JPS59116437A - Production of regenerated cellulose fiber spun yarn excellent in dimensional stability - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a spun yarn using regenerated cellulose fibers having excellent dimensional stability and flexibility.

- More specifically, the present invention relates to a method for producing a spun yarn that improves the dimensional stability of regenerated cellulose fibers in water without substantially impairing the elongation at break or the flexibility of the fibers.

Regenerated cellulose fiber-reduced fibers have the characteristics of excellent hygroscopicity, low static electricity generation, and easy removal of stains, but on the other hand, they have the disadvantage that they have poor dimensional stability against water and shrink significantly when washed at home. Conventionally, it has been difficult to overcome this drawback and obtain a spun yarn made of regenerated cellulose monofilament with excellent dimensional stability.

The present inventors have conducted extensive studies on a method for producing regenerated cellulose 4-fiber spun yarn that completely eliminates these drawbacks and has excellent dimensional stability against water.

- For example, caustic alkali treatment such as mercerization and mercerization of spun yarn of regenerated cellulose fibers,
Treatment with liquid ammonia was simply carried out, but although both showed an effect on dimensional stability against water, the effect was inferior to that of treatment with filament yarn or fabric1)
, and also has the defect that flexibility is significantly impaired.

The present inventors further focused on the correlation between the form of the spun yarn and the mechanism of action of liquid ammonia, and as a result of detailed study, they arrived at the present invention.

That is, the present invention provides regenerated cellulose 1. After treating the R fiber bundle with liquid ammonia, it is opened and spun.The present invention will be specifically described below.

The regenerated cellulose fiber bundles used in the production method of the present invention include viscose process rayon (including polynosic rayon) and 6N ammonia process rayon. The fiber bundle of the present invention refers to a wire, a sliver consisting of one finite length fiber bundle, and a fiber bundle tow consisting of continuous filaments. In addition, it is substantially regenerated cellulose; it does not matter at all that other types of fibers may be mixed within the limits that do not impair the characteristics of the fibers. In addition to being used in conjunction with regenerated cellulose fiber bundles, the permissible limits for 7'lf A & Fibers are both ``''' (generally 50% based on the total weight of the 7's)
% by weight or more.

The liquid ammonia used in the method of the present invention may be diluted with other substances in an amount that does not substantially impair the action of liquid ammonia on regenerated cellulose and fibers. Acceptable concentrations of liquid ammonia are generally greater than 50% by weight, preferably greater than 60 weight - 1 inch.

In the method of the present invention, prior to the liquid ammonia treatment, preferably, the surface of the regenerated cellulose/fiber is treated with a liquid that is sparingly soluble in liquid ammonia and that can be adsorbed to the regenerated cellulose fibers, or a liquid that is sparingly soluble in liquid ammonia and has a film-forming ability. It is effective to prevent single filament adhesions by applying a material that absorbs the fibers and then impregnating the regenerated cellulose fibers with liquid ammonia. Poorly soluble in liquid ammonia,
In addition, the liquid that can be adsorbed to regenerated cellulose fibers is 11
(a) Aliphatic and aromatic hydrocarbons, oils and fats, surfactants, and the like, and among these, those that are liquid at room temperature are preferred. Here, "Th and IG soluble in liquid ammonia" means that the material exhibits a solubility of 107 or less in 100 parts of liquid ammonia at a temperature of -50°C. Furthermore, the liquid that can be adsorbed to the regenerated cellulose fibers means a liquid that is formed by the liquid and the regenerated cellulose fibers and has a contact angle of 110° or less. The amount of the liquid attached is preferably in the range of 0.2 to 15% by weight based on the absolute dry weight of the fibers (hereinafter simply referred to as fiber weight). If it is less than 0.2% by weight, adhesion on the surface of the single fibers may not be sufficiently prevented. Another 15% by weight? : If it exceeds, the impregnation of the liquid ammonia into the fibers may be hindered by the deposits, and there is a risk that a sufficient modification effect may not be obtained.

