WO2011158517A1 - Method for producing perforated hollow tube and mold form for producing perforated hollow tube - Google Patents

Abstract

Disclosed is a method for producing a perforated hollow tube having a plurality of through holes extending from the outer peripheral surface to the inner peripheral surface, wherein a resin is injected into a mold form comprising a core die for forming an inner space of the perforated hollow tube, and a main die comprising a reference surface for forming the outer peripheral surface and projections for forming the plurality of through holes, the main die being constituted with a plurality of main parts so as to be dividable, and after the resin is cured, the main die and the core die are removed in this order.

Description

Method for manufacturing perforated hollow tube and mold for manufacturing perforated hollow tube

The present invention relates to a method for producing a resin-made perforated hollow tube having a plurality of through-holes connected from the outer peripheral surface to the inner peripheral surface, and a mold for producing a perforated hollow tube that can be used for the production thereof. This perforated hollow tube is, for example, a branch pipe for fluids used in automobiles, a fluid collection pipe for gas or liquid separation membrane elements, various water collection pipes for underground drainage, and water or gas spraying It can be used for piping.

Regarding the production of resin-made perforated hollow tubes used as fluid collecting tubes for separation membrane elements, conventional resin-made non-porous hollow tubes produced by extrusion molding or injection molding, and metal hollow tubes are used. A perforated hollow tube having a plurality of through holes has been manufactured by perforating the tube as a post-processing. When such a perforated hollow tube is used as a separation membrane element, for example, when used as a water collection tube of a spiral separation membrane element for water treatment, a separation membrane and a flow path material are wound around the water collection tube. Thus, the permeated fluid flows into the inner space of the perforated hollow tube through the through hole (see Patent Document 1).

However, these perforated hollow tubes are required to be processed in various ways in order to improve performance, so that the manufacturing is complicated and the number of man-hours increases, and the manufacturing cost tends to increase. In addition, with the increase in demand related to water treatment, the demand for perforated hollow tubes has also increased remarkably.

JP 2004-305823 A

An object of the present invention is to provide a method for producing a perforated hollow tube and a mold for producing a perforated hollow tube, which can improve productivity and can be easily processed into a perforated hollow tube.

The present invention relates to a method for manufacturing a perforated hollow tube having a plurality of through-holes connected from an outer peripheral surface to an inner peripheral surface, a core type that forms an internal space of the perforated hollow tube, and the perforated hollow tube Resin is injected into a mold including a reference surface that forms the outer peripheral surface of the pipe and a main mold that is configured to be split by a plurality of main parts, and has a convex portion that forms the plurality of through holes. Provided is a method for producing a perforated hollow tube, wherein the main mold and the core mold are removed in this order after the resin is cured.

The resin to be injected is preferably a thermoplastic resin or a thermosetting resin. Further, it is preferable that the plurality of through holes are arranged in a line or a plurality of lines in the axial direction of the perforated hollow tube.

Further, the present invention is a mold used for manufacturing a perforated hollow tube having a plurality of through-holes connected from an outer peripheral surface to an inner peripheral surface, and a core type that forms an internal space of the perforated hollow tube And a main mold having a reference surface that forms an outer peripheral surface of the perforated hollow tube and a convex portion that forms the plurality of through holes, and is configured to be divided by a plurality of main parts. A perforated hollow tube manufacturing form is provided.

The main mold is preferably composed of a pair of main parts so that the main mold can be divided in a direction perpendicular to the axial direction of the perforated hollow tube. Moreover, it is preferable that the said main type | mold has a protrusion part which forms a groove | channel further in the outer peripheral surface of a perforated hollow tube.

It is preferable that the core type is configured to be divided by a plurality of core parts. Furthermore, it is preferable that the said core type | mold is comprised with a pair of core parts so that the said core type | mold can be divided | segmented in the axial direction of a perforated hollow tube.

The core mold preferably has a tapered portion that continuously increases from an end surface facing the axial direction of the perforated hollow tube, and at least one end of the core mold has one or more steps. It is preferable to expand with

According to the present invention, productivity of a perforated hollow tube can be improved, and various processing to a perforated hollow tube can be easily performed.

