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.
Thermoplastics are divided into two material classes (amorphous and semi-crystalline). Their classification is determined by both their transition temperatures and their structure in different states, which works great for molded silicone parts.
Plastics are either organic or semi-organic materials that have (as their main attribute) a very large molecular weight. These very large molecules, or macromolecules, give them their distinct properties and material behavior, when compared to other materials used in manufacturing or found in nature.
Two shot (2K) injection thermoplastic molding dates back several decades, from the multicolor molding of typewriter keys (to produce permanent characters on the keys), to the integration of the multiple parts that make up a car’s headlights. This process has since advanced to allow for the consistent and cost-effective manufacture of multicolor/multifunction thermoplastic/thermoset products for a variety of innovative applications. SIMTEC Silicone Parts prides itself in being at the forefront of two shot LSR/Thermoplastic technology.
Injection molding of Liquid Silicone Rubber (LSR) has existed and evolved over the past 20 years. Due to the thermosetting nature of the material, injection molding of liquid silicone rubber requires special treatment, such as uniform distributive mixing; in addition, the material must be maintained at a constant temperature up until it is pushed into the heated cavity and vulcanized.