DE1419426A1 - Process to improve the elasticity of wool fiber structures - Google Patents

Description

»Η. * ν. PBCIIMA ^ "^ *" * «^ '-"" ^{ßASSE β}

PATENT LAWYERS

FKOTSCTFAT2NT MCNCHEPT

1A-23 245 ·] 41 9426

Describe i bu η g to the patent application

Deering Milliken Research Corporation, Spartanburg, South Carolina, U.S.A.

concerning

Process for improving the elasticity of wool fiber structures.

The invention relates to the production of elastic wool structures.

Woolen fabrics with considerable elasticity are very popular for dresses, skirts, vests, stockings, etc. in the in general, this material must be knitted in order to obtain the desired elasticity. Unfortunately, you can only smaller pieces are knitted and these cannot be cut, sewn or otherwise processed like it the manufacturer would like to. All of these difficulties are avoided when using woven fabrics, however they do not have the desired elasticity.

809812/1248

It is an object of the invention to provide an elastic wool structure to show that you can cut, sew and otherwise process as desired, in particular relates to the invention the treatment of fabrics to give them a particularly elastic quality. Another object of the invention is the treatment of yarns for weaving into fabrics of high elasticity.

According to the method according to the invention, this is achieved by treating a woolen material, such as yarns and woven fabrics, with an aqueous solution containing about 0.1 to 5 percent by weight of a reducing agent, after which the fiber material is dried. If the fabric or fibrous material is left free in at least one direction during each treatment to contract or shrink, a high degree of elasticity is obtained in that free direction or directions.

"Elasticity" means that structures of Wool fibers are easily stretchable beyond their dimensions after treatment and again after the stretching tension has ceased return to their original level. For example, if a fabric or fiber material has an elasticity of $ 10 in the Weft direction so it can easily go in that direction by $ 10 are stretched and returns to this original level after the stretching tension has ceased.

BATH

809812/1248

The temperature "at which the wool fiber structure is treated with the reducing agent" depends to a certain extent on the selected reducing agent. For some reducing agents, such as sodium bisulfite, sodium borohydride, thioglycolic acid and their water-soluble salts, e.g. ammonium thioglycolate, room temperature is , for example about 18 to 24 ° C. (65 to 75 ⁰ I), suitable for achieving optimal results for a sufficient time, for example 10 minutes to 4 hours Monitoring the process and the risk of excessive degradation of the wool fibers become a problem with these special reducing agents with increasing treatment temperature. Assuming that the Eontaktzeit of the reducing agent with the wool fibers under about 15 minutes is maintained and the concentration of reducing agent in the aqueous medium under ca · 5 wt. -fo is, one can at higher temperatures, as with boiling or with steam, achieve excellent results. Even higher conc Entrations of reducing agent can be used if the wool fibers are only in contact with them for a few minutes or even seconds. The use of higher concentrations and shorter treatment times may be desirable for continuous operation, but greater care must be taken under these conditions to avoid excessive degradation of the wool fibers.

The treatment of the wool fiber material according to the invention The process is most advantageously carried out in the presence of a swelling agent such as urea.

8.0 9812/1 2 48

part of the use of sodium borohydride as a reducing agent is that you get optimal results without .application of a swelling agent.

If, on the other hand, sodium formaldehyde sulfoxylate, for example, is used as the reducing agent, it is necessary to use a boiling aqueous solution of the reducing agent in order to achieve optimal results. "Neovadin AU" to use. As shown in ⁱ Example IX, this particular combination has ie Hatriumfprmaldehyd sulfoxylate and Keovadin AU, a synergistic effect on the wool fiber structure. In this embodiment of the method according to the invention, the wool structure is given a high degree of elasticity by treatment with an aqueous medium containing about 0.025 to 0.125% of each of these components,

Almost all wool fiber materials, such as yarns or fabrics, are due to the presence of longitudinal and torsional stresses characterized within the pas during the manufacturing process. So, for example, the pasers when deburring, carding, stretching, weaving and when hating or Drying drawn and stretched so that in them a longitudinal tension is generated. In the same way, the fibers are rotated during spinning, whereby they receive a twisting tension. These tensions can be seen in the

