JPS6342007B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a polyester yarn, and more particularly to a method for producing a high-twist polyester yarn having a high degree of wrinkleability. When producing a polyester strongly twisted woven or knitted fabric, the highly twisted yarn is usually twisted at high temperature (twist set) to facilitate handling of the yarn during the weaving and knitting process or its preparation process. However, such temporary twisting and fixing treatment at high temperatures thermally deforms the polyester fiber structure and also reduces grain development, making it difficult to obtain grained woven or knitted fabrics of satisfactory quality. Ta. In particular, when weaving polyester strongly twisted yarn in a water jet room with high productivity, the twist must be fixed to a higher degree than when weaving on a general shuttle loom, and therefore the weaving temperature is correspondingly higher. At present, the fiber structure undergoes significant thermal deformation because the twisting is stopped and the desired texture is almost impossible to obtain. The object of the present invention is to solve the above-mentioned problems, and is capable of sufficiently fixing the twist even though the twist is set at a low temperature, and when it is made into a woven or knitted fabric, it is possible to prevent the grain from forming. The purpose of the present invention is to provide a method for thoroughly producing a high-twist polyester yarn, which has better texture and grain quality than conventional polyester, through a spinning process. According to the present invention, polyethylene terephthalate (C ₂ T) is 20 to 90 wt% of the total amount, and polytrimethylene terephthalate (C ₃ T) or/and polytetramethylene terephthalate (C ₄ T) is 80 to 90 wt% of the total amount.
A polyester composition blended at a ratio of 10 wt% is melted and discharged, cooled, heat treated using at least one heating roller, and cut at a speed of 3500 m/min or more until the single yarn fineness is 2.2 de or less. The elongation
Provided is a method for producing a high-twist polyester yarn, which is characterized in that it is wound as a multifilament with a boiling water shrinkage rate of 60% or less and a boiling water shrinkage rate of 7% or less. An important condition in the polyester composition in the present invention is the above-mentioned C ₂ T and C ₃ T, or C ₂ T and C ₄ T, or C ₂ T.
The point is that polyalkylene terephthalates with different carbon numbers in the glycol component, such as C ₃ T and C ₄ T, are combined together as a blend. Since these polyalkylene terephthalates have similar chemical structures, the polymers have good compatibility with each other, and in general, they can be mixed in any ratio to form yarn. However, in the present invention, C ₂ T needs to account for 20 to 90 wt% of the total amount. If the amount of C ₂ T is less than 20 wt%, the texture of the textured fabric tends to deteriorate, and if it exceeds 90 wt%, the low temperature setting property, which is the objective of the present invention, will be lost. . Furthermore, the total amount of C ₃ T and/or C ₄ T
It is necessary that it be 80 to 10 wt%. If the amount exceeds 80 wt%, the texture of the textured fabric will have a strong rubbery, slimy feel, which is undesirable, and the twist fixation will also deteriorate. On the other hand, if the amount is less than 10 wt%, both the twist fixation at low temperatures and the appearance of grain after forming into a woven or knitted fabric will be insufficient. Furthermore, the polyester yarn of the present invention has a breaking elongation of 60
% or less, and the boiling water shrinkage rate must be 7% or less. If the cutting elongation exceeds 60%, the handling of the yarn during the weaving and knitting process and its preparation process will be poor. In addition, if the elongation exceeds 60% or the boiling water shrinkage exceeds 7%, the fiber structure of the polyester yarn is not thermodynamically stable enough, so high twist-fixation is not possible. Structural deformation during the process
Relaxation occurs, and most of the restoring power for graining is lost. As mentioned above, the polyester yarn of the present invention has C ₂ T and/or C ₃ T and/or C ₄ T as its main components, but it also contains polymers and low-carbon materials for various purposes in an amount of 5 wt% or less of the total amount. There is no problem even if molecules or organic and inorganic substances are blended and/or copolymerized. Blending of polyalkylene terephthalates in the present invention may be carried out during the polymerization process of the polymers, or may be achieved by chip-blending them after polymerization. The above polyester yarns are ordinary melt-spun yarns.
It is also possible to spin yarn in separate steps, such as winding, stretching, heat treatment, and winding. However, if high-speed spinning - direct reeling is used to complete spinning of high-twist raw yarn only in the spinning process, in addition to streamlining post-processing processes such as weaving and embossing, it is possible to significantly streamline the raw yarn manufacturing stage. can. There have been many reports on high-speed spinning of polyethylene terephthalate - direct spinning, and at a winding speed of 5,000 to 6,000 m/min, the elongation at break of the wound yarn is approximately 60%. however,
In the polyester composition used in the present invention,
The C ₃ T or C ₄ T molecular chains are elongated more effectively during the high-speed spinning process, and as a result, even at a take-up speed of 4000 to 5000 m/min, the cutting elongation can be kept at 60% or less. In particular, when the single fiber fineness is 2.2 de or less, the cooling rate of the melt-discharged filament becomes faster, and even after cooling and solidifying, the effect of stretching molecular chains due to friction with air becomes relatively large.
It has been found that yarns with an elongation of 40 to 60% can be obtained even at a fairly low spinning speed of 3500 m/min. On the other hand, if the single fiber exceeds 2.2 DE, not only the above-mentioned stretching effect will be reduced, but also the texture of the highly twisted fabric will be undesirable as it will have a strong rough and hard feel. Further, if the spinning speed is less than 3500 m/min, it is usually difficult to suppress the cutting elongation of the wound yarn to 60% or less. After the spun yarn is cooled and solidified, it is necessary to undergo heat treatment using at least one heating roller before it is wound up. If the heat treatment is not performed, crystal formation in the spun yarn will be insufficient, and the boiling water shrinkage rate of the wound yarn will exceed 7%, resulting in poor grain development as a highly twisted yarn. The surface temperature of the heating roller and the contact time with the yarn vary depending on the winding speed and the desired grained fabric quality, but are generally 180°C (preferably 200°C) or higher and 0.01 seconds (preferably 0.03 seconds) or higher. is desirable. There are various ways to carry out this heat treatment, as shown in Figure 1, but they all involve one or more of the rollers placed between the oiling device (not shown) and the winder (W) during spinning. Anything beyond that is a heating roller. In the figure, a indicates roller 1,
b is an example in which rollers 2 and 3 are heated, and c is an example in which rollers 1 and 4 are heated. Of course, the present invention is not limited to heat treatment using only a heating roller; for example, as shown in c, a slit heater, a plate heater 5, or other heating means may be used as an auxiliary heating means. When the polyester yarn spun according to the present invention is made into a strongly twisted yarn as described above, it becomes possible to weave in a water jet room, which was previously impossible. Furthermore, since it has extremely excellent texturing properties, it also becomes possible to perform continuous texturing on highly twisted woven and knitted fabrics, which was previously impossible. These greatly reduce the cost of producing highly twisted woven and knitted fabrics. The present invention will be explained below with reference to Examples. Example 1 Intrinsic viscosity [η] = 0.64, TiO ₂ as a matting agent
C ₂ T containing 0.05 wt% (dried at 160°C for 4 hours) and C ₄ T with an intrinsic viscosity [η] = 0.86 (dried at 120°C for 6 hours) were blended in various proportions in the form of chips and heated at 285 to 295°C.
After melting, it was discharged from a spinneret having 72 round cross-section holes of 0.3 mm in diameter. The discharged yarn was cooled and oiled under normal conditions, and then wound into a 75de/72fil multifilament using the apparatus shown in FIG. 1-A. At this time, the set temperature of the heating roller is 200℃, the number of turns of the yarn around the heating roller is 12 turns, and the surface speed is 4000 m/
It was hot in minutes. Next, the above-mentioned wound yarn was twisted with an Italian twisting material to a number of twists of S2500T/M, and set by steam twisting at 90° C. using a steam-heating vacuum setter.
Table 1 shows the fiber physical properties, residual torque after twist setting, and torque developed by boiling water treatment for these spun wound yarns and highly twisted yarns. However, boiling water shrinkage rate: shrinkage rate when the sample yarn is immersed in boiling water in a free state for 15 minutes Untwisting torque after twisting and setting: A 100cm long piece of highly twisted yarn after twist setting is taken, and 2mg/ After applying a load of de, the number of double twists (T/50
cm) Untwisting torque developed in boiling water: Take a 100cm long piece of highly twisted yarn after untwisting, apply a load of 2 mg/de to the center, and then immerse both ends together in boiling water. Number of twists (T/50cm)

