WO1999042649A1

WO1999042649A1 - Wool with anti-felt finish and method for producing same

Info

Publication number: WO1999042649A1
Application number: PCT/EP1999/001137
Authority: WO
Inventors: Rudi Paul Eugen Breier
Original assignee: Textilchemie Dr. Petry Gmbh
Priority date: 1998-02-21
Filing date: 1999-02-22
Publication date: 1999-08-26
Also published as: DE19807456B4; EP1056899A1; DE19807456A1

Abstract

The aim of the invention is to provide a method for obtaining an anti-felt finish comparable to that achieved with chlorine treatment but which avoids chemical treatment or pretreatment as far as possible. To this end the wool is treated while the wool material is upright and in a moving liquor bath.

Description

Felt-free finished wool and process for its production

The present invention relates to felt-free finished wool or wool fibers, a process for the felt-free finishing of wool and the use of an enzyme in such a process.

For the felt-free finishing of wool, a number of processes are known which, in addition to purely chemical oxidation processes, in particular the so-called chlorine process, also include processes in which an enzymatic treatment with a physical (corona pretreatment) and / or chemical, in particular oxidative pretreatment is combined. The purely enzymatic treatment has also been tried.

The chlorine process has so far been unsurpassed in terms of the felt-free effect. It breaks down the free ends of the scales of the wool fibers and thus smoothes the surface of the wool fibers. This process changes the nature of the wool fibers comparatively strongly. It is also accompanied by a clear yellowing of the goods.

Often this chlorine process is supplemented by the fact that the chlorine-treated fiber is provided with a polymer coating, which leads to an additional smoothing of the surface of the fiber. However, this coating leads to a further change in the nature of the wool fiber.

The previously proposed purely enzymatic processes either do not achieve sufficient freedom from felt or damage the fibers to such an extent (the loss in tear strength is often more than 50%) that the treated fibers no longer meet the usual strength requirements. To this day, the literature has therefore concluded that a satisfactory wool quality can only be combined - 2 -

chemical-enzymatic processes are to be expected (see e.g. the final report on the AiF project No. 9703 GAG of the German Wool Research Institute at RWTH Aachen eV dated May 31, 1997).

In order to be able to take environmental aspects into account at least in part, the above-mentioned combined chemical-enzymatic processes have been proposed, which, however, require a considerable amount of mechanical engineering and have, if at all, only been used to a small extent in practice. Examples of this are the processes described in WO 89/03909 and in DE-A 43 44 428.

The object of the present invention is to propose a method with which a felt-free effect comparable to that of the chlorine treatment can be achieved while largely avoiding chemical treatment or pretreatment.

Such a method should preferably be able to be carried out without major mechanical and technical outlay, if possible using conventional equipment.

This object is achieved in that the wool is treated in a liquor with a proteolytic enzyme while the goods are standing and the liquor is moving.

For the purposes of the present invention, the goods to be treated are wool in the form of flakes, crests, yarns, fabrics, knitted fabrics or the like.

The procedure according to the invention for the flow of the enzyme liquor through the standing goods can be carried out on the one hand in conventional plants. On the other hand, the attack of the proteolytic enzyme of the liquor on the wool fibers can be controlled in such a way that on the one hand a sufficient felt-free effect is obtained, but on the other hand a reduction in the strength of the - 3 -

Wool fiber is limited to a tolerable level. The natural wool character can also be largely preserved without having to compromise on the felt-free finish.

The wool quality obtained is at least comparable in terms of the achieved freedom from felt with that obtained in the more complicated combination processes, while other properties, e.g. the shrinkage are comparable to the results of the pure chlorine process.

Typically, the felt-free finished wool fibers obtained with the method according to the invention have a modified cuticle layer, in which there are at least partially free cuticle ends, which are detached and set up from the underlying fiber structure, the fiber ends of the wool fibers being essentially free of fibrillation phenomena.