BATH ORIGINAL

8098 12/1248

can be essentially canceled by immersing the lasers, in whichever i? o rm, in water at a temperature between approx. 18 ⁰ C (65 ⁰ F) and boiling. The extent of the relaxation of these stresses is primarily a puncture of the temperature of the aqueous treatment medium and is essentially independent of the treatment time at a certain temperature. Thus, for example, C (120 ⁰ F) to substantially the same degree of relaxation obtained in 30 minutes in 4 hours at 49 °. By far the greatest relaxation is obtained when the aqueous medium is brought to a boil. Some of the tensions can be relieved by damping the wool fiber material, but this extent is significantly less than that by immersion in water at temperatures of approx. 49 ⁰ C (120 ⁰ I). In view of this, it is preferred in the method according to the invention to immerse the woolen fiber material in a boiling, aqueous solution, in particular if this treatment is carried out separately from the treatment with reducing agents. When using reducing agents such as sodium bisulphite, sodium borohydride, thioglycolic acid and their water-soluble salts, room temperature is preferred and the relaxation, ie the removal of tension, is preferably carried out either before or after the treatment with the reducing agent. If, on the other hand, sodium formaldehyde sulfoxylate is used as the reducing agent, the stress treatment is advantageously carried out simultaneously. In this embodiment it is preferred to treat the wool fiber material with a boiling aqueous solution of reducing agent and plasticizer.

809812/1248

After treatment with the reducing agent or for relaxation with regard to the longitudinal and torsional stresses, the wool fiber materials should be substantially below stress-free conditions in order to give the end product maximum elasticity. Of course can - if maximum elasticity is not desired, drying the treated fiber mass under a weak one Elongation takes place, provided that the material is in can contract to a certain extent, depending on the desired degree of elasticity. In the same way you can too Apply tension only in one direction, for example either in the direction of the warp or weft, around a fiber material bigger pull in one direction than in that. to receive another.

The tension is adjusted by using a pin frame or in any other conventional way.

While suitable results are obtained when the fiber material is dried under stress-free conditions at room temperature, better results are obtained when the material is processed in air at a temperature between about 49 and 82 ⁰ O (120 - T80 ⁰ F). If wet fibers are treated at higher temperatures, it is assumed that a compression stress is imposed on the fibers, which gives the finished product additional extensibility. The fibers must be moistened during this processing and preferably contain water accordingly

80 98 12/1248

- 7 - ■ U-23 245

their weight before this treatment or above. Obviously the water is gradually driven off during processing and this is preferably continued until the material is completely dry, as the treatment of the dry fiber mass relies on the compaction tension of the fibers has no harmful influence. This treatment becomes beneficial made in a conventional drum dryer.

The most notable effect on the structure of wool fiber material after each of the above types of treatment, i.e. treatment with reducing agents, relaxation of the longitudinal and Torsional stresses and machining to impart a compaction strain resides in that the material contracts noticeably in length and / or area. A wool yarn, for example, contracts strongly in the longitudinal direction, while a woolen fabric contracts flatly contracts .. However, this contraction is not permanent, i.e. there is no matting, as is the case with many Wool materials is noticed. In contrast, the contraction ^ is essentially reversible, in other words, the contracted wool fiber structure in at least one direction under the least tension by at least $ 10 along their length respectively Area to be stretched after treatment, laughing cessation of the, tension returns the tissue back to the contracted one State back so that the wool fiber material actually can be described as elastic. It is believed that the degree of elasticity is proportional to this Degree of contraction achieved by the treatments.

809812/1248

It is known that wool molecules contain cystine disulfide crosslinks the formula

IT

- CH ₂ - S - S - CH ₂ - C

O = C C = O

Ea it is believed that the woolen fiber material contracts by treatment with a reducing agent, because one Number of distilfide linkages of these cross-links in the treatment rip. According to the process according to the invention, any reducing agent can therefore be used which can tear open a number of these networks. Among other things, are suitable as reducing agents? Metal formaldehyde sulfoxylates such as zinc, alkali metal, e.g. sodium formaldehyde sulfoxylate, Thioglycolic acid and "its water-soluble salts, such as ammonium thioglycolate, further itylmercaptan, Alkali metal borohydrides such as sodium, potassium and sodium potassium borohydride, Alkali metal sulfites such as sodium or potassium bisulfites, sulfites, metabisulfites, hydrosulfites (Hyposulfite) et al.

