JP3010224B2 - Method for producing carbon fiber high-density felt - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a carbon fiber high-density felt suitable as a heat insulating material, a buffer material, a material for a secondary battery electrode, or the like during high-temperature heat treatment.

[0002]

2. Description of the Related Art Felt made of carbon fiber is excellent in heat resistance and heat insulation at high temperatures.
It is used as a heat insulating material in a high-temperature furnace such as a vacuum evaporation furnace and a semiconductor single crystal growth furnace.

[0003] This kind of carbon fiber felt is required to have heat insulation, mechanical strength and durability in order to raise and lower the temperature in a short time, reduce power consumption, and reduce the size of equipment. Since these three requirements are achieved by increasing the density of the felt, carbon fiber felts aiming at higher density by various means have been developed.

First, a bat layer made of flame-resistant or carbonized fiber is placed on the upper surface of a base fabric made of a woven or nonwoven fabric of a polymer fiber which is carbonized or graphitized by firing. The base fabric and the bat layer are integrated by needle punching from the bat layer side and fired (JP-A-2-46891).

In the second felt, a base cloth made of carbon fiber woven cloth is brought into contact with one or both sides of a bat layer made of carbon fibers, and a part of the fibers of the bat layer is formed by needle punching. The bat layer and the base fabric are integrated by fiber entanglement, and a resin is impregnated in the integrated material to prevent shape collapse, powdering, and the like (Japanese Patent Laid-Open No. 1-278854). No.).

Further, the third felt is obtained by blending carbon fibers with polymer fibers which are carbonized or graphitized by firing.
It is obtained by entanglement while mechanically compressing the fiber and the polymer-based fiber, followed by firing (JP-A-3-14665).

[0007]

However, these conventional felts have various drawbacks and have never been satisfactory. That is, the first felt had an average bulk density after firing of at most 0.05 g / cm ³ , and was inferior in heat insulation, mechanical strength, and durability.

In the second felt, the bat layer and the base fabric are made of carbon fiber. In particular, it is not only expensive to weave with carbon fiber yarns, but also the needle punching is performed because the elongation of the carbon fiber is extremely small. In this case, the fiber is frequently cut, and the product is easily deformed or powdered.Therefore, a resin impregnation step is required to prevent this, and the number of work steps increases. There is also a problem that the property is reduced.

Furthermore, the effect of tightening by needle punching is generally significantly improved by entanglement with a woven cloth or the like having a high fiber density, but the third felt uses a mixed bat without using a woven cloth or the like. Because of this, it is difficult to tighten, and it is necessary to increase the number of times of needle punching to obtain desired tightening. For this reason, the carbon fiber in the blended bat is cut to have a small strength as a felt, and it is considered that the production itself is particularly difficult for a thin material (2 to 3 mm). The fact that the number of times of needle punching is large also means that the working time is long. In addition, mix homogeneously throughout the vat, and
^It is unavoidable that the non-carbon fiber occupying around _1/2 of the weight decreases in density due to the weight loss accompanying carbonization.

The present invention has been made in view of the above circumstances, and has as its object to provide a felt having an average bulk density of 0.1 g / cm ³ or more and a thickness of 1.5 to 15 mm, particularly a thin material (2 to 5 mm). It is another object of the present invention to provide a method for producing a carbon fiber high-density felt which has made it possible to obtain the carbon fiber felt having good workability.

[0011]

SUMMARY OF THE INVENTION In order to achieve the above-mentioned object, the present invention provides a bat layer made of a fiber-resistant, infusibilized or carbonized fiber contained in a cloth body, which is needle-punched, and then the bat layer is cut from the bat layer. And then baking the bat layer.

The cloth body may be a vinylon cold gauze that has been hardened by gluing.

The needle punching can be performed a plurality of times by turning the bat layer together with the cloth body, or can be performed a plurality of times by turning only the bat layer inside the cloth body.

The cloth body may be composed of an upper cloth body and a lower cloth body sandwiching a bat layer. In this case, both sides of the upper and lower cloth bodies are temporarily sewn by means such as sewing or pinning. Stopped, temporarily pressed by the needle of the endless belt with needles placed on both sides of the needle bed while being pressed by the holding roll or holding plate provided at the exit and entrance of the needle bed, or placed on both sides of the needle bed It may be made to be pinched by the up-down mechanism performed.

