Can Resistance to Compression be Used to Measure Wool Softness?

Resistance to compression (RtC) of wool is defined as the force per unit area required to compress a fixed mass of wool to a fixed volume. It measures the space-filling capacity. It is believed that wools of high resistance to compression tend to have a harsher handle than other wools of the same fibre diameter. Because of this, the RtC value has been implied as an indicator of wool softness. The method may be used to quantify softness of animal fibre like sheep, goat, alpaca and llama. It is important to properly interpret the RtC data for their softness measurement. This paper attempts to answer the question of whether RtC can be used to evaluate the softness of different types. of animal fibres. It reveals that fibre crimp and test specimen preparation play a major role in governing the RtC value; while wool fibre diameter, a factor known to be key in determining wool softness, does not have a very significant effect on RtC, particularly for low crimp animal fibres. It appears that the objective quantification of animal fibre softness remains a contentious issue, and the commonly used resistance to compression method merely reflects changes in fibre crimp rather than softness itself.