JPS606213B2 - Manufacturing method of rubber products - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a rubber product whose surface layer portion is required to partially have desired properties.

．． Here, a floor mat will be used as an example of this type of rubber product, but the invention is not limited to this.

In the case of a floor mat 1 as shown in Fig. 1, the surface layer is required to have abrasion resistance and weather resistance, and in order to enhance the design effect, the surface layer is not completely black, but only partially. Attempts were made to make it out of colored rubber.

The method for manufacturing this floor mat 1 is as follows.

First, colored rubber, which has excellent abrasion and weather resistance, is divided into pieces with a predetermined thickness (0.3 to 1 inch) using a calendar, etc., and then cut into sizes that match the set frame of the mold. An unvulcanized surface layer rubber member is formed. As shown in FIGS. 2 and 4, the surface rubber member 2 is set in each rectangular setting frame 4 of the lower mold 3. At this time, the unvulcanized surface rubber member 2 is thin and lacks rigidity, and its surface is sticky and sticks to the operator's hands, so it is difficult to accurately set the surface rubber member 2 in the setting frame 4. It is difficult, and it may finally be set as shown by the dotted line in Figure 4. Next, as shown in FIG. 2, the unvulcanized base rubber member 5 is placed on the upper end of the set frame 4, and as shown in FIG. 3, the lower mold 3 and the upper mold 6 are clamped. By compressing the surface rubber member 2 and the base rubber member 5,
are molded and vulcanized at the same time.

At this time, if the surface layer rubber section 2 is not set correctly in the setting frame 4, and some parts are in contact with the inner surface of the setting frame 4 and other parts are not in contact with it, the contact may occur at the beginning of vulcanization. The fluidity of this part becomes extremely high compared to that of the pond part, and it flows over the set frame 4 to the base rubber member 5 side as shown by the arrow. For this reason, the set frame 4 cannot be molded according to the pattern, resulting in molding defects. Particularly when the surface rubber member 2 is colored rubber, its fluidity is higher than that of black rubber, and the colored rubber may flow out. This could not be considered a practical method because it would be a cause of fatal product defects. In view of the above, in the method of the present invention, after the surface rubber member is set in the setting frame, the base rubber member is compressed and molded and vulcanized, so that there is almost no outflow of the surface rubber member to the base rubber member side. The purpose is to provide a method for manufacturing rubber products.

Another object of the present invention is to provide a method of manufacturing a rubber product that allows a surface rubber member to be set in a setting frame more accurately than in the past.

The gist of this invention is to set an unvulcanized surface layer rubber member having a fibrous layer and having desired characteristics in a setting frame of a mold so that the fibrous layer does not come to the bottom side of the setting frame. The present invention provides a method for manufacturing a rubber product in which an unvulcanized base rubber member is placed on the upper end of the rubber product, and the surface layer portion is partially imparted with desired properties by simultaneously molding and vulcanizing the rubber product.

Hereinafter, the method of the present invention will be explained based on illustrated examples.

First, unvulcanized rubber materials such as ethylene propylene rubber and chloroprene rubber, which have excellent abrasion resistance and film resistance, are mixed with talc, inorganic pigments, etc. A surface layer rubber having a mesh-like fiber layer 7 is obtained by calender-molding a willow with a predetermined thickness of 0.3 to 1 on one or both sides of the mesh-like fiber surface, and cutting this into a size that matches the set frame 4 of the mold. Member 8 is formed.

At this time, if the fiber layer 7 is made of a relatively fine woven fabric, the RF material having adhesive properties for vulcanization on both sides of the fiber layer 7 is prepared in advance.
Apply adhesive such as L (resorcinol, formalin, latex). As shown in FIGS. 5 and 6, the surface rubber member 8 is set in each rectangular setting frame 4 of the lower mold 3 so that the fiber layer 7 is not on the bottom side of the setting frame 4. At this time, the vulcanized surface rubber member 8 has the fiber layer 7, so it is strong and more rigid than the case without the fiber layer, so the surface rubber member 8 is easier to handle than in the past. It is easy to accurately set the member 8 in the setting frame 4. In addition, when the fiber layer 7 is formed on the surface of the surface rubber member 8, there is no adhesiveness on the side of the fiber layer 7, and the surface layer rubber member 8 is more adhesive.
is easier to handle and is more preferred. Next, as shown in FIGS. 5 and 6, the unvulcanized base rubber member 5 is placed on the upper end of the set frame 4, and the lower mold 3 and the upper mold 6 are squeezed and compressed. The surface rubber member 8 and the base rubber member 2 are simultaneously molded and vulcanized.

At this time, the surface rubber member 8 is rarely set in the setting frame 4 accurately. Therefore, as in the case of a follower, there are parts where the surface rubber member 8 is in contact with the inner surface of the set frame 4 and parts where it is not, so that a part of the surface rubber member 8 is moved toward the base rubber member 5 side. There is almost no leakage and no molding defects occur. Furthermore, even if the setting of the surface rubber member 8 is not accurate and there are parts that are in contact with the inner surface of the setting frame 4 and parts that are not in contact with the inner surface of the set frame 4, "partial leakage of the surface rubber member 8 will cause the fibers to It is stopped by the layer 7. Even if rubber layers are formed on both sides of the fiber layer 7, the amount of outflow from the rubber layer on the side of the base rubber section 5 is very small and can be ignored. This method produces the following effects. [a' After setting the surface rubber member on the set frame, the base rubber member is placed and compressed, and during molding and vulcanization, the surface rubber member is bonded by the fiber layer. There is almost no leakage to the base rubber member side.

'b' The surface rubber member has a fiber layer and is rigid, so
It is easy to set accurately in the set frame, and because there are parts where the surface rubber member comes into contact with the inner surface of the set frame and parts where it does not, there is almost no local leakage of the surface rubber member to the base rubber member side. , coupled with the above (a}), molding defects hardly occur.

[Brief explanation of the drawing]

Fig. 1 is a partial perspective view showing an example of a rubber product, Fig. 2 is a sectional view before mold clamping in the manufacturing method of a subordinate rubber product, Fig. 3 is a sectional view after mold clamping, and Fig. 4 is FIG. 5 is a partial plan view of a lower mold having a set frame, FIG. 5 is a vertical sectional view of the mold according to the method of the present invention, and FIG. 6 is another sectional view of the mold before clamping. 1...Floor mat, 2...Surface rubber member, 3...Lower mold, 4...Set frame, 5
...Base rubber member, 6...Top mold, 7
...Fiber layer, 8...Surface rubber member. Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6

Claims (1)

[Claims] 1. In order to partially impart desired properties to the surface layer, an unvulcanized surface layer rubber member having the desired properties is set in the setting frame of the mold, and then placed at the upper end of the setting frame. A method for producing a rubber product in which an unvulcanized base rubber member is mounted and simultaneously molded and vulcanized by compression molding, wherein a fiber layer is formed on the surface rubber member, and the surface rubber member is A method for manufacturing a rubber product, characterized in that the rubber product is set so as not to come to the bottom side of the frame. 2. The method for manufacturing a rubber product according to claim 1, wherein the fiber layer is cloth or mesh-like. 3. The method of manufacturing a rubber product according to claim 1 or 2, wherein the fiber layer is formed on the surface of the surface rubber member. 4. The method for manufacturing a rubber product according to any one of claims 1 to 3, wherein the surface rubber member is formed of colored rubber.