JPS60155457A - Manufacture of molded sound-insulating material - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of manufacturing a molded soundproofing material. More specifically, the present invention relates to a manufacturing method that allows a molded soundproofing material having a complicated deep drawing shape to be easily molded in one step by simultaneously performing heating compression and vacuum suction.

A sheet-like material made of a thermoplastic resin and/or rubber component and a filler (hereinafter referred to as a "sound insulation sheet"), and a bulky nonwoven fabric containing a thermosetting synthetic resin (hereinafter referred to as a "bulky nonwoven fabric")
A bulky nonwoven fabric is attached to the dash panel of an automobile, etc., and used for sound insulation.

A sound insulating material made of a combination of these sound insulating sheets and a bulky nonwoven fabric is compression molded in a heated state and installed as a molded body having a gate convex shape. However, in compression molding using a simple heating mold, the rigidity of the sound insulating sheet is strong, and the bulky nonwoven fabric acts as a cushion, and the distance between the bottom of the four parts and the top of the convex part, that is, the overhang distance of the convex part, is about 10 m/m. I could only mold things. Therefore, in the case of a molded soundproofing material in which the height of the projecting part of the convex part is 10+a/+n or more,
This requires a very complicated process of forming the sound insulating sheet and the bulky nonwoven fabric individually and then bonding them together, and an improvement is desired.

Conventionally, sound insulation sheet-like materials, bulky nonwoven fabrics, and thermoplastic disease j
It is known that vacuum forming is used to compression mold W films and the like.

For example, according to Japanese Patent Publication No. 48-38783, the first step is to heat-press a breathable felt-like sheet impregnated with a synthetic resin, and after curing, the sheet is moved to a vacuum suctionable male mold of the same type as the heat press. A second step of fitting, a third step of laminating a thermoplastic synthetic resin sheet of 0.3 m/thickness lined with a cushioning material on the outer surface, and a fourth step of vacuum forming and bonding. A manufacturing method has been proposed. However, this proposal only recommends a method for forming a thin thermoplastic sheet with a thickness of 0.3 plows/m, using the breathability of the felt-like sheet and lining the outer surface with a cushioning material. No mention is made of the method of forming a laminate of a highly rigid and thick sound insulating sheet F and a bulky nonwoven fabric into a molded body having an overhang of an arbitrary shape and height on the sound insulating sheet side, which is the theory 2 to 51. This cannot be achieved by using the proposed method. Furthermore, the process is complicated and cannot be put to practical use.

Furthermore, according to JP-A No. 53-136061, the first step is to vacuum-form a sound-insulating sheet in advance using a vacuum mold, and a new bulky non-woven fabric is added onto the vacuum-formed sound-insulating sheet. A manufacturing method has been proposed that includes a second step of sequentially laminating a thermoplastic resin film lined with a plastic resin film and a nonwoven fabric, and a third step of heat-pressing molding. In the proposal, P with a thickness of 1.5 to 3 m/-
Since the thermoplastic resin sheet such as vC is vacuum formed into an uneven shape using a conventionally known normal vacuum forming method, it is possible to create a complex uneven shape. Although this is a step forward in terms of what is possible, it is possible to make a laminate of a thick and rigid sound insulation sheet of 2 to 5 s/m and a bulky nonwoven fabric into a molded body with an overhang of any shape and height. There is no mention of a simple method for molding in one step, and the method has the same drawbacks as conventional manufacturing methods in terms of the complexity of the process.

There has also been a proposal (Japanese Unexamined Patent Publication No. 57-43830) in which air vent holes are formed in a molded core material placed in a vacuum molding mold, and grooves that communicate with each other are formed on the surface of the core material. It is formed for the purpose of discharging air between a material molded product and a skin material attached thereon, and does not suggest anything about deep drawing of a thick sheet.

The inventor of the present invention has completed the present invention as a result of intensive research in view of the above circumstances, and one object of the present invention is to create a laminate of a strong and thick sound insulating sheet and a bulky nonwoven fabric. It is an object of the present invention to provide a manufacturing method that allows a molded article having an overhang portion of an arbitrary height to be easily formed in one step.

That is, the gist of the present invention is to provide a lower mold having vacuum degassing grooves on the mold surface with a sheet-like material made of a thermoplastic resin and/or rubber component and a filler, and a bulky material containing a thermosetting synthetic resin. The present invention relates to a method for manufacturing a molded sound insulating material, in which nonwoven fabrics are sequentially laminated, and then vacuum suction is applied through the vacuum degassing grooves while heating and pressure molding is performed at the same time. The present invention resides in a method for manufacturing a molded soundproofing material using a lower mold provided with vacuum degassing holes.