So far it was assumed that the surface of the wool fibers with their cuticle layer must be smoothed as much as possible to improve the freedom from felt. In this sense, even the coating of the wool fibers was used to create a smooth surface, which of course very largely changed the character of the wool.

In contrast to the aims of the known felt-free finishing methods, where attempts are made to produce the smoothest possible fiber surface, in particular by means of enzymatic and / or oxidative degradation of the flake ends, the present invention achieves a comparable result with a completely different surface structure of the fibers Fiber damage as with the known methods.

The process according to the invention avoids felt-free properties which are comparable with the chlorine process - 4 -

yellowing of the fibers and opens up additional possibilities when dyeing the wool, since it is possible to work without the need to cover up signs of yellowing.

The process according to the invention preferably avoids any use of oxidizing chemicals, in particular chlorine, so that considerable advantages result from the point of view of environmental pollution. In addition, this minimizes the mechanical engineering effort.

The wool is preferably treated in the form of wool yarn, but can also be subjected to the process according to the invention in the form of wool fabric or knitted fabric which has already been processed.

The enzyme content of the liquor is preferably selected in the range from 0.10 to 3.0 g / 1, more preferably in the range from 1.5 to 2.0 g / 1. Sufficient treatment results are achieved here, on the one hand, during reasonable treatment times, while, on the other hand, the enzymatic attack remains controllable and controllable and fibrillation of the fiber ends or in the central region of the fiber lying between the fiber ends is avoided. During fibrillation, the scale structure is eroded to such an extent that the individual fibrils present in the fiber core are exposed.

When choosing the liquor ratio, a value in the range from 1: 3 to 1:20, but in particular from 1: 6 to 1:12, has proven to be advantageous.

For optimal use of the proteolytic enzyme activity, a slightly basic pH value is recommended, which is preferably buffered.

For optimal preparation of the goods, they are wetted and deaerated with a surfactant solution at a slightly higher temperature, ie approx. 30 ° C, for example. Only then will it be more advantageous - 5 -

as the enzyme is added, which ensures a uniform enzymatic treatment of the entire goods in this step.

The proteolytic liquor is preferably kept at a temperature in the range from 45 to 75 ° C. during the treatment period.

Although various proteolytic enzymes, especially those with moderate activity, are of course suitable for the process according to the invention, the best results have been obtained with the enzyme subtilisin, CAS No. 9014-01-1 achieved.

This protease has so far only become known as an enzyme for household detergents, dishwashing detergents and for industrial washing and is available on the market under the name Esperase (Novo Nordisk A / S, Denmark).

Surprisingly, it was found for this specific enzyme that it is a

Temperature of 60 ° C and higher, particularly preferably at about 70

° C, can be used with particularly high activity. Optimal concentrations of this enzyme in the liquor at the above-mentioned elevated temperatures are then considerably lower than at the otherwise recommended treatment temperatures, in the range from 0.10 to 0.55 g / l of subtilisin.

It was also surprisingly found that subtilisin can also be used in the liquor with increased activities at more basic pH values. The possible higher pH values range up to a pH value of 9.5. In principle, this enzyme also permits higher pH values without a drastic decrease in its activity, but at higher pH values a decomposition process of the wool fibers begins to become more and more important, so that in practice, where only a limited loss of strength is tolerable , the limit around pH 9.5 - 6 -

lies. At such high pH values, enzyme concentrations in the liquor of 0.125 g / 1 are already optimal.

In the wool treated according to the invention, a large, if not the majority, of the free ends of the scales are preferably found and detached. The eroding treatment is further preferably carried out to the point at which no fibrous structures can be recognized in the fiber structure lying under the scale ends.

Wool treated in this way has, in addition to maximum remaining strength, excellent freedom from felt.

