Main Menu
| The injection molding process of liquid silicone rubbers |
|
Liquid silicone rubbers are supplied in barrels or hobbocks. Because of their low viscosity, these rubbers can be pumped through pipelines and tubes to the vulcanization equipment. The two components are pumped through a static mixer by a metering pump.
One of the components contains the catalyst, typically platinum based. A coloring paste as well as other additives can also be added before the material enters the static mixer section. In the static mixer the components are well mixed and are transferred to the cooled metering section of the injection molding machine. The static mixer renders a very homogeneous material that results in products that are not only very consistent throughout the part, but also from part to part. This is in contrast to solid silicone rubber materials that are purchased pre-mixed and partially vulcanized. In contrast, hard silicone rubbers are processed by transfer molding and result in less material consistency and control, leading to higher part variability. Additionally, solid silicone rubber materials are processed at higher temperatures and require longer vulcanization times. From the metering section of the injection molding machine, the compound is pushed through cooled sprue and runner systems into a heated cavity where the vulcanization takes place. The cold runner and general cooling results in no loss of material in the feed lines. The cooling allows production of LSR parts with nearly zero material waste, eliminating trimming operations and yielding significant savings in material cost.
About First-rate Mold Solution Co., Ltd. About www.firstratemold.com |