JPS6335740B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to a method for producing a strong linen knitted fabric. More specifically, even though synthetic fiber yarn is used, it is possible to express the excellent graininess and texture of the high quality seen in conventional silk, and to avoid ground cracking (occurrence of pinholes) during the production of strong linen knitted fabrics. The present invention relates to a method for producing a high-grade, high-quality strong linen knitted fabric that is less likely to form horns and horns. (Prior Art) Many methods have been known for producing strong linen knitted fabrics using synthetic fibers, but none of these methods produce strong linen knitted fabrics that have the same graininess and texture as conventional silk. At present, we have not reached the point where we can manufacture it. In other words, conventionally, when producing strong linen knitted fabrics,
In order to temporarily fix the twist of the strong cotton yarn and to make it easier to handle in the weaving and weaving preparation process, weaving and weaving process, etc. without reducing the stiffness and shrinkage rate, it is necessary to It is necessary to twist and fix the yarn using high-temperature heat. However, the temporary twist fixing treatment at such high temperatures itself causes thermal deformation of the synthetic fiber yarn.
This resulted in a reduction in the degree of shattering and shattering shrinkage rate. For this reason, it has been difficult to stably and rationally produce grained knitted fabrics of satisfactory quality. From this point of view, as a method to improve the graininess and grain quality, Japanese Patent Application Laid-Open No. 106840/1983 discloses a boiling water shrinkage rate of 0 to 5% and a heat shrinkage stress of 0.03 at dry heat of 140°C. g/d or more and dry heat 140℃
A method is described in which a strong fiber is applied to a polyester filament in which the ratio of the heat shrinkage stress at 180°C to the heat shrinkage stress at 180°C is 1.0 or more, and then set to prevent twisting by steaming at 70 to 130°C. According to their various studies,
It seems that the magnitude of the heat shrinkage stress values at dry heat of 140°C and 180°C does not necessarily correspond to the quality of graininess, and the invention described in the same publication does not obtain the thermal properties as described above. Therefore, a special strong heat treatment is adopted for this purpose.Generally, when heat treatment is performed, boiling water shrinkage rate naturally decreases, and as mentioned above, one of the requirements for the invention described in the same publication is It is believed that the shrinkage rate is specified as 0-5%. On the other hand, according to various studies conducted by the present inventors, in order to obtain a mild, elegant, and high-quality strong textured knitted fabric, which is the intended aim of the present invention, it is rather preferable that the boiling water shrinkage rate be small. When using a strong cotton yarn with a low shrinkage rate in boiling water, cracks in the ground (occurrence of pinholes) occur in the knitted fabric during the graining process after it is made into a fabric, and this creates the appearance of countless small holes in the fabric. This is not desirable in terms of quality, and there are many cases of horns, which are thought to be caused by the stress of unraveling being concentrated in specific areas during graining. is difficult to say. (Problems to be Solved by the Invention) An object of the present invention is to provide a method for producing a strong linen knitted fabric in which the above-mentioned drawbacks of the prior art are improved. Another object of the present invention is to provide a method for producing a strong linen knitted fabric that is easy to handle, has good grain resistance and grain quality, and is mild, high quality, and elegant. It is. (Means for Solving the Problems) The method for producing a strong linen knitted fabric of the present invention that achieves the above-mentioned object has the following configuration. In other words, "drawing and heat-setting polyester synthetic fiber yarn that exhibits characteristic values of boiling water shrinkage of 5% or more and 15% or less and crystallinity increase rate N (%) of 50% or less A method for producing a strong linen knitted fabric, which is characterized in that after being made into a raw yarn, the yarn is subjected to a strong linen process and a heat setting process to prevent twisting, and then subjected to knitting, weaving, and graining treatment.However, N ( %)=N ₁ −N ₀ /N ₀ ×100 where, N ₀ : Crystallinity of the yarn (%) N ₁ : Crystallinity (%) of the yarn after dry heat setting at 150°C. Note that the crystallinity increase rate N mentioned above is a value measured and defined by the following method. That is,
It is a value related to the stability of the internal structure of the yarn before and after heat setting when the yarn is heat set, and in the present invention, the details are defined as follows. (Note 1) Method for measuring crystallinity increase rate N (%):
The crystallinity N ₀ (%) of the test sample is determined by the usual density method (floating method). Next, the same sample is subjected to dry heat treatment at 150°C for 30 minutes, and the crystallinity N ₁ (%) of this thread is determined in the same manner. The rate of increase in crystallinity N (%) is determined from the values of N ₀ and N ₁ determined in this way using the above formula. (Function) The present invention will be explained in more detail below. The present inventors first applied crepe twist to current materials such as polyester, polyamide, rayon, silk, etc. around 150D (denier) under the same conditions, and compared and examined the appearance of the grain.
