According to the mold structure and product production process, rubber molds are divided into four common molds: compression molds, die-casting molds, injection molds, and extrusion molds, as well as some special rubber molds for producing special rubber products, such as inflatable molds and dip molds.
1. Compression mold
Also known as ordinary compression mold. It is to put the semi-finished rubber material that has been mixed, processed into a certain shape and weighed directly into the mold, and then sent to the flat vulcanizer for pressurization and heating. The rubber material is vulcanized and formed under the action of pressure and heating.
Features: The mold structure is simple, versatile, widely used, and easy to operate, so it occupies a large proportion in rubber molded products.
2. Die-casting mold
Also known as transfer mold or extrusion mold. It is to put the mixed, simple-shaped, limited rubber material or rubber block semi-finished product into the die-casting mold cavity, squeeze the rubber material through the pressure of the die-casting plug, and make the rubber material enter the mold cavity through the pouring system for vulcanization and shaping.
Features: More complex than ordinary compression molds, suitable for making thin-walled, slender and easy-to-bend products that cannot be pressed or barely pressed by ordinary compression molding, as well as rubber products with complex shapes and difficult to add materials. Products produced by this mold have good density and superior quality.
3. Injection molding mold
It injects the rubber material preheated to a plastic state into the mold through the injection mold’s pouring system for shaping and vulcanization.
Features: Complex structure, suitable for large, thick-walled, thin-walled, and complex-shaped products. High production efficiency, stable quality, and can realize automated production.
4. Extrusion molding mold
The semi-finished rubber profiles of various cross-sectional shapes are made through the molding mold of the machine head to achieve the purpose of preliminary shaping, and then after cooling and shaping, they are transported to the vulcanization tank for vulcanization or used as pre-molded semi-finished rubber materials required for compression molding.
Features: High production efficiency, stable quality, and can realize automated production.
II. Molding equipment
The compression molding mold uses a flat vulcanizer. (Steam vulcanizer: Generally, the maximum pressure of saturated steam can reach 0.6~0.8Mpa, and the vulcanization temperature is in the range of 158~168. Resistance wire heating plate, oil pressure plate vulcanizer)
Die casting mold uses die casting machine.
Injection mold uses injection machine. (The working pressure of injection machine is generally 100~140Mpa, the vulcanization temperature is 140~185, and the vulcanization time is 1~5 minutes)
Extrusion mold uses extruder.
