JP5097139B2 - Production method of bag-like separation membrane and bag-like separation membrane - Google Patents

Description

  The present invention relates to a method for producing a bag-shaped separation membrane and a bag-shaped separation membrane.

  Conventionally, a separation membrane used in a membrane separation device that purifies water by osmotic pressure forms a bag-like separation membrane by stacking two separation membranes and bonding the end portions of the three sides with an adhesive. (For example, refer to Patent Document 1).

Japanese Patent Laid-Open No. 10-341

  However, in the conventional bag-shaped separation membrane, when the end of the separation membrane is bonded with an adhesive, the adhesive fills the permeation hole of the separation membrane, so that the water permeation function is lost at the bonded portion. The effective area of the film is reduced.

  Therefore, an object of the present invention is to provide a bag-shaped separation membrane manufacturing method and a bag-shaped separation membrane that can increase the effective area of the separation membrane even when the separation membrane is formed in a bag shape. .

In the first aspect of the present invention, in the method for producing a bag-shaped separation membrane having one end opened, a part that is used as a mold opening along a bag shape and that is used as an opening of the mold is rotated. Forming a base material layer with a solution-like material on the surface excluding, and rotating the mold after drying the base material layer, coating the surface of the base material layer with a solution-like separation membrane material to form a bag And a step of removing the base material layer from the mold after drying the coated skin.

  The second aspect of the present invention is characterized by a bag-like separation membrane manufactured by the manufacturing method of the first aspect.

According to the first and second aspects of the present invention, the mold is rotated to form a base material layer on the surface of the mold, and the mold is rotated on the surface of the base material layer to form a bag-shaped skin Since the demolding is performed after the layer is formed, the demolded bag-shaped separation membrane can be obtained in a desired bag shape without any seams. Therefore, even when the separation membrane is formed in a bag shape, the effective area of the bag-like separation membrane can be increased.

  According to the seventh and eighth aspects of the present invention, since the base material is folded into an envelope shape and the joining end portion thereof is heat-welded, the end surface of the base material is folded in an envelope shape. Since it is folded, the strength reliability can be increased.

It is a schematic diagram which shows the manufacturing process of the bag-shaped separation membrane concerning the 1st Embodiment of this invention later on in order to (a)-(c). It is the longitudinal cross-sectional view which expanded a part of bag-shaped separation membrane concerning the 1st Embodiment of this invention. It is the side view which looked at the bag-shaped separation membrane concerning a 1st embodiment of the present invention from the open mouth side. It is a schematic diagram which shows the manufacturing process of the bag-shaped separation membrane concerning the 2nd Embodiment of this invention later on to (a)-(c). It is a schematic diagram which shows the manufacturing process of the bag-shaped separation membrane concerning the 3rd Embodiment of this invention later on to (a)-(c).

[First embodiment]
A first embodiment of the present invention will be described with reference to FIGS. The bag-like separation membrane of the present embodiment is a separation membrane used in a membrane separation device that purifies water with osmotic pressure, and is formed as a membrane having innumerable fine pores. As shown in FIG. 2, the bag-shaped separation membrane 1 has a bag shape in which an opening 1a is provided on one end (left end in the figure) and the other end (right end in the figure) is closed.

  As shown in FIG. 1 (a), the bag-shaped separation membrane 1 is manufactured by using a mold 2 along a bag shape to be molded in advance, and a portion to be an opening 1a of the mold 2, that is, the mold 2 A bag-like base material layer 3 is formed on the surface 2b excluding the left end surface 2a. The base material layer 3 has innumerable fine transmission holes.

  At this time, the base material layer 3 of the separation membrane is a layer made of the polymer solution P in this embodiment, and the base material layer 3 can be formed by a spray method, a coating method, a printing method, a static method, or the like. An electro atomization method, a vapor deposition method, a dipping method, or the like can be used, and further, the material can be formed by blow molding or press molding.

  Next, after drying the base material layer 3 formed on the surface 2b of the mold 2, the surface 3a of the base material layer 3 is coated with a solution-like separation membrane material S as shown in FIG. A bag-shaped skin layer 4 is formed. And after drying the coated skin layer 4, as shown in FIG.1 (c), the base material layer 3 is demolded from the mold 2, and the bag-shaped separation membrane 1 is manufactured. The skin layer 4 has innumerable fine transmission holes.

  As shown in FIG. 3, the bag-shaped separation membrane 1 manufactured in this way is provided in a state in which the skin layer 4 is formed on the outer side of the inner base material layer 3, and has a two-layer structure. Sufficient strength is ensured even when water is permeated. In FIG. 3, the thicknesses of the base material layer 3 and the skin layer 4 are exaggerated for convenience.

  As described above, according to the manufacturing method of the bag-shaped separation membrane 1 of the present embodiment and the bag-shaped separation membrane 1 manufactured by the manufacturing method, the base material layer 3 is formed on the surface 2b of the mold 2. Since the mold is removed after forming the skin layer 4 on the surface 3a of the base material layer 3, the demolded bag-like separation membrane 1 can be obtained in a desired bag shape without any seams. Therefore, even when the separation membrane is formed in a bag shape, the effective area of the bag-like separation membrane 1 can be increased.

  Moreover, in addition to the said effect, the bag-shaped separation membrane 1 of this embodiment has the various effects shown to following (1)-(4). (1) Since there is no seam, the seal reliability is increased and high quality can be obtained. (2) Since there is no bonding step as in the prior art, solvent outflow to the secondary side can be eliminated. (3) Pinhole inspection can be performed simultaneously with molding, and post-inspection becomes unnecessary. (4) The bag-shaped separation membrane 1 at the time of demolding has flexibility, and any shape can be manufactured by forming the mold 2 in a bag shape to be molded in advance.