The sound insulation sheet constituting the molded sound insulation material of the present invention is made of any rubber selected from natural rubber, synthetic rubber, recycled rubber, etc. and/or thermoplastic synthetic resin such as vinyl chloride resin, bituminous material, etc.
Calcium carbonate, asbestos, which are conventionally known as fillers.
It is possible to mix fillers freely selected from fillers such as talc and magnesium carbonate, and form a flat or patterned sheet using a mill f&calender roll or an embossing roll. There is no problem in adding other conventionally known additives such as anti-aging agents. If the sheet layer is desired to have decorative properties, the surface may be embossed or painted. The thickness of these sheet layers is preferably about 1.5 to 5 m/eh.

The bulky nonwoven fabric that can be used in the present invention is mainly composed of a binder made of one or more of animal, vegetable, mineral, and synthetic resin discontinuous fiber materials and a thermosetting synthetic resin, and is known per se. However, before thermoforming, 5 to 40% of the binder made of a thermosetting resin is in an uncured state based on the total weight of the bulky nonwoven fabric. It is important to prepare the fabric so that it can be handled as a bulky nonwoven fabric by other means such as melting a synthetic resin or using a thermoplastic resin in combination.

If the amount of uncured thermosetting resin is less than 5% of the total weight of the bulky nonwoven fabric, the mold retention property and strength of the molded article will be poor;
% or more, the resin is not mixed uniformly in the nonwoven fabric, resulting in variations in strength, or the rigidity becomes too strong, which is undesirable. The proportion of synthetic a and ii in the mixed HTM fiber material should be changed depending on the area where the soundproofing material is used, for example, if it is used in an engine room, it is closer to the road surface and is more likely to receive rainwater and sand debris, preferably a majority or more. It is preferable to use synthetic fibers.

The bulky nonwoven fabric in this state generally has a thickness of 8 to 50 m/m and an areal density of 400 to 4000 g/m2.

A method of obtaining a molded soundproofing material by laminating a bulky non-woven fabric containing an uncured thermosetting resin with a sheet-like material made of a thermoplastic resin and/or a rubber compound and a filler as a cover, and then molding under heat and pressure. Although the present inventors have previously filed an application, in the present invention, by performing vacuum suction and heating and pressurization at the same time, only one mold is used, and the shape of the overhanging part of the convex part can be improved in one process. It has been improved so that it can be molded sharply.

The lower mold used in the production of the present invention must be capable of heating at least to a temperature that can thermally soften the sound insulation sheet, and must have a groove for vacuum degassing, and must also be provided with a vacuum degassing hole. That is a good thing. In the present invention, vacuum suction is performed auxiliary at the same time during heating and pressure molding, and it is not necessary to provide vacuum deaeration grooves on the entire surface. If the distance to the top is 8 to 60 m/m, several to ten or more grooves may be provided vertically and horizontally on the bottom surface of the four parts of the lower mold corresponding to the convex part. It is preferable to provide a ventilation hole in the groove of the lower mold, especially in a part of the corner, and to apply vacuum suction from outside the mold. The strength of the vacuum suction varies depending on the height of the overhang and the thickness of the sound insulation sheet, but is approximately 400 to 760 m5+Hg.

The upper mold used in the present invention is a heating and pressing mold having a shape corresponding to the desired shape of the molded product, and is heated at approximately 150 to 250°C.
Can be heated to a temperature of approximately 1-100 kg/a
m”.

The upper mold used in the present invention has a T-shaped cross section and a clamping device that has a continuous arbitrary shape (even a rectangular shape) outside the outer periphery of the desired shape corresponding to the molded object, and has a certain amount of self-weight. It is attached in a slidable manner.

When the upper mold is raised, the clamp device is suspended from the upper mold by the protrusion at the top of the T-shaped mold, and as the upper mold gradually descends, the mold part is placed on the lower mold surface. When the placed laminate of bulky nonwoven fabric and V sound insulation sheet is lightly pressed, the clamp presses the outside of the outer periphery of the desired shape with its own weight. If vacuum suction is performed in this state, the air will be in the air-capped state F and the protruding portion of the convex portion will be pulled into the vacuum degassing groove. Next, the molded soundproofing material of the present invention is obtained by being strongly pressed by the mold surface of the heated upper mold that continues to descend without stopping. Since the upper mold and the clamp device exist in a slidable state, even if the upper mold is completely lowered and reaches the zero press state, the clamp device portion will not be subjected to a load greater than its own weight.

Conventionally, when vacuum forming thermoplastic sheets, the outer periphery of the material is completely crimped to form a vacuum chamber, so the material is stretched by vacuum suction, making it difficult to create a uniform thickness surface. By using an upper mold equipped with a slideable lamp device as in the present invention, a vacuum chamber can be formed, and the material is movable and is pushed into the mold by the length of the gate protrusion, so a sound insulating sheet of uniform thickness is provided. It also has the advantage of producing molded soundproofing material.

