||Technology in Australia 1788-1988
Table of Contents
I 1788 - State Of The Art In Textile Technology
II Australian Textiles - The Early Days
III Australian Textiles - The 20th Century
i Technology and Development
ii Australian Wool Textile Research
IV Australian Textiles - To Date
Australian Wool Textile Research (continued)In 1950, while the laboratory in Sydney (Ryde) was setting out to recruit scientists, those in Geelong and Melbourne were already beginning to produce industrial results.
At Melbourne, two processes had been developed for recovering wool from sheepskin pieces and broken skins. They yielded much better products than the traditional procedure which caused considerable damage and discolouration to the wool. One of them, which was based on controlled bacterial digestion, was an inexpensive process and therefore widely applied in Australia and overseas. In some instances, the quality of recovered wool and its auction price were equal to those of shorn wool.
A problem that had been of concern to the wool industry for decades was the removal of sheep branding products from raw wool. This was near to solution when, in 1950, the Geelong laboratory released a formula for a sheep-branding fluid based on lanolin, designated LBE (lanolin-based emulsion). Until this time, all types of materials, ranging from paint to sump oil and tar, had been used by farmers to identify their sheep. These products had quite significant cost disadvantages, both in discounting to the farmer for the contaminated wool and in the subsequent manual removal of the 'stained' fibres at various stages in processing. These losses were estimated to be at least $3 million in the early 1950s, or 2 per cent (worth about $40 million in 1983/84) of the total value of the clip. Provided it was applied as recommended, LBE was scourable, so the losses were avoided. Not surprisingly, it was quickly adopted by industry.
LBE, however, was not perfect, needing several hours to dry on the sheep, otherwise it would run if there were immediate rainfall. Further research eventually led in 1954 to a new, improved formulation, and this was released as Si-Ro-Mark.
LBE had not been registered as a trade mark, and some manufacturers had introduced their own 'improvements', with dire effects. To ensure that the recommended directions were followed, CSIRO registered Si-Ro-Mark as a certification mark. There were 20 licensees in the first year, and each licence was subject to initial and follow-up tests by CSIRO. Some States introduced legislation making the use of Si-Ro-Mark compulsory but, even without this, manufacturers had ceased making the older fluids voluntarily.
Si-Ro-Mark is still manufactured today, with a production averaging over 400,000 litres per annum over the past decade. In hindsight, it was a relatively simple idea (utilising a by-product of wool scouring (lanolin) as a medium for light-stable pigments), yet the requirement was for a very delicate balance between scourability and durability under sometimes severe weather conditions. It is heartening to note that the cost savings accruing to the wool industry through this one development have paid many times over for the total investment made in Australian wool textile research.
Although over the previous century wool scouring had progressed from river washing to continuous operation, at that time not much was known about the science underlying the process. These were days before the widespread use of synthetic detergents, and the scouring medium was water containing soap and soda. Similarly, while the value of wool wax had long been appreciated, techniques for its removal from the waste scouring liquors and for its subsequent processing were by no means optimised.
The mechanics of scouring were relatively simple (Fig. 13). The wool -immersed in scouring liquor -was moved through a series of bowls, typically of about 8000 litres each, by long-tyned rakes. Greasy wool was delivered by a feed hopper into the first bowl which contained the soap-and-soda liquor at a temperature hot enough to melt the grease. The wool progressed through the bowl by mechanical action, arriving at the delivery end after one or two minutes, where it was mechanically lifted to a pair of squeeze rollers. From there it was fed to the second bowl. This also contained similar soap solution to the first bowl. Subsequent bowls were water rinses, and after the final bowl (the fourth or fifth) the wool went to a dryer. Liquor flowed counter to the direction of travel of the wool, compensating for the abstraction of water by the scoured wool, as well as for the liquor carried away with the effluent.
Organisations in Australian Science at Work - CSIRO; Gordon Institute, Geelong
© 1988 Print Edition pages 277 - 278, Online Edition 2000
Published by Australian Science and Technology Heritage Centre, using the Web Academic Resource Publisher