Mitsubishi Rayon Company, Limited

Osamu Fukunaga

Takashi Yamamoto

Hisayoshi Yamamori

Mizuo Shindo

Kiyonobu Okamura

Shindo Mizuo

Porous hollow fibers composed of a high density polyethylene the fibers having rectangular micropores that are oriented in the lengthwise direction of the fibers and having a porosity from 30 to 90% by volume are disclosed. Membranes composed of hollow fibers exhibit a water permeability of greater than 65 (ml/m.sup.2, hr, mmHg) as well as a human serum albumin permeability of greater than 30%. Such fibers are suited for use as filters, particularly as a membrane for simple fractionation of whole blood into it plasma and cellular components. The hollow fibers are obtained by spinning a high-density polyethylene under a high-draft condition followed by cold stretching and hot stretching, and without the use of any solvent or plasticizer.

Process for making microporous polyethylene hollow fibers

Porous hollow fibers composed of a high density polyethylene the fibers having rectangular micropores that are oriented in the lengthwise direction of the fibers and having a porosity from 30 to 90% by volume are disclosed. Membranes composed of hollow fibers exhibit a water permeability of greater than 65 (ml/m.sup.2, hr, mmHg) as well as a human serum albumin permeability of greater than 30%. Such fibers are suited for use as filters, particularly as a membrane for simple fractionation of whole blood into its plasma and cellular components. The hollow fibers are obtained by spinning a high-density polyethylene under a high-draft condition followed by cold stretching and hot stretching, and without the use of any solvent or plasticizer.

Microporous polyethylene hollow fibers

A porous polyethylene film was obtained which is characterized in that micropores are contiguous with one another from one surface to the other surface of the film to constitute a laminar structure, and said micropores assume the form of strips being composed of microfibrils that are arrayed in a direction in which the film is stretched and nodular portions that are coupled to said microfibrils nearly at right angles thereto, wherein the micropores have an average pore diameter over a range of 0.05 to 2 microns as measured using a mercury porosimeter, said film has a porosity over a range of 30 to 90%, and an elastic recovery factor from the 50% stretching ratio is less than 50%.

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Otake, Japan

Osamu Fukunaga