Teflon® PTFE resins are fabricated to form parts by a
number of techniques, including ram extrusion, screw
extrusion, compression molding, and paste extrusion
with an extrusion aid. Although different, these techniques
have three basic steps in common: cold forming,
sintering, and cooling. These fabricating steps refer to
operations that involve, respectively: compacting
molding powder to shape by pressing, bonding adjacent
surfaces of particles by heating, and controlling crystallinity
content of the article by cooling.
Previous work has pointed out that about 15 mechanical
properties plus several electrical and chemical properties
of Teflon® PTFE resins are influenced by molding and
sintering conditions. Most notably affected are flex life,
permeability, stiffness, resiliency, and impact strength.
The five basic factors that influence these end-product