JPH0649306B2 - Method for producing a rubber article having a burr-free three-dimensional effect - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for producing a rubber article having a burr-free three-dimensional effect, and in particular, a rubber having a burr-free three-dimensional effect even when having a complicated design surface. It relates to a method by which an article can be manufactured.

<Prior Art> A rubber article having a three-dimensional effect having a complicated design surface, for example, a tape around the bottom of a shoe, is shown in a plan view in FIG.
Direction, but for the sake of convenience only a part thereof is shown), and a flat plate-shaped base portion (1) as shown in the sectional view taken along the line AA of FIG.
A plurality of strip-shaped protrusions (2) are attached to the upper surface of the base (1) and its base (1).

Conventionally, the bottom peripheral tape (3) as described above is used in FIGS.
It was manufactured by the following process as shown in the sectional view of the main part of the figure.

First, an unvulcanized rubber sheet is formed on the upper surface of a lower mold (5) having a cavity (4) for forming a large number of protrusions as shown in FIG.
(6) is placed and pressed by the upper mold (7) at a temperature that does not cause vulcanization (pressing state is not shown), and unvulcanized in the cavity (4) of the lower mold (5). When filling the rubber sheet (6) and removing the upper mold (7) as shown in FIG. 7, the burr (11) adheres to the periphery of the root of the protrusion (2) and the burr (11) is removed. I had to.
Without completely removing the burr (11), the spacer (8) is placed at a predetermined location as shown in FIG. 8 and the cavity (9) surrounded by the spacer (8) is placed. Put the unvulcanized rubber sheet (10) in the upper part, place the upper mold (7), and press for a predetermined time with a pressing machine having a hot plate at the vulcanization temperature of the rubber sheets (6) and (10). (Not shown), the whole is vulcanized and integrated, and the upper die (7) is removed and die-cut, and it consists of a base (1) and a large number of protrusions (2) on its upper surface as shown in FIG. A bottom edge tape (3) was obtained. However, if the burr (11) is not completely removed in the step shown in FIG. 7, the burr (11) remains around the root of the protrusion (2) of the article shown in FIG. Was unsightly, and there was a possibility that defective products would appear one after another.

<Problems to be Solved by the Invention> As shown in FIG. 9, in order to prevent burrs (11) from being generated at the base peripheral edge of the protrusion (2) of the bottom peripheral tape (3),
Unvulcanized rubber (6) in cavity (4) of lower mold (5) as shown
It was necessary to completely remove the burrs (11) adhering to the root periphery of the protrusions (2) that occurred when the filling was carried out.

However, on the upper surface of the base part (1), a small area of the protrusion (2)
Are densely packed in a small area, so many burrs (11) are generated around the root of the burrs (1).
There is a drawback that it takes a lot of labor and time to completely remove 1).

<Means for Solving the Problems> In order to solve the above problems, the present invention places an unvulcanized rubber sheet on a lower mold cavity portion at an appropriate temperature, and appropriately fabricates the unvulcanized rubber sheet. And press and heat it with an upper mold to such an extent that it does not vulcanize, fill the unvulcanized rubber sheet into the cavity of the lower mold, remove the upper mold, and then peel off the cloth, the cavity of the lower mold. Place a spacer on the periphery, place an unvulcanized rubber sheet of a different color or a different color from the unvulcanized rubber sheet inside the spacer, combine with the upper mold and press at an appropriate temperature to integrally vulcanize the whole. Is a method for producing a rubber article having a burr-free three-dimensional effect.

In carrying out the present invention, natural rubber, styrene-butadiene copolymer rubber, polyisoprene rubber, polybutadiene rubber, etc. are appropriately used as the rubber. It is preferable that it is easy to invade and is inexpensive. Although gold strips and non-woven fabrics are often used, care must be taken as some non-woven fabrics have low strength.

<Operation> Burrs around the root of the unvulcanized rubber that is pressed by the upper mold to the extent that it does not vulcanize and is filled in the cavity of the lower mold penetrates into the weave of the fabric placed on the upper surface of the rubber. Since it is integrated with the cloth, all the burrs are removed at the same time when the cloth is peeled off, and the appearance of the rubber article obtained through the subsequent steps is not impaired at all.

<Example> The above blends A and B are kneaded by a roll machine, aged at room temperature for 1 day, and then rolled by a calendar to a thickness of about 2.0 mm.

As shown in FIG. 1, a lower mold (5) (temperature 150 ° C.) having a large number of rectangular cavities (4) (length 14 mm, width 4 mm, depth 1.5 mm) adjacent to each other with a distance of 4 mm. Prepared and rolled a rolled sheet of the above A having a width of 5 mm (6), placed on the cavity (4), covered with a gold width (12) on the upper die (7) ) (Temperature 150
℃) for 10 seconds. Immediately after removing the upper mold, as shown in FIG. 2, a large number of burrs (11) attached around the roots of the protrusions (2) are attached to the lower surface of the gold width (12), and thus the gold width When the (12) is stripped off, all the burrs (11) attached to the lower surface of the (12) are also simultaneously removed from the upper surface of the lower mold.

Then, after 20 to 30 seconds, a spacer as shown in FIG.
(8) (The cavity (9) has a length of 600 mm, a width of 20 mm, and a depth of 1.5 mm) is placed, and the cavity (9) surrounded by the spacer (8) is placed. Put the rolled sheet (10) containing B in the above,
Place the upper mold (7), heat and press for 10 seconds with a breathing machine (not shown) whose hot plate is at 150 ° C., remove the upper mold (7), and in FIG. 4 and FIG. Length 600mm, width 20m as shown
m, 1.5 mm thick base part (1) and the length of 14 m on the top surface
A shoe peripheral tape (3) consisting of a large number of protrusions (2) of m, width 4 mm, and height 1.5 mm was obtained.

<Effect> Even if a rubber part is made of multiple parts obtained by multiple molding processes, and even if small parts are densely packed in a narrow space on the surface of another part, the appearance due to burrs It was possible to obtain a dirt-free rubber part without adding an extra complicated process.

[Brief description of drawings]

1 to 3 are main-part cross-sectional views showing main steps of the manufacturing method of the present invention, and FIGS. 4 and 5 are main-part plan views of a shoe bottom peripheral tape and a cross-sectional view taken along line AA thereof. FIGS. 6 to 8 are cross-sectional views of main parts showing the main steps of the conventional manufacturing method, and FIG. 9 is a cross-sectional view of main parts of the bottom peripheral tape of the shoe obtained by the conventional manufacturing method. (1) …… Base part, (2) …… Projection part, (3) …… Bottom peripheral tape, (4) …… Hollow part, (5) …… Lower mold, (6) …… Unvulcanized Rubber sheet, (7) …… upper mold, (8) …… spacer, (9) …… cavity, (10) …… unvulcanized rubber sheet, (11) …… burrs, (12)
...... Cloth.

Continuation of the front page (51) Int.Cl. ⁵ Identification number Office reference number FI Technical display area B29K 105: 24 B29L 9:00 31:50 4F

Claims (1)

[Claims] 1. An unvulcanized rubber sheet is placed on the lower mold cavity portion at an appropriate temperature, and the unvulcanized rubber sheet is appropriately covered with a cloth,
Press and heat with an upper mold to the extent that it does not vulcanize, fill the unvulcanized rubber sheet in the cavity of the lower mold, remove the upper mold, peel off the cloth, and put a spacer around the cavity of the lower mold. And place
An unvulcanized rubber sheet of a different or different color from the unvulcanized rubber sheet is placed inside the spacer, and the entire die is vulcanized and integrated by pressing at an appropriate temperature in combination with the upper mold, and a solid body without burrs. A method for producing a rubber article having a feeling.