US3849848A

US3849848A - Method for the treatment of textile fibres

Info

Publication number: US3849848A
Application number: US00253797A
Authority: US
Inventors: F Bekku; R Umehara
Original assignee: IWS Nominee Co Ltd
Current assignee: IWS Nominee Co Ltd
Priority date: 1971-05-20
Filing date: 1972-05-16
Publication date: 1974-11-26
Anticipated expiration: 1991-11-26

Abstract

This specification discloses a method of crimping protein fibres by drafting. Untwisted fibres are treated with an aqueous solution of alcohol, which may optionally contain an acid and a setting agent for the protein fibres, such as formaldehyde. They are then drafted and are subsequently relaxed to form the crimps. The crimps can be set, for example by steam, with the help of the setting agent after processing and the fibres dried. The preferred alcohol and acids are those which will evaporate on drying, notably having boiling points below 120*C. The drafted fibres may be set without applied tension, and the resulting crimp waves set as mentioned above. Alternatively the drafted fibres may be set in tension and the fibres relaxed at a later stage to produce the crimps. They can be relaxed, for example, after conversion into yarn or fabric. The invention also provides apparatus in which the method can be carried out, a preferred feature being the use of a vacuum padding device which causes rapid and complete wetting of the fibres with the alcohol solution. The invention overcomes the disadvantages inherent in crimping conduct by drafting twisted fibres.

Description

llmehara et al. 8 g

METHOD FOR THE TREATMENT or TEXTILE FIBRES [75] Inventors: Ryo Umehara; Fujio Bekku, both of lchinomiya, Japan I [73] Assignee: I.W.S. Nominee Company Limited,

London, England [22] Filed: May 16, 1972 [21] Appl. No.: 253,797

30 Foreign Application Priority Data May 20, 1971 Japan..."v 46-83636 us. 01. 28/7217, 8/128 A, 28/75'WT Int. Cl. D02g 3/36, D02j 1/22 Field of Search 28/721, 75 WT, 76 R, 7217;

19/66 R; 8/127.6, 128 R, 128 A References Cited UNITED STATES PATENTS 3,677,694 7/1972 Sugimoto et al 8/128 A 3,687,605 8/1972 Farmer 8/128 A FOREIGN PATENTS OR APPLICATIONS 3/1965 Great Britain 28/7217 Primary ExaminerLouis K. Rimrodt Attorney, Agent, or Firm-Harold L. Stowell 451 Nov. 26, 1974 [57 ABSTRACT This specification discloses a method of crimping protein fibres by drafting. Untwisted fibres'are treated with an aqueous solution of alcohol, which may optionally contain an acid and a setting agent for the protein fibres, such as formaldehyde. They are then drafted and are subsequently relaxed to form the crimps. The crimps can be set, for example by steam, with the help of the setting agent after processing and the fibres dried. The preferred alcohol and acids are those which will evaporate on drying, notably having boiling points below 120C. The drafted fibres may be set without applied tension, and the resulting crimp waves set as mentioned above. Alternatively the drafted fibres may be set in tension and the fibres relaxed at a later stage to produce the crimps. They can be relaxed, for example, after conversion into yarn or fabric. The invention also provides apparatus in which the method can be carried out, a preferred feature being the use of a vacuum padding device which causes rapid and complete wetting of the fibres with the alcohol solution. The invention overcomes the dis advantages inherent in crimping conduct by drafting twisted fibres.

21 Claims, 3 Drawing Figures I l I 4144-42 METHOD FOR THE TREATMENT or TEXTILE FIBRES This invention relates to a method and apparatus for drafting non-twisted protein fibres to crimp them spontaneously.

Keratin fibres can be crimped in the form of top or carded sliver by a stuffer box method, in the form of top or yarn by the twist-draft-set-untwist method and in the form of yarn by the draft-release method.

In fibres crimped by the stuffer box method the curvature at certain positions in the crimped fibres is exceedingly sharp, and strain is concentrated in these I sharply curved portions. As the fibres are steam set in such a configuration, the tensile strength of the fibres is greatly reduced. Steam-setting produces only a temporary set and when permanent set is required, chemical setting with inorganic or organic reducing agents is employed. Permanent setting further reduces the tensile strength and this causes problems in subsequent processing or in the quality of thefinal product.

In the twist-draft-set-untwist method and the draft- I release method, the fibres are drafted mechanically and sults.

