JPH03213534A - Covered elastic fiber and its preparation - Google Patents

Abstract

PURPOSE:To prepare the subject elastic fiber alternately having integrally bond fiber portions and portions expanded in arch-like shapes by subjecting an elongated elastic fiber and a thermoplastic synthetic fiber filament to a first twisting process and subsequently to a false-twisting process. CONSTITUTION:An elastic fiber 1 such as a polyurethane elastic fiber preferably having a fineness of 10-70 denier is delivered from a fiber-wound tube 3 loaded on surface-driven rollers 4, 4' and elongated between the roller 4 and a feed roller 5 rotated at a high rate. The elongated elastic fiber 1 is paralleled with a thermoplastic synthetic fiber filament 2 such as a polyamide fiber preferably having a fineness of 20-210 denier with the roller 5, followed by subjecting the paralleled fibers to a first twisting treatment and winding the first twisted fibers on a pirn 8 through a traveler 6. The first twisted fibers are fed into a false-twisting machine, false-twisted and subsequently doubled to provide the objective elastic yarn.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a coated elastic yarn suitable for heavy dyeing and a method for producing the same.
The present invention relates to a covered elastic yarn that avoids layer-by-layer dyeing differences in package dyeing and breakage of polyurethane elastic yarn during rewinding by double-twisting, and a method for manufacturing the same.

[Prior Art] Conventionally, as a dyeing method for coated elastic yarns, general filling package dyeing has been employed, and general jetting, cheese, and corn wrapping dyeing have not been carried out.

In the case of the above-mentioned packed package dyeing, the total winding amount is limited by the elasticity of the elastic yarn, and due to differences in the degree of drying after dyeing, lack of expanders, etc., the elastic yarn may be cut during the rewinding process. I had the problem of doing so.

Regarding false-twist coated elastic yarns, see Japanese Patent Publication No. 49-9427, Japanese Patent Publication No. 50-28536, Japanese Patent Publication No. 53-42811.
Publication No. 60-23+836, Special Publication No. 1973
This is known from Japanese Patent Laid-Open No. 48-33143, etc.

The first three patents are based on a composite plate twisting process in which elastic threads and thermoplastic synthetic filament threads are arranged in a core/sheath shape, and the curled multifilament threads are wrapped around the elastic threads in a rational manner with virtually no twisting. This is a technique in which the elastic yarn is coated in a core/sheath shape, and the deterioration of the elastic yarn is prevented by setting the setting range of the false twisting temperature to be low, and the good elasticity of the elastic yarn is maintained. However, in these techniques, the temporary curled yarn has a tendency to reduce its covering properties because the effect of restraining the elastic yarn of the core yarn becomes loose, and the disadvantage is that the covering properties are further reduced when rewinding. It had

In addition, the latter three patents relate to a technology in which elastic yarns and thermoplastic synthetic fibers are first twisted to give a real twist, and then untwisted and temporarily twisted at a normal temporary twisting temperature, resulting in high bulkiness. . However, this also has the disadvantage that the coverage is substantially reduced.

Furthermore, both techniques do not indicate anything regarding yarn dyeing.

[Problems to be Solved by the Invention] All of the above-mentioned conventional temporary twist-coated elastic yarns have insufficient compatibility and entanglement with polyurethane elastic yarns and thermoplastic synthetic fibers, so they cannot be used as guides in the dyeing preparation process. When squeezed, the covering property deteriorates and the core polyurethane elastic thread breaks.

The purpose of the present invention is to eliminate such conventional drawbacks, and to make it difficult for the core yarn and sheath yarn to become misaligned even when they are squeezed in each process.
To provide a coated elastic yarn that has little deterioration in coverage, has good process passability, can be dyed uniformly with little difference in dyeing between layers in package dyeing, and has less elastic yarn breakage during subsequent rewinding. It is something.

[Means for Solving the Problems] In order to achieve the above object, the present invention has a structure in which the elongated elastic yarn and the thermoplastic synthetic fiber filament yarn are false-twisted in a pre-twisted state. By twisting together the false-twisted coated elastic yarns that have been first twisted, the thermoplastic synthetic fiber filament yarn is sandwiched and heated between the elastic yarns in the core, and each yarn is bonded and integrated. and bulky parts in which the thermoplastic synthetic fiber filament yarn of the sheath yarn bulges in an arch shape with respect to the elastic yarn of the core yarn alternately in the longitudinal direction of the yarn. be.

Hereinafter, the covered elastic yarn of the present invention will be explained based on examples shown in the drawings.

