JPS591711A - Spinning of polyester fiber - Google Patents

Abstract

PURPOSE:The super high-speed melt spinning of polyester fiber is carried out using a spinning pack provided with sand layers of fine particle size alumina and a specific filter to achieve the stable production of polyester fiber of uniform quality without yarn breakage. CONSTITUTION:The polymer melted with the back housing 2 is passed through the spinning pack 1 consisting of sand layers 7a-7d mainly containing higher than No.80, preferably higher than No.90 particle size alumina sand and of the filter 8 of a steel fiber nonwoven fabric of less than 20mu, preferably less than 15mu filtration diameter. The yarn is solidified by cooling in the chimney 3, treated with a finishing oil on the oil applicator 4, passed around the godet rollers 5 which rotates at a speed above 5,000m/min and wound up by the winder 6.

Description

Detailed Description of the Invention The present invention relates to a method for stably spinning polyester fibers at an ultra-high speed of 5000 m/min or more without yarn breakage, and more specifically, to stably realize ultra-high speed spinning of 5000 m/min or more. This relates to improvements in filtration within the pack.

When melt spinning polyester, 1000 to 3500
It is common to carry out the spinning at a spinning speed of m7 minutes, and at this speed, the spinning properties are stable and a uniform yarn can be obtained.

On the other hand, spinning speeds have been increasing rapidly in recent years, and high-speed spinning technology has also made great progress. At present, thread breakage and single thread breakage have begun to occur, and stable spinning is not possible. To solve this problem, for example, US Pat. No. 4,134,882 proposes a spinning method that reduces the radial orientation distribution of the discharged yarn, but even if this method is used, it cannot be applied to industrial production processes. As a result, stable spinning results have not been obtained. Especially when the single yarn denier becomes less than 5 denier, 500
Spun yarn breakage tends to occur frequently at 0 m7 minutes or more.
Stable operation cannot be achieved. The inventors of the present invention have continued to study the cause of the rapid increase in yarn breakage and decrease in spinnability when the spinning speed is 5,000 m and 7 minutes or more, and as a result, we have found that sooo
m/min or more, the deformation speed of the polymer becomes extremely high during the process of discharging the polymer and making it thinner.
We came to the conclusion that the main cause is that the polymer is unable to follow the large deformation caused by such high stress, as the elongation stress increases accordingly. To solve this, sooom
The key is to make the discharged polymer in a state that can follow large deformations under high stress at speeds of 5,000 m/min or more. I realized that it was a realistic prescription.

In other words, the pack filtration conditions that have been commonly used in the past,
For example, as a furnace material, one grain of sand of several sizes, specifically quartz sand, alumina sand, metal grains, glass grains, etc., is combined together, and the bottom layer is made of stainless steel to prevent the F material from flowing out. It was discovered that placing a wire mesh was not practical at all. For this reason, as a result of continuing to examine filtration conditions suitable for 5000 m7 minutes or more for various furnace material configurations, we found that
This has led to the present invention.

That is, one configuration of the present invention is to spin polyester fibers at a spinning speed of 50
When performing melt spinning at an ultra-high speed of 00 m/min or more, the filtration section of the spinning bag contains a sand layer whose main component is alumina oxide and whose main component is alumina oxide with a particle size of No. 80 or more. This is a polyester fiber spinning method characterized by spinning using a filter made of a nonwoven fabric of stainless steel fibers and having an absolute filtration diameter of 20 μm or less.

The present invention will be explained in detail below.

The composition of the door material used for the offshore eddy part is that it includes a sand layer whose main component is alumina oxide, at least a sand layer containing alumina oxide with a particle size of 8 o or more, preferably 9 o or more, and that there is a sand layer under the sand layer. It is essential to use a filter made of a nonwoven fabric of stainless steel fibers with an absolute filtration diameter of 20 μm or less, preferably 15 μm or less. Even if the above-mentioned sand layer with a particle size of 80 or more is used, if a stainless steel fiber non-woven filter is not used underneath, or even if it is used in combination with a filter whose absolute filtration diameter exceeds 20μ, fluff and threads may occur. Breaks occur frequently, resulting in poor spinnability. Furthermore, even if the above-mentioned filter with an absolute filtration diameter of 20 μm or less is used, if it is combined with a sand layer composed of sand with a particle size of less than No. 8 or no sand at all, the spinnability is similarly poor. The goal cannot be achieved.

