摘要:
The object of the invention is to provide: a hollow fiber bundle, a method of manufacturing the hollow fiber bundle, a cylindrical module of hollow fiber membrane, and an immersion type module of hollow fiber membrane wherein the hollow fibers are easy to apply scrubbing while maintaining specified intervals among the hollow fibers. A hollow fiber bundle bundling porous hollow fibers, including; hollow fibers 10 that are open at one side end and closed at the other side end; and a closed side potting 60 and an open side potting 50 plate shaped at right angles to the hollow fibers for securing the hollow fibers, in which through holes 30 are disposed on a circumference, the hollow fibers are bundled in a cylindrical shape inside the through holes and disposed with a specified circumferential interval adjacent each other in a circumferential direction and with a specified radial interval adjacent each other in a radial direction, the hollow fibers are bundled outside the through holes disposed at specified peripheral intervals wherein the hollow fibers are disposed with a specified peripheral interval adjacent each other in a peripheral direction in the shape surrounding the outside of the through holes and with a specified peripheral right angle interval adjacent each other in a right angle to the periphery.
摘要:
The object of the invention is to provide: a screen-like object made of hollow fibers, a method of manufacturing a hollow fiber bundle, a cylindrical module of hollow fiber membrane, and an immersion type module of hollow fiber membrane wherein the hollow fibers are easy to bundle while keeping fiber-to-fiber intervals. The screen-like object made of hollow fibers includes: porous hollow fibers 10 disposed parallel at even intervals, tapes 26 for tying together the hollow fibers respectively at both ends of the hollow fibers, and a water-soluble tape for tying together the hollow fibers at a position apart from both ends of the hollow fibers across the hollow fibers. The method of manufacturing a hollow fiber bundle includes: the steps of forming a screen-like object made of hollow fibers, sealing one end or both ends of the hollow fibers, winding up the screen-like object made of hollow fibers so as to bundle the hollow fibers, forming pottings for integrally securing both ends, respectively, of the wound-up screen-like object, and cutting the potting together with the hollow fibers along a plane at right angles to the hollow fibers to cut off a sealed end and to open the hollow fibers.
摘要:
An object of the present invention is to provide a potting agent that enables the reduction of crawling and ensures sufficient penetration between the porous hollow fibers in stationary potting. The potting agent of the present invention is a potting agent for fixing an end portion of a porous hollow fiber group composed of a plurality of porous hollow fibers, and contains a resin material and a filler. The content of the filler is equal to or less than the content of the filler at a rising point of a variation curve of viscosity of the potting agent to filler content.
摘要:
A porous membrane for water treatment of the present invention is made of a resin composition containing 100 parts by weight of a polyvinylidene fluoride based resin, and 5 to 13 parts by weight of a polyvinyl alcohol based polymer having a degree of saponification of 10 to 80 mol %. The porous membrane has a permeation wetting tension of 38 to 72 mN/m, and a tensile strength of 7 to 20 MPa, and thus is characterized by having the excellent mechanical strength and wettability. This is a porous membrane for water treatment essentially containing the polyvinylidene fluoride based resin, which allows water treatment to be highly efficiently performed on raw water (river water, industrial waste water, and the like), in particular. The porous membrane is manufactured, firstly, by melt-extruding a mixture composition containing a polyvinylidene fluoride based resin, a polyvinyl alcohol based polymer, a plasticizer, and a solvent, and then by extracting the plasticizer and the solvent from the substance thus extruded.
摘要:
A composition is formed by blending a vinylidene fluoride resin having a relatively high molecular weight and an improved crystallinity represented by a difference Tm2−Tc of at most 32° C. between an inherent melting point Tm2 and a crystallization temperature Tc of the resin with a plasticizer and a good solvent for vinylidene fluoride resin, and the composition is melt-extruded into a hollow fiber-form. The hollow fiber-form extrudate is then cooled to be solidified from an outside thereof by introduction into cooling medium and subjected to extraction of the plasticizer and stretching, thereby forming a hollow fiber porous membrane of vinylidene fluoride resin characterized by co-presence of crystal oriented portion and crystal non-oriented portion recognizable by X-ray diffraction method. The resultant hollow fiber porous membrane of vinylidene fluoride resin has micro-pores of appropriate size and distribution, is excellent in mechanical strength represented by tensile strength and elongation at break and is useful as a water microfiltration membrane.
