Since PTFE will not flow above its melting point, it cannot be injection molded and requires special processing techniques. Molded PTFE is processed by first compression molding the powder into preforms, and then sintering the preforms in a process analogous to sintered metal processing. This process creates geometric shapes that can then be machined, fused, and/or welded.
Automatic molding, a semi-automated form of compression molding, is the process Sunkoo uses for the manufacture of medium-volume to large-volume net molded and near net molded PTFE components. The automatic molding process requires dedicated tooling, typically requires minimal operator intervention and plastic parts can be fabricated relatively rapidly.
With the use of precise tooling and processing, parts manufactured using the automatic molding process can be produced to relatively close tolerances, but not to the accuracy of a fully machined part. Components are economically molded by utilizing a process of automated filling of the die cavity, applying pressure, and part ejection.