JPS5938886B2 - Manufacturing method of sound-absorbing molded body - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Conventionally, sound-absorbing and heat-insulating molded bodies made of glass fibers have been known, but they can be produced by pressing glass fiber webs of an appropriate thickness with glass fibers mixed with an adhesive. is pressurized to form an overall uniform compression molded body with a low density of about 2/m3, and this rough, low-density molded body is cut into required dimensions to form sound-absorbing and heat-insulating molds in a shape suitable for the desired use. However, since it is cut from a low-density compression molded body, the glass fibers may collapse on the cut surface, or
Fragments of glass fiber were scattered, making the work difficult and often causing inconveniences such as damage to the hands of the workers.

Furthermore, as a subsequent process, the periphery of the cut surface is wrapped with cloth or a sheet to prevent the fiber structure from collapsing, separating, scattering, etc., but the wrapping and binding process is extremely time-consuming, laborious, and time-consuming. This required skill and increased manufacturing costs.

In this case, instead of wrapping and binding with a cloth or sheet, it is possible to apply paint to the cut surface, but since the fiber gaps on the cut surface are coarse, the paint may unnecessarily penetrate into the interior. In order to fill in the spaces between fibers and fix the fiber structure by coating, it is necessary to repeat the application process by spray coating, roller coating, etc. many times, which is inconvenient as it takes a considerable amount of time and requires a large amount of paint. was recognized.

The present invention eliminates the above drawbacks, enables smooth and quick production without causing the above-mentioned drawbacks during production, and furthermore prevents the scattering of the fibers during transportation, use, etc. after production. The present invention provides a method for producing a sound-absorbing and heat-insulating molded product that does not cause damage to hands or hands and still maintains good sound-absorbing properties. The raw material is pressed to form a glass fiber web with a certain appropriate thickness to form a comparatively thick 65 Kli'/m3.
80 Kf/m3 in the main body and its outer periphery with low density below.
After forming a compression molded body having a high-density compressed peripheral edge of approximately 300 KP/m3 or less, the compressed peripheral edge is cut into required dimensions, and then a paint is applied to the cut surface. It is characterized by:

Next, one example of implementing the present invention will be described.

The raw material is short glass fibers with an average thickness of 1μ to 8μ, and a thermosetting synthetic resin adhesive such as uncured phenol resin selected from a range of 3 to 20% is added to this to create a uniform coating. The raw materials are mixed and filled into a pressure molding mold to an appropriate thickness, or passed through a pair of molding rollers to form a glass fiber web of a constant thickness.

In this case, nonwoven fabrics or woven fabrics of various types of fibers may be polymerized on the web, if necessary.

Furthermore, various short fibers other than glass or a mixture of a small amount of powder and short glass fibers can also be used as raw materials.

Next, the above-mentioned web is heated under pressure using a pressurized heating mold to harden the resin and produce 65K5'/, which has good sound absorption properties.
7723 or less low-density compressed main part and its outer periphery 80
K! A compression molded body having a high-density compression periphery of i'/m3 or more is obtained.

Next, the outer periphery is cut within the area of the outer periphery to obtain a compression molded body having a predetermined size and shape.

Next, a synthetic resin paint is applied to the cut surface of the outer periphery by any means such as roller coating or spraying, and then dried.

In this way, the peeling of the fibers, which have a coating film that covers the entire fibers on the cut surface, is prevented, and 6
A sound-absorbing molded article of the present invention having good sound-absorbing and heat-insulating properties of 5 Ky/m3 or less is obtained.

The low density of the main body is 10 Ky/m3 or more to 65
Kfl/m3 is preferable from the viewpoint of sound absorption characteristics, and 65k
g,/m3 or higher, no improvement in sound absorption properties is observed.

If it is less than 1QKp/m3, the density will be too coarse and the sound absorption properties will deteriorate.
It is unsuitable in terms of mechanical strength.

The reason why the density of the peripheral area is set to 80 to 97 m3 or more is because the following fact was discovered through various tests and studies.

In other words, when the compressed part is compressed to 80 Ky/m3 or more, there is almost no scattering of fibers during the cutting operation, and there is also no waste of paint when applying paint to the cut surface. It prevents internal infiltration, and can be easily coated with a single spray coating or roller coating in a small amount, usually from 100 y/m2 to 1000 g/m.
At about 2, the cut surface fiber structure can be encapsulated and bound.

