JP2000265318A - Drawing method for synthetic staple - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a drawing method for synthetic staple effective for reducing emergency stop relating to entanglements by installing a guide having a specific shape. SOLUTION: In a production process for synthetic staple drawing and heat treating after melt spinning a thermoplastic polymer, a ctenoid shaped guide 4 is installed before guiding the undrawn fiber to the drawing process and tearing off the entanglements by this ctenoid shaped guide 4 before entering to the drawing machine.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for drawing synthetic short fibers.

[0002]

2. Description of the Related Art Conventionally, in the production of synthetic short fibers using a thermoplastic polymer, unstretched yarns of about 5 to 80 weights are collectively stored in a large storage container such as a can after melt-spinning the thermoplastic polymer ( Hereinafter, a group of undrawn yarns of several weights is referred to as a “subtow”.) A method of starting up the subtow in the post-processing step, drawing, and heat-treating again is adopted.

[0003] However, when the subtow is stored in a can in the spinning process, a knot may be formed on the subtow (hereinafter referred to as "entanglement"). In addition, even if it does not break at the time of stretching, it causes clogging of the tow with the crimper, and it is necessary to stop the stretching machine, which is a factor that deteriorates operability. Causes of tangling are as follows: firstly, when the subtow has poor convergence and the subtow is unwound, secondly, when the subtow that has a lot of water and falls from the bottom sneaks under the already stored subtow, thirdly the can It is conceivable that the sub-tow is not properly dropped and the storage state is poor.

The convergence of the first factor so far has been:
Take measures such as improving the entanglement of the sub-tow by adjusting the guide position in spinning, etc., and reduce the moisture content to the extent that winding does not occur in the drawing process for the second cause The Japanese Patent Application No. 9-243080 discloses a method for adjusting the drop position, which is the third factor.
For example, the fall position of the sub-tow has been adjusted by blowing compressed air under the gear wheel. The measures described above have made it possible to reduce the frequency of entanglement, but this has not been eliminated, and it is necessary to simultaneously improve the stretching process in order to reduce the number of stretching stops due to entanglement.

[0005]

SUMMARY OF THE INVENTION The object of the present invention is to solve the above-mentioned problems, and an object of the present invention is to provide a method for drawing synthetic fibers which is effective in reducing entanglement stoppages.

[0006]

Means for Solving the Problems A drawing method of a synthetic short fiber of the present invention has the following constitution in order to solve the above-mentioned object.

That is, in the step of producing a synthetic short fiber by drawing and heat-treating a thermoplastic polymer after melt-spinning, a comb-shaped guide is provided before the subtow is drawn to the drawing step, and the tang is inserted before entering the drawing machine. The present invention relates to a stretching method characterized by tearing using a comb-shaped guide.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention relates to a method for drawing synthetic short fibers.

The thermoplastic polymer used in the present invention is not particularly limited, such as polyester, polyamide and polyphenylene sulfide, and can be applied to any thermoplastic polymer.

Hereinafter, the present invention will be described with reference to the drawings and the like.

FIG. 1 is a schematic view for explaining a method for drawing a synthetic short fiber according to the present invention.

The subtow (1) is obtained by cooling a non-drawn yarn melted from a die by blowing cooling air, applying a surfactant thereto, and storing 5-80 weight yarns collectively in a can. The raster, cross section, denier and the like of the undrawn yarn are not particularly limited.

[0013] Regarding the moisture content of the subtow, if the moisture content is too high, the subtow that has fallen down later falls under the already stored subtow, so that the number of stoppages due to entanglement increases. Since the sub-tow is rubbed by various guides in stretching and winding of the stretching roller increases,
In order to reduce the entanglement stoppage and prevent the sub-tow from scratching, it is necessary to set an appropriate sub-tow moisture content by a material, fineness, and a transfer method. The transfer of the subtow into the can is not particularly limited, and may be a dropping by a gear wheel or a transfer by an ejector.

A plurality of subtows (1) are put together so as to have an appropriate total drawing denier, and are set up by a creel (2) and introduced into a stretching machine (3). At this time, a comb guide (4) is conventionally provided before the stretching bath so that adjacent subtows do not interfere with each other in order to stretch several subtows at a time. Of course, the comb guide before the stretching bath (4)
In addition, there is no problem even if a comb guide or an H-shaped guide is provided in the creel portion.