Substances with film-forming ability include molecular substances with a molecular weight of 10,000 or more. If the molecular weight is less than 10,000, it is difficult to form a sufficient film. The amount of the substance having film-forming ability attached to the fibers is preferably in the range of 0.2 to 10% by weight based on the weight of the fibers. If it is less than 0.2% by weight, it may not be possible to sufficiently prevent adhesion of the surfaces of 1. single fibers. If the amount exceeds 10% by weight, the deposits may prevent liquid ammonia from impregnating one fiber, and a sufficient modification effect may not be obtained.

In the present invention, regenerated cellulose and fiber bundles are treated with liquid ammonia, but it is preferable to add water to the fibers before treatment.
It is preferable to adjust it to 12 inches or more, preferably 12 inches or more. If the temperature is less than 5 inches, it will take a long time for the treatment effect of liquid ammonia to fully develop, so it is difficult to
]There is a problem. Regenerated cellulose ifj, iF! Methods for adding moisture to the bundle include placing one fiber bundle in an atmosphere that maintains a certain amount of moisture in the fibers, spraying water on one fiber bundle, and ','lf4 fiber bundle. A method of coating the fiber bundle with water, a method of dipping the fiber bundle in a bath containing water, or 1
After the above method, there is a method in which a portion of the water is removed from the entire fiber bundle to keep the water content in the fiber bundle constant, but any method may be used.

If the deposits added to the surface of the single fibers for the purpose of preventing deposits have an adverse effect on the spinnability, it is desirable to remove them before spinning.

In the method of the present invention, the time period during which the abrasive fibers are completely impregnated with liquid ammonia is 1 second or more, preferably 2 seconds or more. impregnating fibers? i. The temperature of body ammonia is normally preferably in the range of -77°C to -33.4°C under approximately 1 atm, but if it is less than 1 atm or exceeds 1 atm, the freezing point to boiling point of liquid ammonia under that atmospheric pressure. It is fine as long as it is within the range of .

To remove ammonia from the fibers impregnated into regenerated cellulose fibers, it is desirable to heat the ammonia above the boiling point of liquid ammonia. Even below the boiling point, liquid ammonia gradually vaporizes and disperses from the fibers, but having the temperature above the boiling point makes removal easier and more reliable.

Normally, the boiling point of liquid ammonia under 1 atmosphere is -33.4℃
However, when the pressure is less than 1 atm or above 1 atm, it is desirable to maintain the fiber at a temperature equal to or higher than the boiling point depending on the atmospheric pressure.

In addition, if you want to avoid yellowing and crinkling, it is preferable that the temperature does not exceed 200°C, as the fibers may be heated to a higher temperature, causing yellowing due to separation. It should be changed and also depends on the type of fiber. Furthermore, it varies depending on the heating method. Heating methods include a method using a hot air heating device, a drum heating method (a typical example of contact heating), a method in which fibers impregnated with liquid ammonia are immersed in a liquid substance and heated, a method in which the fibers are heated with a hot wire, and a method using microwaves. There are heating methods, but any method may be used as long as it does not impede the effects of the present invention. Since the heating time varies depending on the heating method, heating temperature, and amount of heated fibers, it is not possible to set a specific range. In short, it is sufficient that the time is longer than the time required to remove ammonia from the fibers.

In the present invention, it is preferable to elongate the regenerated cellulose of the tow in a state in which liquid ammonia is applied to one fiber bundle, and then remove ammonia in the elongated state.

Here, the state of being impregnated with liquid ammonia means that 50 g or more of liquid ammonia has adhered to the absolute dry weight of the regenerated cellulose fiber bundle, and preferably, the state of being impregnated with liquid ammonia for 0.5 seconds or more is sufficient for the ladle. This refers to the state in which cellulose fiber bundles are plasticized.

