JPH0518935B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to a method for producing abrasion-resistant polyester crimped yarn useful for athletic clothing, and more specifically, it has significantly improved abrasion resistance during sliding and has a good texture. This invention relates to a method for manufacturing polyester crimped yarn for athletic clothing, including baseball uniforms. (Prior art) Polyester fibers, especially polyester fibers mainly composed of polyethylene terephthalate, are highly crystalline and have a high softening point, so they have excellent mechanical properties such as strength and elongation, as well as heat resistance and chemical resistance. It exhibits excellent performance in terms of durability and other properties, and is widely used in the fields of industrial materials and clothing. As a manufacturing method for polyester crimped yarn used in the clothing field, polyester having an intrinsic viscosity of about 0.60 is spun at a spinning speed of about 1000 m/min, and then stretched at a draw ratio of about 3.5 times. False twisting of drawn yarn is well known, and 3000
A POY-DTY method is known in which partially oriented yarn spun at a speed of around m/min is also subjected to false twisting at the same time as drawing (Japanese Patent Laid-Open No. 48-35112, Japanese Patent Laid-Open No. 49-522, etc.). However, when the polyester crimped yarn obtained by this method is used for sports clothing, the abrasion resistance during sliding is insufficient, the fibers easily break, and the phenomenon of holes in the fabric occurs. . One of the reasons for this is thought to be that the strength of the constituent filaments is not sufficient. As a countermeasure to this problem, attempts have been made to increase the stretching ratio during stretching and false twist processing of high-strength, low-elongation type filaments. Although the polyester crimped yarn obtained by this method can certainly have higher strength than conventional clothing fibers, its abrasion resistance during sliding is still satisfactory when used as athletic clothing. It is not something that will be done. (Object of the Invention) The object of the present invention is to improve the abrasion resistance of polyester crimped yarn, thereby providing a good texture and improved abrasion resistance to athletic clothing such as baseball uniforms that are frequently used for sliding. It is to give gender. (Structure and operation of the invention) As a result of intensive studies to achieve the above object, the present inventors have determined that once an undrawn polyester yarn in which the intrinsic viscosity of polyester and the melt spinning speed of the polyester are within a specific range, It has been discovered that a physical education clothing material made of polyester crimped yarn obtained by false twisting after stretching and heat treatment has significantly improved abrasion resistance due to sliding etc. compared to conventional materials, and has developed the present invention. I reached it. That is, the present invention has an intrinsic viscosity of 0.71 or more with ethylene terephthalate units as the main repeating unit.
Spun yarn obtained by melt-spinning polyester having a weight of 0.99 or less at a spinning speed of 2000 m/min to 3500 m/min,
So that the strength is 5.1 g/d or more, the single fiber strength is 15.9 g or more, the elongation is 33% or less, and the boiling water shrinkage is 8.0% or less.
A wear-resistant polyester crimped yarn characterized by being stretched at a draw ratio of 1.95 to 2.25, heat treated at 120 to 220°C, and then subjected to two-stage heater false twisting under a false combustion coefficient of 0.85 or more and 0.95 or less. This is the manufacturing method. The present invention will be explained in more detail. The polyester used in the present invention mainly refers to polyethylene terephthalate unit polymers, but may also be polyester copolymers containing 90 mol% or more of ethylene terephthalate. In the latter copolymer, the third component that can be copolymerized with the terephthalic acid component and the ethylene glycol component is:
Examples include isophthalic acid, 2,6-naphthalenedicarboxylic acid, adipic acid, oxalic acid, trimellitic acid, pyromellitic acid, diethylene glycol, cyclohexanedimethanol, pentaerythritol, P-oxybenzoic acid, and functional derivatives thereof. Further, these polyesters may contain modifiers and fillers such as a dissipating agent, a stabilizer, a flame retardant, an antistatic agent, a coloring agent, a crystallization accelerator, and a crystallization inhibitor. Here, the intrinsic viscosity of polyester is 0.71 or more
It must be 0.99 or less. When the intrinsic viscosity is less than 0.71, mechanical properties such as strength, fatigue resistance, and abrasion resistance are insufficient. On the other hand, the intrinsic viscosity is 0.99
If this value is exceeded, thread breakage directly under the spinneret will occur frequently during spinning of raw thread, making stable spinning difficult. Furthermore, single fiber breakage is likely to occur during stretching, making it difficult to obtain stable performance. Next, a spun yarn obtained by melt-spinning the above polyester at a spinning speed of usually 2000 to 3500 m/min, with a strength of 5.1 g/d or more,
After stretching at a stretching ratio of 1.95 to 2.25 so that the single fiber strength is 15.9 g or more, elongation is 33% or less, and boiling water shrinkage is 8.0% or less, heat treatment is performed at 120 to 220°C, and then two-stage heater false twisting is performed. It is necessary. Here, if the melt spinning speed is less than 2000 m/min, the birefringence index of the spun yarn becomes too low and it becomes possible to draw at a high magnification in the subsequent drawing and heat treatment process, so the obtained polyester drawn yarn , has mechanical properties of high strength and high Young's modulus. However, when such polyester drawn yarn is subjected to false twist processing, the abrasion resistance for use as sports clothing is not sufficiently improved, and the dimensional stability is also insufficient. On the other hand, when the melt spinning speed exceeds 3500 m/min,