[Table] As can be seen from Table 1, in the case of No. 1 and 2
Even if C ₂ T is 100% or C ₄ T is contained, it is only a small amount, so the elongation of the spun yarn becomes high, and the untwisting torque after twisting and setting of the highly twisted yarn is also large, causing problems in the weaving process and other processes. Handling becomes extremely difficult. On the other hand, in No. 7 and 8, is C ₄ T 100%?
Even if C ₂ T is contained, it is only in a small amount, so the high elasticity of C ₄ T cannot be suppressed, and the residual torque after twist setting becomes high, resulting in poor weaving properties. On the other hand, in the case of Nos. 3 to 6, the elongation of the spun wound yarn is small, the residual torque after twisting and setting is also small, and the handleability in post-processing is much better. At this time, the boiling water shrinkage rate shows a slight increase, but the boiling water developing torque remains at a slight decrease, and the ability to develop grain can be sufficiently ensured. Example 2 The highly twisted yarn of Example 1 was used as the weft, and Root's C ₂ T multifilament (50de/36fil triangular cross section) was used as the warp to create Nissan WJL LW-41 (rotation speed 360 rpm).
Weaving was carried out by The woven fabric was scoured with a weak alkali and then embossed using a rotary washer (boil x 20 minutes).Table 2 shows the results.