In the present invention, tow is 1% impregnated with liquid ammonia.
It is preferable to extend the length by more than 100%. Although the elongation rate can be up to the breaking elongation of the fiber, it is preferably in the range of 1 to 15 inches since there is a risk that the breaking elongation will decrease.

In this way, ammonia is removed from the regenerated cellulose fiber bundle that has been stretched while immersed in liquid ammonia, and the dimensions of the regenerated cellulose, T, IF fiber after ammonia removal are the original size. It is preferable that the elongation is 1 inch or more, preferably 1 to 10%. I
If it is less than S, it is difficult to obtain sufficient dimensional stability, and if the degree of elongation is too large, the cutting elongation may decrease, which is not preferable. You can remove the ammonia once and then maintain the elongation rate with liquid ammonia added, or you can relax it to a range of 10c6 or less depending on the elongation rate without impairing the elongation effect. However, new elongation increases the internal structural strain of the fibers and impedes the purpose of the present invention, which is not preferable.

A feature of the present invention is that in the above-mentioned treatment method, the regenerated cellulose fiber bundle is impregnated with liquid ammonia before and after impregnation, and after that, a certain amount of liquid ammonia remains in the fibers or is removed between the single fibers. A phase difference is generated to prevent or release mutual adhesion of the surface layer portions of single fibers. A state in which a certain amount of liquid ammonia remains in the fiber means less than 40% by weight based on the absolute dry weight of the regenerated cellulose fiber, and a state in which it is removed means 0% by weight. Preferably, the regenerated cellulose fibers are opened by creating a phase difference between the single fibers when the amount of liquid ammonia in the regenerated cellulose fibers is less than 30% by weight based on the absolute dry weight of the fibers.

The opening method for creating a phase difference between the single yarns of a regenerated cellulose fiber bundle includes the fiber bundle length direction, bias direction,
Oil is required to create a phase difference between single yarns in either the warp direction or by combining two or more of these methods, and these methods include combing with a needle (karting method), compressed air, A method using a flow, a method using a compressed liquid flow, a method of imparting a kneading effect in such a fluid, a method of causing shear deformation using equipment with one or more nip points, and methods of Method 2
In both continuous and discontinuous treatment methods in which two or more fibers are combined, the fiber bundle spreadability is significantly improved.

The present inventors have found that among these many methods, the following method is particularly preferable as an extremely effective and practical method.

A more preferable method for opening fibers when the fiber bundle is cotton-like is as follows:
Cotton treated with liquid ammonia is put into an aqueous solution and swollen, and a physical kneading effect is applied to create a phase difference between the single yarns. The aqueous solution used at this time may be 100% water, or it may be an aqueous solution containing other components as long as the treatment effect of liquid ammonia is not impaired. Further, the temperature of the aqueous solution may be within the range of freezing point to boiling point under the atmospheric pressure. As a method for imparting a physical kneading effect, cotton is continuously or discontinuously moved or rubbed in an aqueous solution. Alternatively, there is a method in which an aqueous solution is caused to flow continuously or discontinuously, and the force generated by the flow impacts the cotton. In this case, 6. If the moving speed of the cotton, the liquid flow speed, the moving speed, the liquid flow speed, the moving direction of the cotton, and the contact angle of the fluid are determined in a manner that imparts a kneading effect without impairing the processing effect of liquid ammonia, Either method may be used. Since the kneading time varies depending on the kneading method, the temperature of the aqueous solution, the components of the aqueous solution, and the amount of fiber, a specific range cannot be defined, but it may be set arbitrarily by the person concerned. It is preferable to dry the cotton, which has been given a kneading effect in aqueous solution, in a relaxed state, since this further improves the opening properties. After performing the above-mentioned kneading step 1, the cotton is placed on a flexible sheet-like material, and a metal roller,
Pass it between rubber rollers to apply pressure and create a draft.
Further, it is preferable to rotate the upper and lower rollers in the opposite direction and further knead the cotton, since this can give the cotton even more spreadability. The cotton thus opened can be easily produced into spun yarn by a commonly used spinning method.