As highly drafted fibres are not the stable a-type keratin fibres of natural wool, the fibres are severely damaged. When subjected to setting with boiling water, steam or chemical agents for permanently setting the crimp, the fibres are further damaged, and the tensile strength is further reduced. In methods involving twisting the fibres as described above, it becomes very difficult to dry them and it is uneconomical to untwist them.

A first aspect of the present invention relates to a method for crimping protein fibres by applying to the fibres anaqueous solution of an alcohol, drafting the fibres, and subsequently relaxing the fibres.

Non-twisted keratin fibres are preferably used in this invention. Keratin fibres include sheeps wool, mohair, alpaca, vicuna, llama, cashmere, and camel hair, and may be used in the form of carded sliver, tops and rovings of such fibres, which are non-twisted and arranged uniformly parallel along the fibre axis.

In the preferred practice of the invention, the fibres are well impregnated in an acid-containing or alkalicontaining aqueous solution of an alcohol, which generally contains a high concentration of the alcohol, in

"order to render them draftable more readily and with a reduced energy. Keratin fibres are characterised by a 30 percent index; that is to say that when sheeps wool is drafted by 30 percent and then released, it recovers to the original state without any internal strain. The treated fibre when adequately dried shows the same tensile strength properties as untreated sheeps wool fibres. While the performance of the invention does not depend upon any theory as to its mode of operation, this phenomenon is understood to be due to the opening by water of the hydrogen bonds stabilising the polypeptide chain, which can be reversed on drymonoethanolamine sulphite, monothanolamine bisuling. Additionally there are other reversible bonds having the propertyof stabilising the polypeptide chain, such as salt bonds and hydrophobic bonds. The former bond is opened by adding acid or alkali and the latter bond is opened by an alcohol. Thus the drafting properties of'sheeps wool and other keratin fibres can be further increased.

The impregnating media consisting of an acidcontaining or alkali-containing aqueous solution of an alcohol should be removed in the subsequent drying process. If it is not removed substantially completely in the drying process it greatly reduces the strength of the fibres. The acids, alkalis and alcohols which are preferred are those having a similar volatility to water and preferably not having a boiling point higher than about 120C. For the purposes of this invention, formic acid (b.p. 100.5C) and acetic acid (b.p. 118C) are the most preferred acids, ammonia (b.p. -33.35C) the preferred alkali, and methanol (b.p. 647C), ethanol (b.p. 783C), n-propanol (b.p. 972C), iso-propanol (b.p. 825C), n-butanol (b.p. 1 177C) and iso-butanol (b.p. 108C) are the preferable alcohols, especially npropanol and iso-propanol. The acid or alkali is added in such an amount as to make the pH of the aqueous solution strongly acidic or strongly alkaline. The concentration of the alcohol in water is normally at least 10 percent by volume and is preferably in the range 10-50 percent by volume.

Y Keratin fibres themselves are hydrophobic and if they are impregnated unevenly, the subsequent treatment is adversely affected. As the fibres should be impregnated evenly and rapidly it is desirable to replace the air surrounding the fibres quickly and completely by the impregnating liquid described above or its vapour. It is also desirable to allow the fibres to stand for a time after removal from the impregnating liquid to allow penetration of the impregnating liquor. Unless the fibres are allowed to stand for a sufficient time, they will subsequently be drafted unevenly and it will be difficult to obtain effective crimping.

The fibres treated in accordance with the invention do not have any twist and absorb the liquid much better than twisted fibres. Subsequent drying can be quickly performed, and untwisting is not required. Thus, processing becomes simplified. It is recommended to add simultaneously a small amount of thioglycollic acid,

phite or thiourea dioxide as a setting agent and formaldehyde (formalin, b.p. 96C) as a cross-linking agent for crimp waves produced in a subsequent stage.

The length and the amountof drafting are determined in accordance with the subsequent crimping are applied (grasped length) and the amount of drafting of the fibres. When drafting witha grasped length shorter than the length of the individual fibres, the tension on the fibres increases and when the grasped length is longer than the individual fibres, the amount of fibre slippage increases. When a high tension is applied, fine crimp waves are produced, and when the amount of fibre slippage is greater, so that a lesser tension is applied, large crimp waves are produced. Consequently, for obtaining optimum crimp waves, it is preferable to extend the fibres during drafting by 10 30 percent, and to apply drafting forces to the fibres at at least two points spaced apart by about the average fibre length.