These and other advantages of the invention are explained in more detail below with reference to the drawing and examples. The individual shows:

Fig. 1 scanning electron microscope images in the magnifications 150, 500, 1000 and 2500 of wool as a carded yarn with a titer of 5300 dtex (Nm 1.9 / 1); untreated;

2 scanning electron micrographs of the wool from FIG. 1 to 1 after an enzyme treatment according to the invention for FIG. 5 felt-free finishing;

6 scanning electron microscope images in magnifications 150, 500, 1000 and 2500 of a woolen worsted yarn with a titer of 770 dtex (Nm 13/2) in the untreated state;

FIG. 7 scanning electron microscope images of the yarn from FIG. 6 after a conventional chlorine treatment;

8 scanning electron micrographs of the yarn from FIG. 6 after an enzyme treatment according to the invention; - 7 -

9 scanning electron microscope images of a wool yarn not treated according to the invention;

10 scanning electron microscope images of a wool yarn treated by means of a combined oxidation / enzyme process;

11 scanning electron microscope images of a blind treated carded yarn 5300 dtex;

12 scanning electron microscope images of a carded yarn 5300 dtex treated according to the invention, treatment temperature 15 ° C. at pH 8 for 50 min.

The method according to the invention is explained in more detail below with the aid of examples:

Examples 1 to 4:

The wool yarn (raw yarn 5300 dtex) shown in FIG. 1 in cheese package is treated in a yarn dyeing machine with a liquor ratio of 1:10 as follows:

The goods are first optimally wetted and deaerated at 30 ° C. by adding a surfactant solution (0.5 g / 1 of a surfactant combination based on nonionic fatty alcohol ethoxylates, namely PERLAVIN NIC, available from Textilchemie Dr. Petry GmbH).

A buffer of premixed 2.6 g / 1 sodium dihydrogen phosphate and 0.8 ml / 1 sodium hydroxide solution 50% is then added to adjust the pH of the liquor to 8.0. After a lead time of approx. 5 min, the pH is checked again and, if necessary, adjusted again to 8.0 by adding further buffer. - 8th -

The liquor is then heated to 50 ° C. at a heating rate of 2 ° C./min, the pH value is checked again and, if necessary, adjusted again to 8.0. Now the enzyme Subtilisin, CAS No 9014-01-1 is added in the following proportions:

Example 1 0.25 g / 1 liquor

Example 2 0.5 g / 1 liquor

Example 3 1.0 g / 1 liquor

Example 4 2.0 g / 1 liquor

From the time the enzyme is added, the goods are further treated for 45 minutes (the treatment time for the enzyme used here can easily be varied in the range from 30 minutes to 60 minutes in order to adapt the treatment to the wool quality to be treated), the temperature becomes 50 ° C kept.

Immediately after the selected treatment time has elapsed, the enzymatic activity is stopped by rapid heating to 85 ° C. The temperature of 85 ° C is kept for 10 min, then the liquor is cooled to about 60 ° C. This is immediately rinsed twice with 50 ° C warm water, then once with cold water.

As is usual in the known felt-free finishing process, an aviating process with a 1 to 3% strength aqueous solution of a commercially available wet waxing agent (preferably Perifil 207, Textile Chemistry Dr.Petry GmbH, Reutlingen) also follows here after the enzyme treatment according to the invention Increase the smoothness and suppleness of the yarns and thus improve the processability. - 9 -

The samples thus obtained were dewatered, left to dry and examined in a scanning electron microscope. The results include Figures 2 to 5.

While the unchanged cuticle layer in the electron microscope images of FIG. 1 shows free scale ends lying close to the fiber surface, the fibers treated according to the invention, as can be seen from FIGS. 2 to 5, have an increasing amount with increasing enzyme content of the liquor and under otherwise identical treatment conditions detached and raised scale ends on the underlying fiber structure. Even with the highest enzyme concentration in the liquor, the process according to the invention does not lead to complete erosion of the fiber surface or of the scales, which would expose the fibrils present in the fiber core. Rather, no fibril structure is visible on the fiber surface even in the treatment result of Example 4 (FIG. 5).

