JPS60194121A - Production of carbon fiber and apparatus therefor - Google Patents

Abstract

PURPOSE:A hot gas is blown toward the spinneret from which pitch is extruded downward in the thermally insulated chimney to prevent multifilaments of picth fibers from breaking and sagging. CONSTITUTION:Among hot-gas blowers 7, the uppermost blower 7A jets the hot- gas almost equal to or slight lower than the temperature of the spinneret 4 where the temperature is controlled within + or -1 deg.C. Thus, the following blowers 7B...7H jet hot gasses whose temperature becomes lower in order. Since the number of nozzles can be increased on the spinneret, multifilaments of pitch fibers can be produced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a method and apparatus for producing carbon fiber from pinch.

[Background technology] Conventionally, polyacrylonitrile (PA) has been used as carbon fiber.
N)-based and pitch-based systems are known, but compared to PAN-based systems that are made of polymers and are easy to stretch, low-molecular pitch-based systems are lighter! Not only does it have excellent properties such as being electrically conductive, but it is also a cheap material, but there is a problem in that it is difficult to spin a large number of yarns from a spinneret for mass production.

As a method for producing such pinch carbon fibers, Japanese Patent Publication No. 58-51526 proposes a method of spinning pitch fibers in a hot gas atmosphere, but even this method is not suitable for mass production. This is not the method that we focused on. Therefore, a large number of pinches, e.g.
It is thought that it would be impossible to spin pitch fibers by drawing out as many as 0.000 pitch fibers at the same time, and there has been a desire for a means for producing carbon fibers that can spin such a large amount.

[Purpose of the Invention] An object of the present invention is to provide a method and apparatus for producing carbon #j fibers that are capable of spinning a large number of pitch fibers and have high productivity.

[Structure of IJj] The method of the present invention has been unable to spin a large number of pitch fibers because when attempting to spin from a spinneret having a large number of spinning holes, the temperature distribution in each part of the spinneret is become uneven,
This was done after discovering that the viscosity of pitch changes very sensitively depending on temperature, so the pitch discharge flow rate becomes uneven depending on the location of the spinneret, which made it difficult to spin many threads at the same time. When spinning pitch fibers by discharging a pinch from a spinneret in which a spinning hole is formed toward the lower part of the heat-insulating cylinder, the temperature of the entire spinneret is maintained by spraying a stream of hot gas almost uniformly toward the spinneret. The pitch fibers are spun while maintaining the pitch fibers to be approximately uniform.
The purpose is to achieve the above object by preventing yarn breakage, sagging, etc. of a large number of pitch fibers.

In addition, the apparatus of the present invention has a spinneret having a large number of spinning holes at the lower end of the storage tank in which the pitch is stored, and a heat-retaining tube extending downward from the spinneret is provided. The above object is achieved by providing hot gas blowing means on the upper part of the heat insulating tube for spraying a hot gas flow substantially evenly toward the spinning material.

[Explanation of Examples] Hereinafter, one embodiment of the present invention will be described based on the drawings.

The storage tank 1 is formed of a heat insulating material and is equipped with a heater (not shown) for a constant temperature device, so that the pitch 2 in a molten state stored in the storage tank 1 can be maintained at a predetermined temperature, for example, 400° C., substantially constant. There is. As the pitch 2, petroleum-based pitch, coal-based pitch, or the like is used.

A piston 3 serving as an extrusion means for extruding the pitch 2 is disposed within the storage tank l, and a spinneret 4 is attached to the lower end of the storage tank l. The piston 3 is driven by an air cylinder (not shown) or a drive mechanism including a pinion and a rack driven by a motor. Further, the spindle 4 has a large number of spinning holes 5, and the spinning holes 5 have a diameter of 0.5 mm and a number of 400 yarns, for example.

At the lower end of the storage tank 1, a generally cylindrical heat-retaining cylinder 6, which surrounds the spinneret 4 and is open at the bottom, is provided. The heat insulating tube 6 is formed of a suitable heat insulating material such as quartz glass fiber, asbestos, ordinary lath fiber, preferably quartz glass fiber. Further, inside the heat-retaining cylinder 6, there are hot gas blowing means 7A, 7B, . . . , 7H (hereinafter referred to as
When individually specifying and explaining the hot gas blowing means, the codes 7A, 7B, . The same applies to other symbols. ) are provided. Each of these hot gas blowing means 7A, 7B...7H is formed into a ring shape, and each has a large number of ventilation holes in the lower part thereof, so that each hot gas blowing means 7A, 7B...7H blows out. Partition walls 8'A, 8B, . Temperature sensors 9A, 9B...9H are provided above 8A, 8B...8H, respectively, and are opened on the inner peripheral surface of the heat retaining cylinder 6 and are approximately evenly spaced around the inner circumference of the heat retaining cylinder 6. It is provided with a large number of blow-off ports 10A, 10B, .

