JP2004027469A - Hollow, fibrous formed body - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing a hollow, fibrous formed, having various forms including a complicated bent form and having a uniform thickness by firmly making a plurality of fibrous laminated materials as one unit. <P>SOLUTION: This hollow, fibrous formed body having bent or twisted parts is formed by making the plurality of fiber laminate materials as one unit, and it is preferable to block a plurality of joined parts of the fibrous laminated materials with a new fiber laminate material formed on the inside surface of the body. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for producing a hollow fiber molded article, a hollow fiber molded article, and an apparatus for producing a hollow fiber molded article.
[0002]
Problems to be solved by the prior art and the invention
As a conventional technique relating to a method for producing a pulp molded article, for example, a technique described in Japanese Patent Publication No. 35-9669 is known. In this technique, a core having an expandable / contractible membrane is inserted into a fiber laminate having an opening formed in a papermaking mold from the opening, and a fluid is supplied into the membrane to form the membrane. The molded body is dewatered while being expanded and pressing the molded body against the inner surface of the papermaking mold.
[0003]
By the way, this method for producing a pulp molded article is suitable for molding a hollow container having an opening that opens upward, but is not suitable for producing a tubular hollow fiber molded article having a bent portion or a twisted portion. Not suitable.
[0004]
On the other hand, as a conventional technique relating to the production of a bent hollow fiber molded article, a technique described in Japanese Patent Application Laid-Open No. 52-128412 is known. This technology involves inserting two cores through the openings into a papermaking mold in which a set of split dies is combined to form a cavity with two or more openings leading to the outside, and a square-shaped molding is performed. The paper is dewatered.
In this technique, since the core is taken in and out through the opening of the cavity, in the case of a complicated form where the cavity is bent at two or more places, the core may not be inserted into the cavity. there were. Further, this technique is difficult to apply to the production of a hollow fiber molded article whose inner diameter at the opening end is smaller than the inner diameter of the middle part, or a tubular hollow fiber molded article having a twisted portion.
[0005]
As a method for producing a tubular hollow fiber molded article having a plurality of openings, a technique described in JP-A-2000-239998 is known.
In this technology, fiber laminates individually formed by a plurality of split dies are integrated by combining these split dies to produce a tubular molded body having a uniform wall thickness. It has been desired to develop a method for producing a hollow hollow fiber molded article having a uniform thickness and which is more firmly integrated.
[0006]
Accordingly, it is an object of the present invention to provide a hollow fiber molded body having a complicated bent shape, in which a fiber laminate is firmly integrated and having a uniform thickness, and a suitable method and apparatus for producing the hollow fiber molded body. is there.
[0007]
[Means for Solving the Problems]
The present invention uses a papermaking mold in which a set of split dies is combined to form a cavity having two or more openings communicating with the outside, and an expandable and contractible core disposed in the cavity. A method for producing a hollow fiber molded article,
Before combining the split mold, the first step of immersing the split mold in a fiber slurry to form a fiber laminate on the surface of the cavity, and combining the split mold with which the fiber laminate is formed, A hollow including a second step of disposing the core in a cavity and a third step of dewatering each of the formed fiber laminates in the papermaking mold to form a hollow fiber molded body. The object is achieved by providing a method for producing a fiber molded article.
[0008]
Further, the present invention achieves the above object by providing a hollow fiber molded body integrally formed of a plurality of fiber laminates and having a bent portion or a twisted portion.
[0009]
Further, the present invention provides a papermaking mold in which a cavity is formed by combining a set of split dies, and a core for forming a hollow fiber molded body by dehydrating the fiber laminate formed by each of the split dies. In the apparatus for manufacturing a hollow fiber molded body having
The papermaking mold cavity has two or more openings communicating with the outside,
The object is achieved by providing an apparatus for manufacturing a hollow fiber molded body, wherein the core is expandable and contractible and is bendable so as to be disposed in the cavity between at least two of the openings. It is.
[0010]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described based on preferred embodiments.
[0011]
FIGS. 1 to 3 show a first embodiment in which the method for producing a hollow fiber molded article of the present invention is applied to the production of a tubular fiber molded article. In these figures, reference numeral 1 denotes a hollow fiber molded product (hereinafter, also simply referred to as a molded product), 10 denotes a fiber slurry, and P denotes a pool of the fiber slurry.
[0012]
As shown in FIG. 2B, in the method for manufacturing a molded body according to the present embodiment, a pair (one set) of split dies 21 and 22 are combined to have openings 20a and 20b communicating with the outside and a bent portion. The papermaking mold 2 in which the cavity 20 having the above is formed, and the core 3 which is arranged in the cavity 20 and is freely expandable and contractable are used.
[0013]
Although not shown in the drawings, in the manufacturing method of the present embodiment, the split dies 21 and 22 of the papermaking mold 2 are immersed in the fiber slurry 10 and pulled up and down from the fiber slurry 10; A manufacturing apparatus including a mold clamping mechanism that opens and closes the papermaking mold 2 in the fiber slurry and in the air is used. The vertical movement mechanism is constituted by a hydraulic cylinder, and enables stable vertical movement of the papermaking mold 2. The mold clamping mechanism employs a hydraulic cylinder mechanism so that the split molds can be opened and closed in parallel with the mold opening and closing direction and a predetermined mold clamping force is applied when the papermaking mold 2 is in a closed state. Enables stable opening and closing in fiber slurry. As the vertical movement mechanism and the mold clamping mechanism, a link mechanism, an air cylinder mechanism, a servo mechanism, other drive mechanisms, or a combination thereof may be employed in addition to the hydraulic cylinder mechanism.