When fibres are drafted and temporarily set under tension, and when after spinning the temporary set is removed to produce crimp, it is not recommended to draft highly. When highly drafted fibres are relaxed in the form of yarn, stress concentrates at points where the yarn twist is irregular and produces local hardness in the yarn. In such a case, therefore, it is preferable for the grasped length to equal the average fibre length and to draft moderately, i.e. by 20 percent.

The keratin fibres thus drafted are then set. When they are set without any applied tension, stress release rather than dimensional change is produced, but when they are set under tension, a dimensional change and not a stress release is produced. The results are opposite to each other and the setting conditions can be selected to produce the desired result.

When setting without tension (direct crimping method), fibres highly drafted by 30 percent as described above are released from tension to produce crimp waves, which can be set by steaming or boiling water, followed by drying to evaporate completely the previously absorbed liquid, When adding a setting agent, for example formaldehyde, linkages are introduced into the polypeptides to stabilize the molecular chains, and thus the crimp waves are fixed and set.

When being set under tension, (indirect crimping method) keratin fibres drafted moderately, i.e. by 5 percent as described above, can be steamed and dried under tension to evaporate the impregnating liquid and are set temporarily in the extended state. They can then be spun into yarn in a conventional manner and the fibres are relaxed when in the form of spun yarns or textile material made therefrom: that is, crimps are produced by treatment with steam, hot water or an impregnating liquid asdescn'bed above. On drying to evaporate water of an impregnating solution the molecular chains again become stabilized, and there are obtained bulky yarns or textiles.

In the wool industry, fibres are usually allowed to stand for a long time for top ageing, and this represents a problem in the field. In the indirect crimping method, the period required for top ageing can be greatly shortened to produce end products having an attractive handle. If it is only desired to speed up top ageing the amount of drafting should be selected to be just'enough to remove the natural crimp waves of the fibre, preferably less than about 10 percent. In this method, the drawing process can be performed quickly and continuously and the method is very advantageous.

The invention further provides an apparatus suitable for carrying out the method described above, which comprises means for impregnating the fibres with an aqueous solution of an alcohol, preferably containing at least 10 percent by volume of the alcohol, means for storing the impregnated fibres to allow penetration of the solution, means for drafting the fibres and means for setting and drying the fibres. The means for impregnating the fibres may be a conventional pad mangle or preferably a vacuum pad mangle. The drafting means can comprise at least two pairs of nip rollers, at least the second pair being driven at a surface speed faster than the first pair. If there are three pairs of nip rollers, the third pair can be driven at the same surface speed as the second pair, whereby drafting forces imposed on the fibres between the first and second pair of rollers are retained between the second and third pair or, alternatively, the third pair can be driven at a lower surface speed whereby the drafting forces are released and crimps form in the fibres. The apparatus can further comprise a crimping chamber, a drying chamber provided with means for forwarding the fibres, for example a pair of belts which in one position can co-operate and maintain the drafting forces on the fibres, and a cooling device.

One example of the apparatus is shown in the attached drawings and the method and the apparatus of this invention will be more particularly described hereinafter with reference to the drawings, in which:

FIG. 1 shows a preferred device for completely impregnating or wetting keratin fibres in or by an impregnating liquid.

FIG. 2 shows apparatus for carrying out the process of this invention and incorporates the device of FIG. 1.

FIG. 3 is a photographic showing of crimped Australian merino wool as set forth in Example 1.

The device A shown in the drawings may be termed a vacuum padder and is composed of rollers 1 to 6 arranged to form a hexagonal section. Two of the rollers 2 and 5 are smaller than the others. At either end of the six assembled

rollers pressure plates

7 and 8 are attached to form a closed space 9 on the inside.

Small rollers

10, 11, 12 and 13 are arranged in pairs above and below the main roller assembly.

Endless mesh belts

14 and 15 span round the rollers l, 2 and 3 and the

small rollers

10 and 12 on the left hand side and around the rollers 4, 5 and 6 and the

small rollers

11 and 13 in the right hand side of the drawing respectively. The belts introduce keratin fibres W to be processed and prevent them from winding into the rollers.

