JPH01314740A - Twisted bulky yarn and production thereof - Google Patents

Abstract

PURPOSE:To provide the subject bulky yarn having soft touch and bulkiness and easily permitting the design based on a shrinkage by drawing and false-twisting a highly oriented non-drawn yarn having a specific birefringence, etc., at a temperature of <= the glass transition point thereof and subsequently again treating the drawn and false-twisted yarn at a temperature of >= the glass transition point thereof. CONSTITUTION:A highly oriented undrawn yarn or imperfectly drawn yarn having a birefringence n of 0.02-0.12 is subjected to a substantially uniform drawing and false-twisting process at a temperature of <= the glass transition point thereof and subsequently again treated at a temperature of >= the glass transition point to provide the objective bulky yarn having a shrinking degree of 0.1-80% on the rapid heat treatment thereof in boiling water, a remaining torque twisting number of <=2 turns/50cm and substantially not containing any processed deformation shape in the cross-sectional shapes of the constituting single filaments. It is preferable that the cross-sectional deformation degree of a constituting single fiber defined by the formula (r1 is the inscribed circle diameter of the single fiber cross section of a raw fiber before the twisting procession; r2 is the inscribed circle diameter of the single fiber cross section of a bulky fiber after the twisting procession) is <=10%.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a crimped bulky yarn whose shrinkage rate level can be easily designed and a method for manufacturing the same.

[Prior art]

In high-level processing of fibers, for example, to prevent puckering in interwoven fabrics, to design the pile length of cut-pile warp knitted fabrics, or to use as core or sheath yarns in differential shrinkage mixed yarns, etc. Yarns with different shrinkage rates are used.

However, the shrinkage rate of the raw yarn manufactured by the yarn manufacturer is determined at the manufacturing stage, so in order to use yarns with different shrinkage rates in higher-order processing as described above, it is necessary to The shrinkage rate of the yarn will have to be readjusted.

For example, in order to obtain a yarn with low shrinkage, the raw yarn must be subjected to a reheat setting treatment. However, such shrinkage rate adjustment processing may reduce the strength and elongation characteristics of the yarn, or
At the same time, there were problems such as changes in texture and gloss.

In addition, in order to obtain a yarn with high shrinkage, some polyesters are made into a copolymer to have high shrinkage at the stage of raw yarn. However, this polyester copolymer has problems such as staining during the dyeing process and decreased dye fastness. In addition, since the highly shrinkable yarn of this polyester copolymer is raw silk (Namaito), in other words, it is not processed yarn, it does not have crimps, so it has a hard texture and a slimy feel, and is also bulky. It had the disadvantage of being low.

These problems of sliminess and bulk can be solved by using crimped yarn, but conventional crimped yarn has poor processability, gets caught in guides, etc., and reduces productivity. Otherwise, problems such as sink marks tend to occur when the fabric is made into a fabric due to the generation of abnormal tension.

[Problem to be solved by the invention]

In view of the above-mentioned conventional problems, the object of the present invention is to easily improve the shrinkage rate to a desired level in a wide range from low shrinkage to high shrinkage, and to provide soft wind resistance by providing weak crimpability. To provide a crimped bulky yarn capable of imparting a high gloss with a luxurious feel and without causing staining of dyeing or deterioration of color fastness unlike copolymer yarns, and a method for producing the same. It is in.

[Means to solve the problem]

The crimped bulky yarn of the present invention that achieves the above-mentioned objects has a shrinkage rate of 0°1 to 80% when subjected to rapid heat treatment in boiling water, a residual torque twist number of 2 twists of 150 cm or less, and a cross section of the constituent single fibers. It is characterized by having substantially no processing deformation in its shape.

In addition, the method for manufacturing such a crimped bulky yarn has a birefringence Δn
Highly oriented undrawn yarn or incompletely drawn yarn with a range of 0.02 to 0.12 is subjected to substantially uniform stretching and false twisting at a temperature below the glass transition point, and then It is characterized by being subjected to reheat treatment.

As the material for the crimped bulky yarn of the present invention, thermoplastic polymers such as polyethylene terephthalate, polybutylene terephthalate, and nylon are preferably used. In particular, polyethylene terephthalate, whose glass transition temperature is higher than room temperature, is optimal from the viewpoint of obtaining a high shrinkage rate. Further, the cross-sectional shape of the single fibers constituting the crimped bulky yarn may be circular or irregularly shaped such as a triangle, but irregularly shaped cross sections are particularly preferably used.