[0014]
The vertical movement mechanism includes a rotating shaft for rotating the papermaking mold 2 around its longitudinal axis, a driving source for rotating the rotating shaft, and a papermaking mold support arm disposed at predetermined angles on the rotating shaft. It can also be composed of In this case, a set of split dies constituting the papermaking mold is disposed at the tip of each of the arms in the horizontal direction with respect to the surface of the fiber slurry, and the papermaking mold makes one round with the rotation of the rotating shaft. In the meantime, the split mold can be immersed in the fiber slurry, the fiber laminate can be formed, and the hollow fiber formed body can be dewatered. Then, the papermaking mold is opened outside the fiber slurry, and the hollow fiber molded body after dehydration molding is transferred to a dry mold together with the core 3 by a transfer means described later.
[0015]
Each of the split dies 21 and 22 has a cavity forming surface 21a, 22a, a flow passage 21b, 22b opened at the cavity forming surface 21a, 22a, and a papermaking net (not shown) covering the cavity forming surface 21a, 22a. And each is provided.
[0016]
The flow passages 21b and 22b are connected to a pipeline (not shown) that communicates with a suction unit (not shown) such as a suction pump. Although not shown in the figure, a flow groove is formed in the cavity forming surfaces 21a and 22a so as to connect the flow passages 21b and 22b, and a liquid component in the fiber slurry during papermaking and dewatering is formed. The air is discharged to the outside through the flow passages 21b and 22b.
[0017]
The material of the papermaking net is not particularly limited, for example, natural materials such as plant fibers and animal fibers, thermoplastic resins, thermosetting resins, recycled resins, synthetic resin materials such as semi-synthetic resins, stainless steel , Copper, brass and other metal materials.
[0018]
As shown in FIG. 2B, the cavity 20 has two openings 20a and 20b communicating with the outside. The cavity 20 is bent at two places so that the opening 20b cannot be seen through the opening 20a.
[0019]
The core 3 includes a hollow pressing portion 30 made of a hollow elastic body and capable of expanding and contracting, and pressing portions 31 disposed at both ends of the hollow pressing portion 30. Openings 20 a and 20 b of the cavity 20 are provided. It is provided to be freely bendable so that it can be disposed between the two. The pressing portion 31 is used when it is considered that the pressing of the end of the hollow fiber molded body is insufficient with only the hollow pressing portion 30 or when the hollow pressing portion 30 is surely set in the papermaking mold 2 or the drying mold 4. . A fluid passage (not shown) for the fluid communicating with the inside of the hollow pressing portion 30 is provided in the pressing portion 31. A pipe (not shown) leading to a compressor or a suction pump is connected to this flow passage. By supplying a fluid to be described later into the hollow pressing portion 30 through the conduit or discharging the fluid from the hollow pressing portion 30 through the conduit, the hollow pressing portion 30 expands and contracts.
[0020]
The tapered tip portion of the pressing portion 31 is fitted into the tapered openings 1 a and 1 b of the molded body 1. Since the compact 1 is sandwiched between the tip and the papermaking mold 2 or the drying mold 4 (see FIG. 3), the compact 1 is uniformly dehydrated up to the corners (corners) of the opening. Or dried.
[0021]
The tip of the pressing portion 31 is formed smaller than the opening of the papermaking mold 2 or the drying mold 4 (see FIG. 3) to be described later and the opening of the fiber molded body 1. Longer than the depth of the part. Accordingly, the pressing portion 31 can be smoothly put into and taken out of the papermaking mold 2 or the drying mold 4 or the molded body, and the separation between the molded body 1 and the pressing portion 31 is facilitated. Further, as shown in FIG. 2 (c), the pressing force at the time of molding causes the adhesive to closely adhere to the opening of the papermaking die or the drying die and the corner of the opening of the molded product 1, and the pressing force is applied to the molded product 1. Can be communicated reliably.
[0022]
The material of the hollow pressing portion 30 of the core 3 is not particularly limited as long as it is an elastic body, but from the viewpoint of durability, heat resistance, moldability, etc., in addition to natural rubber, urethane, fluorine-based rubber, silicone-based It is preferable to use synthetic rubber such as rubber or elastomer. Further, the material of the pressing portion 31 may be a rigid body such as a metal in addition to the elastic body.
[0023]
Since the weight 32 (see FIG. 2C) is disposed in the hollow pressing portion 30 of the core 3, the buoyancy of the hollow pressing portion 30 when the core 3 is disposed on the fiber laminate. Floating is prevented. On the other hand, the weight 32 may deform the fiber laminate 10a due to its own weight, and the hollow pressing portion 30 may adhere too closely to the fiber laminate 10a, which may adversely affect the subsequent papermaking of a new fiber laminate. . In addition, since the transfer after dehydration molding may be hindered, it is preferable that the weight has a weight that does not cause these adverse effects. Although the shape of the weight 32 is not particularly limited, a chain, a string-like body, or the like is used because it is not partially deviated in the hollow pressing portion 30 and is easily placed and removed in the hollow pressing portion 30. In addition to the above shape, it is preferable to use a string or the like through a plurality of weights such as a sphere or an ellipse so that both ends of the string are stopped so that the lead does not come off from both ends.