In addition, for slivers of finite fiber bundles, metal rollers,
There are methods such as passing the sliver between rubber rollers to apply pressure and creating a draft, or rolling the sliver by rotating the upper and lower rollers in the opposite direction. Further, it is preferable to knead these in combination because this further improves the opening properties. Note that the draft rate is preferably set in a range of 1.5 times to 5 times. The sliver opened in this manner can be easily used to produce spun yarn by a commonly used spinning method.

In the case of a fiber bundle tow consisting of continuous filaments, the tow is treated with liquid ammonia and then put into an aqueous solution to swell and give a physical kneading effect to create a phase difference between the single yarns. . The aqueous solution used at this time is 100% water and has a concentration of 45%.
Alternatively, an aqueous solution containing other components may be used as long as the performance of the modified regenerated cellulose fibers is not essentially impaired. Further, the temperature of the aqueous solution may be within the range of freezing point to boiling point under the atmospheric pressure. As a method for imparting a physical kneading effect, the tow is moved continuously or discontinuously in an aqueous solution. There is also a method in which an aqueous solution is caused to flow continuously or discontinuously, and the force generated by the flow causes an impact on the tow.

At this time, the moving speed of the tow, the liquid flow rate, the moving direction of the tow, and the contact angle of the fluid can be determined in a manner that provides a kneading effect without essentially impairing the performance of the modified regenerated cellulose tow. Any method is fine.

The time for kneading varies depending on the kneading method, the temperature of the aqueous solution, the components of the aqueous solution, and the amount of fibers, so a specific range cannot be defined, but it may be set arbitrarily by the person concerned. By drying the tow, which has been given a kneading effect in an aqueous solution, in a relaxed state, a modified regenerated cellulose fiber tow with even better spreadability can be obtained. A spun yarn can be easily produced from the tow by a general spinning method.

- In order to further improve the opening properties, it is preferable to add 2
By applying a draft to the tow using equipment capable of creating two or more nip points to generate shearing force between the single fibers, the spreadability is dramatically improved.

It is preferable to set the draft at this time in the range of 1.5 times to 10 times.

Further, it is preferable to carry out the above-mentioned method of applying a rubbing effect in an aqueous solution and then drying and opening the fibers by applying a draft, since this further improves the opening property.

The spun yarn of regenerated cellulose fiber obtained by the present invention is flexible and has extremely excellent dimensional stability against water.

Further, the snake-spun yarn obtained by the present invention or the fabric using this spun yarn may be subjected to post-processing (
For example, it is completely free to carry out the usual post-processing known as resin processing, texture processing such as softening processing, etc. The effects of the present invention are not impaired by post-processing,
Furthermore, the present invention does not impair the effects of post-processing.

The present invention will be explained in more detail with reference to examples below, but the present invention is not limited to the following examples.

In the present invention, before measuring the various physical properties of the fiber, the temperature is set at 20°C.
The sample was left in an atmosphere with a relative humidity of 65 degrees for 48 hours or more to adjust the humidity and use it as a test sample.

Swelling degree: The swelling degree was expressed by the following formula.

(B-A)/Axtoo=swelling degree (%) A: Absolute dry weight of the test sample B: The test sample was immersed in water at room temperature for 30 minutes, and then
Using a centrifugal separator with a diameter of 23 saws, the rotation speed was 350 Or,
Weight of the fiber after dehydration was carried out for 5 minutes to remove water adhering to the surface of the fiber.Dimensional stability with respect to water.Dimensional stability with respect to water was evaluated using the following formula.

