Bmc Injection Molding

1. Because the BMC material contains a large amount of glass fiber and filler, it will block the gap between the workpiece and the exhaust groove during molding. Exhaust is equal to discharge, and the exhaust vent should be easy to clean. The place that cannot be cleaned should be designed to take into account the parting surface structure and the cold trough.





2.The resin and filler will block the gap between the workpieces during molding. It is difficult to disassemble after long-term use and cooling. In addition to the thermal expansion of the metal and the accuracy of the product, the matching gap between the workpieces should be fully considered during processing.




3.Because BMC material contains high glass fiber, the flow is poor, the hardness of the material itself is high, and the mold is very worn. When designing, different materials should be considered, and the quenching hardness of the mold material (vacuum heat treatment) HRC50 or above), tempering temperature and surface treatment have high requirements (the mold core is recommended to use Japan's Datong H13 or Sweden 8407) to effectively ensure the use of the mold.





4.The open cavity distribution pattern should be reasonable: the balance of each cavity in a mold is crucial because it is the direct killer of the pass rate. It also affects the appearance of the product. When the balance is not good, the B mode has a problem when the A cavity is satisfied. Conversely, when the B mode satisfies the A mode, the process is difficult to satisfy.




5.BMC materials are very sensitive to temperature. When the temperature difference is large, the product will be deformed, cracked and oversized. Therefore, the mold should be more temperature-detected, and the temperature balance should be fully considered when designing the heating rod.



6.The design of the runner should be as low-pressure and low-speed as possible. The position and angle of the runner should avoid the direct impact on the easily deformable workpiece and the effective discharge of the gas inside the cavity.