Of course, the objective cannot be achieved by combining sand with a particle size of less than No. 80 and a filter with an absolute filtration diameter of more than 20 μm.

Incidentally, even when a wire mesh door material, a powdered sintered metal P material, etc. were used in combination for a part of the filter, similar defects were obtained.

Therefore, the objective can only be achieved by using the combination defined in the present invention.

Further, the present invention will be explained in detail.

It is still not clear why ultra-high speed spinning of 5000 m7 minutes or more can be stably achieved by adopting the furnace material and two-layer structure specified in the present invention, but judging from the results of basic studies, the following I'm thinking like that.

(1) The sand layer of alumina oxide with a particle size of 80 or higher has the ability to capture relatively large foreign substances in the polymer, and the dispersion that alleviates the effects of foreign substances and gel-like substances that cause turbulence in the discharge flow, fluff, and thread breakage. It is considered to have good performance. FIG. 1 shows basic data showing the dispersion performance of the sand layer, and shows that sand with a particle size of 80 or more has significantly higher dispersibility than sand with a particle size of less than 80.

(2) A filter with an absolute filtration diameter of 20 μm or less is considered to have the ability to capture small foreign particles or gel-like substances that are not captured in the sand layer. In addition, even though it is a standard sashid with a specified size, there is a distribution in the size, so there are fine sands that slip through the sand layer, or fine sands that seem to have broken for some reason during spinning. It is thought that it has the ability to capture

As described above, most of the foreign substances in the polymer are captured by the capture and dispersion performance of the sand layer, and defects in the finely and uniformly dispersed polymer are completely captured by the filter. Therefore, the polymer discharged from the nozzle is uniform with very few defects, which is important.

It is also important that the filter is non-woven so that the polymer stream is redispersed here.

High particle size sand such as No. 80 or higher and absolute filtration diameter of 20
Only by combining filters with a diameter of less than μ can a uniform polymer stream with less foreign matter be discharged from the spinneret, which can sufficiently follow large deformations at spinning speeds of 5000 m/min or more.

By using a multi-layer filter consisting of a filter in which at least one layer is 20μ or less and a high particle size sand of No. 80 or higher, defects in the polymer can be more completely captured and a more uniform polymer with less foreign matter can be discharged. Therefore, it is preferable. This also means that a polymer is discharged from the spinneret that can sufficiently follow large deformations of more than 5,000 m/7 minutes at a spinning speed.

Furthermore, in order to obtain good yarn, package, and spinnability using the filtration conditions specified in the present invention, it is more effective when the single yarn denier of the wound yarn is 5 denier or less.

Here, one example of a specific embodiment of the present invention will be described with reference to the drawings, but the present invention is not limited thereto.

FIG. 2 is a schematic diagram showing an example of the spinning process of the present invention.

The polymer melted by the pack housing 2 passes through the pack 1 and becomes a thread.

The discharged yarn is thinned in the cooling tube 3 and then sent to the oil supply device 4.
It is refueled at a speed of over 5000m/min! It passes through the body roll 5 which rotates at 1 and is wound up by the winding machine B.

FIG. 5 is a longitudinal sectional view showing the main parts of the pack applied to the present invention. The structure of the filtration part in the pack 1 is roughly divided into two parts: a sand layer part 7a-7cL (multilayer) and a filter 8 made of a nonwoven fabric of stainless steel fibers. The main component of the sand layer door material is alumina oxide. The polymer passes through the sand layer, the pressure plate 9, and is discharged from the mouthpiece 10.

At least one of the sand layers has a particle size of No. 80 or more,
It is preferable to use sand having a particle size of 9 o or more. If all the sand layers have a particle size of less than No. 80, there will be a decrease in the ability to capture foreign matter, a decrease in the dispersion performance such as redispersion of foreign matter, and dispersion of gel-like matter, resulting in a decrease in spinnability. Furthermore, it is preferable that the thickness of the sand layer be 4IO+ or more, since this will fully exhibit its effect.

