Evaluation of fibre orientation in fibrewebs

Abstract

A series of fibrewebs has been evaluated for fibre orientation by means of tracer fibre technique as well as Lindsley technique. The fibre orientation distributions as obtained by tracer fibre technique have been explained in the light of a mathematical model. A dimensionless parameter characterizing the anisotropy of fibre orientation in fibrewebs is obtained. The degree of anisotropy is found to decrease with an increase of number of layers in fibrewebs. On the other hand, the application of Lindsley technique results in a set of parameters, namely cutting ratio, combing ratio, and fibre orientation index. With the increase in number of layers in fibrewebs, the cutting ratio and combing ratio are found to increase, but the fibre orientation index is found to decrease. Further, the fibre orientation anisotropy parameter as obtained by tracer fibre technique correlates very well with the fibre orientation parameters as determined by Lindsley technique.