JPH0759373B2 - Manufacturing method of lightweight mat - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for manufacturing an entrance mat, an indoor mat, and the like, and particularly to a method for reducing the weight of these mats.

(Prior art and its problems) Conventionally, a mat in which a base fabric such as a carpet or a carpet and a vulcanized rubber sheet are laminated and integrated is laid at an entrance or the like, and mud or dust attached to the rug is brought into the room. However, this vulcanized rubber sheet requires a certain thickness so that this integrated mat fits well to the floor surface and does not cause positional displacement even when walking on it. Since it is inconvenient to make the wall thin, the integrated mat is large in weight.

However, since the weight of the mat is large, it is inconvenient to carry the mat and handle it for cleaning and regeneration. Therefore, there is a strong demand for reducing the weight of the mat.

Therefore, it has been proposed to add a foaming agent to the unvulcanized rubber sheet to make the vulcanized rubber sheet of the integrated mat sponge (foam) to reduce the weight.

By the way, as a method for producing the integrated mat, the base cloth and the unvulcanized rubber sheet are laminated and heated in a state of being pressed by a vulcanizing press, and the base cloth and the vulcanized rubber are vulcanized together with the vulcanization of the unvulcanized rubber sheet. A method of integrating with a sheet is known from Japanese Patent Publication No. 63-47611 and the like, but when foaming a vulcanized rubber sheet of an integrated mat using this method, the following problems occur. there were.

That is, since the base cloth is generally arranged in the central portion of the rubber sheet, a step corresponding to the thickness of the base cloth is formed between the central portion and the peripheral portion of the mat, and the step is applied by the press with the step. When pressed, the pressing force acts on the unvulcanized rubber sheet located in the region of the thick base fabric as it is,
It does not sufficiently act on the unvulcanized rubber sheet on the peripheral portion, and it is impossible to apply a uniform pressure to the entire unvulcanized rubber sheet. Even if the pressurization is performed through the cushion material, the difference in the applied pressure can be alleviated to some extent.

Therefore, when foaming an unvulcanized rubber sheet simultaneously with vulcanization, the latter is applied to the rubber sheet in the center of the mat where a sufficient pressure acts and the rubber sheet in the peripheral area of the mat where only a weaker pressure acts. Due to insufficient pressure, the rubber sheet was not sufficiently vulcanized, or expanded and expanded more greatly than the former, and as a whole, it was not possible to obtain a foamed rubber sheet of uniform thickness.

Also, when a rubber sheet in which only the central portion of the mat is formed of a sponge rubber layer and the peripheral edge portion of the mat is integrally formed of a solid rubber layer is used for the integrated mat, only a weak pressing force acts on the peripheral edge portion of the mat, as described above. However, since air bubbles are mixed due to insufficient pressurization, the solid rubber layer cannot be sufficiently vulcanized. On the other hand, in order to completely vulcanize the solid rubber layer at the peripheral edge of the mat, if the pressure of the press pressure is increased as a whole, an unnecessarily large pressure acts on the sponge rubber layer at the center of the mat, and the sponge rubber layer Due to this, the expansion of the foam was suppressed, and there was a problem that it did not foam at all or could not foam to a desired foaming ratio.

(Problems to be Solved by the Invention) An object of the present invention is to solve the above-mentioned problems,
For the purpose of providing a method for producing a lightweight mat capable of producing an integrated mat in which a rubber sheet is uniformly foamed over the whole by uniformly exerting a pressure on a mat precursor composed of a base cloth and an unvulcanized rubber sheet. There is.

Even in the case of a lightweight mat in which the rubber sheet of the integrated mat is integrally formed by the sponge rubber layer at the center of the mat and the solid rubber layer at the peripheral edge of the mat, pressure is applied evenly to the mat precursor to generate sponge. Another object is to provide a manufacturing method capable of simultaneously vulcanizing and foaming a rubber layer and vulcanizing a solid rubber layer without problems.

(Means and Actions for Solving the Problem) The present invention provides a mat precursor prepared by laminating an unvulcanized rubber sheet containing a foaming agent and a base cloth by vulcanization adhesion by heating and pressing. Cover the surface of the body with a larger flexible sheet than the unvulcanized rubber sheet, while vacuum suction between the mat precursor and the flexible sheet,
A fluid is press-fitted from the side of the non-contact surface of the flexible sheet with the mat precursor, and the mat precursor is heated in a pressurized state through the flexible sheet, whereby the unvulcanized rubber sheet is obtained. A method for producing a lightweight mat, which is vulcanized and foamed and is simultaneously adhered to the base cloth, has a technical constitution for solving the above problems.