IA-Bl-Dimensional stability against water (Feed A: Wet shrinkage rate (CH)) In an atmosphere of a temperature of 20°C and a relative humidity of 65°C, the end of a spun yarn of 70 crn is Apply a load and make a mark at 10 crn and 60 cm from the end 1. Next, remove the initial load from this sample and immerse the spun yarn in water at room temperature for 30 minutes. Next, remove the wet spun yarn from the water. Take it out, apply the initial load mentioned above,
Measure the length between the marks and call it a. Calculate the wet shrinkage rate using the following formula.

A (%) = 2X (50-a) However, a is expressed in centimeters.

B: After completing the measurement of shrinkage rate A during drying, the initial load was removed and the temperature was 20°C.
, in an atmosphere with a relative humidity of 65 degrees K. After being left for 24 hours, the initial load was applied again, and the length between the marks was measured, and this was determined as b. Increase the drying shrinkage rate using the following formula.

B (%) = 2 (+ to 50-) However, b is expressed in centimeters.

Washing liquid shrinkage rate: Calculated based on the method of JIS T-0217,103.

Example 1 A mixed solution of higher alcohol sulfated oil, dialkyl methyl betaine, fatty acid monoglyceride, and resin acid was used as a liquid that is soluble in liquid ammonia Km and that can be adsorbed to regenerated cellulose fibers. A 70,000 d/28,000 f viscose rayon filament yarn was used. It was attached to the tow by a dipping method. It was dried in a hot air dryer at 100°C for 10 minutes.

The amount of adhesion was i, s% based on the weight of the fiber.

゛Then, this sample was heated to 20°C and 65% relative humidity for 24 hours.
Leave it for a while, adjust the humidity, and the moisture content is 12% based on the absolute dry weight.
Met. Next, the fiber tow was immersed in a liquid ammonia treatment bath at -36°C for 30 seconds.

The fiber tow was then dried with hot air at 120° C. for 3 minutes to remove ammonia. Next, the fiber tow was opened by the following methods (1) to (3).

Spreading method (1): The fiber tow is passed between a pair of metal rollers with an uneven pattern on the surface, and pressure is applied between the metal rollers to nip the tow, and then the metal rollers are rotated in different directions to continuously spread the fiber tow. The tow was opened on a regular basis.

Spreading method (2): The fiber tow is put into a wince dyeing machine containing warm water at 80°C, and the tow □ retained in the warm water is continuously moved by the rotation of the wince dyeing machine's reel and opened. Drying was performed.

Opening method (3): After performing the process of opening method (2) 3
The tow was passed between a pair of rubber rolls and nipped, and the tow was opened continuously while changing the surface speed between each nip roller to create a draft of 6 times.

A 41/- spun yarn obtained by spinning the tow opened by such a method by a tension cutting method was used as a test sample. Comparative example (
As for 1), the tow that was not subjected to the ammonia treatment during the above method was spun to obtain a spun yarn.

As a comparative example (2), viscose rayon spun yarn 40
A liquid that can be adsorbed on the regenerated cellulose fibers similar to those mentioned above was applied to /-, dried, and then immersed in a liquid ammonia treatment tank at -36°C for 30 seconds, and then heated with hot air at 120°C for 30 seconds.
The ammonia was removed by drying for a minute. As Comparative Example (3), a rubbing effect was imparted to the spun yarn of Comparative Example (2) by the opening method (2).

Table 1 Furthermore, using the samples in Table 1 and using a 26GG circular knitting machine, the same
The smooth fabric of the part was knitted. After allowing this fabric to naturally shrink for 72 hours, normal fW kneading and dyeing were performed under the same conditions.
After one piece was finished, the same part was finished using a pin tenter and a sandpaper. Next, the washing shrinkage rate was determined by the method of JIS L-0217,103, and the results are shown in Table 2.

Table 2 Table 19 Table 2 shows that the spun yarn obtained by treating regenerated cellulose fiber tow with liquid ammonia and then opening the bottle does not substantially impair elongation at break and has excellent dimensional stability against water. I understand that Further, the washing shrinkage rate of the fabric using the spun yarn according to the present invention can be greatly improved.

