JPH0376780A - Manufacture of base paper for wet friction material - Google Patents

Abstract

PURPOSE:To eliminate the directionality of a formed base paper by feeding a papermaking stock solution to a wire cloth in a specified manner in a technique for manufacturing a base paper of hollow disc form wherein a papermaking stock solution is fed into a wire cloth in the form of a circular recessed groove to make paper. CONSTITUTION:A method for making a base paper of hollow disc form by feeding (22) a papermaking stock solution 20 containing a fibrous component and a filler to a wire cloth 1 in the form of a circular groove 10 to make paper, wherein the stock solution 20 is fed to the wire cloth 1 almost radially from the center thereof (e.g. by utilizing a conical part 12). Otherwise, a similar effect can be obtained by feeding the stock solution along the direction of the periphery of the wire cloth 1 (e.g. by rotating the cloth 1 by a motor 3).

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for producing a paper base material for a wet friction material used in oil. Wet friction materials are widely used in multi-disc clutches for automatic transmissions in automobiles and other vehicles.

[Prior Art] The 7-reaction plate of a multi-disc clutch has a structure in which paper facings in the shape of a hollow disc as shown in Fig. 4, which are manufactured from a paper base material, are attached to both sides of a core metal. . To manufacture this paper facing, a flat paper material is formed by a papermaking method from a papermaking stock solution containing a fiber component such as pulp and a filler such as cashew dust. A commonly used method is to punch out a predetermined hollow disc shape from the vapor material to obtain a paper base material, impregnate the paper base material with a binder such as a phenol resin, and then harden the paper base material.

By the way, when punching a hollow disc-shaped paper base material from a flat plate-shaped vapor material, there is a problem that a considerable amount of the vapor material is wasted and the yield of the material is poor.

Therefore, for example, in Japanese Patent Application Laid-Open No. 62-72937, a circular recessed groove-shaped paper making section is provided on an endless moving surface, and a papermaking stock solution is supplied to the surface while moving the moving surface.

A method is disclosed in which the papermaking stock solution on the moving surface is scraped off and paper is made in a papermaking section to obtain a paper base material in the shape of a hollow disk. According to this manufacturing method, a punching process is not required, and the yield of the material is improved.

[Problems to be Solved by the Invention] In the method using the above-described circular groove-shaped paper mesh section,
Since the paper making stock solution is supplied to the paper making part while moving in one direction, the orientation direction of the Na-fiber acid component is substantially the same as that of the flat vapor material. As a result, the paper base material becomes directional, resulting in distortion during impregnation and curing of the binder, dimensions differing depending on the direction, and directional strength, resulting in insufficient strength as a friction material. There was a case.

The present invention was made in view of these circumstances, and
The purpose is to eliminate the orientation of paper base materials.

[Means and effects for solving the problems] The method for producing a paper base material of the present invention involves supplying a papermaking stock solution containing a fiber component and a filler to a circular concave groove-shaped papermaking section to form a hollow circle. A method for manufacturing a plate-shaped paper base material, the paper making stock solution being supplied into the paper making section approximately radially from the center of the paper making section, and the paper making stock solution being supplied along the circumferential direction of the paper making section. It is characterized by being supplied.

The fiber components that are the base components of the paper base material include pulps such as link pulp, organic fibers such as rayon and aromatic polyamide fibers, metal fibers such as brass wire, etc.
In some cases, inorganic fibers such as glass fibers and ceramic fibers can be used alone or in combination. The shape of the fibers is not particularly limited and can be selected from among long fibers, short LLI fibers, whiskers, etc. depending on the desired performance.

Fillers are added to improve the friction performance and heat resistance of friction materials, such as barium sulfate, calcium carbonate,
Conventional fillers such as inorganic fillers such as clay and organic fillers such as cashew dust can be used.

The papermaking stock solution contains this fiber component and filler, and water is usually used as a dispersion medium. Note that various additives such as stabilizers can also be used in the same manner as in the past.

It is desirable that this papermaking stock solution is always supplied to the papermaking section at a constant concentration.

One feature of the present invention is that the papermaking stock solution is supplied substantially radially from the center of the papermaking section. As a result, the fiber components come to be oriented radially, and the paper base material as a whole is oriented in 360 degrees, so that no directionality appears.

