Abstract: The purpose of the present invention is to provide a porous membrane that has both high water permeability and excellent protein fractionation performance. Provided is a method for producing a porous membrane, said method comprising a step for discharging a membrane-forming dope that contains a hydrophilic polymer from a slit formed in a mouthpiece, and a step for, after the passage of the discharged membrane-forming dope through a dry part, solidifying the membrane-forming dope in a coagulation bath to give a porous membrane, wherein the cross-section area of the slit is 3-30 times inclusive as large as the cross-section area of the solidified porous membrane.

Abstract: There is provided a porous membrane capable of achieving both virus-removing performance and water permeability. The porous membrane according to the present invention has an average pore minor axis diameter of 10 nm or more and 90 nm or less in at least one surface of the porous membrane; a thickness of 60 ?m to 300 ?m; and an overall adsorption capacity with respect to bacteriophage MS2 of 8×109 PFU/g or more.

Abstract: A hollow fiber membrane module is capable of producing washed platelets having a low total protein amount and a high total platelet count from a platelet suspension. The hollow fiber membrane module for washing platelets by removal of impurities from a platelet suspension includes a housing having a platelet suspension inlet, washed platelet outlet, and filtrate outlet; and a hollow fiber membrane for filtering the platelet suspension, wherein pores through which the platelets do not pass, while the impurities pass, are formed, which hollow fiber membrane is arranged inside the housing; wherein the capacity of the inlet-side space which communicates with the platelet suspension inlet and stores the platelet suspension before being filtered through the hollow fiber membrane in the housing is 30 to 400 mL, and the module water permeability is 50 to 300 mL/Pa/hr.

Abstract: The purpose of the present invention is to provide a porous membrane that has both high water permeability and excellent protein fractionation performance. Provided is a method for producing a porous membrane, said method comprising a step for discharging a membrane-forming dope that contains a hydrophilic polymer from a slit formed in a mouthpiece, and a step for, after the passage of the discharged membrane-forming dope through a dry part, solidifying the membrane-forming dope in a coagulation bath to give a porous membrane, wherein the cross-section area of the slit is 3-30 times inclusive as large as the cross-section area of the solidified porous membrane.

Abstract: The present invention addresses the problem of providing a porous membrane for a water purification purpose, which can be used even under high water pressures and which has both virus-removing performance and water permeability. The problem can be solved as follows: a porous membrane is provided, wherein the average pore shorter-axis diameter in one surface is smaller than that in the other surface, and in a cross section of the membrane in the thickness direction, the pore diameters increase from one surface toward the other surface to have at least one maximum value and then decrease. The membrane has a layer which is provided on the side of the surface having a larger average pore shorter-axis diameter and which has pore diameters of 130 nm or less in the cross section of the membrane, wherein the layer has a thickness of 0.5 to 20 ?m inclusive and the layer has pores each having a pore diameter of 100 to 130 nm inclusive.

Abstract: A free-form surface data generating method for creating a free-form surface by forming trilateral patches expressed by predetermined vector functions over frame spaces. When specifying a transformation of a common boundary, the common boundary is arbitrarily transformed and, simultaneously, the first and second trilateral patches are connected while keeping a relation in surface geometry. When specifying non-transformation of the common boundary, a curvilinear configuration of the common boundary is maintained, and the first and second patches are connected by arbitrarily transforming the surface geometries of the first and second trilateral patches so that the surface geometries of the first and second trilateral patches are selectable by specifying whether the common boundary is transformed or not.