With the development of China's rubber products industry, the types of rubber products are increasing, the production is expanding, prompted by the rubber mold design and manufacturing from the traditional empirical design to the theoretical calculation design. In particular, the rubber production equipment and the continuous improvement of the production process, rubber mold is more and more, mold manufacturing level and mold complexity is also more and more sophisticated. High efficiency, automation, precision, long life has become the trend of rubber mold development.
First, the classification of rubber mold
Rubber molds according to the mold structure and product production process is divided into: compression molding molds, die-casting molds, injection molding molds, extrusion molds four commonly used molds, as well as some of the production of special rubber products of special rubber molds, such as inflatable molds, dip molds and so on.
1. Compression molding mold
Also known as ordinary compression mold. It is mixed, processed into a certain shape and weighed semi-finished rubber directly into the mold, and then sent to the plate vulcanizing machine in the pressurization, heating. The rubber is vulcanized under pressure and heating.
Characteristics: mold structure is simple, versatile, widely used, easy to operate, so in the rubber molding products occupy a large proportion.
2. Die-casting mold
Also known as transfer mold or extrusion mold. It is mixed, simple shape, limited to a certain amount of rubber or rubber block semi-finished products into the die-casting mold cavity, through the pressure of the die casting plug extrusion rubber, and make the rubber through the pouring system into the mold cavity vulcanization.
 Characteristics: It is more complicated than ordinary die casting molds, which is suitable for making thin-walled, slender and easy-to-bend products that can not be pressed or barely pressed by ordinary die casting, as well as rubber products with complicated shapes that are difficult to add materials. The products produced by this mold have good denseness and superior quality.
3. Injection molding mold
It is pre-heated into a plastic state of the rubber material through the injection mold casting system into the mold shaped vulcanization.
Features: complex structure, suitable for large, thick-walled, thin-walled, complex shape products. High production efficiency, stable quality, can realize automatic production.
4. Extrusion molding die
Through the head of the molding die made of various cross-sectional shape of the rubber profile semi-finished products, to achieve the purpose of the initial modeling, and then after cooling and shaping transported to the vulcanization tank for vulcanization or used as a compression molding method required for the pre-molded semi-finished rubber.
Characteristics: high production efficiency, stable quality, can realize automatic production.
Second, the rubber mold structure:
1, the residual material tank (or called flow of rubber tank)
In order to ensure that the rubber filled into the cavity of the compaction, the rubber must be slightly excessive, so it must be placed around the cavity groove storage residual rubber, this is used to exclude the residual material groove is called residual groove, also known as the flow of rubber groove.
2, exhaust holes
Gas sealed in the cavity will produce bubbles, scars, lack of glue and other defects, so we must make the cavity exhaust smooth. In general, the gas can be discharged from the gap in the parting surface, but in some cases, often some parts are not easy to exhaust, which must be open to set a small hole to facilitate exhaust. These holes are called exhaust holes, in Figure 13-29, surrounded by the "O" sealing ring in the gas is not easy to discharge, so you can open a hole in the middle of the gas and flow out of the residual rubber, the diameter of the hole for the ring 1 ~ 3mm, when the O-ring inner diameter of less than 15mm, the middle of the middle of the drilling holes.
3, mold opening (also known as pry mouth)
Open the mouth of the mold is not too deep, do not chamfer, if it is a pair of openings, each pair of openings should be symmetrical with the center of the template, and should be as close as possible to the positioning pin. Usually do not use the beveled mouth, but for thin products mold because of its shallow cavity, the mold do not need to be very strong, more beveled mouth, with a flat prying chisel inserted into the beveled prying mouth, the template that is separated, such as hot water bag mold, slippers with mold mold mold mold can be used for beveled mouth.
4、Handle
Rubber compression mold, there are two kinds of fixed and mobile, fixed operation does not have to move the mold out of the plate vulcanizing machine, generally mechanical operation. Mobile ordinary press mold more manual operation, vulcanization is completed after the mold will be moved out of the plate vulcanizing machine, so when the mold is larger, the labor intensity is very large, in order to move the convenience of heavier molds (generally more than 6 kg) need to be installed handle, so both convenient and safe, but occupies the flat surface area increases, so smaller molds do not install the handle.