. 

Filament yams can exist in an almost twistless form, but this is not the case for staple fibre yams. The twisting of fibres together is still the most practical method of making short fibres into long continuous strands of yam suitable for weaving. See S-Twist and Z-Twist. 

Kobe Steel originally developed originally the strand takeover system to which the twist function was subsequently attached. By development of this system, the tow rope resistance in which the reinforcement fiber passes through the outlet of an impregnation die head was reduced. As a result, the high-speed takeover of the stable strand became possible. For example, in the assembly consisting of GF content 50wt% and PP, a track record, in which the strand was taken over at the rate of 100 m min has been demonstrated. The details of the takeover method are described elsewhere. 

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