Length after Carding (LAC) - a new measurement for Australian Scoured Wool
Principle
A sample of scoured or carbonised wool is carded and the carded web is gilled several times. An Almeter is used to measure the average fibre length of the gilled sliver, expressed as Barbe. Various fibre length distribution parameters are determined and the amount of card waste is calculated.
Why is LAC important?
The processing performance of scoured or carbonised wool is influenced by fibre length. LAC is an objective measurement of length, which can be used for processing prediction and quality assurance purposes
Why use LAC in Australia?
Woollen processors urged AWTA Ltd to offer a test for determining fibre length after carding. An evaluation of the LAC test used in New Zealand confirmed that it provided a very reliable length measurement on Australian woollen types. Research by CSIRO also indicated that the LAC result correlates very well with spinning performance.
What is reported?
LAC (Barbe) – average fibre length
- CV (Coefficient of Variation) of Barbe
- Short Fibre Content - % of fibres less than 25mm
- Long Fibre Content - Length of the longest 5% of fibres
- Card Waste %
It is important to realise that it is the carded or semi-processed length that is reported. The extent to which fibre length is reduced during carding will depend on factors influencing fibre breakage, such as degree of felting, fibre strength, or possible chemical damage during carbonising.
There has been no approved method for determining fibre length since the withdrawal of the Single Fibre Length Test Method by IWTO.
AWTA Ltd has been collaborating with other interested parties to develop the LAC test and progress it to adoption as an approved IWTO Test Method.
In the interim, a Guidance Report service is available from AWTA Ltd. Clients are encouraged to consider evaluating the LAC test as a tool for processing prediction.
Download a PDF version of this FactSheet.
FURTHER INFORMATION
Ian Ashman
General Manager Customer Relations
AWTA Ltd
Ph: 03 9371 4103
Fax: 03 9371 4191
Email: ian.ashman@awta.com.au