Wool from sheep is a very widely used proteinaceous fibre. Wool from other animals, such as goat and llama, as well as silk, are also proteinaceous.

Such fibres can be treated enzymatically. A useful enzyme has been found to be tyrosinase, which can affect tyrosine in both cuticle and cortex of the fibre, cuticle modification being considered desirable to reduce felting shrinkages.

Tyrosinase can be produced from potatoes, and, indeed, from the generally discarded peel thereof, simply by steeping in water. The tyrosinase can be separated from the starch content by adding an electrolyte such as ammonium sulphate to precipitate the protein fraction, which can then be redissolved.

Tyrosinase can also, of course, be produced from other vegetable matter, from fungi and from bacteria.

While tyrosinase, particularly from potatoes, is found to be useful in reducing shrinkage in wool, its effects can differ according to the particular fibre being treated, and also possibly to the way in which the fibre is presented, whether as loose fibre, tops, yarn or woven or knitted fabric. Ageing appears to have an effect on a tyrosinase solution-it appears to give better results when it is a few weeks old.

All this makes the use of tyrosinase in a shrink-resistance treatment less than straightforward.

The invention comprises methods for treating proteinaceous textile materials, comprising subjecting the material to a treatment in tyrosinase.

The treatment in tyrosinase may be carried out after an oxidation treatment, or simultaneously therewith.

The oxidation treatment may be a Simpl-X treatment.

The tyrosinase treatment may be carried out in aqueous solution, and may be carried out at above ambient temperature, maybe with gentle agitation.

The tyrosinase concentration may be in the order of 20mg tyrosinase per gram of material. The tyrosinase/liquor concentration may be in the order of 1: 30.

The tyrosinase treatment may be carried out at a pH level of about 7.

The tyrosinase treatment may be carried out for a time of the order of one hour.

Typical treatment times are between one and four hours.

The invention also comprises proteinaceous textile material treated by a method as described above.

The invention also comprises a method for determining appropriate tyrosine treatment conditions for a particular proteinaceous material, comprising: (a) carrying out a treatment over different time periods on samples of the material ; (b) subjecting the thus-treated samples to shrinkage-inducing treatment; and (c) measuring the resulting shrinkages to determine which treatment time is appropriate.

Samples treated under a range of concentrations of treatment substance may be compared and, in particular, samples treated under a range of concentrations of Simpl-X, where that is used as an oxidation process The method of treatment-and, correspondingly, the method of determining appropriate conditions-may be carried out using aged tyrosinase. The tyrosinase may be aged up to four weeks from preparation.

Methods for tyrosinase treatment of wool according to the invention will now be described with reference to the following Example.

Example A first batch of knitwear was pre-treated with Simpl-X then treated with tyrosinase solution at 500mg/Kg at 40°C under gentle agitation for one hour. The pH was 7, phosphate buffered.

A second batch was similarly treated, but for four hours.

Within each batch, samples were pre-treated with 1.5%, 3.0% and 6.0% Simpl-X.

Once sample in each batch was treated with 60% Simpl-X and tyrosinase precipitated.

Control samples were (a) scoured only, (b) scoured then treated with tyrosinase, (c) treated only with 1.5%, 3% and 6% Simpl-X.

Shrinkage was measured after one and two cotton washing cycles (5A) -the control shrinkage measurements were made after 2 and 3 wool cycles (7A).

The results are shown in the following Table.

TABLE % Shrinkage 1 Hour 2x7A 3x7A 1 x5A 2x5A Scour only 20.3 24.9 1.5% Simpl-X 35.8 53.6 3.0% Simpl-X 23. 7 42. 1 6.0% Simpl-X 10. 7 18. 5 Scour + TY 22.9 27.5 1.5% Simpl-X + TY 30.6 51.1 3.0% Simpl-X + TY 27.2 54.4 6.0% Simpl-X + TY 13.1 13.4 6.0% Simpl-X + TY (B) 2. 3 4. 7 4 Hours Scour only 26. 3 29. 6 1.5% Simpl-X 27.7 47.7 3.0% Simpl-X 3. 9 7.1 6.0% Simpl-X 4. 3 7. 9 Scour + TY 15.3 16.5 1.5% Simpl-X + TY 35.2 59.0 3.0% Simpl-X + TY 18. 6 38.4 6. 0% Simpl-X + TY 1.2 9 6.0% Simpl-X + TY (P) 41. 6-

TY = tyrosinase TY (P) = tyrosinase precipitate The Table shows that pre-treatment with Simpl-X yields better results than use of tyrosinase on its own, which does not, indeed, appear to have any effect, although beneficial effects have been noticed in other trials under different conditions.

It also shows that tyrosinase after pre-treatment with Simpl-X is generally speaking more effective at reducing shrinkage than Simpl-X alone, but not always, hence the desirability of pre-treatment trials, to determine optimal, or at least sufficiently effective treatment conditions.

In the one hour treatment, the tyrosinase precipitate yielded excellent results, but was poor after a four hour treatment.

In other tests, it has been observed that ageing of the tyrosinase after its initial preparation can have beneficial results, and it has also been observed that the treatment can have different effects on different proteinaceous fibre materials and on materials presented differently, as loose fibre, tops, yarn or woven in knitted fabrics.

As there are so many ways of presenting fibres-even within woven and knitted fabrics there may be different effects-it may be impractical to put a tyrosinase product on the market with a standard set of instructions for use. More appropriate, it appears, would be to prescribe a range of processing conditions on samples of the material to be treated to generate a set of treated samples that can be tested for shrinkage to determine the most appropriate conditions for the particular textile as well, if fresh or relatively fresh tyrosinase is to be used, for the age of the tyrosinase. No deleterious effects in handle or appearance were noted from any of the treatments and, indeed, whiteness of undyed materials was found to be improved, as was drape of fabrics.