Wool differences between breeds

The key difference between wool from different sheep breeds is the diameter and the amount of crimp. Merino sheep produce very fine wool with a tight crimp – this makes it suitable for making into high-quality apparel. Coarser diameter wool such as crossbred has a long crimp and is used mainly for heavy apparel and carpets.

Questions to consider:

• What properties, other than a lighter weight, would a finer fibre diameter and a tighter crimp contribute to fabrics?

• Discuss this in relation to the type of products the different fibres are used for.

Transcript

Dr Errol Wood (AgResearch)

The different breeds of sheep produce different types of wool, from the very fine Merino wool, which is used in apparel because of its fineness – it has a high degree of flexibility – through to the crossbred wool, which is quite a lot coarser, coarser diameter, which means it’s more suitable for heavier apparel and carpets.

The key property that determines the usage of wool is its diameter. Along with that, there is the effect of crimp, which is also a genetic effect. If you look at different types of wool, you will find that the crimp or the waviness of the fibre is different from breed to breed. Here, we have a staple from a Merino sheep, fine wool produced in the high country. Here is a staple from a crossbred sheep, in this case, a Romney, which is… almost half of our sheep population are Romney sheep.

And you can see clearly there are differences between the two, both are the result of annual production – 1 year’s growth – and quite a different rate of production of length of fibre has occurred in that time. There is different colour, although, when they are scoured, the colour difference will become less. The shape of the staple – this is a much more rectangular shaped staple as opposed to the tapering tip we get with this one. And finally the evidence of crimp – in the Merino, the crimp is very fine and very delicate, and on the other hand the Romney, the crimp is rather longer in its wavelength.

And that is a good clue wool buyers and wool experts use to tell the difference between a coarse wool and a fine wool. They can judge the fibre diameter of the wool very closely based on their visual assessment of the crimp spacing.

Acknowledgements:
Kerri Afford
Merino infants garments courtesy of Mokopuna Merino and Simon Hoyle, Southlight Studio.
Peter Nijenhuis