Table 1 summarizes the properties found in the examination of the wool samples of the untreated material and of the samples treated according to Examples 1 to 4.

The check of the freedom from felt was carried out on the treated yarn in accordance with the standard method of the International Wool Secretariat (IWS) (test method 31, washing program 5A) and gave satisfactory freedom from felt for all samples of Examples 1 to 4, the test, in particular in the case of the Examples 3 and 4 gave excellent results in this regard. - 10 -

Table 1

Example treatment conditions Loss of tear strength Wash shrinkage / felt behavior Whiteness

1st wash 2nd wash 3rd wash

Comparison untreated - - 38% - 50% -53% - 7

1 0.25 g / l subtilisin 5% - 19% - 31% - 35% - 6

2 0.5 g / l subtilisin 12% - 16% -24% - 28% - 5

3 1.0 g / l subtilisin 27% - 8% -10% - 10% - 1

4 2.0 g / l subtilisin 30% -5% - 9% - 9% 2

In addition, the degree of whiteness of the goods was superior to that of conventionally equipped goods. The degree of whiteness given in Table 1 was measured using Datacolor white metrics (from Datacolor GmbH) and calculated according to Berger.

The loss of strength observed on the fibers was always less than or equal to 30%.

Examples 5 and 6:

The effect of the conventional chlorine treatment and the treatment according to the invention (same procedure as described for example 4) is to be explained here on a wool yarn (worsted):

The results to be discussed here were obtained on a wool yarn which had been processed into a knitted fabric in the form of a worsted yarn (worsted yarn with titers 770 dtex on a flat knitting machine Universal type MC-642/8 single-bed knitted with a cover factor F _c = 1.4 ).

6 shows the wool fiber structure of the untreated starting material. - 11 -

In Example 5 (comparative example), the starting material from FIG. 6 was treated with Basolan DC (manufacturer BASF AG) in accordance with the manufacturer's instructions. This is a typical chlorine process. The result is shown in FIG. 7.

Finally, in example 6, the starting material of FIG. 6 was treated in accordance with the procedure of example 4. The result is shown in FIG. 8.

In the case of the raw material shown in FIG. 6, the free scale ends again lie closely against the fiber surface underneath. FIG. 7 shows the erosion of the scales, particularly at their end regions by the chlorine process, as well as the reduced thickness of the scales themselves. Finally, FIG. 8 again shows the result of the treatment of the wool according to the invention with partially detached and raised free scales.

Table 2 summarizes the test results of the samples from Examples 5 and 6. For comparison, the values for the raw goods are also given. The whiteness was again measured and calculated as described above.

When the results of Examples 5 and 6 are compared, it is clear that the process according to the invention leads to a surface shrinkage or felt behavior which is comparable to that of the chlorine-treated goods, with only slight losses in tear strength. It was not only possible to largely preserve the nature of the wool fibers with the process according to the invention, but also to obtain a degree of whiteness which was considerably better than that of the conventionally treated goods (example 5).

As with the measured values of the degree of whiteness shown in Table 1, it can also be seen in the values contained in Table 2 that - 12 -

that the process according to the invention even leads to improved whiteness levels compared to the raw material.

Table 2

Ex. Treatment- Weight Tear Resistance Surface Shrinkage / Felting Behavior Whiteness Loss Loss Number of washes

1 3 5 10

Comparison blind 0.1% - - 16.0% -22.0% -27.0% -42.7% 10

3%

5 Basolan DC 1.6% approx. 0% - 7.7% -11.0% -12.7% -18.4% 6

2.0 g / l

6 Subtilisin 5.0% 14.2% - 5.2% -10.2% -12.8% -19.3% 16

Example 7:

In this example, the enzyme treatment was carried out on moving goods and a partial complete dismantling of the scales was obtained. The degradation of the fibers has progressed here to such an extent that, in addition to fibrillation of the fibers at the fiber ends, a splicing between the fiber ends in the middle of the fiber can also be observed (FIG. 9).