The results are shown in Table 1. From Table 1, it can be seen that the critical twist coefficient at which grain appears is around 17,000 for silk and rayon, while polyester requires a twist coefficient of around 26,000, and polyamide requires a twist coefficient of around 22,000.

【table】

[Table] In particular, as a result of repeated studies by the present inventors, the reason why conventional polyester-based synthetic fibers are significantly inferior in grain resistance compared to silk is that they are made to be easier to handle in the weaving process. First, it was found that when the twist prevention set was applied, the reduction in restoring torque due to the heat setting was extremely large.
That is, for example, when a strong cotton yarn with a twist coefficient K = 30,000 is set to prevent twisting at 60°C, surprisingly, the torque recovery rate after the setting is less than 60% of the torque before the setting. . The values of such torque recovery rates are also listed in Table 1. Another reason is that conventional synthetic fibers have high heat shrinkability and, along with this, high heat shrinkage stress development properties, which reduces the binding force of the fabric during graining. It is also thought that this may be due to the increase in the grain size and the deterioration of the graininess. On the other hand, swellable fibers such as silk and rayon generally have low heat shrinkage and, along with this, low heat shrinkage stress development.
Furthermore, even with twist prevention set, it is generally 90%
Since it has a characteristic that can be called a so-called low sensitivity to heat type that can maintain the above-mentioned torque recovery rate, it is considered that the strong fiber yarn is sufficiently loosened during graining. From the above points of view, the present inventors have developed a raw yarn made of polyester fibers that is most suitable for use in strong fabric and has a significantly small reduction in restoring torque even when heat set to prevent twisting is applied after the fabric has been fabricated. As a result of their investigation, they found that the boiling water shrinkage rate of the yarn was 5 (%) or more and 15 (%) or less, the crystallinity of the yarn was N ₀ (%), and the dry heat set at 150°C. The crystallinity of the raw yarn after that is N ₁ (%), and the yarn made of a polymer substance with a crystallinity increase rate N (%) defined above of 50 (%) or less is excellent as a raw yarn for strong cotton. They found that it had the best performance and was the most suitable. According to the various findings of the present inventors, the boiling water shrinkage rate of the raw yarn is an appropriate characteristic for the fabric of the strong linen fabric, based on the elongation rate in the vertical and horizontal directions after the embossed finishing process of the strong linen fabric. From this point of view, if the boiling water shrinkage rate of the yarn for strong cotton fabric is less than 5 (%), the aforementioned torque recovery rate will be too large and the width will be increased after the graining. will pop out and the surface of the fabric will become ugly. Furthermore, the elongation rate of the product is too high, resulting in unfavorable phenomena in terms of dimensional stability, such as grain bending and sagging. In addition, cracks in the ground as described above are likely to occur, and numerous pinholes impair the quality. On the other hand, when the fabric has an appropriate boiling water shrinkage rate as specified in the present invention, the fabric shrinks appropriately during graining, so pinholes are less likely to occur. This prevents the stress of the unraveled noodles from concentrating in one place during vertical processing, thereby suppressing the occurrence of horns or kinks. On the other hand, if the boiling water shrinkage rate is greater than 15%, the elongation rate is too low and only a flat texture can be obtained. Therefore, a boiling water shrinkage rate of 5% or more and 15% or less as defined in the text can provide a strong linen fabric with a desirable quality. Furthermore, the raw yarn for strong cotton whose crystallinity increase rate N satisfies the above-mentioned range is a yarn with low sensitivity to heat, and can be used to prevent twisting of strong cotton. The heat-set yarn has a high torque recovery rate of 80% or more, often 90% or more, and can exhibit extremely superior graininess and texture compared to conventional polyester synthetic fibers. A high-strength synthetic fiber yarn can be provided which generally exhibits a grain limit twist coefficient of less than 21,000. In particular, those with a crystallinity increase rate of 45% or less exhibit excellent properties