From Farm to Yarn – The Early Stages of Wool Supply and Processing
A New Era
In the days when wool was just wool, was a traded commodity and blended to compete on price, the focus was just that – price.
Today wool is appreciated as a high-performance natural fibre recognised for its unique characteristics to produce specialised garments designed for targeted market segments.
This has been made possible through the breeding, genetic development and selection of merino sheep as well as new technologies to measure the raw fibre for the elements which directly affect the performance and comfort of the finished product.
Objective measurement enables processing batches to be blended to achieve a predicted performance making merino a fibre of choice.
Add to this the demand by consumers for an assurance that ethical and sustainable farming practices have been used requires the employment of a new supply system.
Spinners provide the specification of tops required to produce each yarn type.
Topmakers provide a greasy wool specification for building topmaking consignments.
Farmers supply greasy (raw) wool
Topmaking consignments are a mix greasy wool lots carefully blended to achieve a specific technical outcome at the finished ‘tops’ stage.
It is very unlikely that all the raw (greasy) wool for a given topmaking specification would come from one farm as wool is not consistent across all mobs of sheep on a farm and seasonal conditions can have a big impact on quality year to year.
To offset these variations in farm production, topmaking lots are usually built using wool from a number farms by selecting technical (measured) qualities which will, when blended, deliver the required tops specification. These farms are often in different regions with different seasonal conditions which cause different outcomes.
The Process – From Farmers to Topmakers
At shearing, all greasy (shorn) wool is grouped into categories in the shearing shed by a professional wool classer. Similar wool, usually from the same mob of sheep, is put together as farm lots and pressed into bales. All bales are numbered, identified by type and marked with the farm brand.
When farm bales are delivered to a broker’s warehouse each bale in the farm lot is weighed and samples are drawn in accordance with a protocol established and supervised by the Australian Wool Testing Authority (AWTA). The brokers warehouse is licenced by AWTA as registered sampling site.
Samples from each bale in the farm lot are combined and delivered to the Australian Wool Testing Authority laboratory for testing. Test results are made available electronically to registered potential buyers prior to sale and as an electronic certificate when sales are concluded. These lots then retain their identity along with test results through the sale process and exporting stage.
Topmaking is the first stage of wool processing. A very simple explanation follows.
Scouring: Greasy wool is washed to remove dust and grease. (The by-product is lanolin)
Carding: Removes some of the vegetable matter (grass seed) which is present when it leaves the farm and in the process the fibres are teased apart and laid roughly parallel into a state called a sliver.
Combing: Straightens the fibres in the sliver giving them a high degree of alignment. It also removes more of the vegetable matter and short fibres (noils).
Gilling: Combed wool is finished by a process known as gilling which creates a uniform sliver called top.
Treatments: These are chemical process options to minimise shrinkage.
How Greasy Wool is Selected
The technical performance of tops is critical to the production of yarn.
The key measured technical elements used to select wool for topmaking are:
- Fibre diameter (micron) and fibre diameter variation (CvD)
- Fibre length (in millimetres) , and variation of fibre length (CvH)
- Fibre strength (nkt) and position of break
- Vegetable matter content
- Fibre colour
- Yield (the weight of clean wool after removal of dust, grease and vegetable a matter)
A mathematical equation known as the TEAM 3 formula, are used to predict the topmaking outcome when various farm lots and volumes are combined. The TEAM formula is used by all topmakers to build processing lots that will meet the specified tops outcome.
All of these elements can be significantly affected mainly by climatic conditions but there are other factors as well.
Why it is important to have a managed supply chain
To select wool for a combing consignment all the measured elements as described above must be considered along with non-measured attributes including farm verification of adherence to animal welfare and land management standards, shearing dates, lead times, quantity and farmers price expectations.
The TEAM 3 Formula
TEAM is an abbreviation of ‘Trials to Evaluate Additional Measurement’ and is a mathematical equation developed to evaluate the relationship of objective measurement of staple length and strength with commercial combing results. Initial development took place between 1981 and 1988 with subsequent revisions as more data becomes available. Current version is TEAM 3.