[0015]

[Function] The bat layer is covered with a cloth around the direction perpendicular to the advancing direction at the time of needle punching, so that it is prevented from spreading in the width direction at the time of needle punching, and the bat layer is needle-punched while being pressed at a high density. You.

Further, when a hard vinylon cold gauze cloth is used, the bat layer can be sufficiently pressed during needle punching, and the bite of the cloth into the bat layer during needle punching is reduced. Peeling from the bat layer after the needle punching is also facilitated, and appropriate friction is generated between the bat layer and the cloth body, so that the bat layer and the cloth body can be favorably integrated.

When the cloth body is composed of an upper cloth body and a lower cloth body sandwiching a bat layer, the cloth body is easily separated from the bat layer after needle punching.

Further, the temporary fixing and the release thereof can be continuously performed by temporarily fixing the both-side mating portions of the upper and lower cloth bodies with the needle of the endless belt with the needle.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be specifically described based on illustrated embodiments. 1 and 2 show a cross-sectional view and a vertical cross-sectional view during needle punching. The bat layer 1 is needle-punched in a state where the periphery of the bat layer 1 in a direction perpendicular to the direction of the needle punching is covered with the cloth 2.

At this time, the bat layer 1 is made of fiber which has been subjected to flame resistance, infusibility or carbonization treatment. In this embodiment, the coal pitch is made infusible and further carbonized, and has a thickness of 13 μm.
m, a fiber having a random length in which a fiber length of 30 to 90 mm occupies most.

The cloth body 2 is made of a cylindrical material which is open in the direction of the needle punching. The material may be a general cloth material. In this embodiment, a vinylon cold gauze which is hardened by gluing is used. Was. Further, the cloth 2 has a material composition of 5 to 15 yarns / c for both the warp and the weft.
m, yarn count: 80 to 25 m count and cloth weight: 60 to 160 g / m ² are selected. In the present embodiment, the yarn count is 10 yarns / cm, and the yarn count is selected. 16
A vinylon cold gauze having a metric count and a cloth weight of 90 g / m ² was used. The material conditions are selected on the basis that the cloth body 2 moves integrally with the bat layer 1 during needle punching and that the cloth body 2 is easily peeled off from the bat layer 1 after needle punching. For this reason, the monofilament woven fabric slips with the bat layer 1 and is difficult to move integrally, so that it is unsuitable for the present invention if the woven fabric itself is not subjected to post-processing. Further, a cloth that is too soft is sunk into the bat layer during needle punching, making it difficult to peel off after needle punching, which is not suitable for the present invention.

Needle punching was performed by integrally moving the bat layer 1 and the cloth 2 while pulling both sides of the cloth 2 outward (in the direction of the arrow in FIG. 1). still,
1 and 2, reference numeral 3 denotes a stripper, reference numeral 4 denotes a needle bed, and reference numeral 5 denotes a needle for needle punching.

The needle punching conditions at this time were as follows. After needle punching, the cloth 2 was peeled off from the bat layer 1 to obtain bat layers A and B shown in Table 1. At this time, the bat layer A is obtained by turning the bat layer 1 together with the cloth body 2 upside down and needle-punching.
Is obtained by turning only the bat layer 1 in the cloth body 2 upside down and downside, and performing needle punching. Needle punching conditions Needle type: 32nd, 9 stitches (3 pieces / row × 3) Number of needles: 175 needles / cm ² Needle depth: 10 mm

[Table 1]

The bat layers A and B obtained in this manner are fired thereafter. However, the thickness does not recover after firing, and a high-density carbon fiber felt maintaining the density before firing is obtained. Was done.

As a control, a bat layer C was obtained by needle-punching only the bat layer 1 having the same material as that of the bat layer without using the cloth body 2. The needle punching conditions at this time are as follows, and the configuration of the bat layer C is as shown in Table 2. Needle punching conditions Needle type: 32nd, 9 stitches (3 pieces / row x 3) Number of needle punches: 50 / cm ² Needle depth: 15 mm

[Table 2]

The product of the present invention (bat layers A and B) has a sufficiently high density despite the fact that the needle depth during needle punching is shallower than that of the control product (bat layer C). Further, in the case of the control product, it is conceivable to further increase the number of stapled stitches in an attempt to increase the density, but doing so will cause the fibers of the bat layer to break and lose shape, and the shape cannot be maintained.