FIG. 2 shows an example of a comb guide before a stretching bath used in a conventional method. In the conventional comb-shaped guide, the main purpose is to adjust the tow, so that the interval (5) between each guide is widened.

FIG. 3 shows an example of a guide which can be suitably used in the method of the present invention. The comb-shaped guide (4) referred to in the present invention is intended to tear off the tangled portion before entering the stretching step, in addition to the towing function, and by narrowing the interval (5) between the guides, Further, the guide has a strength so that the guide is not damaged when the tangled portion is torn. If the distance (5) between the guides is too small, the tow is rubbed, and if it is too wide, the tangled portion passes through and enters the stretching machine. Therefore, the distance (5) between the guides is preferably 3 to 8 mm. .

When the comb guide is installed, the entangled portion is cold-stretched and cut between the comb guide (4) and the stretching machine (3) and does not enter the stretching machine. Dramatically reduced.

However, the sub-tow immediately before being torn off by the comb guide is once cold-drawn between the comb guide (4) and the stretching machine (3), and is again stretched in the stretching step, so that it is in an over-stretched state. There is a slight tendency to light dye. However, the overstretched and lightly dyed portions are extremely small, and in the production of short fibers, several subtows are stretched at a time, so that they are mixed with ordinary raw cotton in a cutting step and a packing step. Furthermore, since the raw cotton is sufficiently mixed in the roving process of spinning, these lightly dyed portions do not pose a problem at the stage of the spun yarn.

The material of the guide is not particularly limited, but there is no particular problem as long as it has sufficient strength to tear the sub-tow and its surface can sufficiently withstand rubbing with the sub-tow.

[0020]

[Embodiments] The effects of the embodiments will be specifically described below. Example 1 In the production of polyester staple fiber, in the process of drawing 13 subtows having a total subdenier of 150,000 deniers, a constituent number per subtow of 3500, and a subtow moisture content of 20%, 13 subtows are collectively drawn. When a guide having an interval between guides of 6 mm was installed in the form shown in FIG. 3 before the stretching bath and the stretching was performed, the number of entanglement stops was 0.8 times / 100 t. Example 2 In the production of polyester staple fiber, the total toughness of the subtow is 150,000 deniers, the number of subtows is 3,500, and the subtow has a moisture content of 20%. When a guide having an interval of 12 mm between the guides and a guide shown in FIG. 3 was installed and stretched before the stretching bath, the number of entanglement stops was 3.5 times / 100 t. Comparative Example 1 In the production of polyester staple fiber, in the step of drawing 13 subtows having a total subdenier of 150,000 deniers, a constituent number per subtow of 3,500, and a subtow moisture content of 20%, 13 subtows are drawn together. When a guide having a space between the guides of 30 mm and a guide shown in FIG. 2 was installed and stretched before the stretching bath, the number of entanglement stops was 9.6 times / 100 t.

[0021]

According to the bowl invention as described above, there is provided a method for drawing a synthetic fiber which is effective in reducing entanglement stoppage.

[Brief description of the drawings]

FIG. 1 is a schematic diagram for explaining a method for drawing a synthetic short fiber of the present invention.

FIG. 2 shows a comb guide used in a conventional method, and is a schematic front view schematically showing an example of an embodiment of a comb guide used in Comparative Example 1. FIG.

FIG. 3 shows an example of a comb guide that can be used in the method of the present invention. FIG. 3 is a schematic front view schematically showing an example of one embodiment of the comb guide used in Examples 1 and 2. It is.

[Explanation of symbols]

 1: Subtow 2: Creel 3: Stretching machine 4: Comb guide 5: Spacing between guides

Claims (1)

[Claims] In a process for producing a synthetic staple fiber by drawing and heat-treating a thermoplastic polymer after melt-spinning, a comb-shaped guide is provided before leading an undrawn yarn to a drawing step, and the entanglement is introduced into a drawing machine. A stretching method using the comb-shaped guide.