NOVELTY - Manufacturing a microporous material, comprises: shaping a melt mixed composition comprising ethylene chlorotrifluoroethylene copolymer, diluent and nucleating agent, where the nucleating agent is uniformly dispersed in the melt mixed composition; cooling the melt mixed composition to induce solid-liquid phase separation of the ethylene chlorotrifluoroethylene copolymer to provide a phase separated material; and stretching the phase separated material to provide the microporous material.    USE - The method is useful for manufacturing the microporous material, which is useful in the composite material, where the microporous material is a membrane or a hollow fiber (all claimed). The microporous material is useful: in ultra and microfiltration application devices for health care, food, beverage, and/or industrial markets; as films and/or components in variety of articles, and vent filters; in microparticle filtration, fuel cell and battery separator applications; and in a filter cartridge or in other devices requiring high surface area materials for filtration applications.    ADVANTAGE - The material is strong enough to withstand is flexed, folded, or pleated without breaking.    DETAILED DESCRIPTION - Manufacturing a microporous material, comprises: shaping a melt mixed composition comprising ethylene chlorotrifluoroethylene copolymer, diluent and nucleating agent, where the nucleating agent is uniformly dispersed in the melt mixed composition; cooling the melt mixed composition to induce solid-liquid phase separation of the ethylene chlorotrifluoroethylene copolymer to provide a phase separated material; and stretching the phase separated material to provide the microporous material, where the material comprises a spherulitic matrix comprising the ethylene chlorotrifluoroethylene copolymer and many pores extending through the matrix and have an average pore size of greater than 0.01 micrometer, and the nucleating agent is substantially uniformly dispersed throughout the ethylene chlorotrifluoroethylene copolymer. INDEPENDENT CLAIMS are included for:    (1) the microporous material comprising: the spherulitic matrix and the nucleating agent; or a first layer comprised of a first spherulitic matrix comprising first ethylene chlorotrifluoroethylene copolymer and first pores extending through the first spherulitic matrix and having an average pore size of greater than 0.01 micrometer, first nucleating agent substantially uniformly dispersed within the first ethylene chlorotrifluoroethylene copolymer, a second layer comprised of a second spherulitic matrix comprising second ethylene chlorotrifluoroethylene copolymer and second pores extending through the second spherulitic matrix and having an average pore size of greater than 0.01 micrometer, and second nucleating agent substantially uniformly dispersed within the second ethylene chlorotrifluoroethylene copolymer, where the average pore size of the first spherulitic matrix and the average pore size of the second spherulitic matrix are different;    (2) a composite material comprising a first layer comprising the microporous material, and a second layer affixed to the first layer, the second layer comprising the microporous material;    (3) an assembly comprising a housing having an inlet and an outlet, and the microporous material disposed within the housing, the microporous material being pleated; and    (4) manufacturing a multilayered microporous material, comprising: shaping many melt mixed compositions comprising at least a first melt mixed composition and a second melt mixed composition to form a multilayered sheet comprised of a layer of first melt mixed composition and a layer of second melt mixed composition joined together along a common interface, the first melt mixed composition comprising first ethylene chlorotrifluoroethylene copolymer, first diluent and first nucleating agent, and the second melt mixed composition comprising a second ethylene chlorotrifluoroethylene copolymer, second diluent and second nucleating agent; cooling the multilayered sheet to induce phase separation of the first ethylene chlorotrifluoroethylene copolymer in the first melt mixed composition and the second ethylene chlorotrifluoroethylene copolymer in the second melt mixed composition to provide a multilayered phase separated material; and stretching the multilayered phase separated material to provide multilayered microporous material having the first and second layers.    DESCRIPTION OF DRAWING(S) - The figure shows a schematic view of an apparatus for producing microporous ethylene chlorotrifluoroethylene materials.    Extruder (10)    Port (11)    Hopper (12)    Reservoir (13)    Extruder exit. (17)