Each company 1 of the hot gas blowing means 7A, 7B...7H
) JIi? Below 8A, 8B...8H are ducts equipped with appropriate heat retention means) IIA, IIB...
It is connected to the blowers 12A, 12B...12H via IIH, and the amount of air necessary for blowing out from the outlet 10A, IOB...IOH of each hot gas blowing IJJ means 7A, 7B...7H can be obtained. It looks like this. Also, each duct 1
Temperature-controllable heaters 13A, 13B...13H are provided in the middle of 1A, IIB...IIH, respectively, so that the air sent from the blowers 12A, 12B...12H can be set to a predetermined temperature. ing.

The output signals from each of the temperature sensors 9A, 9B...9H are input to a control device 15 that has a built-in microcomputer, and this control device '12.15 outputs signals from each of the temperature sensors 9A, 9B...9H. Output signal and control device 15
The heaters 13A, 13B are compared with the ift set in advance in the heaters 13A, 13B so that the temperature of the gas flow blown out from each mature gas blowing means 7A, 7B, . . . , 7H becomes a predetermined value.
...13H is controlled. In addition, the output signal from the temperature sensor 16 provided in the spinner 1-1 metal 4 is also manually input to the control device 15, and the set values of the heaters 13A, 13B, . . . , 13H are adjusted according to this output 4'j. can be adjusted.

Of the hot gas blowing means 7, the temperature of the hot waste flow blown out from the blowing means 7A at the uppermost position varies depending on the nature of the pitch 2, but the temperature of the hot gas flow is approximately equal to or lower than the temperature of the spinneret 4. The temperature is controlled within ±1'C. Further, each blowing means 7B below this
The temperature of the hot gas flow blown out from 7H is set to be one order lower than that of the blowing means 7A located at the second most position. pitch 2
．． For example, the temperature difference is about 2°C to 200°C, and the temperature difference is about 20°C to 100°C. Further, in the blowing means 7 which is set to the lowest temperature, the temperature is not normally set below room temperature, but it may be set below room temperature depending on safety.

In addition, the speed of the hot gas flow blown out from the blowoff +-+ 10 of the hot waste blowing means 7 is set to 1.
Numerous pitches generated #! The speed is set to a level that does not shake the li fibers 18 significantly.

The fibers 18 are sequentially cooled in the heat-insulating tube 6, drawn out from the heat-insulating tube 6, and wound onto a winding roll 19. At this time, the fiber thickness of the pitch fibers 18 is adjusted by appropriately setting the winding speed of the winding roll 19. Further, the winding speed by the winding roll 19 is 100-1500 m/min, and the tension is 0.0001-
0.5 g/denyl.

Note that the hot gas flow blown out from each hot gas blowing means 7 is as follows:
An inert gas such as a cloth, nitrogen gas, or air is used, but a reactive gas such as hydrogen halide, oran, etc. may be mixed therein to promote infusibility.

Next, the operation of this embodiment will be explained.

When the molten pitch 2 stored in the storage tank 1 is taken out one stop from the spinning hole 5 of the spinneret 4 by pushing down the piston 3 to obtain a pitch of 145 Mt t s, this pitch fiber 1
8 is pulled out of the heat insulating cylinder 6 while being cooled and hardened by the hot gas flow blown out from each hot gas blowing means 7,
It is wound up on a winding roll 19.

The cured pitch fiber 1 wound around this winding roll 19
8 is heated at 200 to 450°C in the presence of alcohol, as in the conventional case.
It is heated for about 10 minutes to be crosslinked and infusible, and then carbonized in an inert atmosphere of about 1000 to 2 Q Q O'C to form carbon fibers.

1. According to this embodiment as described above, there are the following effects.

That is, the hot gas flow blown out from the hot gas blowing means 7A in two positions is distributed almost equally around the entire circumference of the spinneret 4 due to the action of a large number of blowout DIOAs, so that The temperature is kept approximately uniform, and therefore, even if a large number of spinning holes 5 are provided in the spinneret 4, a large number of pitch fibers can be smoothly spun from all the spinning holes 5! 1118 can be withdrawn, I, jl
/i′: Characteristics can be significantly improved.