Another feature of the present invention is that the papermaking stock solution is supplied along the circumferential direction of the papermaking section. As a result, the fiber components are oriented in the circumferential direction of the paper screen section, and the paper base material as a whole is oriented in 360 degrees, so that no directionality appears. Furthermore, if the fiber components are oriented along the circumferential direction in this way, there will be no directionality in shear strength when used as a friction material, and there will be no weak parts.

In addition, it is also preferable to rotate the paper screen part during or after feeding substantially radially. In this way, centrifugal force due to rotation acts on the fiber components, causing them to be oriented in the circumferential direction.

The papermaking stock solution supplied to the papermaking section as described above is subjected to papermaking after the dispersion medium is removed by vacuum suction or the like.

Then, the formed paper base material is peeled off from the paper mesh section, dried, impregnated with a binder such as phenol resin, and hardened to form a friction material.

[Effects of the Invention] Therefore, according to the method for producing a paper base material of the present invention, the fiber component in the papermaking stock solution supplied to the papermaking section is 3% as a whole.
Since it is oriented in a 60 degree direction, a paper base material without directionality can be easily and reliably produced. Also, the material yield is good. The friction material formed from the resulting paper base material has no directionality, so dimensional changes and distortions do not occur.
Durability is also improved.

Since it is a single-shot paper making method, there is little variation in weight, making it ideal for small-lot, multi-product production with strict standard tolerances.

[Example] Hereinafter, the present invention will be specifically explained using examples. In addition, in the following examples, a papermaking stock solution having the following composition was used.

Papermaking stock solution link valve 5 parts by weight Diatomyum ± 3 parts by weight Cashew dust 2 parts by weight Water 1000 parts by weight The link pulp was sufficiently beaten and thoroughly mixed together before use.

Further, one method of forming a paper base material is an outer diameter of 150 mm, an inner diameter of 80 mm, and a thickness Q of 5 mm.

(Example 1) FIG. 1 shows the main parts of the paper making apparatus used. This papermaking apparatus is comprised of a papermaking section 1 and a supply section 2. As also shown in FIG.
2, and a suction part 14 fixed to the lower part of the rope part 13. And the cylindrical part 11, the conical part 12 and the rope part 1
3, a circular groove 10 is formed. The tip of the conical portion 12 has a conical shape, and the apex of the cone is located at the center of the opening of the supply pipe 22. The diameter of the conical part 12 is the same as that of the supply pipe 2.
2, and is configured such that the papermaking stock solution flowing down from the supply pipe 22 always comes into contact with the conical part 12. Further, the outer diameter and inner diameter of the rope portion 13 are the same as the dimensions of the intended filter paper base material, the depth is Q, 5 mm, and the mesh is 85 mesh.

The supply unit 2 includes a raw material tank 20 in which papermaking stock solution is stored;
It is composed of a valve 21 and a supply pipe 22. As shown in FIG. 3, it is also preferable to have a configuration in which an adjustment tank 23, an overflow tank 24, a pump 25, and a valve 26 are provided between the valve 21 and the supply pipe 22. In this way, it is possible to prevent the supply amount from the supply pipe 22 from fluctuating due to fluctuations in the height of the liquid level in the raw material tank 20.

A paper base material was manufactured in the following manner using a paper making apparatus configured as shown in FIG. First, the valve 21 is opened to allow the papermaking stock solution to flow down from the supply pipe 22 to the papermaking section 1 . At this time, the papermaking stock solution flows down from the apex of the conical part 12 along the side surface of the conical part 12, flows radially, and is supplied into the circular groove 10. Therefore, the orientation direction of the fiber components is approximately open-air,
As a whole, it faces in each direction of 360 degrees.

Then, by suctioning water with the suction section 14, the fiber components and fillers 13t+, 4, etc. remain on the rope section 13, and a paper base material is produced.

Next, compressed air is supplied from below the rope section 13, and the paper base material is peeled off from the rope section 13 due to the pressure. At this time, a suction loader is located above the papermaking section 1, and the paper base material is suctioned by the suction loader and conveyed to the drying position. Then, it is compressed and dried using a hot press in a drying position.