Example 8:

In this example, a wool treated according to the regulations of DE-A 43 44 428 with a combined chemical-enzymatic finishing process was examined. The scale ends were changed comparatively little, in particular no scale ends protrude from the fiber surface (FIG. 10).

Examples 9 to 16 - 13 -

In this series of examples, under otherwise identical test conditions as in Examples 1 to 4, with a subtilising content of the liquor of 2.0 g / 1 and a pH value of the liquor of 8.0, a woolen worsted yarn with the titer Nm is used 28/2 treated enzymatically for 50 min. The temperature of the treatment was varied as indicated in Table 3. After the 50-minute treatment time had elapsed, the liquor was drained off immediately and washed once with pH 4 of aqueous acetic acid solution at a temperature of 50 ° C. and then rinsed once with cold water (20 ° C.).

Table 3

Example temperature weight tensile strength measurement [° C] loss [%] tensile strength elongation

Comparison untreated - 4.3 N 56 mm

9 40 3.5 3.7 N 44 mm

10 50 5.2 3.2 N 32 mm

11 60 7.8 2.6 N 23 mm

12 65 10.3 1.7 N 16 mm

13 70 10.6 1.6 N 14 mm

14 75 10.7 2.0 N 17 mm

15 80 5.4 3.5 N 35 mm

16 90 4.6 3.7 N 40 mm

This series shows that even at temperatures of 85 ° C and above there is still enzyme activity, so that when subtilisin is used as the proteolytic enzyme, stopping the treatment is preferred by immediately draining off the liquor and rinsing the treated wool (pH ≤ 4) as described above. 14 -

The determination of the values for weight loss, tensile strength and elongation serve to estimate the degree of damage to the wool fibers. A maximum degree of damage is achieved at a temperature of approx. 70 ° C. The degree of damage to the wool at this temperature is, however, intolerable in practice, so that in the series of experiments in Examples 17 to 21 it was checked for an optimal enzyme concentration for such high temperatures.

Examples 17 to 21:

Analogous to Examples 9 to 16, a wool carded yarn with a titer of 5300 dtex was treated in this series at a treatment temperature of 70 ° C. and a pH of the liquor of 8.0 at different enzyme concentrations over a period of 50 minutes. The enzyme concentrations and the results of the wool treatment are summarized in Table 4. The whiteness was determined as described in connection with Examples 1 to 4.

Table 4

Example enzyme conc. Weight Tear-resistant Wash shrinkage / felt behavior Whiteness loss

I. laundry 2. laundry 3. laundry

Comparison untreated - - -38% -53% -54% -7

Blank sample - 2.4% 18% -33% -48% -55% -5

17 0.250 4.2% 26% -11% -19% -23% -2

18 0.375 4.8% 30% -4% -9% -10% -1

19 0.50 5.8% 43% -3% -7% -9% 0

20 1.0 6.6% 55% -1% -3% -3% 1

21 2.0 7.1% 61% -1% -1% -2% 3

- 15 -

This series of tests shows that optimal results are achieved in the liquor at such high treatment temperatures in the range of approximately 0.375 g / l subtilisin.

The results of the treatment are also documented in FIGS. 11 to 15, which each contain scanning electron microscope images at magnifications of 150 times, 500 times, 1000 times and 2500 times.

FIG. 11 shows the blind-treated yarn, while FIG. 12 shows the result of the treatment according to Example 17, FIG. 13 shows the result of the treatment according to Example 18, FIG. 14 shows the result of the treatment according to Example 19 and FIG. 15 shows the result of the treatment according to Example 21.