The reducing agent should be used in such a concentration and apply in a sufficiently long time to remove a number of the cystine disulfide crosslinks with consequent contraction to tear open the wool structure. In general, sufficient contraction is obtained when about 5 to 50% of the existing gystine disulfide cross-links are torn. If more networks are destroyed, the physical ones become

809812/1248

1A-23 245

Properties of the fiber material in an undesirable way reduced * Pur the breaking of the disulfide links aqueous solutions with approx. 0.01 to 5 wt .- $ are suitable Reducing agent. There are reducing agents for cryogenic treatment preferred, i.e. sodium bisulfite, sodium borohydride, Thioglycolic acid and its water-soluble salts, preferably in a concentration of about 1 to 5% by weight, giving outstanding results. In this embodiment According to the invention, any amount of swelling agent up to about 50% by weight can be used, if desired. Urea " is the most easily available and sought-after swelling agent, however, any other material can also be used, which in the aqueous medium for the wool fibers Brings sources, e.g. guanidine compounds, such as the hydrochloride, Formamide, acetamide, thiourea, phenol, lithium salts such as chloride, bromide or iodide and the like.

Pure high temperature treatments, for example with

Sodium formaldehyde sulfoxylate, more than about 0.125 wt .- ^ Λ are required for optimal results. Larger amounts can be used if desired, provided that the treatment time is shortened accordingly. In this embodiment, a plasticizer such as Feovadin AF need not be present in amounts greater than about 0.125% by weight of the solution.

While the inventive method to improve the elasticity of any wool fiber material such as winding, (batts)

8098 12/1248

- ίο - I ^ 9426 _1A _ _{23 245} .

Game or fabric can be applied, it is special suitable for improving the elasticity of woven woolen fabrics.

It should be noted that the influence of the various treatments on the wool fiber structure has a bearing on this aims to contract them in length and / or in area. It has already been stated that the wool fiber structure should be free for eontraction during the various treatments. This is especially true with regard to fabrics that be treated according to the method according to the invention * Es Some problems can arise when using yarns with large longitudinal or twisting tensions during contraction treatment To be kept absolutely free. If a yarn with high Degree of untwisting and high contraction force perfect is released so it can turn up so fast and violently that a number of permanent knots arise over the length of the yarn. These knots largely affect the Elasticity of the finished product. Because of this, pulled forward, the yarn loose but not completely free of tension to immerse in the treatment medium. The loose thread will untwist and pull together so that it becomes very nubby (kinky) yarn, but not up to a knotty one will. These kinks can be taken off and the yarn returns to this nubby state after the stretching tension has ceased.

8098 12/1248

Another embodiment of the invention, in particular for wool yarn, consists in the fact that the yarn is in a "certain" 3? Orm, for example on a rod during treatment with the reducing agent and / or during the Relaxation treatment winds up, fixes and dries in this form. This fixed position is so in the finished product retained so that elastic properties are achieved. The elasticity in this embodiment becomes in the first place Line reached from this fixed position and less by the contraction as in the other embodiments.

Fabrics made from any type of yarn can acquire elastic properties, even if the yarns of the fabric tend to to return to the hunched position they gained from the treatments.

Substances treated according to the method according to the invention visibly contract as a result of the various treatments according to the invention. The weave or Binding of these substances largely determines the degree of Elasticity. For example, the yarns are loosely woven Fabric not only free of contraction but also for the formation of slippages, and for turning, but in the Way that, a greater contraction and thus elasticity is achieved. This effect is generally observed for fabrics with less than 15 weft threads and 20 warp threads per inch with a yarn thickness of approx. .... (5 run) «On the other hand in denser woolen fabrics the yarn contraction and

80.9812 / 1248

untwisting reduced by the weave. The success is a two-dimensional shrinkage, mainly due to the greater height of the loops that form at the point of intersection of the warp and weft. Even such fabrics can reach an elasticity of up to 30fo .

Particularly desirable fabrics are obtained when either the warp or weft yarn of the fabric is larger Has longitudinal and torsional stress. These tensions can be increased by using more twisted ones Yarns or a number of yarns either in the warp or in the weft. If such a fabric according to the invention Treated procedure, the contraction and thus the elasticity is greater in the direction in which the thread the has greater tensions, so that a jersey-like fabric is obtained. It is also according to the invention Process possible to use yarns with different longitudinal and twisting tensions in the warp and / or in the weft, so that crepe effects (puckered) are achieved by the method according to the invention. Similar fabrics can be made when one is in the warp or weft of woolen fabrics synthetic or natural fibers are used. Preferred synthetic fibers include polyamides such as polyhexamethylene adipamide, Polyesters such as poly (ethylene terephthalate) and Acrylic fibers such as acrylonitrile polymers or copolymers with at least 85 $ acrylonitrile such as acrylonitrile / methyl acrylate (85:15). Of the natural fibers, cellulose fibers such as cotton and cellulose ester are preferred.