[0024]
Next, as shown in FIGS. 1A and 1B, a split mold (part of the split mold) 21 is immersed in the fiber slurry 10 with its cavity forming surface (papermaking surface) facing upward, and Solids are deposited on the papermaking net by suctioning the fiber slurry 10 through the passage 21b to form a fiber laminate 10a having a substantially semicircular arc shape.
[0025]
The fiber slurry preferably comprises only pulp fibers and water. In addition, the fiber slurry includes, in addition to pulp fiber and water, inorganic substances such as talc and kaolinite, inorganic fibers such as glass fibers and carbon fibers, and thermoplastic synthetic resin powders or fibers such as polyolefins, non-wood or vegetable materials. Components such as fibers and polysaccharides may be contained. The compounding amount of these components is preferably 1 to 70% by weight, particularly preferably 5 to 50% by weight based on the total amount of the pulp fiber and the components. In addition, a dispersant of pulp fibers, a molding aid, a coloring agent, a coloring aid, a fungicide, and the like can be appropriately added to the fiber slurry, and further, a sizing agent, a pigment, a fixing agent, and the like are appropriately added. You can also.
[0026]
The pulp fiber may be mixed with a material obtained by mixing an acrylic fiber with an esterified pulp. As the esterified pulp, for example, phosphate cellulose cellulose or phosphorus obtained by esterifying synthetic cellulose such as natural cellulose, a derivative thereof, or polyvinyl alcohol as disclosed in Japanese Patent Application No. 52-5200. Acid-based polyvinyl alcohol fibers and the like are included.
[0027]
Further, the fiber slurry may be mixed with an acrylic fiber mixed into a slurry containing the esterified pulp and beaten.
[0028]
Next, as shown in FIG. 2A, the core 3 is arranged so as to cover the fiber laminate 10a. On the other hand, the split mold 22 (the remaining split mold) is immersed in the fiber slurry to form another semicircular fiber laminate 10b (see FIG. 2B).
[0029]
It is preferable to arrange the core 3 on the fiber laminate 10a in a state where the split mold 21 is arranged immediately below the water surface of the fiber slurry 10. Here, the state of being disposed immediately below the water surface of the fiber slurry 10 refers to a state where the joining surface 21c of the split mold 21 is within 100 mm from the water surface of the fiber slurry 10. It is preferably within a range of 0 to 50 mm. If it exceeds 100 mm, it becomes difficult to arrange the core at a predetermined position due to the buoyancy of the hollow core. When the fiber laminate goes out of the slurry, moisture is excessively removed from the fiber laminate due to suction or the like, which causes poor bonding of the fiber laminates in the next step.
[0030]
The fiber laminate 10b is formed in the same manner as the fiber laminate 10a by the split mold 21, except that the cavity forming surface 22a of the split mold 21 faces downward. When the split mold 21 and the split mold 22 are connected by a hinge and one is rotated and combined with the other, the cavity forming surface 22a of the split mold 21 may be directed upward.
[0031]
Next, as shown in FIG. 2B, a papermaking mold 2 is formed by combining the split dies 21 and 22 on which the respective fiber laminates 10a and 10b are formed in the fiber slurry. After forming the papermaking mold 2 in the fiber slurry 10, the fiber slurry 10 is sucked again through the flow passages 21b and 22b, and a new fiber laminate (not shown) is formed on the surface of each of the fiber laminates 10a and 10b. Is made. Thereby, the seam of each of the fiber laminates 10a and 10b hardly remains, and the surface property of the inner peripheral surface of the obtained molded body 1 is improved.
[0032]
Next, the core 3 is expanded in the papermaking mold 2, and the molded body 1 in which the fiber molded bodies 10a and 10b are integrated is subjected to dehydration molding. In this dehydration molding step, the pressed part 31 presses the molded body 1 from both sides to dewater the opening 1a, 1b at both ends of the molded body 1, while supplying a fluid into the hollow pressed part 30, 30 is expanded to press the molded body 1 against the inner surface of the papermaking mold 2 (the surface on which the cavity of each split mold is formed). Thereafter, the papermaking mold 2 and the core 3 are pulled up from the fiber slurry 10, and the molded body 1 is dewatered while being pressed against the inner surface of the papermaking mold 2 to form the molded body 1. As described above, by expanding the hollow pressing portion 30 in the fiber slurry 10, the joints and steps of the obtained molded body 1 can be eliminated, and the strength can be increased. The papermaking mold 2 may be pulled up from the fiber slurry 10 before pressing the molded body 1 or may be pulled up from the fiber slurry 10 while pressing the molded body 1.
[0033]
Examples of the fluid used to expand the hollow pressing portion 30 of the core 3 include air (pressurized air), hot air (heated pressurized air), steam, gas such as superheated steam, oil (heated oil), and the like. Other liquids are included. In particular, it is preferable to use air, hot air, or superheated steam from the viewpoint of operability and the like.
[0034]
The pressure at which the fluid is supplied into the hollow pressing portion 30 of the core 3 can be appropriately set according to the fiber laminate to be subjected to dehydration molding, but is preferably 0.01 to 5 MPa, particularly preferably 0.1 to 3 MPa.
[0035]
In this dehydration molding step, while the molded body 1 is pressed against the inner surface of the papermaking mold 2 by the pressing force of the hollow pressing part 30 and the pressing part 31, the moisture of the molded body 1 is removed by suction through the flow passages 21b and 22b. I do. As described above, in addition to the pressing by the core 3, the moisture of the molded body 1 is sucked and removed, so that the molded body 1 is uniformly pressed, and the dehydration is quickly performed while the thickness of the molded body 1 is made uniform. Done.
