# US 2014/0154495 A1 · Defect inspection apparatus and defect inspection method for porous hollow fiber membrane, porous hollow fiber membrane, and manufacturing method thereof > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0154495 A1 - Document ID: US20140154495A1 - Status: Published application - Kind: A1 - Application number: 14/233,016 - Filed: 2012-07-19 - Published: 2014-06-05 - Earliest claimed: 2011-07-19 - Assignees: Mitsubishi Ryaon Co., Ltd. - Inventors: Kotaro Hiraoka; Toshinori Sumi; Hiroyuki Fujiki - Web page: https://patentgrep.com/patent/US20140154495A1 ## CPC - G01M 3/06: by observing bubbles in a liquid pool - B01D 65/102: {Detection of leaks in membranes} - B01D 69/08: Hollow fibre membranes (manufacture of hollow fibres D01D5/24, D01F1/08) - B29C 44/34: Auxiliary operations - G01M 3/38: by using light (G01M3/02 takes precedence) - G01N 21/952: Inspecting the exterior surface of cylindrical bodies or wires (G01N21/956 takes precedence) - Y10T 428/249962: Void-containing component has a continuous matrix of fibers only [e.g., porous paper, etc.] - G01M: TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR - B01D: SEPARATION (separating solids from solids by wet methods B03B, B03D; by pneumatic jigs or tables B03B; by other dry methods B07; magnetic or electrostatic separation of solid materials from solid materials or fluids, separation by high-voltage electric fields B03C; centrifuges, vortex apparatus B04; presses per se for squeezing-out liquid from liquid-containing material B30B9/02; treatment of water C02F, e.g. softening by ion-exchange C02F1/42; {arrangements of air intake cleaners in gas turbine plants F02C7/05} ; arrangements or mounting of filters in air-conditioning, air-humidification or ventilation F24F13/28) - B29C: SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING (making preforms B29B11/00; making laminated products by combining previously unconnected layers which become one product whose layers will remain together B32B37/00 - B32B41/00) - G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q) - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract The present invention relates to a defect inspection apparatus including: a container storing a fluid; a passage member that is configured such that a hollow fiber membrane travel passage, which allows the porous hollow fiber membrane to pass therethrough continuously, is formed thereinside and the passage member being disposed in the fluid to thereby fill the passage with the fluid; a restrictor that restricts travel of the porous hollow fiber membrane such that the porous hollow fiber membrane passes through the fluid in the hollow fiber membrane travel passage of the passage member; a fluid suction device that flows the fluid in the hollow fiber membrane travel passage to thereby lower the pressure of the fluid in the hollow fiber membrane travel passage; and an air bubble detector that detects an air bubble that is released into the fluid from a defect of the porous hollow fiber membrane. ## Claims ### Claim 1 A defect inspection method, the method comprising: disposing, in a fluid, openings at both ends of a hollow fiber membrane travel passage, which allows a porous hollow fiber membrane to pass therethrough, of a passage member, which is formed such that the hollow fiber membrane travel passage penetrates thereinside, to thereby fill the passage with the fluid; causing the porous hollow fiber membrane to travel continuously through the fluid in the hollow fiber membrane travel passage; lowering a pressure of the fluid in the hollow fiber membrane travel passage by flowing the fluid in the hollow fiber membrane travel passage; and detecting an air bubble released into the fluid from a defect of the porous hollow fiber membrane. ### Claim 2 (depends on 1) The method of claim 1, comprising: disposing, in the fluid, openings at both ends of the hollow fiber membrane travel passage of the passage member, which further comprises a branch passage that is formed to branch off from the hollow fiber membrane travel passage and to communicate with a first wall surface, to thereby fill the passage with the fluid; and lowering the pressure of the fluid in the hollow fiber membrane travel passage by flowing the fluid in the hollow fiber membrane travel passage through the branch passage. ### Claim 3 (depends on 2) The method of claim 2, wherein: an enlarged space in which a width of the passage increases is provided at a part in which the branch passage branches off from the hollow fiber membrane travel passage; and the pressure of the fluid in the hollow fiber membrane travel passage is lowered by flowing the fluid in the hollow fiber membrane travel passage from the enlarged space through the branch passage. ### Claim 4 (depends on 1) The method of claim 1, wherein the air bubble is guided to an air bubble detector by flowing the air bubble along with the fluid. ### Claim 5 (depends on 1) The method of claim 1, wherein the fluid that fills the passage is fed after removing a bubble and dissolved gas in the fluid. ### Claim 6 (depends on 1) The method of claim 1, wherein the air bubble is detected in the fluid that is suctioned and flows from the hollow fiber membrane travel passage. ### Claim 7 A defect inspection apparatus, comprising: a container storing a fluid; a passage member that is configured