Abstract: A separation membrane including a separation-functional layer is provided, wherein the separation-functional layer contains a polyvinylidene fluoride-type resin having a melt viscosity of 3,300 Pa·s or more, and also the separation-functional layer has a three-dimensional network structure. A separation membrane is provided having high virus removal performance, high pure water permeability, and high physical durability and high chemical strength, which can also be used in the field of water treatment.

Abstract: The method for inspecting a length-measurable product includes manufacturing the length-measurable product 1 whose length at least in one direction can be measured, when a defect 4 occurs in the length-measurable product 1, applies a marking 6 to a length-measurable product 1 having the defect 4, and includes the steps of detecting presence of a defect 4 in the length-measurable product, measuring a length of the length-measurable product 1 at least in one direction, and applying a marking to a predetermined marker area 5 in a length direction of the length-measurable product 1 having the defect 4, on the basis of positional information on the defect obtained in the defect detecting step and length measurement information obtained in the length measuring step.

Abstract: Provided is a manufacturing method for a bundle product that includes an inspecting step of inspecting two or more threads continuously running in parallel in the longitudinal direction, a collecting step of collecting the threads, and a cutting step of cutting, after completion of the collecting, all the collected threads at a predetermined position, to obtain a bundle product having plural threads converged into a bundle. In the manufacturing method, an amount of collection in the collecting step is adjusted on the basis of inspection results obtained in the inspecting step so that at least one managed quantity for plural threads selected from a group including a total number, a total weight, a representative weight, a total outside diameter value, a representative outside diameter value, a total surface area, and a representative surface area of the plural threads constituting the bundle product exceeds a predetermined value.

Abstract: A separation membrane including a separation-functional layer is provided, wherein the separation-functional layer contains a polyvinylidene fluoride-type resin having a melt viscosity of 3,300 Pa·s or more, and also the separation-functional layer has a three-dimensional network structure. A separation membrane is provided having high virus removal performance, high pure water permeability, and high physical durability and high chemical strength, which can also be used in the field of water treatment.