AfI QR 1?

The method according to the invention can be used on all types of fabric, dyed and undyed. The low temp he natural treatments with a reducing agent are carried out especially with colored material. High temperature treatments are generally not common for colored goods, since the reducing agents are used at these elevated temperatures the dyes can stand out from the tissues.

The following examples illustrate the invention.

Example I.

A pattern the size of 50.8 χ 50.8 cm (20 χ 20 ») of a dyed non-carbonized wool fabric with 50 warp threads and 25 weft threads per inch with a yarn thickness in the direction of the warp and weft of 5.875 turns with 3 15 revolutions / cm (8 turns per inch) was immersed in an aqueous solution containing a trace of a wetting agent available under the trade name "Tergitol EfPX" and 2 wt .-% sodium borohydride. The solution had a temperature of 21 ° 0 (7O ⁰ F). The tissue was left in this solution for 15 minutes, then removed and immersed in a 2 # peracetic acid solution for 1 minute. The tissue was washed at room temperature and dried in a conventional drum drier at about 65.5 · G ⁰ (150 ⁰ F). The fabric was completely dry after about 30 minutes and showed a hand stretch of $ 33 in the warp direction and $ 27 in the weft direction. After cessation of tension returned

809812/1248

- 14 - «419426 1A-25 245

the tissue returns to its original dimensions. Example II

The procedures of Example I were repeated except that two wool yarn samples were used with one Yarn count of 3.875 run. If the yarns are immersed for 15 minutes, they wind up so violently that they become Form a number of kinks or hatches along their length. Then the yarns are removed from the reducing agent solution. and then dipped and washed in peracetic acid solution. One sample was allowed to air dry without exposure to tension, while the second sample was in a drum dryer was dried according to Example I. Both samples had achieved a high level of elasticity, with that of the in the drum-dried sample was larger than that of the air dried.

Example III

A fabric sample measuring 50.8 by 50.8 cm (20 by 20 ") of a dyed, non-carbonized wool fabric with 32 warp threads and 4 tons of weft threads per inch and a yarn count of 5.0 run in the warp and a twist of 3.15 TTm rotations / cm (8 turns per inch) and as a weft of worsted yarn with a 1/30 thread and a twist of 5.5 u / cm (H turns per inch) was in an aqueous solution of 20 $ urea and 2 wt. ^ Sodium bisulfite immersed. The sample was left in this solution for 15 minutes, then removed and

809812/1248

play I dried in a drum. After this treatment the fabric had contracted by $ 6 in the warp direction and by $ 7 in the weft direction. You pulled the fabric with the Hand apart, an elongation of $ 17 was achieved in the warp direction and $ 33 in the weft direction. After stopping the split returned the tissue to its original dimensions return. The pattern was then immersed in boiling water for 30 minutes dipped and then dried according to Example I in a drum. After that, the warp weave was around $ 7.5 and shrunk by $ 9,500 in the weft direction and could with the Hand stretched $ 15 in the warp direction and $ 33 in the weft direction will. While these $ 15 and $ 33 elongations were not quantitative, like that of the uncooked fabric, it was Quality much better after cooking and drying. The maximum extensibility is achieved with a minimum tensile stress achieved compared to stretching uncooked tissue. In addition, the handle of the cooked tissues was great better. Similar results were obtained when the tissue sample was examined prior to treatment with the sodium bisulfite urea ^ solution boiled.

Example IV

The procedures of Example III were repeated with the exception that a 1% sodium borohydride solution was used instead of the sodium bisulfite-urea solution. After drying the fabric in the drum and boiling, the fabric was warp around. $ 5 and shrunk $ 2 in the weft direction

80 98 1 2/12

- 16 -. 1A-23 245

and showed an optimal elongation in the warp direction of $ 14 and weft from $ 29. This tissue also returned The tensile stress ceases to return to its original dimensions. Next was the grip and the ease of stretching for boiled tissues, boiling before or after the treatment with the sodium borohydride solution, better.

The fabric samples of Examples III and IV had a much greater extensibility in the weft direction, so that the woolen fabrics treated in this way were very similar to a knitted fabric of elastic quality.

