JPH0335413B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a differential shrinkage mixed fiber yarn suitable for obtaining a fabric having a soft surface texture and a high level of drapability. In the past, various attempts have been made to create a texture similar to silk by using polyester filament yarn, and a high level of silk-like luster and fullness has been achieved, and even a soft surface texture similar to silk has been added. To this end, a mixed shrinkage yarn using a multifilament yarn with a single yarn fineness of 0.7 denier or less as one component has also been proposed. Such mixed fiber yarns are provided with a soft touch on the surface using fine denier yarn, which is a low shrinkage component yarn, and are given fullness due to the difference in shrinkage from the high shrinkage component yarn. However, market demands are expanding endlessly,
Nowadays, there is a desire for a texture that surpasses that of silk, that is, super silk, and one of these is the increasing need for high-level drapability. By the way, if a yarn with a high boiling water shrinkage rate (hereinafter referred to as BWS) is used as the high shrinkage component yarn of the different shrinkage mixed fiber yarn, the crimp rate of the woven fabric can be reduced by subjecting it to boiling water shrinkage treatment in the finishing process after weaving. Theoretically, it has been elucidated that a high level of drapability can be obtained. However, in reality, when using high-shrinkage yarn with a BWS of 10% or more, conventional yarns are thermally unstable, which poses a huge problem in handling. In other words, the shrinkage rate of conventional high-shrinkage yarns with a BWS ≥ 10% varies greatly depending on how they receive heat during the textile finishing process, especially the relaxation process. There is a shrinkage difference between the part where the temperature rises immediately to the boil and the part which reaches the boil a little later due to folding and overlapping of the fabric, resulting in relaxation spots. Furthermore, for twisted fabrics, it is necessary to lower the twisting torque by twist setting for ease of weaving handling, but this heat setting lowers the boiling water shrinkage rate of both low-shrinkage component yarns and high-shrinkage component yarns. In this case, the boiling water shrinkage rate of high-shrinkage component yarns is particularly significantly reduced, and therefore, even though it is possible to obtain bulge due to the difference in shrinkage, it is not possible to increase the fabric crimp rate, which depends on the shrinkage of high-shrinkage component yarns. Drapability becomes difficult to obtain. On the other hand, if the boiling water shrinkage rate of the high shrinkage component yarn used is increased to 10% or more, the above-mentioned relaxation spots will become even larger. In addition, because the boiling water shrinkage rate of high-shrinkage component yarns differs depending on how they receive heat, there is a problem that uneven setting occurs in the inner and outer layers of the twisted set bobbin winding. It is mainly used for non-twisted or lightly twisted fabrics such as habutae, which do not require a twist set. On the other hand, when producing medium-high twist fabrics that require a twist set such as voile and jersey, the outer layer and inner layer of the twist set bobbin may be used separately, or the twist set temperature may be lowered to reduce residual torque. Currently, weaving is carried out using various techniques such as using high-quality threads. In actual fabric production, the BWS of high shrinkage component yarns is kept to 10% at most in order to avoid the above-mentioned handling problems, and only the bulge caused by the difference in shrinkage is used. An object of the present invention is to solve the above-mentioned problems and provide a mixed fiber yarn suitable for obtaining a soft-touch fabric that is extremely easy to handle in post-processing and particularly has excellent drapability. While pursuing the causes of the above-mentioned problems, the present inventors discovered that conventional high-shrinkage yarns are used without heat treatment after drawing undrawn yarns near their glass transition point. Since it is a material, we focused on the fact that although it is highly oriented, its crystallinity is low. In other words, such yarns undergo crystallization when they contract during the relaxation process of textile finishing, so they undergo partially different crystallization processes depending on the degree of application of small amounts of heat. As a result, we focused on the fact that shrinkage spots occur as a result, and similarly, when twisting and setting, boiling water shrinkage decreases and inner and outer layer unevenness occurs.As a result, we found that the boiling water shrinkage rate was 10% or more. We solved the above problem by using polyester yarn, which has not been used in the past, as a high shrinkage component, with a crystallinity of 35% or more in the high range (crystallinity comparable to low shrinkage yarn that has been heat set at high temperature). , the present invention has been achieved. That is, the present invention is a mixed fiber yarn in which multifilament yarns having different heat shrinkage rates are mixed, and the low shrinkage component yarn has a single yarn fineness.