1A is a cross-sectional view showing an example of a manufacturing mold for a perforated hollow tube according to the present invention, and FIG. 1B is a cross-sectional view taken along the line IB-IB in FIG. 1A. Sectional drawing which shows the structural example of the core type for perforated hollow tube manufacture in this invention. Sectional drawing which shows the other structural example of the core type for perforated hollow tube manufacture in this invention. Sectional drawing which shows the structural example of the perforated hollow tube which carried out the division | segmentation shaping | molding in this invention. Sectional drawing which shows the structural example of the perforated hollow tube manufacturing formwork dividedly molded in this invention. The perspective view which shows an example of the porous hollow tube obtained by this invention. The perspective view which shows the other example of the porous hollow tube obtained by this invention. The disassembled perspective view which shows the structural example of a spiral type separation membrane element.

The present invention relates to a method for manufacturing a perforated hollow tube having a plurality of through-holes connected from an outer peripheral surface to an inner peripheral surface, a core type that forms an internal space of the perforated hollow tube, and the perforated hollow tube Resin is injected into a mold including a reference surface that forms the outer peripheral surface of the pipe and a main mold that is configured to be split by a plurality of main parts, and has a convex portion that forms the plurality of through holes. After the resin is cured, the main mold and the core mold are removed in this order. If the core mold is removed before the main mold, the convex part of the main mold in contact with the core mold may be damaged.

The cross-sectional shape of the perforated hollow tube is not particularly limited, and various shapes such as a polygon, a circle, and an ellipse can be adopted. The through holes are preferably arranged in a line or a plurality of lines in the axial direction of the perforated hollow tube.

For manufacturing the perforated hollow tube, a known injection molding technique can be used as long as it is a method of removing the main mold and the core mold after injecting the resin into the mold and curing the resin. For example, a gas-assisted molding method in which a gas pressure is applied when a resin solution is injected into a mold and injected as a pressurized fluid, or a resin is injected according to the viscosity of the resin and the shape of the mold It is preferable to use a rotational molding method in which rotation is appropriately applied to the mold into which is injected.

The gas used in the gas-assisted molding method is preferably a gas or liquid at normal temperature and pressure, and does not react or mix with the resin during molding. For example, air, nitrogen gas, carbon dioxide gas, helium gas, water and the like can be mentioned, among which inert gas such as nitrogen gas and helium gas is preferable.

In the present invention, a sufficient amount of molten resin is poured to fill the space (molding chamber) defined by the mold. The resin to be injected is not limited as long as it is a resin capable of forming a perforated hollow tube, but it is preferable to use a thermosetting resin or a thermoplastic resin.

Examples of the thermosetting resin include epoxy resin, phenol resin, melamine resin, urea resin (urea resin), alkyd resin, unsaturated polyester resin, polyurethane, thermosetting polyimide, silicone resin, and diallyl phthalate resin. . Among these, it is preferable to use an epoxy resin, a melamine resin, or a silicone resin.

Examples of the thermoplastic resin include polyethylene resin, polystyrene resin, polypropylene resin, polycarbonate resin, polyacetal resin, polyamide resin, polysulfone resin, polyester resin (for example, polyethylene terephthalate resin and polybutylene terephthalate resin), and modified polyphenylene oxide resin. (For example, modified polyphenylene ether resin), polyphenylene sulfide resin, acrylonitrile-butadiene-styrene copolymer resin, acrylonitrile-styrene copolymer resin, polymethyl methacrylate resin, or a mixture or polymer alloy thereof. .

Further, in order to increase the strength of the resin, a fiber material such as glass fiber or carbon fiber, or a crystalline material such as whisker or liquid crystal polymer may be added to the resin composition. Examples of the glass fiber include glass wool, chopped glass fiber, and milled glass fiber. Examples of the carbon fiber include milled carbon fiber. Examples of the whisker include aluminum borate whisker, potassium titanate whisker, basic magnesium sulfate whisker, calcium silicate whisker, and calcium sulfate whisker.

Furthermore, various additives may be added for the purpose of improving resin properties. For example, flame retardants, stabilizers, pigments, dyes, mold release materials, lubricants, weather resistance improvers and the like may be added to the resin composition. These additives may be used alone, but can be used as a mixture of two or more.

