JPS60224807A - Method for spinning and cooling of thick denier fiber - Google Patents

Abstract

PURPOSE:To cool a thick-denier fiber, sufficiently, by spraying a refrigerant in the form of mist to the spun yarn from the spray nozzle placed at a specific position, in the spinning process to spin a molten polymer along vertical direction. CONSTITUTION:A polymer such as polypropylene is supplied in molten state from above, and the yarn 1 is extruded from the nozzle 2. The yarn is cooled by the refrigerant 4 sprayed in the form of mist from plural spray nozzles placed 0.5-1.5m below the nozzle 2. The quality of a thick-denier synthetic fiber can be improved without causing the lowering of the productivity nor necessitating an extensive reconstruction of the apparatus. The particle size of the refrigerant mist is preferably 1/10-1/50 of the diameter of the undrawn yarn.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cooling method for melt spinning synthetic fibers, and particularly to a method for spinning and cooling synthetic fibers suitable for cooling large denier 1ltN fibers.

Conventionally, for example, polypropylene stable fibers have been used for nonwoven fabrics, spinning, tying, carpets, etc., and usually have a
Although fibers in the range of 30 denier are often used, thick denier fibers in the range of 80 to 200 denier are desired in some carpet fields.

In the production of this type of synthetic fiber, a melt-spinning method is mainly used, and after being taken as an undrawn yarn, it is turned into a product through the steps of stretching, crimping, drying, heat treatment, and cutting.

In this method, during the spinning process, the thread is discharged vertically from a nozzle in a molten state by a melt-spinning machine with one screw, and cooling air is applied to the thread from a direction perpendicular to the running direction of the thread, so that the thread is cooled and solidified. Usually, a large number of them are collected and taken off via a roller that rotates at a circumferential speed of several hundred m7.

However, with the above-mentioned cooling method (hereinafter referred to as the air cooling method), the product denier is limited to a maximum of about 60, and spinning 6-denier fibers beyond this limit is virtually impossible due to various problems as shown below. there were.

In other words, in the air cooling method, large denier materials are not sufficiently cooled, resulting in problems such as fusion of discharged yarns, denier unevenness due to fluctuations in the solidification point, and deterioration of spinning operability due to frequent yarn breakage. This not only reduces the efficiency of the drawing process in the next process, but also results in large variations in denier and physical properties of the final product, as well as a high rate of contamination with sticky threads and abnormally large denier threads, making it difficult to maintain stable quality. I couldn't secure it.

On the other hand, as a method for cooling undrawn yarn used in the production of thick denier fibers, a method has been proposed in which a molten yarn is cooled in water, but this method has the following problems.

That is, this type of method is usually applied to the production of monofilament, and the speed of the undrawn yarn passing through a cooling water tank is about several tens of meters, and after passing through a continuous drawing process, the single filament is Since the fibers are divided into two parts and wound up, the manufacturing equipment is generally such that the spinning machine, drawing machine, and winding machine are installed on the same floor, and the productivity per machine is low due to constraints such as working speed. It's not that expensive.

It is difficult to apply such an underwater cooling method to existing fused stable fiber yarns for the following reasons. That is,
In the water cooling method, it is necessary to maintain a strict gap between the discharge nozzle surface and the water surface of the cooling tank. It is difficult to take the yarn through rollers due to the installation space of the cooling water tank, the workability of spinning, etc., and even if it were possible, it would be necessary to significantly modify the conventional air cooling equipment. It costs a lot of money. In addition, there is a concern that the water adhering to and accompanying the fibers will be scattered to a pulling machine or the like, causing mechanical trouble, and the cohesiveness of the undrawn tow that has been taken will be considerably impaired.

Therefore, the method of cooling in a water tank directly below the discharge nozzle is
It's realistically difficult. On the other hand, as a method of cooling the yarn by bringing it into direct contact with water, it is also possible to apply the down tension method used in solution spinning, etc., but in this method, the discharged yarn is guided into a water tube with a funnel-shaped upper end. The method utilizes the falling speed of water to run the thread, which necessitates changing the diameter of the water pipe for various deniers, and also poses the same problems as cooling using the cooling water tank described above in dealing with falling water. Contains.

On the other hand, I mentioned the problems with the air cooling method earlier, but I would like to add that if you try to sufficiently cool thick denier III with air using existing equipment, the temperature of the air and the time it stays in the air will be dominant. In particular, it is possible to lengthen the residence time of the latter by lowering the collection speed.
This naturally has its limits, and it also results in a decrease in productivity. An alternative method of extending residence time could be to lengthen the distance between the discharge nozzle surface and the circumferential speed roller, but this would involve moving the spinning machine to a higher location and would require considerable construction costs and building remodeling. It takes.

This invention has been made in view of the above-mentioned conventional problems, and its purpose is to eliminate the need for a reduction in productivity and large-scale modification of equipment (based on conventional equipment). The purpose of the present invention is to provide a method for spinning and cooling thick denier fibers that can improve the quality of denier synthetic fibers.