In the present invention, there is no hindrance to laminating a skin material and/or a waterproofing material layer on the high-performance nonwoven fabric surface on which the sound insulation sheet is not laminated, and integrally molding the layer at the same time.

The method for manufacturing the molded soundproofing material of the present invention will be explained in more detail.

A sound insulating sheet and a bulky nonwoven fabric are placed in this order on a lower mold having a vacuum degassing groove in the bottom of the mold recess corresponding to the shape of the convex part of the molded article, and if necessary, a skin material and/or After laminating the waterproof material layer, turn on the operation switch of the vacuum pump. In this state, a vacuum chamber is not formed and the sound insulation sheet is not vacuum suctioned.) Lower the upper mold with the slideable lamp device attached as described above. . When the mold surface of the upper mold lightly pressed the laminate against the four parts of the lower mold, a vacuum chamber was formed by the clamping device, and the sound insulation sheet was pulled toward the vacuum degassing groove, and at the same time continued to descend without stopping. It is strongly pressed by the molding surface of the upper mold and can be easily molded into a desired uneven shape in one step.

At this time, it goes without saying that the lower mold should be heated to such an extent that the sound insulating sheet can be thermally softened, and the upper mold should be heated to a temperature higher than the reaction temperature of the thermosetting resin contained in the bulky nonwoven fabric. .

Also, it is recommended that the vacuum pump switch be linked to the vertical movement of the upper mold.

The present invention can simultaneously form a molded soundproofing material with a desired uneven shape in one step without having to go through the complicated steps of vacuum forming a soundproofing sheet, then laminating other laminates and then applying heat and pressure molding as in the past. It is something that can be obtained.

Examples are given below to provide a more detailed understanding of the present invention.

Naturally, the present invention is not limited to the following examples.

Example Tire recycled rubber: 40 parts by weight, blown asphalt (Shell oil-fired MEX 7 Alto 95/15) 260 parts by weight, calcium carbonate: 150 parts by weight, and asbestos: 50 parts by weight were kneaded with a mixing roll and then kneaded with a calendar roll. A sound insulation sheet having a thickness of 2II/L11 was obtained.

30 parts by weight of recycled wool and 50 parts by weight of fallen cotton were opened and mixed, and the melting point was 1.
25 parts by weight of phenolic resin powder with a reaction temperature of 170°C was sprinkled and mixed at 40°C, formed into 7 leases using a 717 forming machine, and passed through a heating oven at 150°C to a thickness containing approximately 11% uncured phenolic resin. 24m/m, areal density 1000g
/m2 bulky nonwoven fabric was obtained.

The entire surface of the lower mold is made to match the shape of an automobile's dash outer (dash surface on the engine room side), and 10 vacuum degassing grooves with a depth of approximately IIII/I11 are provided vertically and horizontally on the entire surface of the lower mold. The sound insulating sheet and bulky nonwoven fabric obtained above were sequentially laminated on the lower mold. Next, the upper mold, which has a T-shaped cross section around the four peripheries of the mold and has a continuous clamping device that is suspended from a bulge at the top and can be slid up and down, is lowered. At the stage when the upper mold began to descend, the vacuum pump was activated by the limit switch, but at that point the sound insulation sheet was not sucked. As it descends further, when the upper mold pushes the laminate to a certain extent into the recess of the lower mold, the clamping device uses its own weight to hold down the four peripheries of the laminate, creating an air-cut state and pulling the sound insulation sheet toward the vacuum vent almost simultaneously. (After about 0.5 seconds), the upper mold continued to descend without stopping and was heated and strongly pressurized to obtain a molded soundproofing material according to the present invention.

The obtained molded soundproofing material had sharp convex shapes and was extremely excellent.

Patent applicant: Japan Special Paint Co., Ltd. Procedural amendment (formality) May 90, 1982 Commissioner of the Patent Office 1.Display of the incident 1981 Patent i No. 11096 2. Name of the invention Summer yFi V4''s prayerful return.

3. Relationship with the person making the amendment Patent applicant postal code 114 Address 5-16-7 Oji, Kita-ku, Tokyo Telephone 03 (
913) 6131 April 4, 1980 (Shipping date: April 24, 1980) 5. Number of inventions increased by the amendment 0 6. Full text of the specification subject to the amendment 7. Statement of contents of the amendment #I Engraving (no changes to the content)

Claims (1)

[Claims] (1) A sheet-like material made of a thermoplastic resin and/or rubber component and a filler, and a bulky nonwoven fabric containing a thermosetting synthetic resin are sequentially placed in a lower mold having a vacuum degassing groove on the mold surface. A method for manufacturing a molded soundproofing material characterized by laminating and then heating and press-molding the material while applying vacuum through the vacuum degassing groove (2) Providing a vacuum degassing hole in addition to the vacuum degassing groove on the mold surface. A method for manufacturing a molded soundproofing material according to claim 1, which uses a lower mold comprising: