JPH01130933A - Embossing device for rubber extrusion molding - Google Patents

Abstract

PURPOSE:To make it possible to form a nice embossing pattern on rubber extrusion moldings by providing a heating device inside an embossing roller arranged immediately after the discharge gate of the head of an extrusion molding machine and heating the embossing face to a specified temperature. CONSTITUTION:A embossing roller 9 is fitted in front of a head 6, i.e. immediately after the discharge gate of a material path by means of a bracket 10, an outer cylindrical member 11 is heated by an electric heater 16 in such a way that the temperature of an embossing face 12 becomes, for example, 150-200 deg.C, and keeping this state an embossing process following the extrusion molding is carried out. This temperature is controlled based on the detection signal from a temperature sensor 17. That is to say, the sectional shape of the molding extruded continuously from the head 6 expands just after extruded so that the molding contacts and presses the embossing face 12 on the periphery of the embossing roller 9 arranged thereby. Therefore, the pattern of the embossing face 12 is transferred onto the surface of an unvulcanized rubber molding. In this case, because the embossing face 12 is heated at a high temperature, the surface of unvulcanized rubber contacted with the embossing face is hardened by a partial vulcanizing reaction.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a texturing device for forming an uneven pattern, so-called texturing pattern, on the surface of an extruded rubber product at the same time as extrusion molding.

Conventional technology For extrusion-molded products made of synthetic resin, a roughly cylindrical grain roller having a grained surface with an appropriate uneven pattern on its outer surface is placed immediately after the outlet of the mouthpiece of an extrusion molding machine. Texturing devices have been used in the past.

In this texturing device, when the molded product is extruded through the die, its cross-sectional shape tends to expand immediately after passing through the die, so the outer surface of the molded product comes into pressure contact with the textured surface of the texture roller, and the texture is The grain pattern on the surface is transferred to the surface of the molded product in a softened state. Since the grain roller naturally rotates as the molded product is extruded, it is possible to continuously form a grain pattern on the surface of the molded product that is successively extruded.

Note that the molded product that has passed through the grain roller is immediately cooled, thereby preventing the grain pattern from disappearing.

Problems to be Solved by the Invention As described above, in the case of extruded synthetic resin products, it is relatively easy to apply texture using a texture roller, and it is possible to form a beautiful texture pattern. On the other hand, in extrusion molded products made of rubber, the above-mentioned texturing device using a texturing roller is generally not used.

In other words, the extruded rubber molded product is in an unvulcanized state, and after being extruded by an extruder, it is introduced into a vulcanization tank where it is heated to about 120 to 150°C to undergo vulcanization treatment. will be held. Therefore, even if a textured pattern is applied to an unvulcanized molded product immediately after passing through the die, when the molded product is heated again in the vulcanization tank, the surface of the molded product softens and the textured pattern tends to disappear. In addition, not only when the rubber material contains a foaming agent, but even when the rubber material does not contain a foaming agent, some gas is generated and the surface of the molded product tends to swell, so it is necessary to apply the rubber material at an unvulcanized stage. The grain pattern becomes very thin.

Therefore, it is impossible to apply continuous texturing to rubber extrusion molded products, and in order to create a beautiful textural pattern, it is necessary to mold each product individually.

Means for Solving the Problems In order to solve the above-mentioned conventional problems, the present invention provides a texturing device for rubber extrusion molded products, in which a texturing device is provided on the outer surface immediately after the discharge port of the extrusion molding machine. The present invention is characterized in that a substantially cylindrical grain roller is rotatably disposed, and a heating means is provided inside the grain roller to heat the grain surface to a predetermined temperature.

Immediately after passing through the die, the unvulcanized extruded rubber molded product tends to expand in cross-section, so it comes into pressure contact with the surface of the grain roller, that is, the grained surface, and the grained pattern is transferred to the molded product. Ru. Here, since the textured surface is heated to a predetermined temperature, for example, about 150 to 2006C, by an internal heating means, the surface of the unvulcanized molded product that comes into contact with it partially undergoes a vulcanization reaction and hardens. do. Therefore, the grain pattern is prevented from disappearing during the subsequent vulcanization process and the like.

Example Hereinafter, one embodiment of the present invention will be described based on the drawings.

As shown in FIG. 4, this embodiment includes a welt part 22 and a hollow seal part 2 attached to the welt part 22.
4. This is an example applied to extrusion molding of an automobile weather strip 21 comprising A grain pattern is formed in the indicated range. As is well known, the welt portion 22 is bent after extrusion molding, and the final product has a substantially U-shaped cross section.

FIG. 2 shows the main parts of an extrusion molding machine equipped with a texturing device according to the present invention.

In the figure, 1 is a cylinder barrel that has a screw 2 inside and supplies the rubber material kneaded by the screw 2, and 3 is a head part that is fitted to the outer periphery of the tip of the cylinder barrel 1. . A breaker plate 4 for rectifying the flow of the plasticized rubber material is disposed at the tip inside the cylinder barrel 1, and a nozzle holder 5 for guiding and supplying the core metal 24 is disposed. has been done. A disk-shaped mouthpiece 6 is attached to the tip of the cylinder barrel 1 by a holding member 7. Note that the pressing member 7 is screwed onto the tip of the head portion 3. Further, the head portion 3 is provided with a heating cylinder 8 for heating the rubber material to about 80 to 100° C. by passing steam or the like.