[0036]
The moisture content of the molded article 1 after the dehydration molding is preferably 30 to 80%, and more preferably 40 to 70%, from the viewpoint of preventing damage to the molded article 1 at the time of shifting to the drying molding step, improving drying efficiency, and the like. More preferred.
[0037]
Next, the split dies 21 and 22 are opened, and the cores 3 are removed from the papermaking mold 2 while the cores 3 are arranged in the dehydrated molded body 1. Then, as shown in FIG. 3A, these are transferred to a dry molding step.
[0038]
In the transition from the dehydration molding to the drying molding step, a transfer means (not shown) such as a handling robot for gripping the pressing portion 31 and transferring the core 3 to the drying mold 4 together with the hollow fiber molded body 1 is used.
[0039]
As shown in FIG. 3B, the core 3 and the hollow fiber molded body 1 are placed in a drying mold 4 in which a pair of split molds 41 and 42 are combined to form a cavity 40 having openings 40a and 40b. The molded body 1 is dehydrated and dried and molded.
[0040]
The drying mold 4 used for dry molding includes split molds 41 and 42, and includes heating means (not shown) such as a heater. The split dies 41 and 42 are provided with cavity forming surfaces 41a and 42a similar to the split dies 21 and 22 of the papermaking mold 2, and flow passages 41b and 42b opening on the cavity forming surfaces 41a and 42a.
[0041]
Next, the drying mold 4 is heated by the heating means and maintained at a predetermined temperature. The temperature of the drying mold 4 is preferably from 100 to 250 ° C, more preferably from 120 to 220 ° C, from the viewpoint of preventing burning of the molded body 1 and drying efficiency. It is preferable that the drying mold 4 be heated and maintained at a predetermined temperature before the hollow fiber molded body 1 is disposed in the drying mold 4.
[0042]
Then, as shown in FIG. 3 (c), the molded body 1 is pressed from both sides by the pressing part 31, and while the openings 1 a and 1 b at both ends of the molded body 1 are dried, the fluid is supplied into the hollow pressing part 30. Then, the hollow pressing portion 30 is expanded to press the molded body 1 against the inner surface of the drying mold 4 (the surface on which the cavity of each split mold is formed), and dewatering and drying is performed while the molded body 1 is pressed from the inside.
[0043]
The pressure of the fluid when supplying the fluid into the hollow pressing portion 30 can be appropriately set according to the molded body to be dried, but is preferably 0.01 to 5 MPa, particularly preferably 0.1 to 3 MPa. The fluid used for expanding the hollow pressing portion 30 may be the fluid used in the dehydration step.
[0044]
In the dry molding step, as in the dehydration molding, while the molded body 1 is pressed against the inner surface of the drying mold 4 by the pressing force of the hollow pressing part 30 and the pressing part 31, the moisture of the molded body 1 is passed through the flow passages 41b and 42b. Is removed by suction. As described above, in addition to the pressing by the core 3, the moisture of the molded body 1 is suctioned and removed, so that the molded body 1 is uniformly pressed, and the drying of the molded body 1 is quickly performed while the thickness of the molded body 1 is made uniform. Done.
[0045]
When the molded body 1 is dried to a predetermined moisture content, the suction through the flow passages 41b and 42b is stopped, and the fluid in the hollow pressing portion 30 is discharged to contract the hollow pressing portion 30.
[0046]
Then, the split dies 41 and 42 are opened, and as shown in FIG. 3 (d), the molded body 1 is taken out from the drying mold 4, one end of the hollow pressing part 30 is removed from the pressing part 31, and The core 3 is pulled out, and the dehydration drying molding step is completed.
[0047]
The molded body 1 thus formed can be subjected to various processes such as a trimming process, an attachment of another member, a coating process with a resin layer on the inner and outer surfaces, a printing process, and a water-repellent process, as necessary. . In particular, by providing a sodium silicate layer and / or a silicone resin layer on the surface of the molded body 1 after dry molding, the heat resistance and water resistance of the molded body 1 can be improved.
[0048]
As described above, according to the method for manufacturing a molded article of the present embodiment, after the fiber laminate 10a is laminated on the surface of the split mold 21, the split mold 21 is disposed directly below the water surface of the fiber slurry 10. Then, the core 3 is arranged on the fiber laminate 10a, and the split mold 21 and the split mold 22 obtained by forming the fiber laminate 10b are combined to form a papermaking mold 2. Then, the molded body 1 is formed with the core 3. Perform dehydration molding. Therefore, it is possible to efficiently manufacture a molded product having a seamless, thin, lightweight, thick, uniform, and highly bent or twisted form. Since the obtained molded body 1 has high sound absorbing properties, the molded article 1 is also excellent in a silencing effect of a sound generated when a solid, a gas or the like flows therein.
[0049]
Further, in the method for manufacturing a hollow fiber molded article of the present embodiment, after forming the papermaking mold 2 by combining split molds in the fiber slurry, the split mold is pulled up from the fiber slurry, and the fiber laminate is placed inside the core 3 by the core 3. To form the molded body 1 by dehydration molding. Therefore, each fiber laminate in a wet state is integrated while being dehydrated, and a uniform molded body 1 having a seamless wall thickness is formed.