According to the above configuration, while vacuum suction is performed between the mat precursor and the flexible sheet, the mat precursor and the flexible sheet are pressurized by fluid pressure from the non-contact surface side of the mat precursor of the flexible sheet. The air between and is removed, and the flexible sheet adheres to the entire surface of the mat precursor having a step on the peripheral portion, and at the same time, the fluid pressure is evenly distributed to the entire surface of the mat precursor through the flexible sheet. The unvulcanized rubber sheet added to the vulcanizing agent is vulcanized and foamed and adhered to the base fabric with an equal magnification as a whole.

Further, the foaming gas generated during vulcanization and foaming of the unvulcanized rubber sheet is promptly removed to the outside by the vacuum suction.

Further, according to the present invention, an unvulcanized rubber sheet having a non-vulcanized rubber layer containing a foaming agent at the center of the mat and an unvulcanized rubber layer having no foaming agent at the peripheral edge of the mat is laminated with a base fabric. In vulcanizing and adhering the mat precursor formed by heating and pressing, the surface of the mat precursor is covered with a flexible sheet larger than the unvulcanized rubber sheet, and the mat precursor and the flexible sheet are separated from each other. By vacuum suction, pressurizing a fluid from the non-contact side of the flexible sheet with the mat precursor, and heating the mat precursor under pressure via the flexible sheet, A method for producing a lightweight mat, in which an unvulcanized rubber sheet is vulcanized and foamed and simultaneously adhered to the base cloth, has a technical constitution for solving the above-mentioned problems.

According to the above configuration, as in the above configuration, the flexible sheet is adhered to the surface of the mat precursor, and the unvulcanized rubber layer containing the foaming agent in the center of the mat and the unvulcanized rubber containing no foaming agent in the peripheral portion of the mat. A uniform fluid pressure can be applied to the rubber layer, and there is no problem in vulcanizing and foaming the former into a sponge rubber layer and vulcanizing the latter into a solid rubber layer.

(Example) Below, this invention is demonstrated in detail based on an accompanying drawing.

1 and 2 are schematic cross-sectional views of a mat manufacturing apparatus for explaining the manufacturing method of the present invention.

The mat precursor (1) is composed of a joined body of a base cloth (2) and an unvulcanized rubber sheet (3) containing a foaming agent. As the base fabric (2), various base fabrics having a pile portion or a flocked portion of a mat, such as carpets made of natural fibers or synthetic fibers, carpets and flocked cloth materials, can be used. The surface of the base cloth (2) to be joined to the unvulcanized rubber sheet (3) may be packed with rubber latex, synthetic resin emulsion or the like. As the unvulcanized rubber sheet (3), natural rubber containing a foaming agent or various synthetic rubbers can be used.

Of the mat precursor (1), unvulcanized rubber sheet (3)
Is sucked by the suction part (5) formed in the mounting recess of the suction heating part (4). This suction part (5) is constituted by a region of the mounting plate (6) of the suction heating part (4) in which the hole (7) is formed. More specifically, the suction heating unit (4)
Is an unvulcanized rubber sheet (3) of the mat precursor (1)
A mounting plate (6) on which a surface is mounted, a large number of holes (7) formed in the mounting plate (6), a decompression chamber (8) communicating with the holes (7), and a communication pipe. A decompression means (not shown) such as a vacuum pump connected to the decompression chamber (8) via (9) and a heating plate (10) provided under the decompression chamber (8). There is. Further, in this example, the suction portion (5) is formed smaller than the area of the unvulcanized rubber sheet (3). Therefore, by decompressing the decompression chamber (8) by the decompression means, the unvulcanized rubber sheet (3) can be adsorbed and held by the suction part (5) of the mounting plate (6).

At this time, the unvulcanized rubber sheet (3) and the mounting plate (6)
By laying and interposing a heat-resistant sheet, for example, a flow glass sheet, the back surface of the unvulcanized rubber sheet (3) can have a texture pattern.

The decompression degree of the decompression chamber (8) can be appropriately set, but is usually -0.25 to -2 kg / cm ² , preferably -0.5 to -1.5 kg / cm.
² is enough.

Further, the west side of the base cloth (2) of the mat precursor (1) is entirely covered with the flexible sheet (12). In this embodiment,
The end of the flexible sheet (12) is compatible with the gasket (11) provided on the peripheral portion of the suction heating section (4) and the suction heating section (4), and with respect to the suction heating section (4). It is held by the peripheral edge of the lid (13) that can move up and down relatively. By covering the west side of the base cloth (2) with the flexible sheet (12) and sealing the suction heating section (4) with the lid (13), a sealed space (14) is formed as shown in FIG. The closed space (14) and the decompression chamber (8) are separated by the flexible sheet (12). The flexible sheet referred to here includes a substantially thin structure, for example, a film-shaped one. The flexible sheet (12) may be any one as long as it has the flexibility to be able to adhere to both sides of the base cloth (2) of the mat precursor (1) by the gas pressure in the closed space (14), but the heat resistant rubber sheet ,
It is preferably a heat resistant sheet or film.

