Abstract: A distinctive technique for making a microporous film includes a stretching of a layer composed of a polymer material and at least about 5 wt % of a particulate filler material. The particulate filler material has been distinctively treated with an operative amount of surface-active material having a HLB value of not less than about 6. Desirably, the stretching includes a biaxial stretching of the polymer layer.

Abstract: A porous fiber includes a distinctive configuration of voids therein to achieve advantageous levels of wettability, liquid penetration and mechanical properties. The fiber has a denier of not more than about 50, and a percent elongation at break of not less than about 30%. The fiber can also have a tensile strength at break of not less than about 200 MPa.

Abstract: A distinctive technique for making porous fiber includes a stretching of a substantially continuous fiber while the fiber is in an operative association with an effective quantity of surface-active material. The fiber can be produced from a source material which includes a thermoplastic, orientable material and at least about 0.35 weight percent (wt %) of a supplemental material. In particular configurations of the invention, the fiber may be contacted with a first quantity of surface-active fluid and at least a separate, second quantity of surface-active fluid. In other configurations, the fiber may be subjected to an additional incremental stretching.