FIG. 1 shows a schematic diagram of a coated elastic yarn according to an embodiment of the present invention.

In FIG. 1, the coated elastic yarn of the present invention has two elastic yarns 1.1' in the core, and false twisted thermoplastic synthetic fiber filament yarns 2.2' constituting the peripheral edge. It is heated and double-stranded.

The elastic yarn 1 constituting the core is originally aligned with the thermoplastic synthetic fiber filament yarn 2 in the pre-twisting process, and then pre-twisted, but after undergoing a post-false twisting process, it is double-twisted. As a result, the portions where each yarn composing the covered elastic yarn is twisted and integrated, and the thermoplastic synthetic fiber filament yarns 2, 2' of the sheath yarns are connected to the elastic yarns 1, 1' of the core yarns. The coated elastic yarn has loose, arch-shaped bulky parts alternately in the longitudinal direction of the yarn.

That is, between the heating parts, the thermoplastic synthetic fiber filament yarn 2 and the thermoplastic synthetic fiber filament yarn 2' exhibit a bulky shape that swells in an arch shape in different directions.

In other words, the features of the covered elastic yarn of the present invention are as follows: 1.1. ', a portion where the thermoplastic synthetic fiber filament yarn 2.2' is heated and sandwiched, and an elastic yarn 1.2'.
1' and thermoplastic synthetic fiber filament yarn 2.2' are separated in an arch shape, and when subjected to stretching or relaxing action, the elastic yarn 1.1'
In the area where the thermoplastic synthetic fiber filament yarn 2.2' is heated and sandwiched between the two, no yarn displacement occurs.
The core thread and sheath thread are firmly connected. Therefore, even if it is squeezed in the preparation process, knitting process, etc. thereafter, there is no concern that it will get caught, slip, or cause elastic yarn breakage of the core yarn.

In addition, in the present invention, in the opposite direction to the direction of the first twist,
In addition, it is preferable that the number of twists is approximately the same as the number of first twists or less than the number of twists.

The elastic threads used in the present invention include polyurethane elastic threads,
Includes polyester elastic yarn and polyamide elastic yarn,
Among other things, polyurethane elastic threads are widely used.

The polyurethane elastic yarn may be either a monofilament yarn or a multifilament yarn, but from the point of view of elongation recovery power, multifilament yarn generally has stronger recovery power than monofilament yarn and is therefore more preferable.

The denier of the polyurethane elastic yarn is preferably 10 to 70 deniers, and more preferably 20 to 40 deniers for outerwear such as swimsuits and leotards, which require particularly soft stretchability. Further, it is desirable that the elongation at break is 500% or more.

A bright type containing a small amount of a matting agent such as titanium oxide or a clear type containing no matting agent at all is desirable in order to obtain a uniform color in deep dyeing.

Furthermore, in the present invention, the thermoplastic synthetic fiber filament yarn is a filament yarn made of polyamide, polyester, acrylic, polypropylene, vinyl chloride, etc.
A composite yarn of these may be used.

The total denier of the thermoplastic synthetic fiber is 20 to 21
0 denier, 2 for socks, tights and stockings
0-140 denier, 30-70 denier for innerwear and 50-210 denier for outerwear are preferred. The denier of the single yarn may normally be from 0.1 to 5.0 denier, more preferably from 0.25 to 3.0 denier.

The cross-sectional shape is usually a circular cross-section, but may also be an irregular cross-section such as a many-leaf shape or a triangular shape.

Next, in the method for producing a covered elastic yarn according to the present invention, the stretched elastic yarn and the thermoplastic synthetic fiber fillant yarn are first twisted in a aligned state, and then subjected to a false twisting process to form the false twisted covered elastic yarn. The method is characterized in that the false-twisted covered elastic yarn is then twisted together.

In the above method for producing a covered elastic yarn, the number of twists (T w ) in the first twisting step is less than 300 T/M, and while drafting the elastic yarn at a draft magnification of 1.5 to 4.5 times, It is preferable to heat the synthetic fiber filament yarn.

In addition, in the false twisting process, the heating direction of false twisting is the same direction as the first twisting, and the false twisting set temperature (Te) is 140 to 190.
False twist coefficient (k) that satisfies the range of °C and is defined below
It is preferable that the condition of 20,000 to 23,000 is satisfied.

Next, in the present invention, the false twisting coefficient (k) used in the false twisting process is defined by the following equation.

T = ni, /”-A7■ Here, D is the total denier of the thermoplastic synthetic fiber filament yarn, ρ is the specific gravity of the above fiber, and T is the number of false twists (T/M)
It is.