such that a hollow fiber membrane travel passage, which allows a porous hollow fiber membrane to pass therethrough continuously, penetrates thereinside and that openings at both ends of the hollow fiber membrane travel passage are disposed in the fluid to thereby fill the passage with the fluid; a restrictor that restricts travel of the porous hollow fiber membrane such that the porous hollow fiber membrane passes through the fluid in the hollow fiber membrane travel passage of the passage member; a fluid suction device that flows the fluid in the hollow fiber membrane travel passage of the passage member to thereby lower the pressure of the fluid in the hollow fiber membrane travel passage; and an air bubble detector that detects an air bubble that is released into the fluid from a defect of the porous hollow fiber membrane. ### Claim 8 (depends on 7) The defect inspection apparatus of claim 7, wherein: in the passage member, a branch passage is further formed to branch off from the hollow fiber membrane travel passage and to communicate with a first wall surface, and openings at both ends of the hollow fiber membrane travel passage are disposed in the fluid to thereby fill the passage with the fluid; and the pressure of the fluid in the hollow fiber membrane travel passage is lowered by flowing the fluid in the hollow fiber membrane travel passage of the passage member through the branch passage. ### Claim 9 (depends on 8) The defect inspection apparatus of claim 8, wherein: an enlarged space in which a width of the passage increases is provided at a part in which the branch passage branches off from the hollow fiber membrane travel passage of the passage member; and the pressure of the fluid in the hollow fiber membrane travel passage is lowered by flowing the fluid in the hollow fiber membrane travel passage of the passage member from the enlarged space through the branch passage by the fluid suction device. ### Claim 10 (depends on 7) The defect inspection apparatus of claim 7, wherein the air bubble is guided to the air bubble detector along with the fluid flowing. ### Claim 11 (depends on 7) The defect inspection apparatus of claim 7, wherein the air bubble detector is disposed between the hollow fiber membrane travel passage and the fluid suction device. ### Claim 12 (depends on 7) The defect inspection apparatus of claim 7, wherein the air bubble detector comprises a light emitting unit that emits detection light into the fluid and a light receiving unit that receives the detection light having passed through the fluid. ### Claim 13 (depends on 12) The defect inspection apparatus of claim 12, wherein the light emitting unit and the light receiving unit are arranged to face each other. ### Claim 14 (depends on 12) The defect inspection apparatus of claim 12, wherein the light emitting unit and the light receiving unit are arranged such that tip portions thereof are positioned inside the fluid that is suctioned and flows from the hollow fiber membrane travel passage. ### Claim 15 (depends on 7) The defect inspection apparatus of claim 7, further comprising a fluid inflow line through which the fluid flows into the container, wherein a defoamer that removes a bubble in the fluid inflowing is provided in the fluid inflow line. ### Claim 16 (depends on 15) The defect inspection apparatus of claim 15, wherein a deaerator that removes dissolved gas in the fluid inflowing is provided in the fluid inflow line. ### Claim 17 (depends on 15) The defect inspection apparatus of claim 15, wherein the fluid inflow line comprises a fluid feed line through which the fluid inflows from a fluid feed source to the container. ### Claim 18 (depends on 15) The defect inspection apparatus of claim 15, wherein the fluid inflow line comprises a fluid circulation line in which the fluid suctioned from the passage member flows into the container and is circulated. ### Claim 19 (depends on 1) A method of manufacturing a porous hollow fiber membrane, the method comprising: coagulating a membrane forming material liquid comprising a hydrophobic polymer, a hydrophilic polymer, and a solvent by a coagulation liquid, to thereby form a porous hollow fiber membrane precursor; cleaning the porous hollow fiber membrane precursor to thereby remove the solvent remaining in the porous hollow fiber membrane precursor; removing the hydrophilic polymer remaining in the porous hollow fiber membrane precursor to thereby obtain the porous hollow fiber membrane; drying the porous hollow fiber membrane; and inspecting the porous hollow fiber membrane for a defect after the drying with the defect inspection method of claim 1. ### Claim 20 (depends on 1) A porous hollow fiber membrane manufactured by: coagulating a membrane forming material liquid comprising a hydrophobic polymer, a hydrophilic polymer, and a solvent by a coagulation liquid, to thereby forming a porous hollow fiber membrane precursor; cleaning the porous hollow fiber membrane precursor to thereby remove the solvent remaining in the porous hollow fiber membrane precursor; removing the hydrophilic polymer remaining in the porous hollow fiber membrane precursor to thereby obtain the porous hollow fiber membrane; drying the porous hollow fiber membrane; and inspecting the porous hollow fiber membrane for a defect after the drying step with the defect inspection method of claim 1.