It is a multifilament yarn of 0.7 denier or less,
This is a mixed fiber yarn characterized in that the high shrinkage component yarn is a polyester fiber that satisfies (a) boiling water shrinkage rate ≧10% and (b) crystallinity ≧35%. The mixed fiber yarn of the present invention is characterized by its high shrinkage component filament yarn, which can be obtained as follows. That is, the starting material has a birefringence Δn of 0.035 to 0.08.
A polyester yarn containing polyethylene terephthalate as a main repeating unit (generally obtained by high-speed spinning at a spinning speed of 2,800 to 4,500 m/min) is used, and it is spun to a constant length at a temperature of 160°C or higher, preferably 180°C or higher. Or the crystallinity is 35 in the relaxed state.
% or more, preferably 38% or more, and then low-temperature stretching at a temperature of 140°C or less, preferably 115°C or less. Obtained in this way, BWS≦10%, crystallinity
Xρ≧35%, or a polyester filament yarn with BWS≧12% and Xρ≧38% obtained from spinning under the above preferable condition range is used as a high shrinkage component and mixed with a low shrinkage component yarn to achieve the desired differential shrinkage. Manufacture mixed fiber yarn. Here, if the BWS of the high shrinkage component yarn is less than 10%, although it is possible to obtain fullness based on the shrinkage difference, it is not possible to obtain high drapability based on the shrinkage rate itself of the high shrinkage component yarn. It is similar to thread,
Furthermore, if Xρ is less than 35%, the above-mentioned problems during relaxation cannot be solved, and the same problems as conventional high shrinkage yarns with Xρ≒20% occur. Also, if a twist-stop set is required, the BWS may decrease slightly due to the set.
BWS≧12% is preferable, and in order to be more perfect against problems caused by shrinkage unevenness during relaxation and BWS difference between the inner and outer layers of the bobbin due to twist setting, Xρ≧
38% is preferred. On the other hand, low shrinkage component yarns, fine denier yarns, need to have a single yarn fineness of 0.7 denier or less in order to approximate the soft surface touch of real silk. Then,
From the point of view of imparting fullness to the fabric, it is necessary that the BWS is at least 1% lower than the BWS of the high shrinkage component yarn. On the other hand, the polyester used as the high-shrinkage component yarn or low-shrinkage component yarn is a homopolymer made of polyethylene terephthalate, as well as a small amount of so-called third component such as aromatic or aliphatic dicarboxylic acid or glycol added thereto. Even something is fine. In the case of polyethylene terephthalate, the degree of polymerization of such polyester is preferably 0.55 to 0.7 in terms of the intrinsic viscosity [η] determined from the value measured in an o-chlorophenol solution at 35°C. In the present invention, the high-shrinkage component yarn and the low-shrinkage component yarn can be combined as appropriate so as to have different shapes, different colors, and different lusters, and then subjected to the blending process. In this case, the weight ratio of high shrinkage component yarn and low shrinkage component yarn is 20.
It is necessary to have a ratio of ~80:80~20, and outside this range, flexibility, fullness, drapability, etc. cannot be satisfied at the same time. This fiber blending process can be carried out by first opening the high-shrinkage component yarn and low-shrinkage component yarn using static electricity or fluid, and then combining them, or by introducing them into the fluid disturbance area in an aligned state and mixing them. Any known fiber mixing method can be used, such as a fiber/interlacing method.
However, in consideration of productivity, yarn handling (weavability), etc., interlace treatment is most preferable. Regarding this technology, as already described in Japanese Patent Publication No. 36-12230 and Japanese Patent Publication No. 37-1175, high-shrinkage component yarn and low-shrinkage component yarn are aligned and supplied to a turbulent flow nozzle. It is a mixed fiber. in this case,
The standard for mixing fibers is determined by the so-called interlacing degree, and it is usually sufficient to obtain an interlacing degree of about 5 strands/m to 80 strands/m. The total denier of the thus obtained mixed fiber yarn must be at least 30 de; if it is less than this, the threads constituting the fabric will be insufficiently thick, or a sufficient number of filaments required for the mixed fiber yarn will not be secured. Next, the above-mentioned mixed fiber yarn is usually subjected to the weaving process without being subjected to shrinkage treatment, but in this case, it is only necessary to decide whether to use untwisted or twisted (additional twist) depending on the intended fabric. , Furthermore, in terms of yarn use, untwisted and /
Alternatively, it can be used in an additional twist state in various combinations of warp and weft. In the subsequent scouring and finishing process, such fabrics are subjected to shrinkage treatment while immersed in hot water/boiling water (these are sometimes applied in the form of scouring baths or dye liquors). The drapability is obtained by creating a similar fullness and by increasing the crimp of the fabric structure due to the shrinkage of the high shrinkage component yarn. In this case, it is also advantageous to perform alkali treatment (weight loss) in order to improve drapability, but in general, presetting is performed after the scouring fabric is sufficiently shrunk and the crimp rate is increased. By performing the alkali treatment, preferable interfiber voids can be obtained, and as a result, the contact pressure between the warp and weft can be felt effectively. In addition, in the present invention, BWS, boiling water shrinkage rate by boiling water injection method, boiling water shrinkage rate by heating method, crystallinity degree (Xρ)
was obtained by the following measurement method. 1 Boiling water shrinkage (BWS), boiling water injection method Boiling water shrinkage
After processing for 30 minutes, air dry and measure the flute length L′.
