The effects caused by a variation of the key parameters involved in a proprietary process for the production of microporous polyethylene were investigated. The process involved the treating of a polyethylene film with two proprietary solutions at specific temperatures and in some cases required stretching of the material in the solutions.

Specialized equipment was developed to implement the process and determine the conditions under which porous material was produced. The effects of changing these process conditions on the porous nature of the material produced was then determined. lt was determined that for the particular polyethylene film chosen for the investigation, the most uniform porous material resulted when the film was treated with the two proprietary solutions without the use of stretching. The conditions in the first solution were found to be the most important in determining the nature of the material produced. Pore size and distribution were not significantly altered in the variation of the parameters investigated.

The material produced had an average pore size of 0.17 micron and a pore density of 0.9 x 10⁹ pores/cm2. The yield point of this material was found to range from 610 - 840 psl (4.2 - 5.8 MPa).