The resin injected into the mold is cured in the mold. The method for curing the resin at this time is not limited, and may be determined according to the characteristics of the resin, such as heating, cooling, and UV irradiation. For example, although it is generally left at room temperature, a method of heating or cooling using a metal main mold or UV irradiation using a transparent resin main mold is preferably used.

The mold for manufacturing a perforated hollow tube of the present invention is composed of at least a main mold and a core mold. The main mold is configured to be divided by a plurality of main parts, and has a reference surface that forms the outer peripheral surface of the perforated hollow tube and a convex portion that forms a through hole. By making the main mold separable, it is possible to extract the convex portion for forming the through hole from the perforated hollow tube. The main mold may be configured such that the main parts are completely separated from each other, or may be opened and closed by connecting the main parts with a hinge.

The main mold may be composed of a pair of main parts so that the main mold can be divided in a direction orthogonal to the axial direction of the perforated hollow tube (hereinafter also simply referred to as “orthogonal direction”). preferable. If the main mold can be divided in the orthogonal direction, the axial direction of the through hole can be made orthogonal to the axial direction of the perforated hollow tube. It can be as short as possible. When the main mold is composed of a pair of main parts, each main part may be further divided into a plurality of pieces. Further, when the axial direction of the through hole is inclined with respect to the orthogonal direction, the main mold may be divided in the inclined direction.

The constituent material of the main mold is not particularly limited as long as it does not cause problems due to the components of the resin to be injected and the curing conditions. Metals, ceramics, reinforced plastics, and the like can be used as appropriate. . Among these, it is preferable to use a metal main mold from the viewpoints of ease of manufacture and processing, and costs due to repeated use. The inner wall surface of the main mold, that is, the surface in contact with the resin (for example, both the reference surface and the surface of the convex portion) is preferably subjected to a release treatment so that it can be easily separated from the cured resin. As the release treatment, a commercially available release agent treatment or a known fluorine coating treatment can be used.

The material of the convex part for forming the through hole may be different from the main constituent material of the main mold. In this case, the convex portion may be formed separately from the main mold and then combined with the main mold. The convex portion preferably has a slightly tapered shape as the distance from the main mold increases. This makes it easy to extract the convex portion from the cured resin.

The main mold is preferably provided with a ridge extending in a specific direction for forming a groove (non-penetrating recess) on the outer peripheral surface of the perforated hollow tube. In this invention, since it becomes easy to provide a pattern in the outer peripheral surface of a perforated hollow tube, it is preferable to provide the groove | channel according to the usage form of a perforated hollow tube. For example, when manufacturing a perforated hollow tube used for a water collection tube of a spiral separation membrane element, a longitudinal groove 82 and / or a perforated member extending in the axial direction of the perforated hollow tube 8 as shown in FIGS. It can be seen that by providing the lateral groove 83 continuous in the circumferential direction of the hole inner space 8, the flow resistance of the permeating fluid can be lowered, so that the pressure loss can be reduced and the permeation amount of the fluid can be increased. Yes. In this case, the protrusion provided on the main mold can be easily removed by removing the corners and forming a shape with R. Alternatively, when manufacturing a perforated hollow tube used for the water collection tube of a spiral type separation membrane element, it is possible to apply a graining process by transferring the irregularities formed in the main mold to the part where the membrane leaf is bonded It is. Appropriate embossing can improve the adhesion between the perforated hollow tube and the membrane leaf due to the anchor effect and increased surface area.

In the illustrated example, one of a plurality of vertical grooves 82 is arranged on a line in which a plurality of through holes 81 connecting the outer peripheral surface and the inner peripheral surface of the perforated hollow tube 8 are arranged. Although the through hole 81 is opened at the bottom, the vertical groove 82 is not necessarily arranged on the line where the through holes 81 are arranged, and may be arranged at a position away from the through hole 81. In such a configuration, the permeated fluid that has flowed into the groove passes through the flow path material wound around the perforated hollow tube 8 to the through hole 81 by the shortest route. The resistance can be lowered to some extent. However, if the through hole 81 is open at the bottom of either the vertical groove 82 or the horizontal groove 83, the groove functions as a flow path that guides the permeate fluid to the through hole 81, so that the flow resistance of the permeate fluid is greatly reduced. Can do. The number of the vertical grooves 82 and the horizontal grooves 83 is not necessarily plural, and may be one. Further, the extending direction of the groove formed on the outer peripheral surface of the perforated hollow tube 8 is not limited to the axial direction or the circumferential direction of the perforated hollow tube 8, and may be a direction inclined from these.