as fibers for strong cotton fibers. If the crystallinity increase rate is greater than 50 (%), the crystallization of the yarn has not progressed sufficiently, that is, the internal structure is unstable, which is undesirable. If the value of the increase rate of degree of hardening is outside the range mentioned above, it is impossible to obtain good graininess or texture even if the strong tension conditions, heat setting conditions for preventing twisting, etc. are changed. The raw yarn for strong cotton used in the method of the present invention is generally made of the following strong cotton yarn, which is subjected to a special heat setting treatment before the strong cotton process, and is further subjected to a special tension treatment after that. It can be manufactured simply and rationally by using the manufacturing process of raw yarn. That is, spinning is performed using a normal melt spinning machine. Further, the cross-sectional shape of the fibers does not necessarily have to be a circular cross-section, but may be a modified cross-section, or, if necessary, may be a combined cross-section made of different polymers. Further, the spinning temperature varies depending on the components used, but is preferably in the range of 170°C to 290°C. The obtained undrawn yarn is subjected to stretching, and the heat setting conditions applied at this time are one of the first important requirements in obtaining the above-mentioned raw yarn. That is, specifically, FIG. 1 is a process schematic diagram showing the manufacturing process of the raw yarn, in which the undrawn yarn 1 obtained as described above is hot-stretched under normal conditions in a stretching zone 2. This is followed by a tension or relaxation heat treatment in the heat setting zone 3 that is stronger than usual. To explain this point in more detail, the heat setting conditions that can be adopted to obtain the yarn are such that in heat setting zone 3, the hot plate temperature is 140°C or higher, preferably around 190°C;
In addition, in the case of relaxation heat setting, the overfeed rate in the heat setting zone is operated within the range of 0 to 16%, preferably 0 to 5.0%.
In addition, in the case of tension heat setting, the overfeed rate is operated within the range of 0 to -10%, preferably 0 to -10%.
A range of 4.0% is preferred. By adopting such conditions, the contraction behavior of the yarn is actively induced, the orientation and crystallinity are promoted, and a remarkable change is caused, and the above-mentioned crystallinity increase rate is reduced to 50 (%). ) or below.
That is, it performs low heat sensitivity processing. Figure 2 shows the rate of increase in crystallinity by 50 as in Figure 1.
(%) or less. That is, a process outline will be shown in which the above-mentioned undrawn yarn is subjected to temporary twisting at the same time as drawing to impart desired yarn characteristics. In this case, the undrawn yarn 1 is temporarily twisted in the drawn temporary twist zone 2' under normal conditions, and then in the heat set zone 3, it is subjected to a tension or relaxation heat treatment that is stronger than usual. be. The detailed conditions at this time may be substantially the same as those for the embodiment shown in FIG. FIG. 3 shows yet another embodiment that can exhibit a similar effect of reducing the rate of increase in crystallinity. That is, an example will be shown in which the above-mentioned undrawn yarn 1 is made into a drawn yarn or temporarily twisted yarn in a normal state, and this is heat-set in a separate process to impart desired yarn characteristics. In this case, batch-type heat-setting may be performed on the drawn yarn or pre-twisted yarn while it remains in the shape of a paan, cheese 7, cake 8, skein 6, etc., or continuous heat-setting is performed in which heat-setting is performed while it is running. This process imparts the above-mentioned yarn properties. The detailed processing conditions for batch heat setting are as follows: The spool is placed in a wet heat setting machine or a dry heat setting machine, and the heat setting temperature is 100°C to 150°C in the case of moist heat or 120°C to 200°C in the case of dry heat.
before use. On the other hand, detailed processing conditions for continuous heat setting can be achieved by employing almost the same conditions used in heat setting zone 3 in FIG. 1. By performing the heat treatment as described above, the rate of increase in crystallinity can be lowered to 50 (%) or less. Furthermore, since the boiling water shrinkage rate of the yarn has been reduced by such heat treatment, the boiling water shrinkage rate is then increased from 5 to 15% while keeping the crystallinity increase rate substantially unchanged.