Example V

• A tissue sample according to Example III was immersed in a solution containing $ 0.075 sodium formaldehyde for 30 minutes sulf oxy lat, $ 0.05 "Neovadine AN" and $ 0.075 $ 99 acetic acid, that is $ 3 or $ 2 or $ 3 - based on the weight of the fabric - for a bath: wool ratio «40s1, boiled. The fabric was then washed and drum-dried as in Example I. It shrank in the direction of the warp by $ 8 and in the weft direction by $ 10 and had a maximum $ 16 stretch in the warp direction and in the weft direction from $ 31. After the tension ceased, the tissue returned to its original dimensions. ·

8098.12 / 1248

Example VI

■ Ί

The procedures of Example V were carried out on a fabric sample the size 50.8 χ 50.8 cm worsted with 56 warp threads and 46 wefts per inch with a T / 26 yarn of warp and S-twist of 5.5 rev / cm (14 turns per inch) and a 1/26 Weft yarn with a Z twist of 14 turns per inch (5.5 U / cm) repeated. The drum dried fabric had shrunk by $ 9 in the warp direction and by $ 6 in the weft direction and had a maximum elongation in the warp direction of $ 20 and in the weft direction of $ 17. It returned when the extension tension has ceased, immediately return to the original Dimensions back.

Example YII

The measures of Example Ύ were repeated with a fabric sample the size 50.8 χ 50.8 cm (20 χ 20 inches) of worsted fabric with 114 warp threads and 70 weft threads per inch and in warp and weft a 1/26 yarn with an S- Rotation of 5.5 TJ / cm (14 turns per inch). The product was drum dried and shrunk $ 15 in the warp direction and $ 5 in the weft direction. It had a maximum stretch in the warp direction of $ 32 and in the weft direction of $ 13. After the end of the tensile stress, it immediately returned to its original dimensions. The difference in elasticity makes the fabric a very popular jersey-like fabric.

80 98 12/1248

- 18 - 1A-23 245-

A thread of a 1/16 woolen yarn with an S twist of 5.5 TJ / cin (H turns per inch) was wound onto a glass spindle 3.18 mm in diameter and boiled in the solution according to Example V for 15 minutes. The yarn was dried at room temperature on the spindle, to d'em removing the spindle, the yarn was wound up so that they could stretch, it was stretched to the windings substantially overall *. When the tension ceased, it returned to its coils.

Example IX

A tissue sample according to Example VII was 30 minutes / ater, a second sample in water with 0.05 wt. ~ I <r "Neovadine old," a third in water with 0.125 $ sodium formaldehyde sulfoxylate (Kaps) and finally in Y fc fourth boiled in water with $ 0.075 FaFS and $ 0.05 ueovadin AlT * A bath: fabric ratio of 40: 1 was always maintained. A fifth sample was subjected to the same treatment, but the aqueous medium was shaken during the treatment. The samples were dried, measured, wetted and drum dried as above. The values for shrinkage and maximum elongation are summarized in the following table.

80 98 12/1248

1A-23 245

TABEIIE

Shrinkage

max, extensibility

treatment

air-dried in the drum (fo) dried

Chain shot chain shot chain shot

1. 30 min.
cooked 7

2. cooked with

2fo Neovadin AW "+ 3i ° acetic acid 6

3 · cooked with 5 $> NaPS +
3 $ acetic acid 7

4. cooked with

i NaPS +
Neoyadin + acetic acid 9

5. like 4 »shaken 9

3 3

12th

14th

15th

16

26th

26th

25th

32

13th

14th

From the above data, "perfectly the synergistic one results Effect of sodium formaldehyde sulfoxylate along with "Neovadin AN" and the improvement that one gets through Shake receives. As above, these tissues also return to their original dimensions after the tensile stress has ceased.

Patent claims

809812/1248

Claims (16)

