JPS60209005A - Wet or dry jet-wet spinning method and apparatus therefor - Google Patents

Abstract

PURPOSE:To remove fine foreign materials from a spinning dope and improve strength and elongation characteristics of carbon fibers obtained from raw material fibers prepared from the dope, by keeping a spinneret union and a filter provided just before the spinneret union in the same atmosphere. CONSTITUTION:A filter 8 is provided just before a spinneret union 6 in the same coagulation bath as the spinneret union 6, and fine foreign materials consisting mainly of gelatinous materials newly formed in a spinning dope in a path from a filter body 3 to the filter 8 are removed. The extrusion property of the spinning dope, however, is not changed. The maximum diameter of the foreign materials contained in acrylic fibers is reduced to 2-3mum as compared with the conventional 20-30mum.

Description

Detailed Description of the Invention (Technical Field) The present invention relates to a wet or dry-wet spinning method and an apparatus thereof, particularly a method for substantially eliminating fine foreign substances in a spinning dope during spinning, and its @ Regarding the location.

(Prior art and its drawbacks) Fiber-forming polymer 9 To produce a fibrous material from, for example, polyacrylic nitrile, the acrylic polymer is first dissolved in a solvent to form a solution (hereinafter simply referred to as a spinning stock solution). fil! It is discharged from the mouthpiece via a pump. The yarn obtained here is usually subjected to a solvent removal step, stretched, washed with water, and heat treated, and further subjected to treatments such as crimping as necessary.

It is also well known that carbon fibers can be obtained by firing this yarn at a high temperature as a precursor.

By the way, in the above-mentioned spinning process, it has been known empirically that if foreign substances or gel-like substances (hereinafter simply referred to as foreign substances) in the spinning dope are removed by filtration in advance, yarn breakage during the process is reduced. ing. For this reason, in a normal case, for example, in wet spinning as shown in FIG. (In the figure,
2; liquid feed pump; 5; conduit; 7: coagulating liquid bath); and C, the amount of foreign matter was reduced to a sufficiently acceptable level in the case of textiles for clothing.

However, in the field of carbon fibers, as research on the physical properties of the fibers progresses, there is a close relationship between the yarn properties, especially foreign substances in the spinning dope, and the physical properties of carbon fibers, and it is necessary to keep the foreign substances virtually free. It has become clear that the strength and elongation properties of carbon III are greatly improved by this process, but the filtration system or means used in the conventional spinning stage removes the foreign matter to a state where it is virtually non-existent. No such consideration was given.

That is, in normal spinning, as mentioned above, foreign substances in the spinning dope are once removed by the filter 3 installed between the storage tank 1 and the metering pump 4, but in an actual industrial process, foreign substances are removed from the filter 3. The spinning stock solution flow path, ie, the conduit 5, up to the spinneret union 6 is relatively long. Therefore, even if the spinning stock solution has been filtered by the filter body 3, gel-like substances may be generated again in the conduit, especially at the pipe connections such as valves, flanges, branch pipes, etc. that are interposed therein, and at the bent pipe section of the pressure gauge mounting seat. Mainly foreign matter is generated, and this foreign matter is significantly finer than that which is removed by the filter 3.

On the other hand, with conventional filter media such as wire mesh or cloth-like materials fitted inside the mouthpiece union 6, the main purpose was originally to prevent clogging of the mouthpiece pores, so the removal of relatively coarse foreign matter was limited to the above-mentioned Such fine foreign matter cannot be removed at all, and even if the filtration accuracy of the filter medium is improved to remove this kind of foreign matter, especially when the amount of spinning stock solution passing through the spinneret is large, such as in the case of acrylic fibers, , a new problem arises in that the pressure loss due to the filter medium increases dramatically and it cannot withstand continuous use for a long period of time.

As described above, it is an important issue to solve the problem of how to efficiently remove minute foreign matter from the spinning dope for raw yarn for carbon fibers and how to spin the yarn in a state where there are virtually no foreign matter. Ta.

(Objective of the Invention) The object of the present invention is to substantially completely eliminate foreign matter in the spinning dope during wet or dry-wet spinning, especially the fine foreign matter that has not been a problem in the field of textiles for clothing.

Furthermore, the aim is to remove the carbon fibers efficiently and further improve the strength and elongation characteristics of the carbon fibers obtained from such yarns.

(Structure of the Invention) 1 The structure for achieving the above object of the present invention is as follows.

(1) In spinning a fiber-forming cloth 11 polymer solution, a wet or dry-wet spinning method is characterized in that a filter is provided immediately before the die union, and the die union and the filter are maintained in the same atmosphere. .

(2) A wet or dry-wet spinning machine consisting of a spinneret union and a filter connected immediately before the spinneret union, both of which are placed in the same atmosphere.

Hereinafter, the present invention will be specifically explained using wet spinning as an example with reference to the drawings.