The second important requirement is to apply a special treatment to increase the temperature to 20%, and applying tension treatment is effective for this purpose. It is effective to perform tension treatment at a stretching rate of about 5 to 10%. By adopting the special heat-setting treatment conditions and tension treatment conditions before the toughening process as described above, it is possible to achieve a boiling water shrinkage rate of 5 to 15% without the need to make any major changes to the conventional equipment. It becomes possible to easily and rationally produce a preferable raw yarn for strong cotton fibers with a crystallinity increase rate of 50 (%) or less. Typical yarn properties of the polyester fiber yarn for strong cotton used in the method of the present invention obtained as described above are shown in Table 2. In addition, in the present invention, polyester fibers have particularly good heat setting properties, and therefore exhibit remarkable effects. When using other fibers, even if there is a difference in effectiveness between cases that satisfy the thermal property values of the yarn for high-strength fabric stipulated in the present invention and cases that do not, it is difficult to say that the difference is that large. It is. The raw yarn for strong fabric obtained as described above is coated with strong fabric and is further set to prevent twisting. Next, it is made into a fabric and subjected to a grain treatment. In the method of the present invention, the degree of strength is not particularly limited, but preferably the twist coefficient K is
It is preferably around 21,000 or more, more preferably 25,000 or more. As mentioned above, the yarn used for the strong fabric of the present invention generally has a fairly low limit twist coefficient of less than about 21,000 for producing grain. By applying a strong fiber having K of preferably 25,000 or more, an even more elegant strong fiber knitted fabric can be obtained. It is best to set the product to prevent twisting using moist heat of 80°C or higher. Even if the yarn is coated with the above-mentioned strong fibers, it is best to set it under such high temperature conditions in order to make it easier to handle, and it is better to use steam for moist heat setting. The steam heat set is the most practical. The grain raising process is a method that can be used as is, and it is possible to obtain good grain raising properties, grain quality, and an elegant appearance without using special grain raising treatment conditions. This is also the gist of the present invention. In addition, in the above, the twist coefficient K is a value obtained by K=T×√. However, T: Number of twists (times/m) D: Thread fineness (denier).

[Table] (Effects of the invention) The raw yarn for strong linen as described above used in the method for producing the strong linen knitted fabric of the present invention has high internal structure orientation and crystallinity, so It can be said to be a low-sensitivity type, and the torque recovery rate can be maintained at an extremely high level even when a high-temperature heat setting is applied to prevent twisting after applying strong reinforcement. As a result, by making good use of this yarn and using the method of the present invention, it is possible to obtain excellent graininess and grain quality as described above, as well as a mild, high-grade, high-quality, and elegant appearance and characteristics. This makes it possible to produce strong linen knitted fabrics that exhibit the following properties. Hereinafter, the specific structure and structure of the present invention will be explained based on the examples.
Explain the effects. Example 1 According to the process shown in Figure 1, a normal polyester component was melt-spun at a spindle temperature of 285°C, and at 85°C it was 3.6
It was hot-stretched to double its original size and then heat-set at an overfeed rate of 2.0% and a heat-set temperature of 180°C.
The yarn thus obtained has a stretch rate of 8% at room temperature.
Tension treatment was performed under these conditions. The obtained thread is
150 denier, and the rate of increase in crystallinity is
48 (%), and the boiling water shrinkage rate was 8.0%. On the other hand, in normal yarn heat-set at a heat-setting temperature of 95°C with an overfeed rate of 0, the crystallinity increase rate is 70 (%).
