Scouring and Washing Wool, Fibre and Fleece in
Commercial and Mini Mills

Research and formulation of Unicorn Power Scour, Fibre Wash and Fibre Rinse products have achieved our goals of providing optimised scour chemistry to maximise cleaning at low temperatures, while imparting fibre protection and conditioning for ease of handling and processing of natural fibres. Furthermore, the biodegradable environmentally sensitive ingredients have fulfilled our high priority for Earth-friendly status so vital in today’s world.

Australia’s prestigous CSIRO Research Labs stated that “Scouring at reduced temperatures is of particular interest as this can lead to significant energy savings...”. Reducing scouring bowl temperatures can also result in reduced fibre entanglement, which in turn can be beneficial in terms of maximising processing yields. As stated by a chemist at Australia’s CSIRO Research Labs, Unicorn’s fibre cleaning products “could well be the solution to potential energy savings” and “...even small increases in top length can be worth $1m/annum in increased revenue”.

Example: Savings is the difference between higher and lower temperatures. For example, rather than scouring wool in 50g/200L of water at 70°C (158°F), it is now possible to scour at 60°C (140°F) which results in a 12.91% energy savings.*

If you were scouring Alpaca in 50g/200L of water at wool scouring temperatures of 60°C to 70°C (140°F to 158°F), it is now possible to scour at 50°C (122°F) which would result in energy savings of 14.74% to 29.56% respectively.

* Efficiency depends on the type of fuel used for heating and other variables.

Current practices simply mimic wool scouring operations using high heat and strong detergents. Unfortunately, fibres without high levels of surface wax (ie Alpaca and Cashmere) are subjected to fairly harsh conditions that are probably not necessary, and may indeed be detrimental to the fibre as well as the environment.

Unicorn Power Scour is designed to effectively scour the finest low micron fibre at working temperatures of 40°C to 50°C (104°F to 122°F) and, with a slightly higher detergent to water regimen and modest 5° to 7° increase in water temperature, effectively scour higher micron wools which present a more coarse and waxier fibre.

In the course of our research and formulation work we discovered a potential need for a rinse additive during fibre scouring. We found it beneficial, during the last rinse step, to add a processing aid with anti-static benefits: Unicorn Fibre Rinse. This has proved to be true based on studies conducted at the Australian CSIRO Research Labs. This particular product helps relax the fibre resulting in easier handling, potentially higher throughput and a higher end quality fibre bundle.

We support the development of industries which utilise the primary products of fleece producing animals and appreciate an open dialogue within the fibre community to enhance these goals.

We have completed our testing and analysis for raw fibre scouring operations and can make the following recommendations.

Unicorn Power Scour was designed and tested to achieve optimum cleaning with minimal fibre damage during processing. In addition, we have formulated the product to be environmentally safe and perform not only as well but better than typical alcohol ethhoxylates while using cooler water temperatures.

The composition is an optimum blend of both nonionic and anionic surfactants combined with a natural source alkalinity package to provide a buffered bath pH for fibre care and moderate bath life. The products should be used at similar initial charge concentrations and make-up rates as that currently being employed in fibre scour processing arrangements. It should also be recognised that water quality and bulk fibre cleaning rates will also play a role in the initial charge concentration and subsequent make-up rates. A certain amount of trial and error should be expected during start-up to avoid over- or under-use of the products.

Due to the rigour of current scouring processes, along with temperatures exceeding 65°C to 70°C (149°F to 158°F), a certain amount of inter-tangling and stress can be imparted to natural fibre, especially to high-end luxury fibre with little wax, ie, alpaca, cashmere, qiviut, bison, angora. This invariably leads to matting/felting, breaks and frays resulting in damaged fibres and consequent reduced fibre yield. To improve the end quality of the scoured fibre we sought to achieve cleaning at the lowest possible bowl temperature. Our studies indicate that excellent cleaning for wool can be achieved in the temperature range of 50°C to 60°C (122°F to 140°F) and for the non-oily/waxy fibres in the temperature range of 45°C to 50°C (113°F to 122°F). Lower temperatures for less oily/waxy fibre, upper range for heavier oily/waxy fibre.

In the course of our research and formulation work we discovered a potential need for a rinse additive during fibre scouring. We found it beneficial, during the last rinse step, to add a processing aid: Unicorn Fibre Rinse. This particular product helps relax the fibre resulting in easier handling and potential higher throughput as well as a higher end quality fibre bundle.

Power Scour and Unicorn Fibre Rinse can be used with existing scour lines typically employed for fibre cleaning. The following example will illustrate the application for a four to six wash tank/bowl cleaning operation:

Suggested Start-up Conditions

Unicorn Power Scour and Unicorn Fibre Rinse
for raw, greasy sheep wool, waxy mohair, and for less oily/ waxy luxury fibre.

Step 1: Initial Wash
Dose the Unicorn Power Scour at an initial working concentration of 2% of the fibre weight. For example, to scour 100kg of fibre, use 2L of Unicorn Power Scour.

Working temperatures for scouring wool with Unicorn Power Scour should be in the range of 50°C to 60°C (122°F to 140°F) depending on fibre characteristics, and for less oily/waxy fibres like alpaca and cashmere temperatures should be in the range of 45°C to 50°C (113°F to 122°F.) Use lower temperatures for low micron alpaca, bison or cashmere fibre and higher temperatures for higher micron sheep wool fibre or oily/waxy fibre. In situations where raw, exceptionally greasy fleece is to be scoured, consider a pre-soak for 15 to 20 minutes in 60°C (140°F) water before the first scouring bath.

Cleaning performance will be optimal in this range, and problematic fibre damage/tangling should be improved. In addition, operations will be improved due to the lower energy costs in maintaining these temperatures.

Step 2: Additional Washes
Follow identical conditions to that of Step 1, except use 1 to 2% (or for example for every 100kg of fleece use about 1 to 2L). Again use a lower percentage dosage for less oily/waxy fibres and a higher percentage for oily/waxy fibres. Oily/waxy fibres like wool may require two additional washes and less oily/waxy fibres like alpaca or cashmere may require one additional wash.

Step 3: Rinses
Use 45°C to 50°C (113°F to 122°F) water for non-greasy fibre and 50°C to 60°C (122°F 140°F) water for greasy, waxy fibre. Oily/waxy fibres may require two rinses and less oily/waxy fibre one rinse.

Step 3: Final Rinse
Here we recommend the use of Unicorn Fibre Rinse. This product will help strengthen the fibre, ease the final processing steps and maximize ease of handling. Depending on the fibre type, this product would be added to the bowl at approximately 2% of the fibre weight. For example: to rinse 100kg of fibre use 2L of Unicorn Fibre Rinse.

Note: To maximise the adherence of colour dyes to fibre that might receive such post treatments, we suggest conditioning with Unicorn Fibre Rinse AFTER the dyeing process.

Water hardness not to exceed about 17 grains (100 ppm Ca/Mg).

Each operation is expected to be slightly different and the above recommendation should be used as a starting point for final optimisation.

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