Yarn hairiness – Theory about total number of fibre hair

Abstract

Yarn hairiness is determined using projection of hairs perpendicular to the yarn axis. Measurement is done using photo cell which receives light from a small area above the yarn surface. The hairs that project beyond the specific adjusted distance – which is generally 3mm – intercept the beam of light that falls on the photo cell, causing photo cell to generate a signal. Using this signal, number of hairs in a given length of yarn can be determined. However, the measurement does not cover full circumference of the yarn. A theory is developed in the present work to overcome this problem.