The boiling water shrinkage rate was 18%. These yarns have a twist coefficient K=30000 (S)
After applying the strong cotton fibers (Z), the twist was temporarily fixed with moist heat at 85℃, and after weaving Futakoshi crepe using these strong fiber yarns as the weft yarn, weaved it with hot water at 98℃. When graining treatment was carried out, it was found that the fibers using the raw yarn for strong cotton according to the present invention had extremely good grain quality and texture, and were of excellent quality with an elegant feel compared to conventional yarns. I was able to obtain a grained fabric. In addition, the material using the yarn for strong cloth according to the present invention has a grain limit twist coefficient.
It showed a value of around 17,000, and the torque recovery rate when temporarily fixing the twist mentioned above showed a value of 90%. Example 2 A conventional polyester component was melt-spun at a spindle temperature of 275°C to obtain an undrawn yarn. Subsequently, according to the process shown in FIG. 2, temporary twisting was performed at the same time as stretching, and heat setting was performed at an overfeed rate of 7.5% and a heat setting temperature of 190°C to obtain a 150 denier yarn. The yarn thus obtained was subjected to tension treatment at a dry heat temperature of 60°C and a stretching rate of 10%. The crystallinity increase rate of this yarn was 45%. The raw yarn for such strong cotton has a grain limit twist coefficient.
18000, showing excellent grain expression. Example 3 Ordinary polybutylene polymer was used at a mouth temperature of 235°C.
It was melt-spun at 70°C and hot-stretched to 3.5 times. The yarn thus obtained was subjected to a tension treatment using dry heat at 60°C and a stretching rate of 10%. The obtained drawn yarn has a denier of 75, a boiling water shrinkage rate of 12 (%), and a crystallinity increase rate of
It was 47 (%). This yarn is coated with a strong yarn with a twist coefficient of 11,000, and the twist is temporarily fixed by moist heat at 90℃, and then a warp yarn of 75 denier is used to create a textured yarn with a warp and width density of 70 yarns/2.54cm. As a result, the wrinkle shrinkage rate was 67%. The grain texture was also good. (Note 2) Definition of torque recovery rate R (%): As a test sample, a drawn yarn with a fineness of around 75 denier is used, and this yarn has a twist coefficient K.
= Center load 2 after applying S twist strength of 25000
mg/d and immersed in hot water for 5 minutes,
Measure the number of thread stops (T/M), and determine the degree of stiffness R ₀ (-) of the thread by using the following formula. R ₀ (-) = Number of kinks on the fabric yarn T/M x √ 2 x fineness () In the same way, the strong fabric fabric was set in a vacuum for 40 minutes at 85°C, and then immersed in hot water for 5 minutes. After that, the number of set failures (T/M) is measured, and the degree of set failure R ₁ (-) is determined by the following equation. R ₁ (-)=Number of set rises (T/M) x √2 x fineness () From the values of R ₀ and R ₁ obtained in this way, the torque recovery rate R is determined by the following equation. R (%) = R ₁ /R ₀ ×100

[Brief explanation of the drawing]

FIGS. 1, 2, and 3 are diagrams showing an example of the manufacturing process of drawn heat-set raw yarn for strong cotton fabric used in the method for producing strong cotton fabrics of the present invention. 1: Undrawn yarn, 2: Stretching zone, 2': Stretched temporary twist zone, 3: Heat setting zone, 4: Pern,
5: temporary spindle, 6: skein, 7: cheese,
8: Cake.

Claims (1)

[Scope of Claims] 1 Polyester synthetic fiber yarn is stretched and heat-set to have a boiling water shrinkage rate of 5% or more and 15% or less, and a crystallinity increase rate N (%) as defined below of 50% or less. After forming a drawn heat-set raw yarn exhibiting characteristic values, the yarn is subjected to a strengthening process and a heat-setting process to prevent twisting,
A method for producing a strong linen knitted fabric, which is then subjected to knitting, weaving, and graining treatment. However, the rate of increase in crystallinity N (%) is a value determined by N (%) = {(N ₁ −N ₀ )/N ₀ }×100. Here, N ₀ : Crystallinity of the yarn (%) N ₁ : Crystallinity of the yarn after dry heat setting at 150°C (%)