For Two Shot Molding, a multi-shot mold is needed. There are several types of multi-shot molding available, such as over-molds, core-back, and multi-station molds. The right mold selection depends on part geometry, volume, quality, and molder capacity/capability.
In 2-Shot injection molding, a polymer is injected over a molded plastic insert to combine the best features of different materials while reducing or eliminating additional assembly operations. This reduction or elimination of post-processing steps is one of the biggest economical advantages of the 2-Shot silicone injection moulding process. For this kind of silicone injection moulding, a multi-shot mold is needed. There are several types of multi-shot silicone injection moulding available, such as over-molds, core-back, and multi-station molds. The right mold selection depends on part geometry, volume, quality, and molder capacity/capability.
Semi-crystalline thermoplastic polymers show more order than amorphous thermoplastics. The molecules align in a structured crystalline form. The size of the crystals or spherulites is much larger than the wavelength of visible light, making semi-crystalline materials translucent, rather than transparent. Crystalline regions are small with molecular chains comprised of both crystalline and amorphous regions. The degree of crystallinity in a typical thermoplastic will vary from grade to grade, as for example in polyethylene, where the degree of crystallinity depends on the branching and the cooling rate.
Polycarbonate (PC), first introduced in 1958, is an amorphous engineering thermoplastic with exceptionally high impact strength, transparency, high temperature resistance, and dimensional stability. It has a high surface gloss and is available in many colors and color intensities. Additionally, it is impact resistant and maintains high strength and stiffness in a temperature range from -150 to +135˚C.