The softness of alpaca fibres

Softness is a unique selling point for luxury fibres such as alpaca. However, there is very little objective data on the softness of animal fibres. This study first establishes that the resistance to compression (RtC) behaviour of alpaca and wool fibres is quite different, and that the RtC method can not be used to examine the softness of different animal fibres. It then reports a new method for evaluating fibre softness. This method is based on the measurement of the force required to pull a fibre bundle through a series of parallel pins. This force, reflecting the combined effect of fibre surface properties, fibre diameter and rigidity, can achieve reasonable discrimination between fibres of varying levels of softness, such as alpaca and wool. Mechanisms responsible for the superior softness of alpaca fibres are discussed also.