A liquid-supplying and discharging device and an exhaustion device are arranged outside the rollers. A tank 16 of an impregnating liquid, is connected with a closed tank 19 by way of a control cock l7 and a pipe 18. A flexible pipe 20 and a flexible pipe 21 are disposed between the pipe 18 and the lower part of the closed space 9 and between the closed tank 19 and the upper part of the closed space, respectively. To the root of the 'pipe 21, an exhaustion pipe 22 is attached, and is connected with a vacuum pump. A cock 23 is disposed under the closed tank 19.

In operation, an impregnating liquid is introduced into the tank 16, at which time the

cocks

17 and 23 are shut. Then the cock 17 is opened to introduce the liquid through the

pipes

18 and 20 into the lower part of the closed space 9 to fill it, as shown at 24. The liquid is also introduced to the closed tank 19. The air is exhausted from the pipe 22 to reduce the pressure in the closed space 9, which becomes saturated with vapour of the liquid. The liquid is an acidor alkali-containing aqueous solution containing lO-50 percent by volume alcohol; its pH is adjusted to L0 4.0 or 9.0 l 1.0, and 0.5 5.0 percent formalin and thioglycollic acid, monoethanolamine sulphite or bisulphite, or thiourea dioxide may be added.

Non-twisted keratin fibres W are introduced from the upper side into the closed space 9 by the two

endless mesh belts

14 and 15, and pass downwardly through the impregnating liquid 24 retained in thenip between rollers 1 and 6. The closed space 9 is kept under reducedpressure (about l00-760 mm Hg) by the pressure-reducing means described above. In the space above the liquid the air in the interstices between the fibres is quickly replaced by the vapour saturated with the impregnating liquid, and then the fibre is padded in the liquid. By this means the keratin fibres can be quickly and uniformly wetted. The fibres are passed between the rollers l and 6 to be squeezed to 50 100 percent wet pick up.

In the apparatus of FIG. 2, a U-type duct storage chamber B is positioned under the vacuum padder A, and there are further provided a drafting chamber C, a steaming chamber D, a drying chamber E and a cooler F. The drafting chamber, the steaming chamber and the drying chamber form a single assembly packed in a closed unit 26, divided by

walls

25 and 25. The keratin fibres W which have been passed through the padder A to improve their drafting properties are passed through the'storage duct B and the chambers C, D and E and finally pass over the cooler F.

The inlet arm of the U-type storage duct B is positioned under the padder, and the outlet arm is under the drafting chamber C. In the horizontal part of the duct B, two rollers 27 and.28 are provided and an endless mesh belt 29 spans them. The outer wall 30 of the duct is double, and the inside of the double wall is maintained at 20 25C by passing cooling water through

pipes

31 and 32 and is closed tightly from the ambient air.

In the drafting chamber C, the fibre bundle W passes upwardly over forwarding

rollers

33, 34 and 35, which control the applied loading tension, and then passes over

rollers

36 and 37 which are disposed horizontally. Three co-operating pairs of

grip rollers

38, 39 and 40, are arranged horizontally for drafting the fibres and their distance apart and the surface speed rate can be adjusted to any suitable value.

In the subsequent steaming chamber D, an endless mesh belt 44 passes over

rollers

41, 42 and 43 so as to forward the fibres W at the same level as that in the drafting chamber. Above the rollers, a little apart from them, an endless mesh belt 48 similarly passes over

rollers

45, 46 and 47 and the distance of the assembly from the lower roller is adjustable. In carrying out the direct crimping method, the latter belt and the rollers are positioned as shown by solid lines, and for the indirect crimping method they are lowered to the position shown by broken lines so as to maintain the tension on the fibres, and the fibres are given tension by both

endless belts

44 and 48. A plurality of small rollers are provided over which the

belts

44 and 48 pass so as to be tensioned satisfactorily. A steam jet is directed against the fibres passing over the belt 44 by means of a pipe 50 provided with many jet holes disposed adjacent to the spaces between the

rollers

41, 42 and 43. A pipe 51 is additionally positioned under the chamber through which steam can be introduced from an external source to keep the temperature in the chamber D in the range 80 125C.

, The subsequent drying chamber E is similar to the setting chamber D. In the drawing, the parts similar to those in the chamber D are shown by the same numerals with an added prime. The steam jet pipe 50 is omitted. The chamber is kept at a temperature in the range of 1l0C.