In the obtained paper base material, the orientation direction of the fiber components is radial, and the orientation direction as a whole is oriented in each direction of 360 degrees, so that no directionality occurs.

This paper base material is impregnated with phenolic resin and cured to form a hollow disk-shaped clutch facing as shown in FIG. It is then attached to a core metal and used as a multi-disc clutch.

(Comparative Example) A paper base material of the same shape as in Example 1 was manufactured from the same material as in Example 1 based on the method disclosed in JP-A-62-72937. Then, the clutch facing was formed in the same manner.

(Evaluation) The tensile strength of the clutch facings obtained in Example 1 and Comparative Example was measured in two orthogonal directions.The results are as shown in FIG.
In contrast, there is no difference in tensile strength depending on direction in the facing of Comparative Example, whereas there is a large difference in tensile strength depending on direction in the facing of Comparative Example.

Also, for each facing, the rotation speed is 500O
Durability was measured by the number of cycles until it engaged with a mating material at high rpm and broke.

As a result, the facing of the example was 1.3 to 1.5
Durability has been improved.

Furthermore, a large number of facings were manufactured using the manufacturing methods of Example 1 and Comparative Example, and the amount of dimensional change and its frequency were calculated in two orthogonal directions of the facing when the shape of the paper base material was used as the standard shape. investigated.

In the facing obtained by the manufacturing method of the comparative example, the amount of dimensional change varied depending on the direction, but in the facing obtained in Example 1, no directionality occurred in the amount of dimensional change.

From these results, it is clear that the clutch facing manufactured by the method of Example 1 has no directionality in each performance and is uniform.

(Example 2) FIG. 6 shows the main parts of the paper machine used. This device is configured such that the paper making section 1 is rotationally driven by a motor 3,
It does not have a conical part. This embodiment is roughly the same as the first embodiment except that the supply pipe 22 is located above the circular groove 10.

Using this papermaking apparatus, a paper base material was formed in the same manner as in Example 1, except that the papermaking stock solution was supplied from the supply pipe 22 while rotating the papermaking section 1 at a speed of 6 Orpm. In the obtained paper base material, the fiber components are oriented in the circumferential direction. Therefore, since the whole faces in each direction of 360 degrees,
No directionality occurs. A clutch facing was then formed in the same manner as in Example 1. This clutch facing also has the same performance as that formed in Example 1.

In this example, the paper stock solution was supplied while rotating the paper making part 1, but even if the paper making part 1 was fixed and the supply pipe 22 was rotated along the circular groove 10, the same paper base material could be supplied. can be manufactured.

(Example 3) In this example, a paper base material was formed by combining the methods of Example 1 and Example 2. That is, while supplying the paper making stock solution from the upper part of the conical part 12, As a result, the fiber components are oriented along the direction of the resultant force of the force directed outward in the radial direction and the force along the circumferential direction, and the fiber components are oriented in the direction of 360 degrees as a whole. , no directionality occurs.

[Brief explanation of drawings]

1 to 5 relate to a manufacturing method according to an embodiment of the present invention,
Fig. 1 is an explanatory diagram of the configuration of the paper making device used, Fig. 2 is a perspective view of the main parts of the paper making section, Fig. 3 is an explanatory diagram showing another aspect of the supply section, and Fig. 4 is the formed clutch. FIG. 5, a perspective view of the facing, is a diagram showing the results of a tensile strength test. FIG. 6 is an explanatory diagram of the main parts of the paper making apparatus used in the second embodiment.

Claims (2)

[Claims] (1) A method for manufacturing a paper base material in the shape of a hollow disk by supplying a papermaking stock solution containing a fiber component and a filler to a circular groove-shaped papermaking section and making paper, the method comprising supplying the papermaking stock solution containing a fiber component and a filler to 1. A method for producing a paper base material for a wet friction material, characterized in that the material is supplied into a paper screen section substantially radially from the center of the screen section. (2) A method for manufacturing a paper base material in the shape of a hollow disk by supplying a papermaking stock solution containing a fiber component and a filler to a circular concave groove-shaped papermaking section and making paper, the method comprising: 1. A method for producing a paper base material for a wet friction material, characterized in that the paper base material is supplied along the circumferential direction of a paper mesh section.