Staple Measurements

Staple Length & Strength measurements utilise staples selected at random from the grab sample taken at the time of core sampling.

This grab sample is the same sample that is placed in display boxes for inspection by the buyers prior to sale.

AWTA Ltd developed a Mechanical Tuft Sampling machine which automatically grid-samples the display sample to obtain approximately 60 tufts of wool. This sub-sample of 60 individual tufts is stored on a removable reel which can then be transported to the testing laboratory.

When the tuft samples are received by the laboratory, trained operators remove one sample at random from each tuft. Four (4) operators are used to reduce bias in selecting these staples. The staples are placed in trays, which are designed to keep the staples separate.

The staples are stored in a constant atmosphere to allow them to equilibrate to a constant moisture content and to relax and regain their original conformation. Then each staple is measured for Length and for Strength using the CSIRO developed ATLAS instrument. The average Staple Length, the average Staple Strength, the Coefficient of Variation of Length and the average Position of Break can then be calculated.

While the availability of objective measurements for Yield, Vegetable Matter and Mean Fibre Diameter improved many aspects of the prediction of processing performance, it was acknowledged that it is also influenced by other parameters, of which Staple Length & Strength were considered to be the most important: 

• Research work at AWTA Ltd and CSIRO Division of Wool Technology led to the development of sampling procedures and instrumentation for the measurement of Staple Length & Strength.
• Commercial testing commenced in 1985.

Demand for this service grew steadily, and was boosted in the late 1980's by the inclusion of a premium in the Reserve Price Schedule for the provision of Staple Measurement data. Requests for Staple Measurement testing dropped after the collapse of the Reserve Price Scheme, but has grown rapidly since 1992/93 as mills have become familiar with the use of the measurements.

Industry understanding of the role of the new measurements for Staple Length & Strength play in predicting processing performance was facilitated by research projects involving AWTA Ltd, AWC and CSIRO Division of Wool Technology during the 1980s and early 1990s:

• An 8 year project involving 20 mills throughout the world, known as Trials Evaluating Additional Measurement (TEAM) led to the development of predictive formulae for Hauteur (fibre length in the Top), Coefficient of Variation of Hauteur, and Romaine (percentage of Noil produced). These formulae have become benchmarks for individual mills to develop formulae which best suit their purchases and processing conditions
• A second project known as Australian Staple Measurement Programme (ASMAP) was established to assist other mills to become familiar with the measurements and their application in the prediction of processing performance.

Subsequently, commencing in 2001 AWTA Ltd funded the TEAM-3 trial.  This was essentially a repeat of the the earlier TEAM and ASMAP trials, but aimed at providing data to update the TEAM formulae to reflect improvements in combing performance that have occurred since the original formulae were derived. The results of this trial were reported to IWTO in 2005, and recommended changes to the TEAM formulae were accepted by IWTO, taking effect from 1st July 2006.

AWTA Ltd then commenced the TOPMARK program. TOPMARK is a free benchmarking service for processing mills and topmakers around the world. Participation is very simple, with mills providing AWTA Ltd with greasy wool test information on their batches as well as their own processing test data.

AWTA Ltd collates the data from all participating mills and determine ‘benchmarks’ for all the major processing results. These benchmarks allow each mill to confidentially compare its performance against the average of all the other mills participating in this program. Regular reports are provided to mills detailing their performance against key characteristics such as Hauteur, Romaine, Top & Noil Yield, and Core/Comb Fibre Diameter.

Participation in TOPMARK is FREE OF CHARGE. To join TOPMARK, all a mill or Topmaker needs to do is contact AWTA Ltd and agree to provide greasy wool and top test results on processing batches. These results will be entered into a confidential database by AWTA Ltd from which the processing performance of each mill can be compared. A standard form has been created to assist mills in submitting the required data to AWTA Ltd.

Unlike TEAM-3, participating mills do not need to send top samples to AWTA Ltd for measurement. For the purposes of the benchmarking service, the top measurement results from the individual mill’s laboratory are be used.

Over 85% of Australian combing length wool is now Staple measured and the ATLAS instruments used to conduct the measurements have been exported to Belgium,New Zealand, South Africa and China.

To assist wool growers and wool brokers to understand the commercial importance of Staple Measurements AWTA Ltd over recent years has commissioned The Woolmark Company to analyse the premiums and discounts applied to measured and unmeasured wool in the market.

Historically buyers have always applied discounts to tender wool. Their evaluation was subjective, based on selecting a few staples from the display sample and applying a "flick test" to see if they would break.

The availability of the measurements now means that even tender wool, provided that it has been tested, will achieve a premium over apparently tender wool that has not been tested.

The major affect of the measurements in the market has been whereas previously fibre diameter determined about 90-95% of the price, today, staple strength determines about 20-25%, particularly for fine and superfine wool.