In the BMC material molding process, different molding processes can be selected according to product requirements. Among the more commonly used molding processes include die casting and injection molding. The so-called BMC material die-casting refers to a molding method between pressing and injection molding, also called transfer molding, injection molding or injection molding.
When adopting this molding process, it is first necessary to put an appropriate amount of BMC material molding compound into the feeding chamber for preheating, and then press the molding compound in the die casting chamber into the closed hot mold cavity by the plunger. After the mold is pressed and heated, and the product is completely cured and shaped, the mold is opened and the product is taken out. This molding process is not suitable for large-scale products, and is generally used for processing products such as insulating parts, supports, structural parts, and the like which have complicated structures, openings, many inserts, and irregular shapes. In addition, it can also be used for plastic parts, which have the effect of insulation, anti-corrosion and anti-vibration.
Under normal circumstances, BMC material die casting molding process requirements mainly include: 1, molding temperature: mold temperature range of 120 to 150 ° C, preheating temperature is lower than the mold temperature 15 with 20 ° C, to prevent materials in the die casting room due to high temperature Pre-curing; 2, forming pressure is 1.5~2.5 times higher than press forming, 14~28MPa; 3. Preheating time is 40~60 seconds/mm; 4. Filling time is usually controlled at 10~30 seconds; 5. Curing Time: 10~30 seconds/mm.
In addition, in view of the good fluidity of the BMC material itself, it is very suitable for processing by injection molding. The injection pressure is not high during molding, and the injection time is short, and the mold can be filled quickly and evenly. BMC material injection molding differs from other thermoset plastics in that it is difficult to feed the putty-like agglomerates and requires a forced feeding device.