The structure of the sand layer in FIG. 6 is that the upper layer 7a is the middle layer 7b,
It is preferable to use a sand with larger particles (that is, a smaller particle size) than 7c, and a sand with larger particles than the middle layer in the lower layer 7d, in order to prevent the furnace material in the middle layer from flowing out. Furthermore, if the middle layer is multi-layered, the upper middle layer 7b
It is preferable to arrange particles with larger particles than the middle and lower layer 3c, and arrange particles with smaller particles (larger particle size (number)) than the upper layer.

In this way, the method of making the F layer into multiple layers and placing the larger sand particles in the upper layer and the smaller sand particles in the lower layer (hereinafter referred to as normal layer filtration) enables efficient capture of foreign substances and redispersion of foreign substances. This improves spinnability and pack life.

Therefore, by using the sand layer as normal layer filtration, the effect is further promoted. A filter 8 made of a nonwoven fabric of stainless steel fibers with an absolute p-diameter of 20 μm or less, more preferably 15 μm or less is used as the lowest layer of the filtration section. If it exceeds 20μ, the ability to capture foreign matter and gel-like substances will decrease, resulting in a decrease in spinnability.

As already mentioned, by adopting the filtration conditions in the puncture specified by the present invention, the present invention makes it possible for the first time to stably perform ultra-high-speed spinning at a speed of sooom/min or more with less fuzz and yarn breakage. .

■ Being able to stably spin at a spinning speed of 5000 m/min or higher has the advantage of high productivity. 5000
Since the yarn obtained at a spinning speed of m7 minutes or more can be used as a practical fiber without going through a drawing process afterwards, it also has the advantage of streamlining the process. Therefore, significant cost reduction is possible.

■ Because it is an ultra-high-speed spinning process, the yarn is not affected by atmospheric temperature variations, cooling spots, and outside air currents during the spinning process, and the resulting yarn has extremely uniform quality. It is possible to obtain.

Furthermore, the control of atmospheric temperature, cooling, etc. does not have to be severe in low-speed spinning, so process control is easy.

The polyester fiber referred to in the present invention is a polyester having at least 70 molar units of ethylene terephthalate units, and polyethylene terephthalate is most preferably used.

The sand defined in the present invention is primarily intended for fused alumina abrasives. The particle size standard is J Engineering S Standard R60.
Conforms to 01. The absolute p diameter defined in the present invention refers to the maximum particle diameter that can pass through a filter.

The present invention will be specifically explained below using Examples.

Example 1 Orthochlorophenol Intrinsic viscosity &O,6 at 25°C
Dry the ordinary polyethylene terephthalate chips of No. 6, and use the dried chips to spin at a spinning temperature of 300°C and a discharge rate of 50.
When spinning was carried out at a spinning speed of 5,000 m and 7 minutes using a nozzle with 36 holes and a spinning speed shown in Table 1, the following results were obtained.

The sand used was Morundum Sand manufactured by Showa Denko K.K. The filter is a non-woven fabric made of stainless steel fiber manufactured by Prinswick International Limited and has an absolute p diameter of 20μ within the range specified in the present invention, and a stainless steel mesh/U-shaped wire mesh filter of 507/U ( It has a 6-layer structure with 0.315 mm mesh openings on the front and back.

Level A is a comparative example for clarifying the effects of the present invention. Level A had large sand grains outside the range specified by the present invention, and the spinnability was unsatisfactory due to a large amount of fuzz and thread breakage. Levels B and O were sands within the range specified by the present invention, and had good spinnability with little fluff and thread breakage.

Therefore, in order to stably carry out ultra-high-speed spinning at a spinning speed of 5000 m7, it is essential that the sand grains have a particle size of No. 80 or more as defined in the present invention.

Table-1 Example 2 Orthochlorophenol Kel intrinsic viscosity at 25°C 0.6
Dry the ordinary polyethylene terephthalate chips of No. 6, and use the dried chips to spin at a spinning temperature of 300°C and a discharge rate of 45.
The following results were obtained by spinning at a spinning speed of 5,000 m and 7 minutes under the conditions shown in Table 2 using a nozzle with 60 g/min and nozzle holes. As for the sanding conditions, Morundum sand manufactured by Showa Denko Co., Ltd. was used in the upper layer with a grain size of 6o as specified in the present invention.