[0050]
Moreover, since the papermaking mold 2 is formed by combining the split dies 21 and 22, it is possible to form a complicated bent or twisted cavity shape, and to manufacture hollow fiber molded bodies having various complicated shapes. can do.
[0051]
Moreover, since the cores having the pressing portions 31 on both sides of the hollow pressing portion 30 are used, and the tapered openings 1a and 1b of the molded body 1 are formed by the pressing portions 31, the corners of the openings are also formed. Excellent molding accuracy.
[0052]
Further, since the core 3 used in the dehydration molding step is used as it is in the dry molding step, the transition from the dehydration molding step to the dry molding step is smooth, and the production efficiency of the molded body is improved.
[0053]
Further, in the drying and molding step, the molded body 1 is dehydrated and dried while pressing the molded body 1 from the inside to the inner surface of the drying mold 4 with the core 3, so that the molded body 1 can be efficiently dehydrated and dried, and the wall thickness is uniform. Moreover, it is possible to produce a thin and high-strength molded body.
[0054]
FIG. 4 shows an embodiment in which the hollow fiber molded article of the present invention is applied to a tubular molded article having a bent portion. In FIG. 4, reference numeral 1 indicates a tubular molded body (hereinafter, also simply referred to as a molded body).
[0055]
The molded body 1 shown in FIG. 4 is formed by integrating two fiber laminates.
The molded body 1 has two openings 1a and 1b, and has a bent portion 11 between them. The opening 1b of the molded body 1 cannot be seen through the opening 1a. Further, the molded body 1 is formed with flange portions 1c and 1d for protecting the openings 1a and 1b. The flange portions 1c and 1d curl outward, respectively, and when the molded body 1 is joined to another tubular molded body or the like, damage to the openings is prevented.
[0056]
The molded body 1 is preferably made of only pulp fibers. The molded article 1 may be made of an inorganic material such as talc or kaolinite, an inorganic fiber such as a glass fiber or a carbon fiber, a powder or a fiber of a thermoplastic synthetic resin such as a polyolefin, a non-wood or vegetable fiber, a polysaccharide, or the like, in addition to the pulp fiber. A component may be contained. The compounding amount of these components is preferably 1 to 70% by weight, particularly preferably 5 to 50% by weight, based on the total amount of the pulp fiber and the components. Further, a molding aid, a coloring agent, a coloring aid, a fungicide, a sizing agent, a pigment, a fixing agent, and the like can be appropriately added to the molded body 1.
[0057]
The material obtained by mixing the above-mentioned esterified pulp with acrylic fiber can also be mixed into the molded body 1.
[0058]
Further, the molded body 1 preferably includes a sodium silicate layer and / or a silicon resin layer from the viewpoint of imparting high heat resistance and high water resistance.
[0059]
Next, an embodiment of a manufacturing apparatus of a hollow fiber molded article of the present invention will be described with reference to the drawings.
As shown in FIG. 5A, the manufacturing apparatus 100 of the present embodiment includes a papermaking mold 2 in which a pair of split molds 21 and 22 are combined to form a bent cavity 20, and FIG. As shown, a core 3 for dehydrating the fiber laminates 10a and 10b formed by the split dies 21 and 22 to form the hollow fiber molded body 1 is provided.
[0060]
As shown in FIG. 5A, the split dies 21, 22 are formed with cavities forming surfaces 21a, 22a, flow passages 21b, 22b opened at the forming surfaces 21a, 22a, and a papermaking net covering the forming surfaces 21a, 22a. (Liquid permeable material, not shown). Each of the split dies 21 and 22 has a joint surface (only 21c is shown) formed substantially on one plane.
[0061]
The flow passages 21b and 22b are integrated into one flow passage (only 22d is shown) in the split dies 21 and 22, and the openings of these flow passages are connected to suction means (not shown) such as a suction pump. It is connected to an open conduit (not shown). A flow groove (not shown) connecting the flow paths 21b and 22b is formed in the cavity forming surfaces 21a and 22a, and the liquid in the fiber slurry passes through the flow paths 21b and 22b during papermaking and dewatering. It is discharged to the outside smoothly.
[0062]
The cavity 20 has two openings 20a and 20b communicating with the outside. Since the cavity 20 is bent at two points, the opening 20b cannot be seen through the opening 20a.
[0063]
The core 3 has a tubular shape made of a hollow elastic body, is capable of expanding and contracting, and is bendable so that it can be disposed between the two openings 20 a and 20 b of the cavity 2.
[0064]
Both ends of the core 3 are detachably attached to the head 33. Each head 33 is connected to a pipeline (not shown) that leads to a compressor, a suction pump, or the like. When the core 3 is attached to the head 33, the inside of the core 3 communicates with the pipe. Then, a fluid to be described later is supplied to the inside of the core 3 or discharged from the inside of the core 3 by a compressor or a suction pump.
[0065]
The manufacturing apparatus 100 is immersed in a fiber slurry in conjunction with a vertical movement mechanism of a papermaking mold described later, and disposes the core 3 on the formation surfaces 21c and 22c of one or both cavities of the split dies 21 and 22. It has a core disposing mechanism.