Calculate by L-L'/L x 100 (%). In the main text, when simply referring to BWS, this
Refers to BWS. 2 Boiling water shrinkage rate using heating method The sample was immersed in water at a temperature of 20°C, the temperature was raised at a rate of 2.5°C/min, and after boiling, the boiling water shrinkage rate BWS was determined by the boiling water shrinkage measurement method described above. . 3 Crystallinity (Xρ) The specific gravity (ρ) is measured by a conventional method at 25°C using an n-heptane-carbon tetrachloride density gradient tube, and the crystallinity (Xρ) is calculated by the following formula. Xρ=0.7491-1/ρ/0.06178×100 (%) Next, the reason why the mixed fiber yarn of the present invention is excellent for high drape fabrics will be explained. BWS accounts for 10% of blended yarns for high drape fabrics.
It is known that it is necessary to have a BWS of 10% or more, but with conventional differential shrinkage blend yarns using highly oriented, low crystallinity yarns, when blending yarns with a BWS of 10% or more,
As mentioned above, if you are not careful during the relaxation treatment and do not relax while gradually raising the temperature, shrinkage spots may occur and problems may occur.
The reason for this is thought to be that the effect of heat on the fabric during relaxation treatment is extremely large, whereas in the blended yarn of the present invention, the crystallization of the high shrinkage component yarn has already been promoted, so the effect is small. It will be done. In order to confirm this phenomenon, each yarn was treated using different typical boiling water treatment methods, and the difference in boiling water shrinkage rate BWS (%) was measured. In this experiment, the following two types of mixed fiber yarns were used. That is, BWS5.2% as a low shrinkage component yarn,
32de/72f (spinning at a spinning speed of 3750 m/min, 150
Using polyester multifilament yarn (heat set at a temperature of ℃), conventional type blended yarn ()
A high shrinkage component yarn with a round cross section of BWS 16.5%, An example of the mixed fiber yarn of the present invention () is a filament yarn mixed with an interlace degree of 50 threads/m, and contains high shrinkage components of BWS 15% and
Filament yarn with Δn0.048 spun at 180℃
A round cross-section, 30de/12f polyester multifilament yarn (heat-treated to a fixed length at
A mixed fiber of m was used. These mixed fiber yarns were subjected to boiling water shrinkage treatment under different boiling water treatment conditions. That is, the boiling water injection method BWS and the temperature raising method BWS were measured using the above measurement method. The results were as shown in Table 1.

[Table] The BWS of conventional mixed fiber yarns in No. () differs greatly depending on the boiling water treatment method; on the other hand, in No.
The difference in the mixed fiber yarn (), which is an example of the present invention, is slight. In the actual relaxation of textiles, intermediate treatment conditions of the boiling water treatment mentioned above are used, and the effects of heat on the textiles are more complex. It is understood that shrinkage spots occur in woven fabrics unless they are relaxed with sufficient care, whereas shrinkage spots do not occur in the case of the mixed fiber yarn of the present invention because they are less affected by processing conditions. Next, we investigated the reduction in BWS due to the twist set of the twisted yarn. Using the above two types of mixed fiber yarn, the number of additional twists
Twist the yarn at 800T/m(S) and set the twisting set at the temperature
This was carried out at 80° C. for 30 minutes, after which the BWS of the yarn was measured. The results are shown in Table 2.

[Table] What is noteworthy about these results is that for the conventional type yarn (), the BWS decreased by 10.4 due to the twist set.
In this case, since the BWS was as low as 6.1%, the crimp rate did not increase much even after relaxing after weaving, and the drapability was insufficient. Additionally, there was a 3.6% difference in BWS between the inner and outer layers of the no-twist set bobbin, which manifested as a difference in dyeing in the fabric. Generally, the difference between the inner and outer layers of BWS must be kept within 2.5% to allow for differences in dyeing. In this way, with conventional blended yarns, the BWS decreases due to the twist set, so it is necessary to use raw yarn with a high BWS.
