Injection Molding Injection Molding is the mostwidely used technique forfabricating thermoplasticmaterials because it canmass produce parts forrelatively low costs. Melted plastic is pressurizedand forced into aprefabricated mold. There, itis allowed to cool and willtake the shape of the mold asit solidifies.
Thermoplastics used inInjection Molding Polyethylene Polypropylene Polystyrene Poly(vinyl chloride)
PolyethylenePolyethylene is used for everything– Grocery bags– BottlesIt’s structure is [-CH2-CH2-]Not good for high heat applications
Polypropylene Polypropylene is not as versatile Can be used as a plastic or fiber It’s used mostly for applications like outdoorcarpet Also used for dishes
Polystyrene Polystyrene is a vinyl polymer It has a phenyl group every other carbon atom In plastic form it’s used for computer shells In foam form it’s commonly used for packingboxes
Poly(vinyl chloride) Pvc is used for plumbing in homes Can withstand fire and water The chlorine atoms will inhibit combustion