Example 2 Liquids that are sparingly soluble in liquid ammonia and adsorbable to regenerated cellulose fibers include primary alcohol sulfated oil, dialkylmethyl betaine, 11-fatty monoglyceride, and a mixed group of fatty acids of 66,000 d and 15,000 f of copper. It was attached to a tow made of ammonia-method rayon filament by a dipping method. It was dried in a hot air dryer at 100° C. for 10 minutes to adhere the above compound to the surface of the regenerated cellulose fibers. The entire sample was left at 20°C and a relative humidity of 70°C, and the humidity was controlled for 24 hours. The moisture content was 13% based on the bone dry weight. Next, the fiber tow was immersed in a liquid ammonia bath at -36°C for 30 seconds.
It was dried with hot air at 0° C. for 3 minutes to remove ammonia.

Next, the fiber tow was opened by the following methods (1) to (3).

Spreading method (1) The fiber tow is placed between a pair of metal rollers having an uneven pattern on the two surfaces. : The tow was nipped by applying pressure between all the culm rollers, and then the metal rollers were rotated in mutually different directions to continuously open the tow.

Spreading method (2): Put the 1-fiber tow into a wince dyeing machine containing warm water at s o ℃, and spread the tow by continuously moving the tow retained in the warm water by rotating the reel of the wince dyeing machine. After that, it was dried.

Spreading method (3): After performing the processing of fiber opening method (2), the tow is nipped between 3 pairs of rubber rolls at j%, and the surface speed between each nip roller is changed to create a 6x draft. Continuous total hearing was achieved in this state.

A 40/- spun 'gli' yarn obtained by spinning the tow opened by this method by the tension cutting method was used as a sample. As Comparative Example (1), a tow that was not subjected to liquid ammonia treatment in the above method was spun to obtain a spun yarn.

As a comparative example (2), viscose rayon spun yarn 40
/- was coated with regenerated cellulose 7 similar to the above, with a liquid that can be adsorbed on the fibers, dried, immersed in a liquid ammonia treatment tank at -36°C for 30 seconds, and then dried with hot air at 120°C for 3 minutes. Ammonia was removed.

As Comparative Example (3), a rubbing effect was imparted to the spun silk yarn of Comparative Example (2) by the opening method (2).

Table 3 Furthermore, using the samples shown in Table 3, smooth fabrics were knitted in the same amount using a 260G circular knitting machine. After allowing this fabric to naturally shrink for 72 hours, it was scoured and dyed in the same way as usual, and then finished using a pin tenter dryer (2018) to the same amount of pouring. Next, the washing shrinkage rate was determined by the method of JIST-0217,103.

The results are shown in Table 4.

Table 4 Table 31 According to Table 4, the spun yarn obtained by treating regenerated cellulose carbon fiber tow with liquid ammonia and then opening the fibers was as follows:
It can be seen that it has excellent dimensional stability against water without substantially impairing cutting elongation. Furthermore, the washing shrinkage rate of the fabric using the spun yarn according to the present invention is also greatly improved.

Example 3 Is high-grade sulfated oil a liquid that is poorly soluble in liquid ammonia and can be adsorbed to regenerated cellulose fibers? .

Tun thread 2. It was attached to viscose cotton with a fiber length of 5 by a dipping method and dried with hot air at 100° C. for 10 minutes. The amount of adhesion was 2 cm based on the weight of the fiber. Then, connect this line to 20°C and 65° relative humidity.
Humidity was controlled for 4 hours. The moisture content is 'C1 based on the absolute dry weight of the fiber.
It was 3 chi. Next, the ridge was immersed in a liquid ammonia treatment tank at -36°C for 30 seconds. The cotton was then dried with hot air at 120° C. for 3 minutes to remove ammonia from the cotton. Next, the ridges were opened using the following two methods.