Then, as shown in FIG. 2, in the closed space (14),
Air is press-fitted through a gas press-fitting pipe (15) provided in the lid (13). The flexible sheet (1
The uniform pressure efficiently acts on the entire surface of the mat precursor (1) through the (2), and the flexibility (12) adheres to the base cloth (2) side of the mat precursor (1). At that time, air existing between the mat precursor (1) and the flexible sheet (12) is sucked and removed, and the decompression chamber (8) and the closed space (14) are partitioned by the flexible sheet (12). Therefore, the flexible sheet (12) can be adhered to the surface of the base fabric (2) of the mat precursor (1) with a uniform pressure with a small gas pressure.

In such a state, that is, in a state where the unvulcanized rubber sheet (3) is sucked by the suction portion (5) and air pressure is applied to the flexible sheet (12) in the closed space (14), the heating plate By (10), the unvulcanized rubber sheet (3) is heated from the side to decompose and foam the foaming agent contained in the unvulcanized rubber sheet (3) and simultaneously vulcanize. The foaming condition and the vulcanizing condition can be appropriately selected depending on the type of the foaming agent, the unvulcanized rubber and the like, but usually, the heating can be performed at a temperature of about 120 to 200 ° C. for 10 to 60 minutes.

Not only air but also various gases such as nitrogen gas can be pressed into the closed space (14), and the pressure in the closed space (14) at the time of foaming heating is the raising of the base cloth (2). there but not compressive deformation, yet is flexible sheet (12) can be appropriately set adherable range for mat precursor (1), usually 0.1~3kg / cm ^2, preferably at about 2 kg / cm ² Is enough.

According to the above-mentioned manufacturing method, the gas pressure applied in the closed space (14) can be applied uniformly to the mat precursor (1) through the flexible sheet (12). As shown, the sponge rubber sheet (31) vulcanized and bonded to the base fabric (2) has a central portion (A) and a peripheral portion (B) of the mat.
Regardless of the type, a lightweight mat having a uniform foam as a whole and a substantially uniform thickness is manufactured.

The rubber sheet (31) contains 100 parts of NBR, 100 parts of SRF carbon black, 30 parts of DOP, 5 parts of Zinc Hua No. 1 and 1 part of stearic acid.
Parts, sulfur 1.5 parts, accelerator MSA 1.5 parts, accelerator TS 0.2 parts, foaming agent DPT (manufactured by Eiwa Kasei Co., Ltd., product cellular D)
3 parts, 3 parts foaming agent K5 (produced by Eiwa Chemical Industry Co., Ltd., trade name Cellpaste K5) (3 parts by weight)
In the manufacturing apparatus shown in FIG. 2 for producing the mat precursor, vacuum suction of 75 cmHg at the suction part, gas pressure of 2.0 kg / cm ² in the closed space,
A rubber sheet having a uniform thickness of 1.5 mm was formed by uniformly pressing 1.8 times under a heating temperature of 150 ° C. for 10 minutes.

FIG. 4 shows a mat obtained according to another embodiment of the present invention, in which the rubber layer (32) in the central portion (A) of the mat is a sponge layer having the same composition as in the above embodiment, and the peripheral portion of the mat is Rubber layer (33) of (B), NBR 100 parts, SRF carbon black 60 parts, calcium carbonate 20 parts, DOP 20 parts, zinc white 5
Part, stearic acid 2 parts, sulfur 1.5 parts, accelerator DM 1.5 parts, accelerator TS 0.5 part (all are parts by weight) to form a solid layer, which is integrated into a rubber sheet during vulcanization molding. It is vulcanized and adhered to the base cloth (2).

Also in the case of this example, just as in the above example, the rubber sheet of the mat precursor is vacuum-sucked and heated and vulcanized by evenly acting the gas pressure through the flexible sheet closely attached to the surface thereof. It is a thing.

FIG. 6 is a schematic sectional view of another mat manufacturing apparatus in which the method of the present invention can be carried out. For convenience of explanation, the same members as those shown in FIG. 1 and FIG. 2 will be described with the same reference numerals.

In this example, the pressure reducing pipe (18) connected to the pressure reducing means is connected to the hole (7) of the placing plate (6) through the communication pipe (19), and the suction unit (5). The non-vulcanized rubber sheet (3) side of the mat precursor (1) is sucked. Further, in order to enhance the vulcanization efficiency of the unvulcanized rubber sheet (3), a heating plate (10) is provided on the lower surface of the placing plate (6). Even if such a device is used, in the same manner as described above, a lightweight mat in which a rubber sheet is uniformly foamed or a lightweight mat in which only the mat peripheral portion is formed of solid rubber and the mat center portion of a wide area is formed of sponge rubber is used. The unvulcanized rubber sheet (3) can be efficiently vulcanized because the decompression chamber (8) is not interposed between the heating plate (10) and the mounting plate (6) while being manufactured. .

