From Wikipedia: Compression Molding is a method of molding in which the moulding material, generally preheated, is first placed in an open, heated mould cavity. It is a high-volume, high-pressure method suitable for molding complex, high-strength fiberglass reinforcements. Today’s object is Compression Molding Silicone. The manufacture of aluminum extrusion dies is one of the key factors to determine its quality and service life.
Before making the silicone mold, you need to make a prototype. The prototype can use the more common is Aluminum.
Five Main Steps
There are five main steps to the thermoset composite compression molding silicone process:
Stage 1 - preheating pre-pressure stage.
The main purpose of this phase is to melt the resin, remove the volatiles, impregnate the fibers, and gradually solidify the resin to the gel state. The molding pressure at this stage is 1/3-1/2 of the total pressure.
Stage 2 -- -intermediate thermal insulation stage.
The effect of this phase is to allow the adhesive to solidify at a lower reaction rate. It is necessary to pay close attention to the flow glue of resin during the heat preservation process. When the resin has been gelled and cannot be drawn into filaments, full pressure should be added immediately.
Stage 3 -- -heating stage.
The aim is to increase the reaction temperature and accelerate the curing rate. At this point, the heating rate cannot be too fast, otherwise, it will cause the over concentration of the solidification reaction, which leads to the stratification of the material layer.
Stage 4 --- thermal insulation stage.
The aim is to make the resin sufficiently solidified. This is called the thermal pressure phase from the total pressure to the entire heat pressure. And the time from the specified hot pressure to the end of the hot pressure is called constant temperature time. The temperature, pressure, and constant temperature of the thermal pressure phase are also determined by the formulation.
Stage 5 --- cooling stage.
In the case of pressure protection, take natural cooling or forced cooling to room temperature, then unload and remove the product. The cooling time is too short, product easy to prod,warping, cracking and other phenomena.
The advantage of compression molding is its ability to create very complex parts. While this technique can not quite reach the production speed of plastic injection molding. More information please click here. If you are interesting or any comments are welcome! SG PROTOTYPE will provide profession advice.