If the birefringence of the spun yarn becomes too high, even if it is subjected to the drawing and heat treatment of the present invention as well as subsequent false twisting, the resulting crimped yarn will have low strength and its abrasion resistance due to sliding etc. will also improve. Not done. The obtained spun yarn is drawn and heat treated, and in this case, the strength, elongation, single fiber tenacity, and boiling water shrinkage of the drawn yarn are important factors. That is, when the strength of the drawn yarn is less than 5.1 g/d and the elongation exceeds 33%, the molecular orientation caused by the drawing is insufficient, resulting in insufficient mechanical properties for obtaining good abrasion resistance. Furthermore, if the single fiber strength is less than 15.9 g, the abrasion resistance (during sliding) will not be improved. Also,
If the boiling water shrinkage rate exceeds 8.0%, it is not only difficult to obtain a high-strength polyester drawn yarn, but also the cross-sectional aspect ratio of the polyester crimped yarn after false twisting increases, resulting in a decrease in abrasion resistance during sliding. do. Strength 5.1g/d or more, elongation 33 as intended by the present invention
% or less, single fiber strength 15.9g or more and boiling water shrinkage rate
In order to obtain a drawn yarn of 8.0% or less, the spun yarn may be drawn at a draw ratio of 1.95 to 2.25 and then heat treated (heat set) at 120 to 220°C. The polyester yarn thus drawn and heat-treated is then subjected to two-stage heater false twisting with a false twist coefficient (α) of 0.85 or more and 0.95 or less. Here, the false twist coefficient α is defined as follows in the case of polyester yarn. α=TW/32500/vDe However, TW: Number of false twists (T/m) De: Total yarn denier after false twisting When false twisting is performed with α less than 0.85, the strength of the resulting polyester crimped yarn The decline will be lower, but
The crimp rate decreases, the torque, especially the torque during boiling water development or dyeing increases, and when it is made into a fabric, the texture due to mesh becomes poor, making it unsuitable for use as sports clothing. Furthermore, when false twisting is performed with α exceeding 0.95, the strength decreases significantly and the cross-sectional aspect ratio of the single fibers increases, resulting in poor abrasion resistance during sliding. In addition, since athletic clothing requires vigorous body movements, highly stretchable clothing is preferred, and therefore knitted fabrics are often used. Therefore, when knitted fabrics are made, it is preferred that the stitches have a clean appearance. Therefore, knitted fabrics that exhibit stitches without diagonal properties are produced by heat-treating the false twisted yarn while running it continuously in an overfeed state to reduce the torque. It is preferable to Therefore, it is necessary to perform a two-stage heater false twisting process so that the torque developed after boiling water treatment is 50 or less per 25 cm of yarn length. (Function) In the present invention, it is necessary to once draw the spun yarn and then perform false twisting, which is called the so-called simultaneous drawing and false twisting method (DTY) in which drawing and false twisting are carried out simultaneously.
does not apply. This is because, with the DTY method, as shown in Comparative Example 1 below, it is not only difficult to obtain a high-strength polyester crimped yarn, but also the cross section tends to become flattened, resulting in a decrease in sliding abrasion resistance. . In other words, the purpose of the present invention is based on the premise that a sequential drawing false twisting process (including cases in which false twisting is performed after winding the drawn yarn) is adopted as a false twisting method, and in this case, the intrinsic viscosity of the polymer, the melt spinning This can only be achieved by setting the speed, physical properties of the drawn yarn, and α during false twisting within the range of the present invention. The polyester crimped yarn thus obtained must have a single fiber strength of 15.9 g or more. If the single fiber tenacity is less than 15.9 g, it becomes difficult to obtain a polyester crimped yarn that exhibits significantly improved abrasion resistance than conventional yarns, which is the object of the present invention. The single fiber strength mentioned here is a value calculated by the following formula. Single fiber strength (g) = strength (g/d) x single fiber denier (d) In the present invention, the reason for adopting single fiber strength is that, according to the research of the present inventors, it is possible to As a result of abrasion tests, it was found that the single fibers on the surface of the fibers in contact with the ground were gradually rubbed by friction, and after the single fibers were broken, the entire fiber was destroyed, so it was found that the strength of the polyester yarn was simply higher. This is because the polyester crimped yarn does not necessarily have improved abrasion resistance. That is, in order to obtain a polyester crimped yarn with improved abrasion resistance during sliding, it is necessary to increase the single fiber tenacity, which is the product of strength and single fiber denier. Therefore, the larger the single fiber denier, the lower the strength, but on the other hand, it gives the impression of being hard when worn, making it undesirable in terms of texture. Therefore, in order to balance the strength of the single fibers and the texture, the denier of the single fibers is preferably 3 deniers or more and 7 deniers or less. (Effects) As described above, the abrasion-resistant polyester crimped yarn provided by the present invention, which skillfully combines the intrinsic viscosity, melt spinning speed, physical properties, and drawn yarn physical properties of the polymer with sequential stretching and false twisting processing, is The abrasion resistance during sliding is significantly improved compared to the conventional case, and the texture when used as a knitted fabric is good.