[Table] In the case of the present invention (No. 3 to No. 6), weaving can be performed in a water jet room, and the texture is also good. Example 3 C ₂ T and C ₄ T from Example 1 were blended at a ratio of 70% to 30% and melt-spun under the same conditions as Example 1.
In this case, the speed of the heating roller and winder is set to 1000.
It was changed in the range of m/min to 6000 m/min. Table 3 shows the elongation of the spun yarn at this time.

[Table] As can be seen from Table 3, in the case of Nos. 1 and 2, the winding speed was low, so the cutting elongation was large, and the handling of the yarn in the post-processing process was poor. On the other hand, No. 3~
In No. 5, the cutting elongation was lower than 60% and there were no particular problems in handling. Example 4 C ₂ T and C ₄ T from Example 1 were blended at a ratio of 70% to 30% and melt-spun in the same manner as in Example 1. In this case, by changing the discharge amount variously, the single yarn de, the total
multifilaments with different de. Table 4 shows the elongation of the spun yarn at this time.

[Table] No. 1 has a large single yarn denier, so the cut elongation of the wound yarn is high. On the other hand, in Nos. 2 to 5, the elongation was lower than 60%, and there was no particular problem in handling in the post-processing process. Example 5 C ₂ T and C ₄ T from Example 1 were blended at a ratio of 70% to 30% and melt-spun in the same manner as in Example 1.
In this case, set the heating roller temperature to between room temperature and 230℃.
changed within the range. Table 5 shows the elongation and boiling water shrinkage of the spun yarn.

[Table] In this example, the heating roller setting temperature is 180℃
Only in the above manner can a polyester yarn having the fiber physical properties intended by the present invention be obtained. Example 6 Intrinsic viscosity [η] = 0.64, using TiO ₂ as a matting agent
C ₂ T containing 0.05 wt% (dried at 160°C for 4 hours) and C ₃ T with intrinsic viscosity [η] = 0.65 (dried at 120°C for 6 hours) were blended in various ratios in the form of chips, and the same as in Example 1 was carried out. Raw yarn and highly twisted yarn were obtained. Table 6 shows the physical properties of the raw yarn (wound yarn), the residual torque after the highly twisted yarn was set to stop twisting, and the boiling water development torque.

[Table] In the case of the present invention (Nos. 3 to 6), the residual torque after twist setting is low, and the airter, jet,
It is possible to weave in the room. At the same time, the torque developed by boiling water treatment maintains a considerably high value.
The texture is also good.

[Brief explanation of drawings]

FIGS. 1a, 1b, and 1c are side views each showing an example of a heating device used in carrying out the present invention. 1, 2, 3, 4...heating roller, 5...auxiliary heating means, W...winder.

Claims (1)

[Claims] 1 Polyethylene terephthalate (C ₂ T) is blended at a ratio of 20 to 90 wt% of the total amount, and polytrimethylene terephthalate (C ₃ T) or/and polytetramethylene terephthalate (C ₄ T) is blended at a ratio of 80 to 10 wt% of the total amount. The polyester composition is melted and discharged as a filament, further cooled and solidified, and then heat treated with a heating roller, and then processed at a speed of 3500 m/min or more to obtain a filament with a single fiber fineness of 2.2 de or less and a cutting elongation of 60.
% or less, and winding it as a multifilament with a boiling water shrinkage rate of 7% or less.