Furthermore, in the twisting step of the false twisted coated elastic yarn obtained in the previous step, it is important to twist the false twisted coated elastic yarn in the opposite direction to the first twisting.

In addition, the direction of twisting, which consists of simultaneous processing of each single yarn with two twists from S in the same false twisting process, may be either S twist or two twists, and the number of twists Td (T/M) is the first twist Tw300T. /M
Equal to or less than less is desirable.

Hereinafter, the method for manufacturing a covered elastic yarn of the present invention will be explained based on the drawings.

0 Figures 2 and 3 are process schematic diagrams showing one embodiment of the method for producing covered elastic yarn of the present invention, Figure 2 is a preliminary twisting process diagram, and Figure 3 is a false twisting process diagram. It is a diagram.

The first twisting process diagram shown in FIG. 2 is a conventional ring twisting machine, in which the elastic yarn 1 is supplied from a winding tube 13 and its surface drive roller 4.4'.
By rotating the elastic thread 1, the elastic thread 1 is let out from the winding tube 3 at a constant speed. The let-out elastic yarn 1 is drafted between the feed-out roller 5, which rotates at a faster circumferential speed than the surface drive roller 4.4', and is stretched to a constant elongation state, and the twisting is done by the ballooning mechanism. It passes through the traveler 6 on the ring 7 and is wound onto the pirn 8.

On the other hand, the thermoplastic synthetic fiber filament yarn 2 is supplied by being unwound from the surface of the winding body 9 by the feeding roller 5, and being fed by the elastic yarn 1 and the feeding roller 5.
The pieces are pulled together and the first twist is applied.

1 The process shown in Fig. 3 is a false twisting machine equipped with a one-stage heater, and the first twisted yarn (combined twisted yarn) consisting of the elastic yarn 1 and thermoplastic synthetic fiber filament yarn 2 obtained in the process of Fig. 2 is used. The yarn is unwound from the surface by the first feed roller 11 from the wound body 8 and is fed out, during which time it passes through the yarn path guide group, passes through the tension adjustment device 10, and reaches the first feed roller 11-. A heater 12 and a false-twisting spindle (or spinner) 13 are arranged between the first feed roller 11 and the second feed roller 1-4, and the false-twisting spindle 13 can perform false twisting at an appropriate magnification and at any desired number of false twists. is applied and heat-fixed at an arbitrary temperature using heater 1-2.

Finally, it is stretched to an appropriate magnification between the third feed roller (or winding roller) 15 and the second feed roller 14, and wound up as a covered elastic yarn 16.

Although the twisting process is not shown, the false-twist coated elastic yarn that has undergone the above-mentioned false twisting process is then subjected to the twisting process as described above in the present invention.

The properties of the obtained coated elastic yarn that should be noted are: 2. Since it is covered by the lower twist and heated in the same direction during false twisting, there is little deterioration of the elastic yarn, and the elongation at break is 1-0.
It becomes 0% or less.

■ In common with tip twist false twisting, when the actual twist is in the stretched state of the elastic yarn, it prevents sufficient crimp development.
Initial crimp elongation is reduced.

■ Elastic yarns and synthetic fibers are stretched and heat treated by false twisting, which reduces the stretch power and boiling water shrinkage of elastic yarns.

■■ It has a lower twist, is made of interlaced fibers (where the twists are densely gathered), and has a spring-like shape (similar to the restoring force of a spring), so it has a high elongation recovery stress.

■ Partially untwisted, it has the appearance of intertwined mixed fibers, and is characterized by the coexistence of alternating parts where the thermoplastic synthetic fiber filament yarn covers the elastic yarn with high coverage, and parts where the fibers are opened on the contrary. It means that it has a shape.

Therefore, there is no decrease in coverage, which is common with false-twisted crimped yarns that are simply made of elastic yarns and thermoplastic synthetic fiber filament yarns, and the yarn has coverage similar to that of covering twisted yarns. .

Note that the method in which the direction of false twisting is the same as the direction of twisting of the first twist provides substantially higher coverage than false-twisted yarns that are false-twisted in the opposite direction or over-untwisted.

Next, the relationship between cheese wrapping density and dyeability will be described.

In the present invention, the cheese winding density (ρ
) is preferably 0.3 g/ad or less.