In the present invention, the shrinkage rate due to rapid heat treatment in boiling water refers to the shrinkage rate based on the shrinkage that occurs when the thread is instantaneously inserted into boiling water, and the temperature is gradually increased by exposing it to steam etc. before inserting it into boiling water. Excludes cases where processing is required. The shrinkage rate when it is placed in boiling water while gradually increasing the temperature in this way is about 1/2 to 173 of the shrinkage rate when it is inserted instantly.

The crimped bulky yarn of the present invention has a shrinkage rate ranging from 0.1 to 80% when subjected to rapid heat treatment in boiling water, and
This makes it extremely easy to design the shrinkage rate. That is, according to the crimped bulky yarn of the present invention, a low shrinkage of 3% or less, which was extremely difficult to achieve with conventional techniques, and a shrinkage of 20%, which could only be achieved with copolymer yarns. It also enables high shrinkage of up to 80%.

Further, the crimps of the crimped bulky yarn of the present invention are weak crimps,
Although it is a false twisted yarn, it has an extremely low residual torque twist count. In the case of ordinary false twisted yarn, the residual torque twist number is, for example, in the case of polyester fiber, 30 twists of 150 cm or more at 75 denier, but in the case of the crimped bulky yarn of the present invention, it is 2 twists of 150 cm or less, A major feature is that it has almost no residual torque.

In addition, in this specification, the residual torque twist number refers to the number of twists when a small load of 2 mg/D is hooked to the center of 1 meter of the test yarn, and the yarn ends are aligned, folded in half, and suspended. The number of times the small load rotates is considered as the residual torque twist number.

Figure 1 shows a model of the yarn form of the crimped bulky yarn of the present invention, whereas Figure 2 shows a model of the yarn form of a conventional false twisted yarn. be.

The crimped bulky yarn Y (Fig. 1) of the present invention has a weakly crimped form with gentle undulations, and this form hardly changes even after being stretched and false-twisted before being reheated. do not have. On the other hand, the conventional false-twisted crimped yarn Y' (FIG. 2) has a crimped form with a large number of characteristic snarls S produced by the false-twisting process on its surface. The crimped bulky yarn Y of the present invention is characterized in that it does not have such snarls S that are unique to false twisted yarns.

By having such weak crimp, the crimped bulky yarn of the present invention has a soft feel and is imparted with bulkiness. In particular, in applications such as thin fabrics using raw silk, its soft texture and bulking effect become noticeable. In addition, since there is almost no residual torque twist, there is no twisting such as snarl even though it is a false twisted yarn, and the yarn handling properties are very good. That is, process passability is improved, tension fluctuations when passing through guides, etc. are reduced, and operability is improved.

Furthermore, the present invention is characterized in that the cross-sectional shape of the single fibers constituting the crimped bulky yarn has substantially no processing deformation. In other words, the raw silk of the original yarn undergoes almost no cross-sectional deformation due to the false twisting process, and even if there is deformation, the cross-sectional deformation is extremely small. More specifically, the cross-sectional deformation rate of a single fiber defined by the following formula is 10
% or less.

I However, rl: Radius of the inscribed circle of the single fiber cross section of the raw silk before crimping r2: Radius of the inscribed circle of the single fiber cross section of the bulky yarn after crimping If the false twisted yarn is false twisted from normal drawn yarn. The above-mentioned cross-sectional deformation rate is over 15%, and in the case of false-twisted yarn produced by drawing and false-twisting high-speed spun yarn (highly oriented undrawn yarn) called POY, it is over 18%. Considering these, it can be seen that the cross-sectional deformation rate of the crimped bulky yarn of the present invention is extremely small.

As mentioned above, crimped bulky yarn made of single fibers with almost no cross-sectional deformation due to processing maintains the luster of raw silk, so it can exhibit a high gloss with a luxurious feel. can. In particular, when the constituent single fibers are made of threads with irregular cross-sections, such as triangular cross-sections, the luster effect becomes even more remarkable.

That is, in the crimped bulky yarn of the present invention, even if the cross-sectional deformation rate is close to the upper limit of 10% immediately after false twisting,
When subjected to heat treatment such as dyeing, the cross-sectional shape of raw silk is restored to near its original shape, and in products such as textiles, the phenomenon is observed where the cross-sectional shape is reduced to less than 5%. Therefore, it exhibits extremely high gloss.