The chambersare divided by

walls

25, 25' and 26, and enclosed by the outer wall. The fibres are passed through the chambers by way of holes provided in the

walls

25, 25 and 26. In the setting chamber D and the drying chamber E, holes 52 and 53 communicating with a conventional solvent-removal device are provided in the upper parts, and ventilation holes 54, 55 and 56 and 57 are provided in the bottom of the drafting chamber, the steaming chamber and the drying chamber and the upper part of the wall between the drafting chamber and the steaming chamber.

A cooler F having a funnel-like section is positioned after the drying chamber E. It is provided with an end less belt 60 passing over

rollers

58 and 59, and the fibres W passing over the belt 60 are cooled by air drawn through the belt by a suction pipe 61, and are then introduced into a can by a pair of forwarding rollers 62.

In the indirect crimping method the treated fibres are further processed by conventional methods and pass to spinning apparatus and dyeing and finishing apparatus, and can optionally be knitted into a fabric using a conventional knitting machine. As a device for stress releasing the. fibres in yarn form there may be used a conventional hank washing machine, hank dyeing machine or a steam box. For knitted fabrics a conventional paddle dyeing machine, a Hofmann press or a winch dyeing machine can be used.

Keratin fibres can be impregnated rapidly and uniformly with an impregnating liquid in the vacuum padder A illustrated in FIG. 1 and then pass to the U-type storage duct B in FIG. 2, in which they are allowed to stand for 5 10 minutes to allow penetration of the liquid into the fibres.

The fibres are passed to the drafting chamber C by way of the

tension adjusting rollers

33, 34 and 35, and are forwarded to the pair of

grip rollers

38 and 39. The spacing of the grip rollers is adjusted, depending on the average length of fibres to be treated, and the rate of surface speed of the pair of grip rollers 39 is controlled to be 1.0 1.3 times as fast as that of the pair of rollers 38, so as to draft the fibres. The rate and the amount of drafting depend on the treating method to be employed later, as described previously. In the direct crimping method, the surface speed of the rollers 40 is adjusted to be the same as that of the rollers 38 so that the fibres are overfed by the rollers 39 and become crimped. The fibres are then forwarded to the steaming chamber D and remain for 30 60 seconds under no applied tension. A steam jet is directed from the pipe 50 against the fibres through the mesh belt 44 to evaporate the impregnating liquid and set the fibres at 80 125C. The evaporated impregnating liquid is discharged out of the exhaust hole 52 to a collector and there collected for re-use. The fibres are then introduced into the drying chamber, wherein they are dried under no applied tension for 30 60 seconds at 80 C to evaporate completely the remaining volatile impregnating liquid. Then, thefibres are forwarded to the cooler F to be cooled.

In the indirect crimping method, the endless mesh belts 48 and 48' positioned above the rollers in the steaming set chamber D and the drying chamber E are both lowered to co-operate with the lower endless belts 44 and 44', so as to maintain drafting forces on the fibres in the drafting chamber. The fibres are drafted with a small amount of drafting, usually 20 percent but more especially less than percent by adjusting each pair of rollers and the fibres remain under tension while passing through the steaming chamber D and the drying chamber E. The fibres passing through between the

endless belts

44 and 48 are contacted with steam from steam jets 50 in the steam setting chamber D for 30 60 seconds, to evaporate the volatile impregnating liquid and temporarily set the fibres at 80 125C. Then they are dried in the drying chamber E at 80 110C for 30 60 seconds, also under tension, to complete the evaporation of the volatile liquid and .this is followed by cooling by the cooler F.

The fibres can subsequently be sent to a gill and then spun into yarns on a conventional spinning machine. Yarns or textile fabrics produced from the yarns can be treated in dyeing and finishing apparatus using steam or boiling water as a medium, for 30 60 seconds in the case of yarns and for 10 minutes in the case of textile fabrics. Then, they can be dried and cooled to produce crimps and bulked spun yarns or textiles obtained having a good handle. If necessary they may be treated with the impregnating liquid described above after the above-described treatment.

The invention is further illustrated by the following Examples.

EXAMPLE 1 50% by volume 47% 3% water n-propanol formaldehyde solution (40%) The top was then squeezed to 84 percent wet pick-up by the vacuum padder and allowed to stand for 5 minutes at room temperature. It was drafted to 30 percent extension at room temperature using a grip roller spacing of 76 mm, and the tension was released at room temperature to produce crimp waves. The crimpedtop was then set by steam at 2 kg/cm pressure, while maintaining an ambient temperature of 120C, for 30 seconds without applied tension and dried with an indirect heater at 105C for 60 seconds without applied tension. The crimped fibres exhibited 7 crimps/4 cm as shown in FIG. 3. The top treated by the above crimping method was wound round a glass bar and exposed to boiling water for 10 minutes, but crimp waves still remained.