FIG. 3 shows another embodiment of the present invention.
Is composed of an upper cloth body 3 and a lower cloth body 3 so as to sandwich the bat layer 1, and both side mating portions 6a, 7a of the upper and lower cloth bodies 6, 7 are temporarily fixed with pins 10 to form a cylinder. It has a shape. This embodiment has an advantage that the cloth body 2 after the needle punching can be easily peeled off. Further, in the present embodiment, the temporary fixing may be performed by sewing instead of the temporary fixing of the pin 10.

FIG. 4 shows still another embodiment of the present invention. In the present embodiment, the cloth body 2 is composed of an upper cloth body 6 and a lower cloth body 7 sandwiching the bat layer 1, and both upper and lower cloth bodies 6, 7 are aligned at both sides of the needle bed. While being pressed by the holding rolls 11 and 12 provided, the temporary stop is performed only at the time of needle punching with the needle 14 of the endless belt with needle 13 disposed on both sides of the needle bed, and the temporary stop is automatically released after the needle punching. It is supposed to be.

At this time, the press rolls 11 and 12 may be constituted by press plates. Further, in place of the endless belt 13 with a needle at this time, an appropriate upper and lower mechanism may be provided so as to sandwich both sides of the upper and lower cloth bodies 2. Thus, in the other modified embodiments, a high-density carbon fiber felt can be obtained as in the first embodiment.

[0030]

According to the method for producing a high-density felt made of carbon fiber according to the present invention, a high-density felt having an average bulk density of 0.14 g / cm ³ or more using carbon fiber having extremely low elongation can be produced in a short working time. (Minimum number of needle punching) and efficient production.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view (a direction perpendicular to a traveling direction) during needle punching of the present invention.

FIG. 2 is a longitudinal sectional view (a direction along a traveling direction) during needle punching of the present invention.

FIG. 3 is a cross-sectional view of another embodiment of the present invention during needle punching.

FIG. 4 is a side view of still another embodiment of the present invention at the time of needle punching.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Bat layer 2 Cloth 6 Upper cloth 7 Lower cloth 6a, 7a Matching part 10 Pin 13 Endless belt with needle 14 Needle

Claims (7)

(57) [Claims] The present invention is characterized in that after a bat layer made of a flame-resistant, infusible or carbonized fiber contained in a cloth body is needle-punched, the cloth body is peeled off from the bat layer, and then the bat layer is fired. Of producing high density felt made of carbon fiber. 2. The method for producing a carbon fiber high-density felt according to claim 1, wherein the cloth body is vinylon cold gauze that has been hardened by gluing. 3. The needle punching is performed a plurality of times by turning over a bat layer together with a cloth body.
The method for producing a high-density felt made of carbon fiber according to the above. 4. The method for producing a high density felt made of carbon fiber according to claim 1, wherein the needle punching is performed a plurality of times by turning over only the bat layer in the cloth. 5. The cloth body comprises an upper cloth body and a lower cloth body sandwiching a bat layer, and both upper and lower cloth bodies are temporarily fixed by means of sewing, pinning, or the like. The method for producing a high-density felt made of carbon fiber according to claim 1, wherein 6. The cloth body is composed of an upper cloth body and a lower cloth body sandwiching a bat layer, and both upper and lower cloth bodies are provided with a press roll or a press plate provided at the entrance and exit of a needle bed. The method for producing a high-density felt made of carbon fiber according to claim 1, characterized in that the high-density felt made of carbon fiber is temporarily fixed with needles of an endless belt with needles arranged on both sides of the needle bed. 7. The cloth body includes an upper cloth body and a lower cloth body sandwiching a bat layer, and both upper and lower cloth bodies are sandwiched by a vertical mechanism arranged on both sides of a needle bed. The method for producing a high-density felt made of carbon fiber according to claim 1.