[Second Embodiment]
A second embodiment of the present invention will be described with reference to FIG. Note that the same components as those in the first embodiment are denoted by the same reference numerals, and redundant description is omitted.

  As shown in FIG. 4, the bag-like separation membrane 1 </ b> A of the present embodiment has a bag-like shape in which one end side is an open port 1 a like the bag-like separation membrane 1 of the first embodiment. As shown in FIG. 4 (b), the manufacturing method of the film 1A is such that, after the end portions 3b of the base material 3A formed in a cylindrical shape are stacked and heat-welded, as shown in FIG. The surface 3a (see FIG. 4 (b)) of the material 3A is coated with a solution-like separation membrane material to form the skin layer 4 to produce a bag-like separation membrane 1A.

  In particular, in the present embodiment, as shown in FIG. 4A, the base material 3A is formed by extruding a base material made of a polymer into a cylinder by blow molding using a blow molding die 5. As shown in 4 (b), one end portion 3b of the cylindrical base material 3A is heat-welded.

  As described above, according to the manufacturing method of the bag-shaped separation membrane 1A of the present embodiment and the bag-shaped separation membrane 1A manufactured by the manufacturing method, the bag-shaped separation membrane 1A connects the end 3b of the base material 3A. In the case of overlapping bonding, the portion where the end 3b of the base material 3A is overlapped is heat-welded. Therefore, the permeation holes of the separation membrane 1A are not filled with the heat-welded portion, and the permeation holes in the overlapping portion are mutually connected. It will be in the state of communicating with. Therefore, even when the separation membrane is formed in a bag shape, the effective area of the bag-like separation membrane 1A can be increased.

  In the present embodiment, the base material 3A may be extruded into a cylindrical shape by blow molding, cut into a predetermined size, and the one end portion 3b may be heat-welded. Thereby, since continuous molding of the base material 3 </ b> A having a cylindrical shape is possible, productivity can be improved.

  Furthermore, the bag-like separation membrane 1A of the present embodiment has various effects shown in the following (1) and (2) in addition to the above-described effects. (1) Cost reduction can be achieved by mass production by continuous molding. (2) No adhesive is required and there is no concern about environmental pollution.

  The molding of the base material 3A is not limited to blow molding but can be applied to any molding method in which the base material 3A is formed into a cylindrical shape, such as extrusion molding and centrifugal molding. It doesn't matter.

[Third embodiment]
A third embodiment of the present invention will be described with reference to FIG. Note that the same components as those in the first embodiment are denoted by the same reference numerals, and redundant description is omitted.

  As shown in FIG. 5, the bag-shaped separation membrane 1B of the present embodiment has a bag shape in which one end side is an open port 1a, similar to the bag-shaped separation membrane 1 of the first embodiment. As shown in FIG. 5B, the manufacturing method of the film 1B is such that the end portions 3c and 3d to which the folded base material 3A is joined are overlapped and thermally welded, and then, as shown in FIG. The surface 3a of 3A (see FIG. 5 (b)) is coated with a solution-like separation membrane material to form the skin layer 4, thereby producing a bag-like separation membrane 1B.

  In particular, in the present embodiment, as shown in FIG. 5A, the base material 3A is formed by folding the base material in a sheet shape into an envelope shape and thermally welding the joining end portions 3c and 3d thereof. ing.

  Here, as shown in FIG. 5A, the envelope-like fold is provided with fold lines B1 and B2 at regular intervals at the center of the rectangular sheet base 3A, and is sandwiched between the fold lines B1 and B2. A folded end 3d is provided at the lower edge of the portion. Then, as shown in FIG. 5B, the folding method is such that first, both end portions 3c are overlapped by folding at folding lines B1 and B2, and then the folded end portion 3d is folded.

  As described above, according to the manufacturing method of the bag-shaped separation membrane 1B of the present embodiment and the bag-shaped separation membrane 1B manufactured by the manufacturing method, the bag-shaped separation membrane 1B is similar to the third embodiment. Since the end portions 3c and 3d of the base material 3A are overlapped and heat-welded, the permeation holes of the separation membrane 1B are not filled with the heat-welded portions, and the permeation holes in the overlapping portions are in communication with each other. . Therefore, even when the separation membrane is formed in a bag shape, the effective area of the bag-like separation membrane 1B can be increased.

  Moreover, in this embodiment, since the base material 3A folded the sheet-like base material into the envelope shape and thermally welded the joining end portions 3c and 3d thereof, the end surface is folded back by the envelope-like folding. , Strength reliability can be increased.

  Furthermore, since the bag-like separation membrane 1B of the present embodiment can be formed with a single sheet-like base material in addition to the above-described effects, the bonding (fusion) step can be reduced.

  The present invention is not limited to the above embodiment, and various other embodiments can be adopted without departing from the gist of the present invention.

DESCRIPTION OF SYMBOLS 1, 1A, 1B Bag-like separation membrane 1a Open port 2 Mold frame 2b Surface of mold frame 3 Base material layer 3a Surface of base material layer 3A Base material 3b, 3c, 3d End of base material 4 Skin layer

Claims (2)

In the manufacturing method of the bag-shaped separation membrane whose one end side is opened,
Forming a base material layer with a solution-like material on the surface excluding the part that becomes the opening of the mold by rotating the mold and using the mold along the bag shape;
A step of rotating the mold after drying the base material layer, coating the surface of the base material layer with a solution-like separation membrane material to form a bag-shaped skin layer ;
And a step of demolding the base material layer from the mold after drying the coated epidermis.   A bag-like separation membrane manufactured by the manufacturing method according to claim 1.

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