EXAMPLE 2 By the same treatment as described in Example 1, except that drafting ratios of 10 percent and 20 percent respectively were used, there were obtained crimp waves of 5 crimps/4 cm fibre and 6 crimps/4cm fibre. The crimped top was wound round a glass bar and treated in boiling water for 10 minutes, but the crimps were not removed by this treatment.

EXAMPLE 3 The same treatment as described in Example 1 was employed, except that the impregnating solution composition was as follows:

water 50% by volume n-propanol 45% by volume 86% formic acid 571 by volume pH 2.5

There were obtained 8 crimps/4 cm fibre. The crimped top was treated in boiling water for 10 minutes, and crimp waves of longer frequency, namely 4 crimps/4 cm fibre, were obtained.

EXAMPLE 4 Australian merino 50S wool top of 20 g/m, 3477 1., mean fibre length, 199.69 mm and oil content 0.60 was immersed in a solution having the following composition, squeezed to 80 percent pick-up with a mangle and allowed to stand at room temperature for 5 minutes:

water 5071 by volume n-propanol 4771 do. formaldehyde 3% do.

After the impregnated top had been allowed to stand, it was drafted to an extension of 30 percent with grip roller spacing of about 120 mm, which equalled the mean fibre length, at room temperature. The drafted top was then quickly released from drafting to produce crimp waves and was steamed with 2 kg/cm steam, in a chamber maintained by an indirect heater at 120C, for 30 seconds without applied tension to set the fibres, and was then dried at 105C for seconds without applied tension. There were obtained 7 crimps/6 cm fibre. The crimped top was wound round a glass bar and exposed to boiling water for 10 minutes, but the crimp waves were not eliminated.

EXAMPLE 5 Australian merino S top of 20 g/m mean fibre length 75.00 mm 21.14 1. and oil content 0.26, and having received an anti-shrinking treatment with 4.5 percent on the fibre weight of sodium dichloroisocyanate, was immersed in a solution of the following composition, squeezed to percent pick-up with a pad mangle and allowed to stand at room temperature for 5 minutes:

water 50% by volume n-propanol 47% by volume 86% formic acid 3% by volume pH 2.5

After being allowed to stand, the top was drafted to 20 percent extension with a grip roller spacing of 75 mm (the mean fibre length) and then relaxedquickly from drafting at room temperature to produce crimp waves. The crimp top was steamed at 3 kg/cm presure for 30 seconds and at a temperature of 125C, maintained by an indirect heater, without applied tension and dried at C for 60 seconds without applied tension. There were obtained 8 crimps/4 cm fibre. The crimped top was treated with boiling water for 10 minutes without tension, and crimp waves were not removed by this treatment.

EXAMPLE 6 Australian merino 64S top of 20 g/m, meanfibre length 75.84 mm 2122p. mean fibre diameter and oil content 0.68 was immersed in a solution of the following composition, squeezed with a mangle to 84 percent wet pick-up and allowed to stand at room temperature for minutes:

water 50% by. volume n-propanol 47% by volume 86% formic acid 3% by volume pH 2.5

After being allowed to stand, the top was drafted to percent extension at room temperature with a grip rol- EXAMPLE 7 By the same treatment as described in Example 1 was employed, except that the impregnating solution composition was as follows:

water 50 '74 by volume iso-propanol 49.9% by volume 28% ammonia 0.1% by volume pH 10.5

There were obtained 10 crimps/4 cm fibre, the crimped top was treated with boiled water for 10 minutes, and there were obtained 8 crimps/4 cm fibre.

EXAMPLE 8 By the same treament as described in Example 1 was employed, except that the impregnating solution composition was as follows:

water iso-propanol thioglycollic acid 50% by volume 47% do. 3% do.

There were obtained 8 crimps/4 cm fibre. The crimped top was treated with boiled water for 30 minutes and there were obtained 8 crimps/4 cm fibre.

EXAMPLE 9 By the same treatment as described in Example 1 was employed, except that the impregnating solution composition was as follows:

water 50 by volume iso -ypropanol 49.9 by volume 28 o ammonia 0.1 by volume o.w.f.

thiourea dioxide 3 There were obtained whiter and brighter wool composed of 10 crimps/4cm fibre. The crimped top was treated with boiled water for 30 minutes and there were obtained 10 crimps/4 cm fibre.