The fiber damage in Examples 19 to 21 is so great (see FIGS. 14 and 15) that the fiber structure aimed at according to the invention with a modified cuticle layer, which has at least partially free cuticle ends, which are detached from the underlying fiber structure and set up without it however, the fiber ends of the wool fibers show noticeable fibrillation phenomena, can no longer be achieved, but rather detachment of entire scales is observed (FIG. 14; example 19) or even destruction of the bevel with partial dissolution in individual fibrils (FIG. 15; example 21).

Examples 22 to 26:

In this series of experiments, the pH of the liquor was again varied using a procedure analogous to that in Examples 9 to 16, while the temperature during the treatment period varied from

Was held at 70 ° C for 50 min. The enzyme concentration was 0.125 g / l in all examples, since at very high pH values - 16th

at pH 8.0, the optimal enzyme concentration found turns out to be too high. The results are summarized in Table 5 together with the varying pH values.

Table 5

Example pH value Weight loss% Tear strength Wash shrinkage / felt behavior

Tear strength loss% I. laundry 2. laundry 3. laundry

Comparison - - 18.7 N - -38% -53% -54%

22 8.0 3.2 15.6 N 16 -14% -20% -28%

23 8.5 4.1 14.2 N 24 -10% -14% -19%

24 9.0 6.0 13.2 N 29 -6% -10% -12%

25 9.5 6.4 13.0 N 30 -6% -11% -11%

26 10.0 6.8 12.0 N 36 -8% -10% -10%

Overall, it can be determined on the basis of this series of experiments that working with the enzyme subtilisin is possible in principle at very high pH values, but is accompanied by side effects with increasing pH, which make implementation more difficult in practice. For example, the maximum pH value on a large industrial scale is pH 9.0, which in particular allows reproducible results and easier pH control.

Claims

- 17 patent claims

1. A method for finishing felt-free wool using a fleet containing a proteolytic enzyme, characterized in that the treatment of the wool is carried out with the goods standing still and moving fleet.

2. The method according to claim 1, characterized in that the treatment is carried out chlorine-free and free of other oxidizing chemicals.

3. The method according to claim 1 or 2, characterized in that the wool is treated in the form of wool yarn or woven or knitted fabrics made therefrom.

4. The method according to any one of claims 1 to 3, characterized in that the enzyme content of the liquor is 0.10 to 3.0 g / 1, preferably 1.0 to 2.0 g / 1.

5. The method according to claim 4, characterized in that the liquor ratio is 1: 3 to 1:20, preferably 1: 6 to 1:12.

6. The method according to any one of the preceding claims, characterized in that the pH of the liquor is adjusted to be alkaline.

7. The method according to any one of claims 1 to 6, characterized in that the treatment with the proteolytic liquor is carried out at elevated temperature, in particular at about 45 to 55 ° C. - 18 -

8. The method according to any one of the preceding claims, characterized in that the goods are wetted and vented with a surfactant solution at elevated temperature before treatment with the enzymatic liquor.

9. Use of the enzyme subtilisin, CAS No. 9014-01-1 for the felt-free finishing of wool fibers while maintaining a treatment temperature above 60 ° C.

10. Use of the enzyme subtilisin according to claim 9, characterized in that the enzyme is used in a solution with a pH in the range from 8 to 9.5.

11. Use according to claim 9 or 10, characterized in that the enzyme is used in the solution in a concentration of 0.10 to 0.55 g / 1.

12. Use of an alkaline solution of the enzyme according to one of claims 9 to 11 for the treatment of wool in the felt-free finishing.

13. Felt-free treated wool fibers with a scale layer in which at least parts of the free, visible on the fiber surface scale ends are changed, characterized in that the modified scale layer has at least partially free scale ends, which are detached and set up by the underlying fiber structure, and that the fiber ends of the wool fibers are essentially free of fibrillation phenomena.

14. Wool fibers according to claim 13, characterized in that the predominant number of free scale ends are detached from the underlying fiber structure and set up. - 19 -

15. Wool fibers according to claim 13 or 14, characterized in that the fiber structure lying under the scale ends is essentially free of visible fibril structures.