In order to achieve the above object, the present invention provides a method for spraying a plurality of sprays at a position of 0.5 TrL to 1.5 m below the synthetic fiber discharge nozzle in a synthetic fiber melt spinning process in which threads are run in the vertical direction. The method is characterized in that a nozzle is provided, and the synthetic fibers are cooled by spraying a mist of refrigerant with the spray nozzle.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

The figure schematically shows a method for spinning and cooling thick denier fibers according to the present invention, in which a high molecular weight polymer such as polypropylene is supplied from above in a molten state, and a large number of holes are formed on the same circumference. a nozzle 2 that discharges the molten yarn 1 downward; and an air cooling device 3 that forcibly blows cooling air from the side immediately after the molten yarn 1 is discharged.
and a spray nozzle 5 which is disposed at a distance of 0.5 m to 1.5 m from the discharge end of the nozzle 2 and sprays a refrigerant 4, for example water, in the form of a mist from the side of the yarn 1. Spun and cooled.

The spray nozzle 5 is preferably arranged so that its ejection port is 0.5 m to 1.5 m below the discharge port of the nozzle 2, and if it is closer than this, it will become noticeable after the yarn 1 has been cooled. On the other hand, if the yarn is separated too much, troubles such as yarn breakage will occur due to yarn sway of the yarn 1, etc.

In addition, the spray angle, pressure, and spray amount of the nozzle 5 vary depending on the denier of the yarn 1 to be manufactured, the take-up speed, etc.
For example, the injection angle is 30~
70 degrees, the injection pressure is 0.5 to 1.56/cjG, the injection water amount is 10 to 30 CC/min per spindle, and the particle size of the mist is 1710 to 1150, preferably 1
When the ratio is from /20 to 1/40, favorable results can be obtained, such as the cooled yarn 1 having a good surface condition and no excess refrigerant 4 remaining on the yarn surface.

Furthermore, the spray from the nozzle 5 is preferably spread out in a fan shape on the same plane, and the particle size of the sprayed mist is preferably within the range described above. If the diameter is too small, the cooling effect will be diminished.

In the embodiment shown in the figure, a forced air cooling 113 is provided before the cooling process of the spray nozzle 5, but if a distance for natural cooling is ensured, the cooling device 13 may not be provided. good.

Table 1 shown below shows more specific examples of the method for spinning and cooling thick denier fibers according to the present invention.

In this example, polypropylene was used as the raw material.
460 as undrawn yarn. 700.1000 denier is manufactured and stretched at a predetermined magnification to 80.1
20. A 180 denier product was created.

In addition, in this embodiment, the above-mentioned air cooling device [3 is used together, and the above-mentioned spray nozzle 5 is fixed at a position 1.2 m from the discharge end of the nozzle 2, and is arranged at approximately 90 degrees in the circumferential direction on the same plane. A mist of water was sprayed onto the yarn 1 from the front, back, left and right using four nozzles 5 arranged at intervals of , and each spray nozzle 5 was placed at a horizontal distance of 150 shoes from the center of the running yarn 1.

Table 2 The above Table 2 shows the measurement results of the denier fluctuation rate, breaking strength, elongation, and Young's modulus of 80 denier polypropylene synthetic fiber yarns made by the above-mentioned examples and the conventional air cooling method.

As is clear from this result, according to the spinning/cooling method of the present invention, the yarn 1 discharged from the nozzle 2 is cooled while the temperature is lowered to some extent by air.
Since 1 and 4 are cooled by spraying them in a mist, the undrawn yarn 1 is sufficiently cooled, which eliminates the fusion of the yarns together, which was a problem when spinning thick denier yarn using the air cooling method. Problems such as thread breakage and denier unevenness can be solved.

In addition, since the refrigerant 4 injected from the spray nozzle 5 has a mist-like microparticle size, it can be adjusted so that it does not adhere to and remain on the surface of the cooled yarn 1. To enable high-speed collection without post-processing.

Furthermore, since water, which has a high thermal conductivity, such as water, can be used as the coolant 4, the yarn 1 can be cooled homogeneously and evenly, and the mist injection conditions can be selected according to the preferred stretching conditions that differ depending on each denier. This allows for stable control of the yarn quality after drawing, and significantly improves mechanical strength, Young's modulus, etc. compared to conventional methods.

As described above in detail in the Examples, the method for spinning and cooling thick denier fibers according to the present invention utilizes conventional equipment for vertically melt-spinning high molecular weight polymers to increase productivity. A thick denier undrawn yarn can be taken off in a homogeneous state without deterioration, and therefore a homogeneous fiber with high physical properties can be produced.

[Brief explanation of drawings]

The figure is an explanatory diagram of an embodiment of the present invention. 1... Thread 2... Nozzle 3...Air cooling device 4... Refrigerant 5...Spray nozzle Patent applicant: Ube Nitto Kasei Co., Ltd.

Claims (2)

[Claims] (1) In the synthetic fiber spinning process in which a 14-molecule polymer is melt-spun in the vertical direction, 0.5 mm below the yarn discharge nozzle.
A method for spinning and cooling thick denier fibers, which comprises arranging a plurality of spray nozzles at positions of m to 1.5 m, and cooling the yarn by spraying a mist of refrigerant onto the yarn using the spray nozzles. . (2) The method for spinning and cooling thick denier fibers according to claim 1, wherein the particle size of the refrigerant mist is 1710 to 1150 of the undrawn yarn denier diameter.