In the present invention, the double thread plying provides superior level dyeing properties compared to using a single thread. This is a result of the difference in cheese winding density, and the winding density (ρ) of the double yarn plied twist in the present invention was 0.21 to 0.27 g/ad C before dyeing, but decreased to 0.32 to 0.32 g/ad C after dyeing. The amount increased to 0.35g/ad, while the amount of soft cheese made using regular single threads increased by 0.23g/ad before dyeing.
~0.27g/c- was 0.38~ after dyeing
The amount increased to 0.41 g/c, and there was a slight difference in dyeing between the outer layer and the inner layer with a winding amount of 500 g. Furthermore, various combinations of double yarn plying configurations were found.The combinations of the final twisting/false twisting (ply twisting) conditions in the previous stage were changed to bottom twist (from S + S), top twist from Z, and bottom twist.
(From Z + From Z) / From top, from S, from bottom (+ from S)
From Z)/Top from S (or from bottom (+Z from S)
The properties of the final coated elastic yarns obtained by changing the direction (from Z)/from top twist Z) are all very close to each other. 200.
When changing to 250.300.350.400.500 T/M, if Td is 150 T/M or less, the cheese will easily lose its shape, and if it is 350 T/M or more, the cheese shape will be highly stable. However, it was found that there were differences in dyeing depending on the layer. Therefore, the number of twists (Td) is 200±5
At 0 T/M, a suitable flow flow effect can be obtained during dyeing, and the occurrence of cheese shape deformation can be prevented and good results can be obtained.

The coated elastic yarn of the present invention can also be used in the compression type package dyeing method by selecting an appropriate compression ratio.

As mentioned above, by first twisting the elongated elastic yarn and the thermoplastic 5 synthetic fiber filament yarn, by false twisting in the subsequent process, the first twist is untwisted, giving the appearance of an intertwined mixed fiber. At the same time, by applying double yarn ply twisting, the thermoplastic synthetic fiber filament yarn can be sandwiched and heated between two elastic yarns, making it stable for soft cheese wrapping and dyeing for use in blow-opening cheese dyeing. They work. In this case, it is important that the effective conditions to be applied are that the boiling water shrinkage rate (S) of the coated elastic yarn of the present invention is 7.0% or less, and the stretch recovery rate (CR) is 55% or less. The means for achieving such characteristics is by setting the false twisting temperature specified in the present invention. Both properties result in small processing changes during cheese dyeing, and work to prevent differences between layers of cheese. It was nearly impossible to reduce the winding density (ρ) of cheese to 0.3 g/cId or less using ordinary elastic yarn covering twisted yarn, but by applying a false twist set to elastic yarn. This and the fact that the thermoplastic synthetic fiber filament yarn has a bulky, arch-like shape due to double-twisted yarns help the dyeing liquid penetrate through the dyed object and prevent compression of the inner layer.

For the above-mentioned reasons, when the dyed cheese of double threads is twisted and used for circular knitting or woven fabrics, the two elastic threads obtained by twisting the double threads are in the core. Since the thermoplastic synthetic fiber filament yarns are twisted together and spread out to form an arch shape, the passing properties during weaving are smooth and the resulting product surface is smooth, has a synthetic luster, and has a soft texture. Work easily.

Next, the present invention will be specifically explained with reference to examples, but the present invention is not limited to these in any way.

Example 1 Using a nylon thread of 70 denier, 34 filament, round cross section thread (manufactured by Toshi Co., Ltd., registered trademark "Amiran") and a twisting machine equipped with an elastic thread active feeding device shown in Fig. 2 (A),
The polyurethane elastic thread was a type 127.20 denier (manufactured by DuPont Toshiba, registered trademark "Operon"), and the draft was set at a draft magnification of 3.degree. to 5.times. A false twisting machine of 1 heater/1 spindle type (manufactured by Toshiba Machine ■, F-103) was used, and then the twin yarns were twisted using a normal ring twisting machine.The manufacturing conditions for each are shown in Table 1. A coated elastic yarn was obtained. In addition, as a comparison yarn, a single covered yarn (the raw yarn used was the same as above, N7O-34-205 was used as a woolly nylon yarn under normal conditions; 8270-E, manufactured by Toshi DuPont Co., Ltd., single covered yarn) was used. Using. Soft winder for cheese dyeing (manufactured by Kozu Seisakusho; RT
winder) and a normal cheese dyeing machine (manufactured by Hisaka Seisakusho Co., Ltd.; "LLC" type package dyeing machine).

The properties of the obtained covered elastic yarn were as shown in Table 1. As is clear from Table 1, the double yarn plied twist of covered elastic yarn with a boiling water shrinkage rate of 7.0% or less and a stretch recovery rate of 55% or less,
It can be seen that the cheese level staining properties are good in all cases. However, when using a single yarn, the level dyeing performance slightly decreased, probably due to an increase in the winding density of the dyed cheese.