Fig. 2 is a process flow diagram showing an example of a filtration system in wet spinning of the present invention, Fig. 3 is a process flow diagram showing an example of a filtration system in wet/dry spinning of the present invention, and Fig. 4 is a process flow diagram showing an example of a filtration system in wet spinning of the present invention. FIG. 5 is an enlarged sectional view of the filter medium component of the filter in FIG. 4.

The feature of the filtration system in the present invention is that the ferrule union 6
The reason is that a filter 8 is provided immediately before the ferrule union 6 and in the same coagulating liquid bath.

That is, the spinning solution sent from the metering pump 4 to the conduit 5 is filtered by a filter 8 connected in front of the mouthpiece union 6 in the coagulation bath.

In the filter 8, between the filter body 3 and the filter 8.

Not only is the microscopic foreign matter mainly composed of newly generated gel-like substances removed substantially completely, but also because the filtration lI8 is in the same coagulation liquid bath as the mouthpiece union 6.

The moisture conditions that affect the discharge properties of the spinning dope can be kept exactly the same as in the spinneret union.

Next, the structure and operation of the filter 8 according to the present invention will be explained. The filter 8 has a core body 10 and a packing 11. Downstream large plate 12. Filter medium part 13. *Output plate 14°filter media part 13. Inflow plate 15. ......Inflow plate 15. Filter material part 13. Outflow plate 14.11 material part 13. Upper inflow plate 16, packing 17
and 17', and the upper plate 18 are assembled in this order, and after these are engaged with the core body 10 with the presser bolts 20 through the gaskets 19, they are covered with a case 22 through the gaskets 21. There is. However, the inside of the filter 8 should have a structure that does not reduce abnormal retention as much as possible throughout.

The top of the case 22 of the filter 8 is connected to the conduit 5 through the packing 23, and the end of the core body 10 is connected to the connector 9 through the packing 24. is formed.

The filter medium section here is shown as 13 in FIG.
To use glass fiber filter paper 24 as a filter medium, sandwich it between both sides with polyester plain woven cloth 25, 25'.
A structure in which the outlet plate 14 and the inlet plate 15 are supported through Teflon packings 26, 26' is preferred. Furthermore, since the glass fiber filter paper 24 itself has a low shear strength,
It is desirable that each part of the member be rounded. Furthermore, filter media other than the glass fiber filter paper, such as fine particle sintered bodies and fine metal non-woven fabrics, have mechanical and chemical durability against the spinning dope, and at the same time have nominal filtration accuracy (foreign matter that will be captured by the filter media with a certain probability). Any particle size may be used as long as the minimum particle diameter (minimum particle diameter) is about a few microns to several microns.

A conventionally known connector 9 is used to connect the filter 8 and the cap union 6, for example, the one disclosed in Japanese Utility Model Publication No. 48-1776.
The use of the simple attachment/detachment device described in Japanese Patent No. 7 is convenient because workability at the start of operation, especially bleeding of the spinning dope, can be easily performed.

Now, in the filter 8, the spinning stock solution sent from the conduit 5 passes through the inner wall of the case 22, is guided to the filter medium part 13 through the inlet plate 15, and there, fine foreign matter is filtered out as desired by the filter medium (glass fiber filter paper) 24. is carried out, and then the outflow plate 14
The fibers are discharged through the center of the core body 1o, and sent to the spinneret union 6 as a spinning stock solution substantially free of fine foreign matter.

The configuration of the present invention has been described above only with respect to an example of wet spinning, but since the example of wet/dry spinning can be easily understood from the above, the explanation thereof will be omitted here.

As mentioned above, the present invention is provided immediately before the base union.

In addition, a filter is installed in the same atmosphere as the mouthpiece union to remove fine foreign substances mainly consisting of gel-like substances, and this filter can reduce the maximum particle size of foreign substances contained in, for example, acrylic fibers. is significantly reduced to 2 to 3 μm compared to the conventional 20 to 30 μm, Ii, and as a result, carbon fibers using this fiber as a chain yarn have a remarkable effect of increasing strength and elongation properties.

[Brief explanation of drawings]

Fig. 1 is a process flow diagram showing an example of a filtration system in conventional wet spinning, Fig. 2 is a process flow diagram showing an example of a filtration system in wet spinning of the present invention, and Fig. 3 is a process flow diagram showing an example of a filtration system in wet spinning of the present invention. FIG. 4 is a process flow diagram showing an example of a filtration system. FIG. 4 is a partial sectional view showing an example of a filter provided immediately before the mouthpiece union in the present invention. FIG.
It is an enlarged sectional view of a certain part of filter medium #I of the filter in the figure. (Explanation of symbols) 3: filter body 4; metering pump 5; conduit 6; mouthpiece union 7; coagulating liquid bath 8; filter 9: connector 13; filter medium section 14; outflow plate 15; inflow plate 24; glass fiber filter paper Patent applicant: Toshi Co., Ltd. Figure 1 Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] (1111fl! In the spinning of a forming organic polymer solution, a wet type or Wet-dry spinning method. (2) A wet-type or wet-dry spinning apparatus, characterized in that a spinneret union and a filter connected immediately before the spinneret union are arranged in parallel, and both are arranged in the same atmosphere.