Ultra high molecular weight polyethylene, Powder processing

At a conceptual level, polyethylene consists only of carbon and hydrogen, as was described in the previous chapter. However, if the discussion of polyethylene is to proceed from ideal abstractions to actual physical implants, three "real world" steps need to occur. First, the ultra-high molecular weight polyethylene (UHMWPE) must be polymerized from ethylene gas. Second, the polymerized UHMWPE, in the form of resin powder, needs to be consolidated into a sheet, rod, or near-net shaped implant (Figure 2.1). Finally, in most instances, tire UHMWPE implant needs to be machined into its final shape (Figure 2.1). A small subset of implants are consolidated into their final form directly, in a process known as direct compression molding (DCM), witiiout need of additional machining. 

HaUdin G.W., and I.L. Kamel. 1977a. Powder processing of ultra-high molecular weight polyethylene. I. Powder characterization and compaction. Poly Eng Sci 17 21-26. 

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