The main mold is provided with a resin inlet. The number of the resin injection ports is not particularly limited, but it is preferable to provide a plurality of resin injection ports because injection leakage hardly occurs.

The core type may be any shape that forms the internal space of the perforated hollow tube, and the material is not particularly limited, and the same material as the main type can be used.

The shape of the core type is not particularly limited, but the core type that is in close contact with the inner peripheral surface of the perforated hollow tube is generally difficult to remove, so the following method should be used. Is preferred. For example, the core type can be divided into multiple core parts and the contact area of each core part can be reduced. The core type is continuous from the end face of the perforated hollow tube in the axial direction. For example, there is a method in which a taper portion that is thicker is provided and the core mold is pulled out in a direction in which the taper portion becomes thicker. When a separable core type constituted by a plurality of core parts or a core type having a tapered portion is used, it is preferable to use in combination with a mold release process or to appropriately combine the respective methods. Further, when the core type is constituted by a plurality of core parts, the core type is constituted by a pair of core parts so that the core type can be divided in the axial direction of the perforated hollow tube. It is preferable. According to this configuration, the core mold can be removed from the perforated hollow tube simply by pulling out the core parts on both sides. When the core type is configured with a pair of core parts, each core part may be further divided into a plurality of pieces.

Furthermore, when using the perforated hollow tube obtained by the present invention as a water collecting tube of a spiral separation membrane element, a connection portion is provided at the end of the perforated hollow tube to connect with other separation membrane elements and pipes. It is necessary to provide. In that case, it is preferable that at least one of the end portions of the core type located at the end portion of the perforated hollow tube is enlarged with one or more steps. By doing so, the space at the end of the perforated hollow tube is widened, and connection with the connecting tube becomes possible.

For example, FIG. 2 and FIG. 3 show an example of a two-divided core mold 3 constituted by a pair of core parts 41 and 42 that can be fitted to each other. The pair of core parts 41 and 42 are fixed to the main mold in contact with each other. In FIG. 2, one end portion and a central portion of each core part 41, 42 are formed in a shape such that a cylinder is cut along a surface slightly inclined with respect to the center line as an axial portion. These shaft portions become cylindrical after fitting. Furthermore, the other end part of each core part 41 and 42 is formed in the column shape of a larger diameter than a shaft part. In other words, both ends of the core mold 2 are enlarged with one step.

On the other hand, in FIG. 3, the pair of core parts 41 and 42 respectively have end surfaces facing the axial direction of the perforated hollow tube that are in contact with each other at the center of the perforated hollow tube. Moreover, the one end part and center part of each core part 41 and 42 comprise the taper part which becomes thick continuously from the said end surface. In addition, the other end part of each core part 41 and 42 has a shape similar to FIG. By the way, when providing a taper part in the core type | mold 3 as shown in FIG. 3, only the one core part 41 is provided with the taper part extended over the full length of the perforated hollow tube 8, and the other inside The child parts 41 may be shaped so as to form an enlarged space at the end of the perforated hollow tube 8.

According to the manufacturing method of the present invention, even a relatively long perforated hollow tube can be easily manufactured. For example, even when the diameter is within 10 cm, a perforated hollow tube having a diameter of about 30 cm to 150 cm can be manufactured. When a longer perforated hollow tube is required, it is preferable to connect and use two perforated hollow tubes 9 as shown in FIG. The method for connecting the two perforated hollow tubes 9 is not particularly limited, and a known technique such as resin adhesion, heat fusion, ultrasonic fusion, or rotational friction fusion can be used as appropriate. . When connecting two perforated hollow tubes 9, for example, as shown in FIG. 5, a core type configuration in which a step does not occur at the end of the perforated hollow tube to be connected, For example, it is preferable to change the configuration of the main mold and the core mold so that they can be connected. It is also possible to manufacture a water collecting tube of a spiral separation membrane element by connecting three or more perforated hollow tubes obtained by the manufacturing method of the present invention.