In the present embodiment, as shown in FIG. 5 (b), the core disposing mechanism has a gutter-shaped guide cover 34 which is bent corresponding to the bent shape of the cavity forming surface 21c of the split mold 21 on one side. The guide cover 34 is moved in the opening and closing direction of the split die 21 so that the core 3 can be disposed on the cavity forming surface in accordance with the position of the split die 21. And a drive mechanism (not shown) for moving to a position where there is not. Inside the guide cover 34, suction means (for example, a vacuum pad) for sucking and holding the core 3 is provided, and the core 3 is kept in a bent state that matches the shape of the surface of the split mold 21 in which the cavity is formed. It is.
The drive mechanism is constituted by a hydraulic or pneumatic cylinder, other general drive means, and a transmission mechanism such as a link or a gear.
A plurality of core disposing mechanisms can be disposed for one set of split molds. Also, a plurality of cores can be arranged by one core arrangement mechanism.
[0066]
As shown in FIG. 6A, the manufacturing apparatus 100 of the present embodiment includes a drying mold 4 for drying the hollow fiber molded body 1 and a drying mold for drying the core 3 together with the hollow fiber molded body 1 obtained by dehydration molding. 4 (not shown).
[0067]
The drying mold 4 includes a pair of split molds 41 and 42. The split dies 41 and 42 include heating means 41e and 42e such as a heater. The split dies 41 and 42 of the drying mold 4 are formed with cavities forming surfaces 41a and 42a similar to the split dies 21 and 22 of the papermaking die 2, flow passages 41b and 42b opening at the forming surfaces 41a and 42a, and joining surfaces 41c and 42c. , And a plurality of flow passages (only 42d is shown) communicating the flow passages 41b and 42b to the outside.
[0068]
As the transfer means, a handling robot or the like which holds the head 33 and transfers the hollow fiber molded body 1 to the drying mold 4 together with the core 3 is used. It is preferable that the handling robot is provided with a take-out jig or the like having a shape corresponding to the outer shape of the molded body from the viewpoint of preventing the molded body from being damaged when the molded body is transferred to the drying mold.
[0069]
Although not shown in the drawing, the manufacturing apparatus 100 includes a vertical movement mechanism for immersing the papermaking mold 2 in the fiber slurry or pulling the papermaking mold 2 out of the fiber slurry, and And a mold clamping mechanism (mold opening and closing mechanism) that opens and closes in the air. The vertical movement mechanism is constituted by a hydraulic cylinder mechanism, and the hydraulic cylinder mechanism can move the papermaking mold 2 up and down stably. The mold clamping mechanism uses a hydraulic cylinder mechanism and a link mechanism so that the split molds are opened and closed in parallel with the mold opening and closing direction and a predetermined mold clamping force is applied when the papermaking mold 2 is in a closed state. A configuration is employed. The mold clamping mechanism can stably open and close the papermaking mold 2 in the fiber slurry. As the vertical movement mechanism and the mold clamping mechanism, an air cylinder mechanism, a servo mechanism, and other drive mechanisms can be employed in addition to the hydraulic cylinder mechanism.
[0070]
The structure and operation of the vertical movement mechanism are the same as those described above.
[0071]
Next, a second embodiment of the method for producing a hollow fiber molded article of the present invention will be described based on an embodiment applied to a method for producing the molded article 1 using the production apparatus 100. Note that description of points common to the manufacturing method of the first embodiment is omitted. Therefore, the description in the first embodiment is appropriately applied to the points that are not particularly described.
[0072]
FIGS. 5A to 5D schematically show a procedure of a papermaking step (first step) in a step of manufacturing the molded body 1.
[0073]
First, split molds 21 and 22 are immersed in a fiber slurry pool (not shown) to suck the fiber slurry, and as shown in FIG. The fiber laminates 10a and 10b having a semicircular arc shape are formed.
[0074]
In the second step, the split molds 21 and 22 on which the fiber laminates 10a and 10b are formed are combined in the fiber slurry, while the core 20 is formed in the cavity 20 formed by combining the split molds 21 and 22. 3 is installed.
[0075]
The core 3 is placed on the fiber laminate 10a of the split mold 21 on one side before the split molds 21 and 22 are combined.
When the core 3 is arranged, as shown in FIG. 5 (b), the core 3 is arranged in the guide cover 34 having a bent shape corresponding to the cavity forming surface 21a to form a fiber laminate. Place on 10a. After the core 3 is arranged, the guide cover 34 is separated from the core 3 and taken out of the cavity.
[0076]
Then, as shown in FIG. 5C, the split molds 21 and 22 are combined at the joint surface, and the papermaking mold 2 is closed. When the papermaking mold 2 is closed, the fiber slurry is sucked, and another fiber is deposited inside the fiber laminates 10a and 10b. The molded body obtained in this way has no seams or steps, and has high strength.
[0077]
After disposing the core 3 in the cavity, the process proceeds to a dehydration step (third step). The dewatering is performed by lifting the papermaking mold 2 and the core 3 in the state shown in FIG. 5C from the fiber slurry. However, the dehydration may be performed before the papermaking mold 2 and the core 3 are lifted from the fiber slurry.
In this dehydration step, a fluid is supplied to the core 3, the core 3 is expanded, and the fiber laminates 10a and 10b are pressed against the inner surface of the papermaking mold 2, and then the papermaking mold 2 and the core 3 are subjected to fiber slurry. The fiber laminates 10a and 10b are dehydrated to form the molded body 1 by continuing to press the core 3 described above. In this way, by expanding the core 3 in the fiber slurry in the pool, the obtained molded body can be made to have a high strength without seams and steps.