摘要:
A hollow-fiber porous membrane comprising a hollow-fiber form of vinylidene fluoride resin and satisfying the following properties (A) and (B), is provided as a hollow-fiber porous membrane of vinylidene fluoride resin having an average pore size and a further uniform pore size distribution (A) and a large water permeation rate regardless of good efficiency of blocking minute particles (bacteria) (B), as represented by: (A) a ratio Pmax (1 m)/Pm of at most 4.0 between a maximum pore size Pmax (1 m) measured at a test length of 1 m according to the bubble point method and an average pore size Pm of 0.05-0.20 μm measured according to the half dry method; and (B) a ratio F (L=200 mm, v=70%)/PM2 of at least 3000 (m/day·μm2), wherein the ratio F (L=200 mm, v=70%)/Pm2 denotes a ratio between F (L=200 mm, v=70%) which is a value normalized to a porosity v=70% of a water permeation rate F (100 kPa, L=200 mm) measured at a test length L=200 mm under the conditions of a pressure difference of 100 kPa and a water temperature of 25° C. and a square Pm2 of an average pore size Pm. The hollow-fiber porous membrane is produced by a process, comprising: subjecting a stretched hollow-fiber porous membrane of vinylidene fluoride resin to at least two stages of relaxation treatment in a non-wetting environment.
摘要:
A hollow-fiber porous membrane, comprising a hollow fiber-form porous membrane in a network texture of vinylidene fluoride resin showing a pore size distribution in a direction of its membrane thickness including an outer surface-average pore size P1 as measured by a scanning electron microscope and a membrane layer-average pore size P2 as measured by half-dry method giving a ratio P1/P2 of at least 2.5. The hollow-fiber porous membrane is excellent in long-term water filtration performance including efficiency of regeneration by air scrubbing. The hollow-fiber porous membrane is produced through a process, wherein a mixture of vinylidene fluoride resin, a plasticizer and a good solvent for vinylidene fluoride resin, is melt-extruded in a hollow-fiber film and cooled and formed into a solidified film within a cooling medium containing at least a certain proportion of a good solvent for vinylidene fluoride resin.
摘要:
A composition is formed by blending a vinylidene fluoride resin having a relatively high molecular weight and an improved crystallinity represented by a difference Tm2−Tc of at most 32° C. between an inherent melting point Tm2 and a crystallization temperature Tc of the resin with a plasticizer and a good solvent for vinylidene fluoride resin, and the composition is melt-extruded into a hollow fiber-form. The hollow fiber-form extrudate is then cooled to be solidified from an outside thereof by introduction into cooling medium and subjected to extraction of the plasticizer and stretching, thereby forming a hollow fiber porous membrane of vinylidene fluoride resin characterized by co-presence of crystal oriented portion and crystal non-oriented portion recognizable by X-ray diffraction method. The resultant hollow fiber porous membrane of vinylidene fluoride resin has micro-pores of appropriate size and distribution, is excellent in mechanical strength represented by tensile strength and elongation at break and is useful as a water microfiltration membrane.
摘要:
A hollow fiber-form porous membrane of vinylidene fluoride resin having a high crystallinity as represented by a crystal melting enthalpy of at least 58 J/g is produced by forming a composition of a vinylidene fluoride resin having a relatively high weight-average molecular weight of at least 3×105 blended with a plasticizer and a good solvent for vinylidene fluoride resin, melt-extruding the composition into a hollow fiber-form film, and solidifying the film by cooling it from an outside thereof by contact with a cooling liquid inert to vinylidene fluoride resin while crystallizing the vinylidene fluoride resin at an appropriately moderate speed. The resultant hollow fiber-form porous membrane is excellent in mechanical strength represented by tensile strength and elongation at break, and also excellent in chemical resistance, thus being effectively used as a water micro-filtration membrane.
摘要:
There is provided a porous hollow fiber of vinylidene fluoride resin which has a water permeation rate that is large per fiber and little dependent on the length, has a large treatment capacity per volume of a filtering module, and is therefore suitable as a microfilter element. That is, a porous hollow fiber, comprising a vinylidene fluoride resin having a weight-average molecular weight of at least 3×105, having a water permeation rate F (m3/m2·day) measured at a pressure difference of 100 kPa and at a water temperature of 25° C. in a range of test length L=0.2-0.8 (m) and expressed in a linear relationship with the test length L of: F=C·L+F0 (formula 1) and satisfying requirements (a)-(d) shown below: (a) a average slope C (/day) of: −20≦C≦0, (b) an intercept (basic permeability) F0 (m3/m2·day) of: F0≧30, (c) a relation between F0 (m3/m2·day) and an average pore diameter P (μm) according to half-dry method of F0/P≧300, and (d) an outer diameter of at most 3 mm.