Hereinafter, the present invention will be described in detail based on the drawings, but the present invention is not limited thereto.

1A and 1B are cross-sectional views showing an example of a mold used for manufacturing the perforated hollow tube of the present invention. This mold 100 is for producing a perforated hollow tube 8 having a longitudinal groove 82 formed on the outer peripheral surface thereof as shown in FIG. In the present embodiment, the mold 100 includes a main mold 1 that surrounds the molding chamber 5, a core mold 3 that is disposed inside the main mold 1, and an auxiliary member 7 that fixes the core mold 3 to the main mold 1. For example, as the main mold and the core mold, a metal mold made of stainless steel or steel for molds can be preferably used, but a reinforced plastic mold can also be used.

The main mold 1 can be divided in a direction perpendicular to the axial direction of the perforated hollow tube 8 and is composed of a pair of main parts 21 and 22 that are fastened in contact with each other. The main mold 1 also includes a reference surface 25 that forms the outer peripheral surface of the perforated hollow tube 8, a convex portion 23 that forms the through-hole 81, and a protrusion 24 that forms the vertical groove 82. In the present embodiment, the protruding portion 24 protrudes from the reference surface 25, and the protruding portion 23 further protrudes from the distal end surface of the protruding portion 24. The reference surface 25 is a cylindrical surface having a constant diameter, for example. However, the reference surface 25 is not necessarily a cylindrical surface having a constant diameter, and may have a plurality of diameters according to the shape of the perforated hollow tube 8 to be manufactured. In the present embodiment, the convex portions 23 are provided in two rows on the bottom and ceiling of the molding chamber 5. In other words, the convex portion 23 is provided on each of the lower main part 21 and the upper main part 22 so as to be opposite to the central axis of the perforated central tube 8 by 180 degrees. Yes. However, the convex part 23 may be provided in a line only in either main part (21 or 22). The ridges 24 are arranged, for example, at equiangular intervals.

The core mold 3 is the same as the core mold 3 described with reference to FIG. That is, the core mold 3 can be divided in the axial direction of the perforated hollow tube 8 and is composed of a pair of core parts 41 and 42 that are fixed to the main mold 1 in contact with each other. One end portion and the other end portion of each core part 41, 42 constitute a shaft portion formed into a tapered shape when combined, and these shaft portions can be fitted with each other. is there. The other end of each core part 41, 42 is enlarged so as to form an enlarged space at the end of the perforated hollow tube 8.

Next, a method for manufacturing the perforated hollow tube 8 using the mold 100 of the present embodiment will be described. After injecting resin into the mold 100 from the resin injection ports 6 provided at two locations of the main mold 1 using an injection molding apparatus and the gas pressure of nitrogen gas, the resin is left to cool and cured, and then the main mold In the removal direction B, the main mold 1 is removed for each of the main parts 21 and 22, and the auxiliary member 7 for fixing the core mold is further removed. Thereafter, the core mold 3 is removed for each of the core parts 41 and 42 in the core mold removal direction C shown in FIG. Through the above steps, the perforated hollow tube 8 shown in FIG. 6 is obtained. As shown in FIG. 8, the perforated hollow tube 8 includes a membrane leaf in which a permeation-side channel material 13 is disposed between the separation membranes 14 around the perforated hollow tube 8 and a supply-side channel material. When 12 laminated bodies are wound, it can be used as a spiral separation membrane element.

Note that FIG. 3 shows a core type configuration different from that in FIG. The core mold 3 includes a pair of core parts 41 and 42 that are approximately half the length of the perforated hollow tube 8. Each core part 41, 42 has a conical taper portion that is tapered toward the end face, in other words, without a tip portion. Further, FIG. 4 shows a case where a perforated hollow tube 9 produced by dividing is fused at an end portion and used as a single perforated hollow tube. As the mold at this time, as shown in FIG. 5, it is preferable to use a mold configured so as not to form a stepped shape at one end of the perforated hollow tube 9. In the case of FIG. 5, one of the core parts 41 and 42 shown in FIG. 3 may be used as a core type.