Opening method (1): Place the ridges in a cylindrical bath containing warm water at 80°C, and stir using a stirrer at 10 Or, p-m for 30
A kneading effect was given in water by stirring for a minute. I'm here.

The bath ratio (sample weight/water weight) was 1150.

Next, 21% of a softener (mainly composed of polyoxyethylene, molecular weight approximately 5,000) was added to the bath and soaked for 10 minutes, then dehydrated and dried.

Spreading method (2): After kneading in water and applying a softener in the bath as in the opening method (1), the cotton is spread on a cotton mesh having a total thickness of 0.2 apm at a density of about 50 t/rl. ride 10
It was dried at 0°C for 5 minutes. The sample was passed between a pair of metal rollers having a concavo-convex pattern on the surface.
A pressure of Kt)/ca was applied and the rollers were rotated in different directions to open the fibers.

The cotton opened in this way is passed through a cotton blending machine, a roughing machine, a finishing cotton spinning machine, a Cord filament machine, a first spinning machine, and a fine spinning machine using a normal cotton spinning method. /- spun yarn was obtained. As a comparative example, a spun yarn spun using the trench method described in (1) and (2) above without using the opening method was used. In the same manner as in Example 1, a smooth fabric was knitted using this spun yarn (1), and the shrinkage rate after washing was measured. The results are shown in Tables 5 and 6.

According to Tables 5 and 6, the present invention (fi5Na1.m2. Table s
After treatment with liquid ammonia, the resulting spun yarn has very good dimensional stability against water, and the washing shrinkage rate of silk fabric braided using the spun yarn is very low. is also extremely small.

Table 5 Table 6 Example 4 High sulfated oil was used as a liquid that was poorly soluble in liquid ammonib and adsorbable to regenerated cellulose fibers.

Spray method on copper ammonia rayon sliver of 1.3 d single yarn): Adhered at a ratio of 2.0 to the weight of the fiber, 1
It was dried for 5 minutes in a hot air dryer at 00°C. Next, the sliver was left at 20° C. and a relative humidity of 80° C. for 12 hours to condition the humidity. The moisture content was 15 inches based on the bone dry weight of the fibers. Next, the sliver was immersed in a liquid ammonia treatment tank at -36°C for 30 seconds. Next, the sliver was pulled out of liquid ammonia and dried with hot air at 120° C. for 3 minutes to remove ammonia from the sliver. In addition, in 71'f, body ammonia immersion (during 1), the surface speed of the pair of mangles before and after the immersion tank was changed to maintain the dimensions before immersion in liquid ammonia (hereinafter referred to as the original size). When removing it, I did not stretch or relax it so that the original size could be maintained.Next.

The sliver was fully opened using the following two methods.

Opening method (1): The sliver was opened continuously according to the opening method (1) of Example 1. The pressure between the rollers was 5 cm/cni.

Opening method (2): The sliver f, 1 IT, 1 L was nipped between three pairs of rubber rolls, and the sliver was fully opened continuously while changing the surface speed between the nip rollers and applying a draft of 4 times.

The sliver obtained by the above method was subjected to ordinary spinning to obtain a filament-like, front-spun, all-through yarn of 40/-. As a comparative example, spun yarns spun in the same manner as in (1) and (2) above without using the opening method were used. In the same manner as in Example 1, a smooth fabric was knitted using this spun knit 1 yarn, and the washing shrinkage rate was measured.

The results are shown in Tables 7 and 8. According to Tables 7 and 8,
The spun yarn of the present invention (Table 7, Table 1, Table 8, Figure 22, Table 8, + m1, m2) was opened after being treated with ammonia, and was found to have very good dimensional stability against water.

The washing shrinkage rate of the knitted fabric made using the spun yarn is also extremely small. Margin table below 7 Table 8

Claims (1)

[Claims] A method for producing regenerated cellulose fiber spun yarn with excellent dimensional stability, which comprises treating regenerated cellulose fiber bundles with liquid ammonia, then opening and spinning them.