This invention involves forward integration of the art paste extrusion
process by adding a step to the processing sequence to change the
uniaxially-oriented art form to a desirable planar biaxially-oriented
form. This invention also involves the backward integration of the resin
preparation to reduce the commercial coagulated dispersion resin particle
size (average 500 micron) to the size range of colloidal size particles
contained within the original 500 micron particle. In this small
particulate form, the polytetrafluoroethylene (PTFE) resin can be blended
more homogeneously and extruded with less turbulence in the plug
extrusion process, the rheological mechanism of this extrusion process.
The size reduction makes processing of micron size fillers possible in up
to 90 percent volume of the PTFE resin. This invention also provides a
direct and simple method of producing planar biaxially-oriented sheet and
a source of resin formulations for fabricating other forms and shapes.