Therefore, it has extremely great utility in the field of athletic clothing, such as baseball uniforms and training wear, where sliding is particularly required. Hereinafter, the present invention will be explained in detail with reference to Examples. In the Examples, each measurement value was measured by the following method. (a) Strength and elongation Using a tensile tester, the yarn length was 25 cm and the tensile speed was
Measure at room temperature at 200cm/min. (b) Developed torque Remove approximately 100cm of the sample from the pirn and apply a light load of 0.005g/d to the center. Suspend the load downward and secure both ends of the sample to the stand with tape. After the sample is immersed in boiling water until it stops rotating, it is attached to a test twister and untwisted. Measure the number of untwists per 25cm sample length. (c) Crimp ratio (TC) Apply a tension of 50 mg/d to the polyester crimped yarn and wind it around a skein frame to make a skein of approximately 3000 de. After making the skein, a load of 2 mg/d+200 mg/d is applied to one end of the skein, and the length l ₀ (cm) is measured after 1 minute has elapsed. Next, with a load of 200 mg/d removed.
Treat in boiling water at 100℃ for 20 minutes. After the boiling water treatment, a 2 mg/d load was removed and the sample was allowed to air dry for 24 hours. Add 2 mg/d+ again to the air-dried sample.
Length after 1 minute with a load of 200 mg/d
Measure l ₁ (cm). Next, a load of 200 mg/d was removed, the length l ₂ (cm) was measured after 1 minute had elapsed, and the crimp rate was calculated using the following formula. TC (%)=l ₁ −l ₂ /l ₀ ×100 (d) Abrasion resistance evaluation A 30 kg dummy is covered with a fabric knitted with the polyester crimped yarn of the present invention at a knitting density of about 300 g/m ² .
The test sample was driven by car at a speed of about 20 km/hr for 10 minutes.
It is pulled over a ground made of mountainous land containing 40 to 60% (by weight) of sand of 80 to 80 tons. 1000m
Fabrics with only a few single fiber breaks on the surface with almost no damage are considered to have good abrasion resistance (○), and those with loop breaks are considered to have insufficient abrasion resistance (△). Those with holes were marked (×) as having poor wear resistance. (e) Texture It was evaluated by a sensory test, and (○) was considered good and (x) was bad. Example 1 Intrinsic viscosity is 0.55, 0.64, 0.71, 0.80, 0.99 and
1.25 polyethylene terephthalate was melt-spun at a spinning speed of 2500 m/min, and the birefringence index was
Undrawn polyester yarns having a diameter of 0.023, 0.025, 0.030, 0.032, 0.034 and 0.046 were obtained. Next, the undrawn yarn was drawn at a drawing temperature of 89°C (constant), and the drawing ratio was
The heat setting temperature was appropriately changed as shown in Table 1, and a drawn yarn having a filament structure of 150 denier/48 filaments was obtained at a drawing speed of 500 m/min. This drawn yarn is false-twisted using a commercially available two-stage heater-type spindle false-twisting machine at a false-twist coefficient of 0.90 and a first-stage heater temperature of 215°C, and then continuously
By running it through the second stage heater set at 185℃ with 10% overfeed,
Relaxation heat treatment was performed. The false twisted yarn thus obtained was knitted with a 20 gauge Motsukuro Day to obtain a fabric for wear resistance testing. The physical properties of the drawn yarn, the physical properties of the crimped yarn, and the fabric properties are shown in Table 1. As is clear from Table 1, if the intrinsic viscosity of the polyester, the strength and elongation of the drawn yarn, and the heat shrinkage rate deviate from the range of the present invention, loop breaks and holes will occur, and the abrasion resistance will be poor or insufficient. I understand that there is something. That is, in the process of the present invention, if the intrinsic viscosity of the polymer is less than 0.71 (lower limit in the present invention) as shown in Nos. 1 to 3, no improvement in wear resistance can be expected. Furthermore, in the process of the present invention,
As shown in Nos. 4, 11, 12, 20, 21 and 25, when the physical properties of the drawn yarn do not satisfy the scope of the present invention, loop breakage occurs and the abrasion resistance is not improved. In addition, No. 26 has an intrinsic viscosity higher than 0.99, and during melt spinning, there are many single filament breakages, and the section unevenness of each filament is large. occurred frequently.

