Kinks/ crimps

Form kink refers to a constriction in the hair shaft and was determined by scoring hair samples as follows 0 = no kink 1 = kink. Curvature was determined by placing hair samples between 2 glass slides and matching circles of known radius to the shape of hair. Crimp refers to the number of changes in direction of the hair shaft per unit length. 

Pre-tension ipre- ten(t)-shon [pre- + tension] (1937) vt. The relatively low tension applied to remove kinks and crimp when mounting a specimen preparatory to making a test or to a textile processing operation, etc. 

Bulked continuous filament (BCF) processes are similar to CF processes, but one main difference is that in BCF a texturizer is an integral part of the process, to impart bulk to the fibers, through crimps or kinks. Commonly, BCF fibers are of ca. 20 dpf, with yarns being in the vicinity of 2000 denier. Polypropylene homopolymer with MFRs in the range of 12-20 MFR and normal MWD is typically used. BCF yarns are mainly used as carpet face yarns and in fabrics for upholstery. 

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