The placing plate (6) is not limited to a flat shape and may have an uneven portion. For example, in the case of producing a mat having a vulcanized rubber sheet with uneven portions for preventing slippage, the uneven portion may be formed on the surface of the mounting plate (6) in correspondence with the uneven portion of the vulcanized rubber sheet. .

The heating may be performed at least from the unvulcanized rubber sheet (3) side. However, as long as the raised fabric of the base fabric (2) is not damaged, the heating is performed from the unvulcanized rubber sheet (3) side and the base fabric (2). ) Side may heat.

The heating means for heating the unvulcanized rubber sheet (3) is not limited to the heating plate (10) and the heater, but may be a heating means using a heating medium such as pressurized steam or heating oil.

The end of the flexible sheet (12) does not need to be held between the gasket (11) of the suction heating section (4) and the peripheral edge of the lid (13), but is held in advance by the lid (13). May be.
In this case, since the flexible sheet (12) also moves together with the relative movement between the suction heating unit (4) and the lid body (13), the covering operation of the flexible sheet (12) on the mat precursor (1) and the suction operation. This can be performed in conjunction with the sealing work of sealing the heating portion (4) with the lid body (13). The flexible sheet (12) is larger than the unvulcanized rubber sheet (3), and may have a size capable of covering the entire surface of the base fabric (2) of the mat precursor (1). It does not have to extend outside the lid.

Further, in the above-described embodiment, the rubber sheet side of the mat precursor is sucked, but the base cloth side may be brought into contact with the mounting plate to suck the rubber precursor.

(Effects of the Invention) As described above, according to the present invention, it is possible to apply a uniform pressure to a mat precursor having a step in the central part and the peripheral part of the mat, and the rubber sheet of the integrated mat is sponged. In this case, the whole can be foamed at a uniform expansion ratio. Therefore, a lightweight mat having a uniform thickness and good appearance can be obtained.

Further, even when only the peripheral edge of the mat is formed of the solid rubber layer, the foam molding of the sponge rubber layer and the vulcanization molding of the solid rubber layer in the central part of the mat can be simultaneously performed without any trouble, and a rubber having a uniform thickness is formed. A lightweight mat with integrated sheets is obtained.

Further, since the foaming gas generated during the foam molding of the rubber sheet is quickly discharged to the outside, the lightweight mat in which the rubber sheet of the integrated mat is foamed can be easily manufactured without any problem.

[Brief description of drawings]

1 and 2 are schematic sectional views of a mat manufacturing apparatus for explaining the manufacturing method of the present invention, FIGS. 3 and 4 are partial sectional views of a mat obtained by the method of the present invention, and FIG. Is a plan view of the mat, and FIG. 6 is a schematic cross-sectional view of another mat manufacturing apparatus used in the method of the present invention. (2) …… Base fabric, (3) …… Unvulcanized rubber sheet, (4)
…… Suction heating section, (5) …… Suction section, (7) …… Hole,
(8) ... Decompression chamber, (10) ... Heating plate, (12) ...
… Flexible sheet, (13) …… Lid, (14) …… Closed space, (15) …… Gas injection pipe, (18) …… Decompression pipe, (31)
…… Sponge rubber sheet, (32) …… Sponge rubber layer,
(33) …… Solid rubber layer.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location B32B 31/04 7148-4F // B29K 21:00 105: 04 105: 24 B29L 7:00 9: 00 31:00

Claims (2)

[Claims] 1. When the mat precursor formed by laminating an unvulcanized rubber sheet containing a foaming agent and a base fabric is vulcanized and bonded by heating and pressing, the surface of the mat precursor is coated with the unvulcanized rubber sheet. Covered with a larger flexible sheet, while vacuum suction between the mat precursor and the flexible sheet, the fluid is press-fit from the non-contact surface side of the flexible sheet with the mat precursor, Of the lightweight mat, characterized in that the uncured rubber sheet is vulcanized and foamed at the same time as being adhered to the base fabric by heating the mat precursor under pressure through a flexible sheet. Production method. 2. An unvulcanized rubber sheet having an unvulcanized rubber layer containing a foaming agent at the center of the mat and an unvulcanized rubber layer not containing the foaming agent at the peripheral edge of the mat, and a base cloth are laminated. In vulcanizing and bonding the mat precursor by heating and pressing, the surface of the mat precursor is covered with a flexible sheet larger than the unvulcanized rubber sheet, and the space between the mat precursor and the flexible sheet is Along with vacuum suction, press-fit a fluid from the non-contact surface side of the flexible sheet with the mat precursor,
By heating the mat precursor under pressure through the flexible sheet, the unvulcanized rubber sheet is vulcanized and foamed and simultaneously adhered to the base cloth. Method of manufacturing mat.