[0078]
The pressure of the fluid when supplying the fluid into the core 3 can be appropriately set according to the fiber laminate to be subjected to dehydration, but is preferably 0.01 to 5 MPa, particularly preferably 0.1 to 3 MPa.
[0079]
In the dewatering step, while the core 3 is pressed, the moisture in the fiber laminates 10a and 10b is sucked through the flow passages 21b and 22b. As described above, by performing the pressing, the formed body 1 to be formed is pressed uniformly, and the dewatering of the formed body 1 is rapidly performed while the thickness is made uniform.
[0080]
When the molded body 1 is dehydrated to a predetermined moisture content, the suction through the flow passages 21b and 22b is stopped, and the fluid in the core 3 is discharged to contract the core 3. Then, as shown in FIG. 5D, the split dies 21 and 22 are opened to separate the wet molded body 1 and the core 3 from the papermaking mold 2.
[0081]
The moisture content of the molded body 1 after the dehydration step is preferably from 30 to 70% from the viewpoint of preventing damage to the molded body 1 at the time of shifting to the drying step, drying efficiency in the next drying step, and the like, and is preferably 40 to 70%. ~ 60% is more preferable.
[0082]
The molded body 1 and the core 3 in the wet state after the dehydration are moved between the split dies 41 and 42 of the drying die 4 by the above-mentioned transfer means (not shown) as shown in FIG. (Fourth step) is started.
[0083]
First, as shown in FIG. 6B, the split dies 41 and 42 are combined at the joint surface, and the molded body 1 and the core 3 are disposed in the cavity of the drying die 4.
[0084]
Next, the drying mold 4 is heated by the heating means 45 and maintained at a predetermined temperature.
The temperature of the drying mold 4 is preferably from 100 to 250 ° C, more preferably from 150 to 220 ° C, from the viewpoint of preventing the molded article 1 from burning and drying efficiency.
[0085]
A fluid is supplied to the core 3 to expand the core 3, and the molded body 1 is pressed against the inner surface of the drying mold 4 to dehydrate and dry the molded body 1.
The pressure of the fluid when supplying the fluid into the core 3 can be appropriately set according to the molded body to be dried, but is preferably 0.01 to 5 MPa, particularly preferably 0.1 to 3 MPa. The fluid used in the dehydration step can be used for bulging the core 3.
[0086]
In the drying step, in addition to the pressing by the core 3, the moisture of the molded body 1 is sucked through the flow passages 41b and 42b. As a result, the molded body 1 is pressed uniformly from the inside, and the drying is quickly performed while the thickness is made uniform.
[0087]
When the molded body 1 has been dried to a predetermined moisture content, the suction through the flow passages 41b and 42b is stopped, and the fluid in the core 3 is discharged to contract the core 3.
[0088]
After a lapse of a predetermined time, as shown in FIG. 6C, the split dies 41 and 42 are opened, and the molded body 1 is taken out from the dry mold 4. Further, one end of the core 3 is removed from the head 33, the core 3 is pulled out from the molded body 1, and the dehydration and drying step is completed. Before opening the split dies 41 and 42, one end of the core 3 may be removed from the head 33.
[0089]
After the drying step, the ends of the openings 1a and 1b of the molded body 1 are pressed against the grooves of a mold (not shown) having a ring-shaped groove having a cross-sectional shape of a predetermined curvature. The portions are curled outward to form the flange portions 1c and 1d.
[0090]
The molded body 1 can be subjected to various processes such as trimming, mounting of another member, coating of the inner and outer surfaces with a resin layer, printing, and water repellency, if necessary. In particular, by providing a sodium silicate layer and / or a silicone resin layer on the surface of the molded body 1, heat resistance and water resistance of the molded body can be improved.
[0091]
The molded body 1 of the present embodiment manufactured in this manner has a complicated bent shape bent at two places, has no seams, is thin, lightweight, has a uniform thickness, and has high strength. Since the end portions of the molded body 1 are protected by the flange portions 1c and 1d, the end portions can be prevented from being damaged. Furthermore, since the molded body 1 has high sound absorbing properties, it has an effect of reducing the intensity of sound caused by solids, gases, and the like flowing inside the molded body 1.
[0092]
In the method for manufacturing a hollow fiber molded body of the present embodiment using the manufacturing apparatus 100, the split molds 21 and 22 are combined in the fiber slurry to form the papermaking mold 2, and then the split molds 21 and 22 are pulled up from the fiber slurry. Since the fiber laminates 10a and 10b are pressed and dehydrated by the core 3, the wet fiber laminates 10a and 10b are integrated while being dehydrated to form a seamless molded body 1 having a seamless thickness. can do.
[0093]
Further, when disposing the core 3 in the cavity, the guide cover 34 having a shape corresponding to the bending of the cavity forming surface 20 is used, so that the core 3 matches the bending shape of the forming surface 21 a of the cavity 20. Since the shape can be maintained and the split molds 21 and 22 are closed after the core 3 is arranged on the fiber laminate 10a, the core 3 can be reliably disposed in the cavity even when the bent form is complicated. it can.
[0094]
Further, since the papermaking mold 2 is divided into the split molds 21 and 22, a complicated cavity shape can be formed, and a hollow fiber molded body having various complicated shapes can be manufactured.
[0095]
In addition, since the process proceeds to the dehydration / drying process while the core 3 used in the papermaking process is kept in the molded body 1, the transition from the papermaking process to the dehydration / drying process becomes smooth in a short time.