80 Ky/m3 or more is preferably up to about 300 KP/m3, and if it greatly exceeds 300 Ky/m3, cracks are likely to occur in the compressed periphery of the molded article due to the impact during cutting.

The paint should preferably be one that has good binding properties, maintains elasticity, and forms a coating film that can follow the bending of the molded object; such paints include rubber paints such as chloroprene, etc. Plasticized vinyl chloride or other flexible synthetic resin paints are used, and in this case, flame retardants and the like are added depending on the purpose of use.

When fiber cloth is laminated, the heat and pressure treatment described above will cause
It is firmly bonded to the object through the curing adhesive of the curable resin.

Depending on the purpose of use, use fire-resistant or heat-resistant fibers such as glass fiber cloth.

What is shown in the drawing is one example of a sound-absorbing and heat-insulating molded body manufactured according to the present invention, and 1 is the molded body, and the entire periphery is several 11 L.
b 180 Kli'/m3, and the main body part 1b, which occupies most of the internal surface area, has a thickness of 20 mm and a density of 45 Kp/m3, for example.

The molded body is a bent molded body having a U-shaped cross section and has a fitting groove frame 1c running vertically and horizontally on the back surface to fit the uneven surface shape of the outer surface of the engine, and is used as an engine cover for an automobile. The vertical and horizontal projecting frame portions 1e are made of the same high-density and thin wall as the high-density peripheral portion 1a to increase mechanical strength.

2 shows a protective coating film in which the fiber structure of the cut surface 1d all around the high-density peripheral edge 1a is coated and bound all around the predetermined shape of the engine by one roller coating.

In the production of the above-mentioned molded body, short glass fiber a is
Add uncured phenolic resin adhesive of approximately 100 mm (by weight), stir to mix uniformly, pass through a pair of rollers to form a layer to a certain thickness, for example, several tens of mm thick. For example, the main body part 1b and the peripheral edge part 1a having different densities and thicknesses are compression-molded by a pressure-heating hardening process, and the surface area of the rear limb peripheral edge part 1a is The cover was cut to obtain an engine cover having the required dimensions and shape, and then 40097 m2 of chloroprene black paint 2 was coated on the cut surface 1d by one roller coating and dried to obtain a product.

In this way, an advantageous sound-absorbing and heat-insulating engine cover is obtained in which the main body portion 1b has a relatively thick wall and has good sound-absorbing and heat-insulating properties, and the cut fibers at the outer peripheral edge 1a do not collapse or separate.

As described above, according to the present invention, the main body has a low density of 65 Kp/m3 or less and the outer periphery has a density of 80 Kp/m3 or more.
After forming a high-density compressed periphery of approximately 0 Kf/m3 or less, cutting is performed at the periphery, so that scattering of glass fibers can be almost completely eliminated, and at the same time, the fibers at the cut portion during cutting can be cut. There is no cracking, making the manufacturing work smooth and easy, and when applying paint to such a high-density cut surface, the fibers on the cut surface can be coated and fixed easily and quickly with a small amount of coating. It can be manufactured efficiently and economically, and in its use, there are no disadvantages such as collapse of fibers from the periphery, and its large surface area provides better sound absorption properties than the low-density main body. It has the following effects.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway perspective view of an embodiment of the present invention, and FIG. 2 is a cutaway sectional view taken along the line A--A. 1...Sound absorbing molded body, 1b...Main part,
1a...Peripheral part, 1d...Cut surface, 2
...Coating film, a... Short glass fiber, b.
·····glue.

Claims (1)

[Claims] 1 Glass fibers made by adding and mixing an adhesive or a glass fiber raw material mainly composed of glass fibers are pressed to form a glass fiber web of a certain appropriate thickness, and then pressed to form a relatively thick 6
5 K9 = 8 on the outer periphery of the main body with a low density of /m3 or less
After forming into a compression molded body having a high-density compression periphery of 0 KP/m3 or more and 300 KP/m3 or less,
A method for producing a sound-absorbing molded article, which comprises cutting the compressed peripheral edge to a required size, and then coating the cut surface with paint.