A material passage corresponding to the cross-sectional shape of the weather strip 21 is formed through the base 6 . Therefore, the rubber material sequentially supplied under pressure by the screw 2 is extruded into a predetermined shape together with the core metal 24 supplied through the nozzle holder 5, and continuous molding is performed. Note that the molded product extruded from the die 6 is in an unvulcanized state,
The material is guided into a vulcanization tank (not shown) placed after the extrusion molding machine, where it is heated to about 120 to 150°C and vulcanized.

A grain roller 9 is attached via a bracket 10 to the front surface of the mouthpiece 6, that is, immediately after the discharge port of the material passage, and forms a grain pattern continuously on the surface of the extruded molded product. .

FIG. 1 is a sectional view showing the structure of the wrinkle roller 9. As shown in FIG.

This wrinkle roller 9 is made of a cylindrical metal outer cylinder member 1.
1, and a fixed shaft 13 that is supported by the bracket 10 in a cantilevered manner.

The outer cylindrical member 11 is formed to be relatively thin, and has a textured surface 12 with a suitable textured pattern on its outer peripheral surface. Note that the textured pattern of the textured surface 12 may be not only an irregular pattern but also a regular pattern. Further, the fixed shaft 13 has large diameter portions 14 at both ends, and both ends of the outer cylinder member 11 have ball bearings attached to the large diameter portions 14.
It is rotatably supported via 5.

An electric heater 16 is housed on the inner peripheral side of the outer cylindrical member 11 as a heating means. This electric heater 16 has a cylindrical shape and is fixed to the fixed shaft 13. Further, a temperature sensor 17 made of a thermistor or the like is attached near the electric heater 16.

On the other hand, as shown in FIG. 3, the bracket 10 is bent into an abbreviated shape, and one end of the fixed shaft 13 passes through its vertical portion 10a, and is secured by a plurality of screws 18. Fixed. A heat insulating material 19 made of ceramic or the like is disposed at a portion of the fixed shaft 13 that fits into the bracket 10. Note that the electric heater 16
The harness 20 of the temperature sensor 17 is led out through the inside of the fixed shaft 13.

Now, in the texturing device configured as above,
The outer cylindrical member 11 is heated by the electric heater 16 so that the textured surface 12 reaches a temperature of, for example, about 150 to 200° C., and in this heated state, the texture accompanying extrusion molding is performed. Note that the temperature control is performed based on a detection signal from the temperature sensor 17.

In other words, the molded product continuously extruded from the die 6 is
As mentioned above, the cross-sectional shape tends to expand immediately after exiting the discharge port of the mouthpiece 6, so the grain roller 9 disposed here
It is pressed against the textured surface 12 on the outer periphery. Therefore, the grain pattern of the grain surface 12 is transferred to the surface of the unvulcanized molded product, specifically, to the surface of the welt portion 22 described above.

Here, since the textured surface 12 is heated to a high temperature,
The surface of the unvulcanized rubber that comes into contact with this part undergoes a vulcanization reaction and is cured. In other words, since the grain pattern is transferred and vulcanized in its original form, a very clear grain pattern is formed.

The molded product with the textured pattern transferred to it is then led to a vulcanization tank and vulcanized, but since the surface area with the textured pattern has already been vulcanized, even if it is reheated, the surface remains It never melts. Furthermore, even if the surface of the molded product swells somewhat due to the generation of internal gas, the already hardened grain pattern will not disappear.

That is, similar to the case of extrusion molded products made of synthetic resin, a grain pattern can be continuously formed simultaneously with extrusion molding.

In addition, as a heating means, in addition to the electric heater 16 mentioned in 1.
For example, the textured surface 12 may be heated by introducing steam or the like.

Effects of the Invention As is clear from the above explanation, according to the texturing device for rubber extrusion molded products according to the present invention, the texturing surface of the texturing roller is heated to vulcanize the surface portion at the same time as the pot pattern is transferred. Therefore, it is possible to prevent the grain pattern from disappearing during the subsequent vulcanization process, etc.

Therefore, even in the case of an extrusion molded product made of rubber, continuous graining can be performed in the same manner as in the case of synthetic resin, and a very beautiful grained pattern can be formed.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a crimp roller showing an embodiment of the present invention, FIG. 2 is a sectional view of the main part of an extrusion molding machine equipped with this crimp roller, FIG. 3 is an external perspective view of the crimp roller, and FIG. FIG. 2 is a cross-sectional view showing an example of a molded product molded according to an example. 6... Mouthpiece, 9... Grain roller, 11... Outer cylinder member, 12... Grain surface, 13... Fixed shaft, 16... Electric heater. ■F＾υ's

Claims (1)

[Claims] (1) Immediately after the discharge port of the mouthpiece of the extrusion molding machine, a substantially cylindrical grain roller having a grain surface on the outer surface is rotatably disposed, and a heating means is provided inside the grain roller,
A texturing device for rubber extrusion molded products, characterized in that the texturing device is configured to heat the texturing surface to a predetermined temperature.