[Table] *: Comparative Example Example 2 Polyethylene terephthalate having an intrinsic viscosity of 0.71 was melt-spun at a spinning speed of 2500 m/min to obtain an undrawn polyethylene terephthalate yarn having a birefringence index of 0.030. The stretching temperature, stretching ratio, and heat setting temperature of this undrawn yarn were set to 87℃, 2.25, and 150℃, respectively.
Stretching heat treatment was performed under conditions of ℃ and the strength was 6.7.
A drawn polyester yarn having an elongation of 17%, a boiling water shrinkage rate of 4.8%, and a filament structure of 150 denier/48 filaments was obtained at a speed of 500 m/min. Next, the obtained drawn yarn was subjected to a false twisting coefficient of 0.80 using a commercially available two-stage heater type spindle false twisting machine.
Example 1 except that the settings were 0.85, 0.90, 0.95, and 1.0.
The false twisting process was carried out according to the method. For comparison, the material with a false twist coefficient set to 0.90 was wound directly onto a winder without passing through the second stage heater. The false twisted yarn thus obtained was knitted with a 20 gauge Motsukuro Day to prepare an abrasion resistance test fabric. These false twisting conditions, crimped yarn physical properties, and fabric properties are shown in Table 2. As is clear from Table 2, it was found that both texture and abrasion resistance were good only when the false twisting process was performed using the false twisting coefficient specified in the present invention.
It can be seen that those that do not use a two-stage heater have a high torque and have a poor texture when made into a fabric.

[Table] * Comparative Example Comparative Example 1 Polyethylene terephthalate with an intrinsic viscosity of 0.71 was melt-spun at a spinning speed of 3000 m/min.
An undrawn yarn of 270 denier/48 filaments was obtained. This undrawn yarn was drawn at a temperature of 200°C by a factor of 1.8, and at the same time was false-twisted with a false twisting coefficient of 0.90 (simultaneous stretching and false-twisting), and then continuously stretched to 180°C under 10% overfeed. Relaxation heat treatment was performed by running it through a set second-stage heater. The obtained polyester crimped yarn had a strength of 5.0 g/d, a single fiber tenacity of 17.1 g, an elongation of 20%, and a developed torque of 30 pieces/25 cm. However, in the same sliding abrasion test as in Example 1, The abrasion resistance was extremely poor, and holes had already appeared in the fabric after running 500 meters. This is because simultaneous stretching and false twisting caused a decrease in the strength of the crimped yarn and an excessive flattening of the single fiber cross section. That is, the radius R of the circumscribed circle and the radius r of the inscribed circle of the single fiber cross section are measured, and (R-r)/R
The flattening rate was calculated by ×100 (%) and expressed as the average of 10 pieces. Due to the flattening ratio being 46% and the decrease in single fiber strength, the flattening ratios of all of the products of the present invention are 30% or less, whereas those of the simultaneous stretching and false twisting are much more than 30%. In particular, when the stretching ratio of simultaneous stretching and false twisting is large or when α is large, the flatness becomes large. Even in the case of the sequential drawing/false-twisting process, if the boiling water shrinkage rate of the drawn yarn characteristics exceeds 10%, the flatness of the false-twisted yarn will exceed 30% and the abrasion resistance will deteriorate.

Claims (1)

[Claims] 1. A spun yarn obtained by melt spinning a polyester having an ethylene terephthalate unit as a main repeating unit and having an intrinsic viscosity of 0.71 or more and 0.99 or less at a spinning speed of 2000 m/min or more and 3500 m/min or less, with a strength of 5.1 g. /d or more,
After stretching at a stretching ratio of 1.95 to 2.25 so that the single fiber strength is 15.9 g or more, elongation of 33% or less, and boiling water shrinkage of 8.0% or less, heat treatment is performed at 120 to 220°C, and then false twisting of 0.85 or more and 0.95 or less A method for producing a wear-resistant polyester crimped yarn, characterized by performing two-stage heater false twisting under a constant temperature. 2. The method for producing a wear-resistant polyester crimped yarn according to claim 1, wherein a two-stage heater false twisting process is performed so that the developed torque of the crimped yarn is 50 or less per 25 cm of yarn length.