DESCRIPTION OF SYMBOLS 1 Main mold | type 21,22 Main parts 23 Convex part 24 Projection part 25 Reference surface 3 Core type | mold 41,42 Core part 5 Molding chamber 6 Resin injection port 7 Auxiliary member 8,9 Perforated hollow tube 81 Through- hole 82 , 83 Grooves 12, 13 Channel material 14 Separation membrane 100 Form for manufacturing a perforated hollow tube A Axial direction (flow direction)
B Main mold removal direction C Core mold removal direction

Claims (16)

1. In a method for manufacturing a perforated hollow tube having a plurality of through-holes connected from the outer peripheral surface to the inner peripheral surface, a core type forming an internal space of the perforated hollow tube, and an outer peripheral surface of the perforated hollow tube A resin is injected into a mold that includes a reference surface that forms a plurality of main parts, and a main mold that is configured to be divided by a plurality of main parts, and the resin is cured. Then, the manufacturing method of a perforated hollow tube, wherein the main mold and the core mold are removed in this order.
2. 2. The perforated hollow tube according to claim 1, wherein the main mold is composed of a pair of main parts so that the main mold can be divided in a direction orthogonal to the axial direction of the perforated hollow tube. Manufacturing method.
3. The method for manufacturing a perforated hollow tube according to claim 1 or 2, wherein the core mold is configured to be divided by a plurality of core parts.
4. The perforated hollow tube according to claim 3, wherein the core type is configured with a pair of core parts so that the core type can be divided in the axial direction of the perforated hollow tube. Production method.
5. The method for producing a perforated hollow tube according to any one of claims 1 to 4, wherein the resin to be injected is a thermoplastic resin or a thermosetting resin.
6. The method for producing a perforated hollow tube according to any one of claims 1 to 5, wherein the plurality of through holes are arranged in a line or a plurality of lines in the axial direction of the perforated hollow tube.
7. The method for producing a perforated hollow tube according to any one of claims 1 to 6, wherein the main mold has a protrusion that forms a groove on an outer peripheral surface of the perforated hollow tube.
8. The method for producing a perforated hollow tube according to any one of claims 1 to 7, wherein the core mold has a tapered portion that continuously increases from an end surface facing the axial direction of the perforated hollow tube. .
9. The method for producing a perforated hollow tube according to any one of claims 1 to 8, wherein at least one end of the core type is enlarged with one or more steps.
10. A mold used for manufacturing a perforated hollow tube having a plurality of through holes connected from an outer peripheral surface to an inner peripheral surface,
    By a plurality of main parts having a core type that forms an internal space of the perforated hollow tube, a reference surface that forms an outer peripheral surface of the perforated hollow tube, and a convex portion that forms the plurality of through holes A mold for manufacturing a perforated hollow tube, comprising: a main mold configured to be separable.
11. The perforated hollow tube according to claim 10, wherein the main mold is composed of a pair of main parts so that the main mold can be divided in a direction orthogonal to the axial direction of the perforated hollow tube. Manufacturing formwork.
12. The perforated hollow tube manufacturing form according to claim 10 or 11, wherein the main mold has a protrusion that forms a groove on an outer peripheral surface of the perforated hollow tube.
13. The perforated hollow tube manufacturing form according to any one of claims 10 to 12, wherein the core mold is configured to be split by a plurality of core parts.
14. The perforated hollow tube manufacturing method according to claim 13, wherein the core type is composed of a pair of core parts so that the core type can be divided in the axial direction of the perforated hollow tube. Formwork for.
15. The mold for producing a perforated hollow tube according to any one of claims 10 to 14, wherein the core mold has a tapered portion that continuously increases from an end surface facing the axial direction of the perforated hollow tube. frame.
16. The perforated hollow tube manufacturing form according to any one of claims 10 to 15, wherein at least one end of the core mold is enlarged with one or more steps.

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