What is Crimp?

	crimp is the term given to the natural wave that occurs in wool fibres
	when fibres are aligned within a staple or lock the staple crimp frequency or quality is highly visible
	in a wool staple or lock the fibres are aligned to show the crimp wave pattern. This crimp pattern can be measured to give the staple crimp frequency and assessed to determine the character or boldness of the crimp
	the crimp in the wool fibre is related to the bilateral structure of orthocortex and paracortex within the wool fibre. The orthocortex has been observed to be always present on the outside of the crimp curve
	wool fibres with a diameter less than 25µm have a clear bilateral segmentation
	fibres with diameters between 25µm and 35µm have less clear bilateral arrangements, and over 35µm other arrangements can be seen
	the extent to which orthocortex and paracortex are present in any wool fibre determines the chemical and physical properties of the wool fibre
	wools of low crimp frequency tend to have increased proportions of orthocortex, while more highly crimped fibres have more paracortex

Measuring Staple Crimp

	staple crimp frequency is equal to the number of crimps (crests or troughs of the waves) per centimetre (cm) of staple length (or the number of waves per inch)
	crimp frequency is similar to the traditional Quality Numbers or Bradford Counts used to describe wool, that were originally based on the number of crimps per inch
	staple crimp frequency correlates with the OFDA measurement of Mean Fibre Curvature
	staple crimp frequency in fine wool flocks is very poorly correlated to mean fibre diameter. Therefore the quality number or crimp frequency of wool is not a good indicator of fibre-fineness
	staple crimp frequency can be easily assessed with a ruler or with other simple devices that can match the crimp pattern. With a ruler, simply place a staple alongside one edge and count the number of crimps over 2 to 4cm of the staple. Divide the number of crimps by the length (ie 2 to 4cm) to give a figure of crimps per cm
	an automated measurement of staple crimp frequency on wool bale grab samples is being developed by CSIRO Division of Wool Technology for use prior to staple length and staple strength testing. This device is also being developed to measure other wool style attributes such as crimp definition, dust penetration, greasy wool colour and brightness