The crimped bulky yarn of the present invention described above has a birefringence Δn of 0.02.
~0.12 by subjecting a raw yarn made of a thermoplastic polymer to substantially uniform stretching and false twisting at a temperature below the glass transition point, and then reheating it at a temperature above the glass transition point. Obtainable.

Raw yarns with birefringence Δn in the range of 0.02 to 0.12 include highly oriented undrawn yarns (POY) obtained by ultra-high speed spinning and incompletely drawn yarns obtained by stretching undrawn yarns at a low ratio. This applies and is preferably used. Especially highly oriented undrawn yarn (P
OY) is preferred.

The stretch false-twisting process carried out in the present invention may be a sheet-twisting process during stretching, in which the false-twisting process of heating--heat setting below the glass transition point--untwisting is performed simultaneously while stretching--or, alternatively, the false-twisting process is performed at the same time as the stretching process - heat setting below the glass transition point - untwisting process. Once stretched, the sheet may be stretched and then subjected to a false twisting process of heating, heat setting below the glass transition point, and untwisting. However, in view of the uniformity of the obtained yarn quality and yarn processability, the former method of drawing and twisting is preferable in the present invention.

In the stretch false twisting process of the present invention, the heat set temperature must be below the glass transition point. If this temperature is higher than the glass transition point, the shrinkage after false twisting will decrease significantly and the residual torque will increase, making it impossible to obtain the crimped bulky yarn of the present invention as described above.

The number of false twists in this stretch false twisting process is not particularly limited, but is generally used in the range of 1500 to 5000.
A range of times/m is preferred.

Further, the false twisting speed is preferably 100 to 900 m/min.

Further, the stretching is performed substantially uniformly.

Since there is a problem that cold drawing at a temperature below the glass transition point tends to cause the yarn to become uneven, it is necessary to draw the yarn so that it is uniform in the length direction and uniformly among the constituent single fibers.

In order to achieve such uniform stretching, it is preferable to set the stretching ratio relatively high, and more specifically, it is preferable to stretch at a natural stretching ratio or higher.

The higher the draw ratio, the higher the shrinkage rate of the yarn after false twisting. For example, highly oriented undrawn polyethylene terephthalate yarn (PO
Y,) can be made into a highly shrinkable bulky yarn with residual elongation of 35 to 36% and shrinkage rate of 65% by stretching at 1.8 to 1.9 times.

In the present invention, the reheat treatment performed after the false twisting process is very important. The temperature must be above the glass transition point, but the upper limit should be the melting point. Also,
This reheat treatment is preferably carried out under relaxed conditions, with a relaxation rate of +0.5 to +10%.
It is best to keep it within the range.

By performing reheat treatment after the above false twisting process, the shrinkage rate of the obtained crimped bulky yarn after rapid boiling water treatment is 0.1 to 8.
You will be able to control it so that it is within the 0% range. In particular, when the reheat treatment temperature is set to a high temperature higher than the softening point, the shrinkage rate is 20% or less, which was extremely difficult to achieve with conventional technology, and even 3% or less, which is extremely low shrinkage and low crimp. It becomes possible to obtain a certain crimped bulky yarn.

FIG. 3 shows an example of a process diagram of the manufacturing method of the present invention.

In FIG. 3, numeral 11 is a package in which raw yarn Yo consisting of highly oriented undrawn yarn or incompletely drawn yarn is wound up. The raw yarn Yo is transferred from the package 11 to the feed roller 12
The sheet is pulled out by the feed roller 12 and the delivery roller 15, and then stretched between the feed roller 12 and the delivery roller 15. While being stretched in this manner, it is heated in the upstream region by the twister 14, heat-set by the heater 13 at a temperature below the glass transition point, and untwisted in the downstream region to undergo a stretching and false-twisting process. .

This drawing and false twisting process results in a crimped bulky yarn with weak crimps, and while the yarn is being taken from the delivery roller 15 by the second delivery roller 17, it is heated to a temperature higher than the glass transition point under relaxed conditions by the second heater 16. It is reheated at a temperature of The crimped bulky yarn thus reheated is subjected to air pressure treatment by the interlacing nozzle 18 while passing through the third pre-heli roller 19, and light entanglement is performed between the constituent single fibers to form the crimped bulky yarn of the present invention. It becomes Y. Next, this crimped bulky yarn Y is wound onto a pan cage 21 by a winding roller 20. In addition, the interlacing nozzle 18
Alternatively, the delivery roller 15 may be provided immediately after passing, and after once entangling, the second heater 16 may be used to relax and reheat.