We claim:

1. A method of crimping protein fibres comprising the steps of: applying to said fibres an aqueous solution containing at least 10 percent by volume of an alcohol; drafting said fibres; and releasing-said drafting forces applied to said fibres whereby said fibres become crimped.

2. A method according to claim 1 including the additional steps of: setting the crimps in said crimped fibres; and drying said fibres.

3. A method according to claim 1, wherein said aqueous solution applied to said fibres additionally comprises an acid.

4. A method according to claim 3, wherein said acid has a boiling point below C.

5. A method according to claim 1, wherein said aqueous solution additionally comprises formic or acetic acid.

6. A method according to claim 1, wherein said aqueous solution applied to said fibres additionally comprises an alkali.

7. A method according to claim 1, wherein said aque ous solution additionally comprises ammonia.

8. A method according to claim 1, wherein said alcohol has a boiling point below 120C.

9. A method according to claim 1, wherein said alcohol is selected from the group consisting of n-propanol and isopropanol.

10. A method according to claim 1, wherein said alcohol is selected from the group consisting of methanol, ethanol, n-butanol and isobutanol.

11. A method according to claim 1, wherein said im- 15..A method according to claim 1, wherein said v fibres after impregnation with said solution are allowed to stand prior to drafting to allow said solution to penetrate into said fibres.

16. A method according to claim 1, wherein said fibres are drafted by applying drafting forces at at least two points spaced apart by the average fibre length.

17. A method according to claim 1, wherein said fibres are extended during drafting by about 10 30 percent. v

18. A method according to claim 1, wherein said fibres are in a form selected from the group consisting of carded slivers, tops and rovings in which said fibres are nontwisted and arranged uniformly parallel along the axis of said fibres. V

19. A method of crimping protein fibres comprising the steps of: applying to said fibres an aqueous solution.

containing at least 10 percent by volume of an alcohol; drafting said fibres; setting said fibres while maintaining drafting forces on said fibres; drying said fibres; and subsequently relaxing said fibres whereby said fibres become crimped.

20. A method according to claim 19, wherein said drafted and set fibres are formed into a yarn and said fibres in said yarn are subsequently relaxed.

21. A method according to claim 19, wherein said drafted and set fibres are formed into a yarn, said yarn is formed into a fabric, and said fibres in said fabric are subsequently relaxed.

Claims

1. A METHOD OF CRIMPING PROTEIN FIBRES COMPRISING THE STEPS OF: APPLYING TO SAID FIBERS AND AQUEOUS SOLUTION CONTAINING AT LEAST 10 PERCENT BY VOLUME OF AN ALCOHOL; DRAFTING SAID FIBERS; AND RELEASING SAID DRAFTING FORCES APPLIED TO SAID FIBERS WHEREBY SAID FIBERS BECOME CRIMPED.

4. A method according to claim 3, wherein said acid has a boiling point below 120*C.

7. A method according to claim 1, wherein said aqueous solution additionally comprises ammonia.

8. A method according to claim 1, wherein said alcohol has a boiling point below 120*C.

11. A method according to claim 1, wherein said impregnating solution additionally comprises a setting agent for said fibres.

12. A method according to claim 11, wherein said setting agent is selected from the group consisting of thioglycollic acid, monoethanolamine sulphite and bisulphite and thiourea dioxide.

13. A method according to claim 1, wherein said impregnating solution additionally comprises a cross-linking agent for said fibres.

14. A method according to claim 13, wherein said cross-linking agent comprises formaldehyde.

15. A method according to claim 1, wherein said fibres after impregnation with said solution are allowed to stand prior to drafting to allow said solution to penetrate into said fibres.

17. A method according to claim 1, wherein said fibres are extended during drafting by about 10 - 30 percent.

18. A method according to claim 1, wherein said fibres are in a form selected from the group consisting of carded slivers, tops and rovings in which said fibres are nontwisted and arranged uniformly parallel along the axis of said fibres.

19. A method of crimping protein fibres comprising the steps of: applying to said fibres an aqueous solution containing at least 10 percent by volume of an alcohol; drafting said fibres; setting said fibres while maintaining drafting forces on said fibres; drying said fibres; and subsequently relaxing said fibres whereby said fibres become crimped.