When you are looking to replace metal with plastic, it is often the case that you try to re-design your part to take account of the lower properties of the particular plastic chosen. What if your design flexibility is limited? Then you have to look to materials that are themselves near to what metals can supply, or use a technology that simulates the production of metal parts. Here we look at three possible routes: one using an un-reinforced plastic, one using a method of injection molding to produce metal parts and lastly a method of combining plastics and metal by a novel process.
There are a number of polymers out there that are towards the top of the material pyramid in terms of strength, stiffness and temperature performance. One lesser known material is self-reinforced polphenylene (SRP), available as PrimoSpire® from Solvay. This plastic is the world's stiffest, strongest un-reinforced polymer and finds applications in mechanical parts for the aircraft and automotive industries.