〔Example〕

Example 1 Birefringence Δn obtained by high-speed spinning at a spinning speed of 3500 m/min
A highly oriented undrawn polyester yarn of 75 denier and 36 filaments with a circular cross section of 0.09 was stretched 1.89 times at a temperature of 70°C, a number of false twists of 3400 times/m, and a false twist speed of 400 m/min. After false twisting, the yarn was then reheated at a relaxation rate of 2% and a temperature of 180°C to produce a crimped bulky yarn according to the present invention.

When this crimped bulky yarn is subjected to rapid heat treatment in boiling water, the shrinkage rate is 1.5%, and the residual torque is 0.1 times 15
It had a weak crimp of 0 cm or less and a stretch recovery rate of 1.5%. Further, the cross section of the single fiber had the same circular cross section as that of the raw yarn, and the cross section deformation rate was 5.1%.

The above crimped bulky yarn was 75 denier at a shrinkage rate of 15%, 36
The composite yarn was mixed with the polyester yarn of the filament to make a composite yarn, and this was used as the warp yarn, and a 150 denier polyester yarn was used as the weft yarn to make a plain woven fabric. Furthermore, when this plain woven fabric was dyed, a shrinkage mixed fiber fabric with a very soft texture with a bulge could be obtained.

Example 2 The same highly oriented undrawn yarn as in Example 1 was stretched and false twisted under the same conditions, and then reheated at a relaxation rate of 2% and a temperature of 100°C to obtain a crimped bulky yarn of the present invention. .

When this crimped bulky yarn was subjected to rapid heat treatment in boiling water, the shrinkage rate was 16.1%, and the residual torque was 1.5 times 1.
It had weak crimp with a length of 50 cm or less and a stretch recovery rate of 21%.

Further, the cross section of the single fiber was the same circular cross section as that of the raw yarn, and the cross section deformation rate was 5.0%.

〔Effect of the invention〕

As mentioned above, the crimped bulky yarn of the present invention has a wide range of shrinkage rates from 0.1% to 80% when treated with rapid boiling water, so it is possible to obtain a desired shrinkage rate level from a wide range from low shrinkage to high shrinkage. can be easily designed. Moreover, since the crimped bulky yarn of the present invention has weak crimpability with almost no residual torque, it is possible to obtain bulkiness as well as a soft feel. In particular, this effect can be significantly exhibited in applications such as thin fabrics using raw silk. In addition, by having a weak crimp, it is possible to improve process passability and improve operability.

Further, although the crimped bulky yarn of the present invention is a false twisted yarn, it has substantially no processing deformation in its cross section, so it can maintain the luster of raw silk and exhibit high gloss. Furthermore, since the crimped bulky yarn of the present invention does not need to be made from a copolymer, it does not cause staining or deterioration in color fastness.

Further, according to the manufacturing method of the present invention, a crimped bulky yarn having the above characteristics can be easily manufactured.

[Brief explanation of the drawing]

Fig. 1 is a side view showing a model of the form of the crimped bulky yarn of the present invention, Fig. 2 is a side view showing a model of the form of the conventional false twisted yarn, and Fig. It is a process diagram showing an example of a manufacturing method. Y: crimped bulky yarn, Yo: raw yarn (highly oriented undrawn yarn or incompletely drawn yarn), 12: feed roller, 1
5.17... Pre-heli roller, 13.16... Heater, 14... Life force.

Claims (3)

[Claims] (1) Shrinkage rate due to rapid heat treatment in boiling water is 0.1~
80%, residual torque twist number is 2 turns/50cm or less,
The crimped bulky yarn also has substantially no processing deformation in the cross-sectional shape of its constituent single fibers. (2) The cross-sectional deformation rate of the constituent single fibers defined by the following formula is 1
The crimped bulky yarn according to claim 1, wherein the crimped bulky yarn has a content of 0% or less. Cross-sectional deformation rate (%) [(r_1-r_2)/r_1]×1
00 However, r_1: Radius of the inscribed circle of the cross-section of single fibers of raw silk before crimping r_2: Radius of the inscribed circle of cross-section of single fibers of bulky yarn after crimping (3) Highly oriented undrawn yarn or incompletely drawn yarn with birefringence Δn in the range of 0.02 to 0.12 is subjected to substantially uniform stretching and false twisting at a temperature below the glass transition point, and then the glass A method for producing crimped bulky yarn by reheating at a temperature above the transition point.