Then, the inner and outer layers of the bobbin will be
The problem is that the BWS difference becomes large. On the other hand, with the blended yarn of the present invention (), the decrease in BWS due to twist setting is as small as 1.4, and even after setting, it is only 10%
Since the above BWS is maintained, the crimp rate increases due to weaving relaxation, and a high drape fabric that could not be obtained with conventional mixed fiber yarns was obtained.
In addition, the BWS difference between the inner and outer layers of the bobbin was as small as 0.4%, and no difference in dyeing was observed. According to the blended yarn of the present invention, there is no need for special relaxation conditions or low-temperature twist sets that tend to cause weaving troubles, as described above, and it can be easily twisted in normal handling, which cannot be achieved with conventional blended yarns. It is possible to obtain fabrics with high drape properties that were previously unattainable. Example BWS5.4%, 50d/100f polyester multifilament yarn (filament thickness 0.5de) was used as the low shrinkage component yarn, and round cross section brights No. 1 to No. 11 shown in Table 3 were used as the high shrinkage component yarn. Using 30d/12f, mixed fibers with an interlace degree of 60/m, each
It was made of 80d/48f different shrinkage mixed fiber yarn. The item of high shrinkage component yarn in Table 3 is that the high shrinkage component yarn is produced by heat-shrinking crystallization at a fixed length using undrawn yarn at the spinning speed and Δn shown in the table, and then drawing it. , the BWS and Xρ of drawn yarn, that is, high shrinkage component yarn, are listed. Note that No. 9 and No. 10 were simply stretched at room temperature without being crystallized by heat treatment. The section on blended yarn properties shows BWS and twist set (800T/m) of blended yarn.
The figure shows the BWS of the inner and outer layers of the bobbin (after additional twisting and setting at 80°C for 30 minutes). Fabric evaluation was conducted on lightly twisted fabrics and heavily twisted fabrics. In other words, the soft twist fabric is 300T/m in different shrinkage mixed fiber yarn.
(S) additional twisting is applied without heat setting.
Habutae was woven at a density of 130 threads/3.79cm and a weft of 126 threads/3.79cm. In addition, high twist fabrics are made of different shrinkage mixed fiber yarns.
Additional twists of 2400T/m (S) and (Z) were applied, and the twist was set at a temperature of 80℃ for 30 minutes, with two (S) and (Z) twisted alternately, warp 120/3.79 cm, weft 115/ The jersey was woven at a density of 3.79 cm. In these finishing processes, the relaxation process that causes shrinkage is important in terms of texture, but the yarn of the present invention uses special conditions such as gradually and carefully raising the temperature from room temperature like conventional mixed fiber yarns. Since it is characterized by the ability to uniformly relax even without using water, we adopted a method of directly adding it to the boil bath.
%) was applied. The dyed finished fabric was visually evaluated for relaxation spots and dyeing spots, and the fullness, drapability, and soft touch were sensitively evaluated by touch.

【table】

[Table] No. 1 is a comparative example, with high BWS but Xρ of 35
%, the difference in BWS between the loading method and the heating method was large, and even when the twist was set, the BWS difference between the inner and outer layers of the bobbin was large, resulting in relaxation spots and dyeing spots. No. 2 is also a comparative example,
BWS is less than 10%, so drapability is lacking. No. 3 to No. 8 are examples of the present invention, with high shrinkage components.
Since the BWS was 10% or more and the Xρ was 35% or more, there were no uneven finishes and excellent drapability. Among them, Nos. 5 to 7, which simultaneously satisfied BWS≧12% and Xρ≧38%, were particularly excellent. No.9 and No.11 are comparative examples and have high BWS, but Xρ
Because of the low quality, the drapability was uneven, but the finish was uneven. No. 10 is also a comparative example and had the same problem as No. 1 because of its low Xρ.

Claims (1)

[Claims] 1. A blended yarn in which multifilament yarns with different heat shrinkage rates are mixed, wherein the low shrinkage component yarn has a single yarn fineness.
It is a multifilament yarn of 0.7 denier or less,
A blended yarn characterized in that the high shrinkage component yarn is a polyester fiber that simultaneously satisfies (a) boiling water shrinkage rate ≧10% and (b) crystallinity ≧35%. 2. The mixed fiber yarn according to claim 1, wherein the high shrinkage component yarn has (a) boiling water shrinkage rate≧12% and (b) crystallinity≧38%.