Understanding Wool Processing #3
Lately on our blog, we’ve been exploring the process of wool – from the pastures to the finished product – to help you gain a better understanding of the wool we use to make our organic bedding products.
Previously we discussed the first stage of wool processing, Selecting Wool Growers, and the second stage, Shearing.
This week we are exploring the third stage… skirting, grading and baling!
Skirting
Once the fleece is removed from a sheep, it’s passed to a skirting table. At the skirting table, dirtier parts of the fleece from the sheep’s belly and rear are removed. This less desirable wool is put aside and sold for different purposes.
At this point the wool is called “grease wool.” Grease wool is still quite dirty and greasy with lanolin. Lanolin is the oil that sheep produce to protect their skin and make their coats waterproof.
Read more about the characteristics of the wool fiber.
Grading
The grease wool is also “graded.” Wool grade is determined by fiber thickness and the amount of debris in the wool. This information helps buyers purchase the correct quality and type of wool.
There are three major grading systems that have evolved over the years:
- The Blood System is the oldest, originating at the time of the early American colonies. It is based on the bloodline or breeding of sheep.
- The Count System is more extensive and involves the number of “hanks” of yarn that can be spun from one pound of wool. A hank is 560 yards.
- The Micron System is the most technical and accurate system of grading. This system separates wool into grades according to the average fiber diameter as measured by a micrometer.
Woolgatherer Carding Mill, our wonderful source for wool, uses the Micron System almost exclusively. Their batting is comprised of several micron ranges and staple lengths. By blending the fiber this way, they are able to create exceptional resilience and loft.
Baling
Skirted and graded grease wool is then stacked and pressed into bales for more efficient shipping. Each bale contains about 500 pounds of grease wool from up to 100 sheep.
Once all the spring clip is sheared, skirted and baled, it’s collected at Woolgatherer and labeled for transport.
Stay tuned to learn how this wool is cleaned in our next installment of “How is Wool Processed?”