8 Example 2 The thermoplastic synthetic fiber filament yarns used were nylon, polyester, and acrylic yarns, and the polyurethane elastic yarns were used according to the "Operon" type (described above), and the experiment was carried out using the same process and model as in Example 1.

The various yarns used, the twisting yarn production conditions, and the properties of the obtained covered elastic yarn are shown in Table 2.

As is clear from Table 2, coated elastic yarns, which have improved heat setting properties compared to nylon yarns depending on the material, have low boiling water shrinkage and stretch recovery rates, and are relatively easy to dye with cheese. Among these, "Silparon" and "Lumilet" have excellent low-temperature setting properties.

(Hereinafter, blank space) 0 [Effects of the Invention] As described above, according to the present invention, the following effects can be achieved.

b) By false twisting the yarn made by first twisting the elongated elastic yarn and thermoplastic synthetic fiber filament yarn, and then twisting the double yarn, the coated elastic yarn for heavy dyeing can be obtained by twisting the core elastic yarn 2. False-twisted thermoplastic synthetic fiber filament threads are sandwiched and heated between the books, and the thermoplastic synthetic fiber filament threads are spread out in an arch shape around the periphery of the sheath, allowing dyeing to occur inside the cheese. Good penetration of liquid. At the same time, since it is a coated elastic yarn that has been given a false twist set, the boiling water shrinkage rate and stretch recovery rate are reduced, so that the inner layer of cheese does not become compressed, and uniform dyeing is possible.

(Example) If the number of first twists (Tw) is less than 3007/M, the false twisting heating is in the same direction as the first twist, and the number of double yarn twists (Td) is 300T in the first twist (Tw). Same as less than /M,
or less, it is possible to obtain a covered elastic yarn with a pre-twisted, untwisted tone and the appearance of interlaced mixed fibers, and it is also possible to obtain a covered elastic yarn with an untwisted, untwisted tone and an appearance of interlaced mixed fibers. Since the parts with high elasticity and the oppositely spread parts coexist alternately, it becomes a low stretch coated elastic yarn with high elongation recovery stress.

As a result, when fed to circular knitting after cheese dyeing, the knitting properties are good, and the passing through is very good without any concerns about elastic yarn breakage without getting caught in any guides or causing misalignment of the twin yarns. be. The obtained nine-silk fabric has a smooth surface, is highly stretchable, and has good stretch recovery properties.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing an embodiment of a covered elastic yarn according to the present invention. 2 and 3 are process schematic diagrams showing one embodiment of the method for producing covered elastic yarn of the present invention, FIG. 2 is a preliminary twisting process diagram, and FIG. 3 is a false twisting process diagram. It is a diagram. 1.1'... Elastic yarn 2.2'... Thermoplastic synthetic fiber filament yarn 7 ・
...Ring 3 10...Tension adjustment device 12...Heater 1-3...False twisting spindle

Claims (5)

[Claims] (1) By combining and twisting the false-twisted coated elastic yarn which has been subjected to the first twist, which is obtained by subjecting the elongated elastic yarn and the thermoplastic synthetic fiber filament yarn to a false twisting process in a first twisted state. , a thermoplastic synthetic fiber filament yarn is sandwiched and heated between the elastic yarns of the core to combine and integrate each yarn, and a thermoplastic synthetic fiber filament yarn of the sheath yarn is connected to the elastic yarn of the core yarn. 1. A coated elastic yarn characterized in that it has arch-shaped bulky parts alternately in the longitudinal direction of the yarn. (2) After first twisting the elongated elastic yarn and the thermoplastic synthetic fiber fillant yarn in a aligned state, they are subjected to a false twisting process to form a false-twisted covered elastic yarn, and then the false-twisted covered elastic yarn is made. A method for producing a covered elastic yarn, which comprises plying and twisting the yarn. (3) The number of first twists (Tw) is less than 300 T/M, and the elastic yarn is stretched at a draft magnification of 1.5 to 4.5 times. Method for producing coated elastic yarn. (4) Claim (2) or (3) characterized in that the twisting direction of the first twist and the twisting direction of the false twisting process are the same twisting direction.
The method for producing the described covered elastic yarn. (5) Set temperature (Te) for false twisting is 140 to 190
The false twist coefficient (k
) is 20,000 to 23,000.
The method for producing the described covered elastic yarn.