- 20 - iA-23 245 141SA26 patent claims (American fit) 1. Process for improving the elasticity of wool fiber structures, characterized, that this is treated with a reducing agent "and then dried, both process steps essentially can be made under stress-free conditions, whereby the elasticity in at least one direction at least amounts to. 2, a method for improving the elasticity of wool fiber structures according to claim 1 _t, wherein the wool fibers have longitudinal and twisting tensions, characterized in that the wool fiber structure is soaked with an aqueous solution of a reducing agent, the longitudinal and twisting tensions of this structure are equalized or vice versa and the structure is dried, all measures being carried out under essentially stress-free conditions so that an elasticity in at least one direction of at least 10 $ is obtained. 3. Process for improving the elasticity of wool fiber fabrics, characterized, that wool fabrics with longitudinal and torsional stresses are treated with an aqueous solution containing a reducing agent, soaks, the longitudinal and torsional tension of the tissue 8 Q 9a 12/1248 side, the fabric dries and that under essentially stress-free conditions, so that an elasticity in at least one direction of at least 10 ^ is achieved. 4. A method for improving woolen fabrics according to claim 5 with warp and weft yarns and longitudinal and twisting tensions, characterized, that the fabric is soaked with an aqueous solution containing about 0.01 to 5 wt. 56 reducing agents, the longitudinal and eliminates torsional stresses in the fabric, the fabric dries under essentially stress-free conditions, so that elasticity in at least one direction of at least ΪΟ56 is obtained. " 5. A method for improving the elasticity according to claim 4 * characterized in that the aqueous solution contains a swelling agent, preferably urea. 6. A method for improving the elasticity of woolen fabrics with Eett and weft yarns and longitudinal and twisting tensions, characterized in that, that the tissue with an aqueous solution of a reducing agent treated for a period of time sufficient by about 5 - 50 $ of the cystine bisulfide cross-links present in the full molecule break open, the tissue dries and all measures are carried out under essentially tension-free conditions, creating elasticity in at least one direction 809812/1248 - 22 - 141 9426 1A-23 245 · of. at least about $ 10 is reached. · - / v ^ io &i'ir * 7. A method for improving the elasticity according to claim 6, dadur chgek e η η ze ic hn et that the aqueous solution contains approx * 1-5 wt. - $> reducing agent ', preferably sodium borohydride. -. · ■ _.- .. 8. Process for improving the elasticity of woolen fabrics with warp and weft yarns and longitudinal and twisting tensions, da d u r c h ge k e η η ζ ei c h η e t, that the fabric with an aqueous solution containing about 1-5 wt .- ^ reducing agent and about 5-50 wt .- $ swelling agent Treated during such a time that about 5 - 50 $ of the cystine disulfide cross-links contained in the wool molecule tear open, the tissue is removed from the aqueous solution and immersed in boiling water for at least 50 minutes, the fabric dries, all measures under essentially tension-free conditions, whereby the elasticity in at least one direction is at least about 10 $. 9 · Method for improving elasticity according to claim 8, d ad u r c h characterized in that either the warp yarn or the weft yarn has a greater longitudinal and twisting tension than the other component. 10. A method for improving the elasticity according to claim. 9, d a characterized in that the fabric is dried by leaving it at an air temperature 809812/1248 - 23 - 1419 A 26 1A-25 245 between approx. 49-82 ⁰ C (120-180 ⁰ P) in order to give the yarns a compression tension. 11. The method for improving the elasticity according to claim 10, characterized in that that one ice reducing agent and sodium bisulfite as a swelling agent Urea used. 12. A method for improving the elasticity of fabrics with warp and weft yarns and longitudinal and twisting tensions, characterized in that the ^ toff is immersed in a boiling aqueous solution containing a reducing agent for a time sufficient to about 5 to 50 $ break the wool contained in the molecule cystine disulfide crosslinks and sufficient to lift the longitudinal and twisting stresses substantially to the fabric by treatment with air at a temperature between about 49-82 ⁰ C (120 ⁰ -18O P) is exposed, whereby a compression ^ j tension is imposed on the yarns of the fabric, and the various treatments are carried out under essentially tension-free conditions, the fabric being given an elasticity of at least one direction. - · ■ .-- ,. 13. A method for improving the elasticity of woolen fabrics according to claim 12 * d a du rc h g e k e η η ze i c h n e t that either the warp yarn or the weft yarn is a has significantly greater longitudinal and torsional stress 80.9812 / 1248-.:,.· - ²⁴ "1419 ^ 26 than the other component. 14. A method for improving the elasticity of woolen fabrics according to claim 12, characterized in that that one uses an aqueous solution containing about 0.01 to 0.125 wt .- ^ reducing agent. 15. A method for improving the elasticity of woolen fabrics according to claim H, characterized in that that the reducing agent used is sodium formaldehyde sulfoxylate used. 16. A method for improving the elasticity of woolen fabrics according to claim 15 _f, characterized in that an aqueous solution is used with an additional 0.01 to 0.125 wt .- ^ plasticizer. 809812/1248