Further, since the heat-retaining cylinder 6 is provided below the storage tank l, the temperature around the pitch fibers 18 can be maintained at a uniform temperature at all times, and from this point of view as well, smooth spinning can be performed. Furthermore, since the hot gas flow of the hot gas blowing means 7A at the two most positions is set to the highest temperature, and the hot gas flows of the hot gas blowing means 7B...7H below it are made to be sequentially lower temperature, the pitch m The fiber 18 can be cooled smoothly,
Moreover, since the double temperature setting matches the natural temperature distribution inside the heat-insulating cylinder 6, the gas flow inside the heat-insulating cylinder 6 will not be disturbed, and the pitch fibers 8 will not be cut. Never. Moreover, each blow-off port 10 of each hot gas blow-off means 7
Since the hot gas flow is blown out slightly downward, the pitch fibers 18 are not blown up and cut. Furthermore, since the lower part of the heat-retaining cylinder 6 is narrowed toward the center to make the opening small, the heat-retaining state inside the heat-retaining cylinder 6 can be maintained well, and stable spinning can be performed. In addition, air blower fi1
Since the hot gas from the hot gas blowing means 7 is dispersed over the entire circumference of the hot gas blowing means 7 by the action of the partition wall 8, the hot gas stream can be blown out almost uniformly from the entire circumference of the hot gas blowing means 7.

In carrying out the present invention, the blow-off port 10 of the hot gas blow-off means 7 is not limited to a large number of small holes as in the above embodiment, but may be formed by combining several small holes in a horizontal direction into a long hole shape. Alternatively, it may be a slit-like shape that extends substantially all around the circumference, and in short, any shape that allows a hot gas flow to be sprayed substantially uniformly from the entire circumference toward the spinneret 4 may be used. Further, the number of hot gas Suita r stages 7 is not limited to 8 stages as in the above embodiment, but may be 7 stages or less, or 9 stages or more, and may be set as appropriate depending on the nature of the pitch 2. The length of the tube 6 also changes depending on the number of stages of the hot gas blowing means 7, but in this case, the hot gas blowing means 7 is not provided over almost the entire length of the heat retaining tube 6, and only the portion of the heat retaining tube 6 without the hot gas blowing means 7 is provided. It may be provided relatively long. In addition, the blower 12 and the heater 13 are not limited to those provided outside the heat insulation cylinder 6, but may be provided inside the cylinder. It may also have a built-in heater with separate temperature control. Moreover, the extrusion at pitch 2 is not limited to the piston 3, but may be performed by other types of extrusion means such as a screw extruder.

[Effects of the Invention] As described above, according to the present invention, there is an effect that it is possible to provide a carbon fiber manufacturing method and apparatus suitable for mass production, which can spin a large number of pitch fibers at the same time and has a capacity of 11 fibers.

[Brief explanation of the drawing]

The figure is a sectional view showing a schematic configuration of an embodiment of the present invention. 1: Storage tank, 2: Pitch, 3: Piston as extrusion means, 4: Spinneret, 5: Spinning hole, 6: Heat insulation cylinder, 7.7A
, 7B...7H: hot gas blowing means, lO, IOA,
IOB...IOH: Air outlet, 12, 12A, 12B.
...12H: Blower, 13, 13A. 13B...13H: Heater, 18: Pitch fiber.

Claims (6)

[Claims] (1) Pitch is discharged from the spun 1'' gold, which has a large number of spinning holes, downward into the heat-insulating cylinder. When spinning the chi fiber M1, a stream of hot waste is sprayed almost evenly from the periphery of the heat insulating tube toward the center, so that one part of the entire spinneret is spun.
1. A method for producing a promoting fiber, which comprises spinning pitch fibers while maintaining a substantially uniform pitch, making the pitch fibers infusible, and then carbonizing the pitch fibers to produce carbon fibers. (2)4. Claims Paragraph 1 is characterized in that the heat residue generated in the spun pitch fibers is multi-staged, and the flow of these heat residues is successively lowered in temperature as it goes downward. A method for producing carbon m-fiber. (3) In claim 1 or 2, the temperature of the hot gas flow is set to a temperature equal to or lower than the temperature of the spinneret. (Charged as ￥) 1 person manufacturing capacity for borosilicate fibers. (4) At the lower end of the storage tank in which the pinch punches are stored, take a spinning 1" gold with a large number of spinning holes (-J), and provide a heat-insulating cylinder extending downwards from this spinning gold. This thermal cylinder
Blow hot gas approximately evenly toward the 110th spin point in a part 4
= A carbon fiber manufacturing apparatus characterized by being provided with hot gas blowing means. (5) In claim 4, the heat retention 1.1
In addition to the hot gas blowing means, there is one or more hot gas blowing means in the axial direction of the heat insulation α1. Q. A carbon fiber manufacturing apparatus characterized in that the temperature of the hot gas stream blown out from these hot gas blowing pile means is set to be mn-th lower from the top to the F side. (6) In claim 1111 No. 5 Jft, the eddy electric current of the hot gas flow blown out from the hot gas blowing means at the 14th stage is a carbon fiber whose 4,ν characteristic is approximately equal to the temperature of the spinneret. Fiber M [manufacturing equipment.