The middle layer has a particle size of 80, the lower layer has a particle size of 30, and the thickness of each layer is 6 mm.

The IU level is a comparative example for clarifying the effects of the present invention. The standard filter is a stainless steel mesh-like wire mesh F material that has been used in the past, and its composition is three pieces stacked on top of each other with 325 mesh (mesh opening 0.043 mm) and 50 mesh (mesh opening 0.043 mm). Opening 0.31
5m) arranged on the front and back. At this level, there was 1 fuzz, yarn breakage occurred frequently, and the spinnability was extremely poor. Level E
, F, and G filters are made of stainless steel 507 mm (aperture 0.315
mm) wire mesh on the front and back. Level E is a condition in which the absolute filtration diameter is large outside the range specified in the present invention, and there are many fluffs and thread breakages, and the spinnability is not satisfied.

Levels F and G were at the level of the absolute filtration diameter specified in the present invention, and had a level of fluff and thread breakage, and had significantly fewer trees than E, and had better light properties.

Therefore, in order to stably carry out ultra-high-speed spinning at a spinning speed of 5000 m7, it is essential that the absolute filtration diameter of the nonwoven fabric filter disposed at the bottom layer of Paulownia is 20 μm or less as defined in the present invention.

Table 2 Example 3 Ordinary polyethylene terephthalate with an intrinsic viscosity of 0.65 was dried and the dried chips were used to spin the fibers at a spinning temperature of 300°C.
The following results were obtained by spinning at a spinning speed of 6000 m7 minutes under the filtration conditions shown in Table 5, with a discharge rate of 35 g/min, and a spindle with 12 holes.

Level H was a combination of the sanding conditions specified in the present invention and a stainless steel menoneue filter that was commonly used in the past, resulting in frequent fuzz and yarn breakage, and extremely poor spinnability.

The leveling process was a filtration condition using a combination of sand and filter specified in the present invention, and both fuzz and yarn breakage were significantly reduced compared to Level H, and the spinnability was good.

Level J uses the filtration conditions defined by the present invention in combination with sand and a filter, and uses finer sand grains than the level method. The spinnability was good with less fluff and thread breakage compared to level (■).

The level is a filtration condition that combines sand and a filter specified in the present invention, and uses finer sand grains and filter than the level. In addition to leveling, there was less fluff and yarn breakage than J, and the spinnability was extremely good.

The standard is the filtration conditions that combine sand and filter specified in the present invention, especially when the filter is multi-layered (20% from the upper layer).
．． 15.10μ), and the spinnability was very good, as was the standard.

As shown in the above results, the conditions specified in the present invention are essential in order to stably carry out ultra-high speed spinning of 6000 m7 minutes.

Table 3: As the sand, Morundum Sand manufactured by Showa Denko K.K. was used.

Also, the thickness of each layer is quite large.

The non-woven filter is made of stainless steel fiber non-woven fabric manufactured by Brunswick International Limited, and has a 5° mesh on the front and back.
A mesh-like filter of 15 ttan) was used.

[Brief explanation of the drawing]

FIG. 1 is a graph for explaining the dispersion performance of the sand layer. FIG. 2 is a schematic diagram showing an example of the spinning process of the present invention. FIG. 3 is a longitudinal sectional view showing the main parts of the pack applied to the present invention. 1 Pack 2 Pack housing 6 Cooling tube 4 Oil supply device 5 Body roll 6 Winder 7a to 7d Sand layer 8 Filter 9 Pressure plate 10 Mouth Patent applicant Toshi Co., Ltd. - Thick 7 layer thickness Figure 1 U Figure 6 Figure 2

Claims (1)

[Claims] (11 When polyester fibers are melt-spun at an ultra-high speed of 500 m or more for 7 minutes or more, a sand layer whose main component is alumina oxide and whose particle size is at least No. 80 is formed in the p-vortex part of the spinning bag. (2) A method for spinning polyester fiber, which comprises spinning a sand layer whose main component is alumina oxide and a filter made of a nonwoven fabric of stainless steel fibers with an absolute filtration diameter of 20 μm or less. (2) The absolute filtration diameter of the filter is made finer in order from the upper layer to the lower layer, and at least one layer is 20μ.
The polyester fiber spinning method according to claim 11, which is a multilayer filter consisting of the following filters.