Further, in the dehydration drying step, since the molded body 1 is dried while pressing the inner surface of the drying mold 4 with the core 3, the molded body 1 can be efficiently dried, and the thickness is uniform, thin, and high. A strong molded body can be manufactured.
[0096]
The present invention is not limited to the above embodiments, and can be appropriately modified without departing from the spirit of the present invention.
[0097]
According to the present invention, as in the manufacturing methods of the first and second embodiments, a pair of substantially semi-arc-shaped fiber laminates is formed, and these are joined together to form a hollow fiber molded body by dehydration molding. For example, as shown in FIG. 7A, a pair of semicircular arc-shaped fiber laminates 10a and 10b having flange portions 10c and 10d on both sides of a joint portion are formed, and the laminate is formed as shown in FIG. As shown in (1), the hollow fiber molded body 1 having the flange portion 1c can be dehydrated and formed by joining them and integrating them.
[0098]
When it is desired to form a mounting flange portion on a hollow fiber molded body to be formed, as shown in FIGS. 7C and 7D, a fiber laminate 10a provided with a flange portion 10e corresponding to the mounting flange portion. 10b, and as shown in FIGS. 7 (e) and (f), the respective fiber laminates can be joined and integrated to form a hollow fiber molded body 1 having a mounting flange 1d by dehydration molding.
[0099]
In the present invention, the fiber laminate is pressed against the inner surface of the papermaking mold 2 by the core 3 and included in the fiber laminate through the flow passages 21b, 22b, etc., as in the production methods of the first and second embodiments. It is preferable that the molded body is dewatered and formed by sucking the water to be removed, but the dehydration method in the dewatering and molding step is not limited to this. For example, after dewatering by pressing and dehydrating through the flow passage due to expansion of the core, fluid is extracted from the core, and blow dewatering is performed to blow dehydrating fluid into the gap between the core and the surface of the fiber laminate. You may. In addition, a plurality of dehydration methods can be combined as appropriate.
[0100]
According to the present invention, as in the manufacturing methods of the first and second embodiments, after forming the molded body 1 by integrating the fiber laminate during dehydration, the molded body 1 is further pressed from the inside in the drying mold 4. Although it is preferable to perform dehydration drying while performing the dehydration step, the wet molded body 1 and the core 3 can be separated and only the molded body 1 can be dehydrated and dried with various tunnel-type dryers. .
[0101]
Further, in the manufacturing methods of the first and second embodiments, the fiber laminates 10a and 10b are integrated to form the molded body 1 having the two openings 1a and 1b. And forming a molded body having one opening and the other end closed, and then cutting the other end to form a molded body having two openings.
[0102]
In the present invention, as in the manufacturing methods of the first and second embodiments, the dewatered hollow fiber molded body is preferably transferred to a dry mold by the transfer means. The molded body can also be directly transferred between the papermaking mold and the dry mold by utilizing the suction or the like in (1).
For example, first, the split mold and the core 3 are moved together while the molded body 1 is sucked into the split mold through the flow passage of one of the split dies of the papermaking mold. Then, a drying mold is arranged opposite to the mold, and after the both molds are combined, the molded body 1 is sucked through the flow passage of the drying mold, while the paper mold is divided. The molded body 1 is separated from the split mold of the papermaking mold by injecting compressed air from the flow passage of the mold. Then, instead of the mold for the papermaking mold, a corresponding mold for the dry mold is provided, and both molds for the dry mold are combined to form the molded body 1 and the core 3 together in the cavity of the mold for drying. Make it installed.
This method is particularly suitable for the transfer of a long molded article or a thin molded article.
[0103]
Further, in the manufacturing methods of the first and second embodiments, a papermaking mold and a dry mold including two split molds are used. However, by combining three or more split molds according to the shape of a molded body to be manufactured, A papermaking mold or a drying mold in which a cavity having a predetermined shape is formed can also be used. Further, the molded body is formed by integrating a pair of fiber laminates, but the molded body may be formed by integrating three or more divided fiber laminates.
[0104]
Further, it is preferable that the joining surfaces of the split dies are flush with each other as in the manufacturing methods of the first and second embodiments. However, in the case of a specific molded body, it is easy to take out the molded body. The bonding surface may be non-planar (for example, a curved surface) so that the bonding can be performed in a uniform manner.
[0105]
Further, the shapes of the cavities of the papermaking mold and the drying mold are preferably substantially the same as in the manufacturing methods of the first and second embodiments. By pressing the molded body 1 against the inner surface of the drying mold 4 with the core 3 in the dry molding step, it is possible to impart bending or twisting to the molded body 1.
[0106]
Further, the method for producing a hollow fiber molded article of the present invention is particularly suitable for producing a hollow fiber molded article having two openings as described in the first and second embodiments. The present invention can be applied to the production of a hollow fiber molded body having three or more openings.
[0107]
Further, the cavity of the papermaking mold or the drying mold used in the present invention may be two-dimensionally bent or three-dimensionally bent.
[0108]
Further, in the present invention, it is preferable to use a split mold having a papermaking net covering the surface on which the cavity is formed, as in the manufacturing methods of the first and second embodiments. The surface on which the cavity is formed can be covered with a permeable material. Further, the papermaking mold may be constituted by a split mold made of a porous material, and the liquid permeable material may be omitted.
[0109]
In the first and second embodiments, one core is used. However, a plurality of cores can be used according to the shape of the obtained hollow fiber molded body.
[0110]
In the present invention, as in the second embodiment, it is preferable that the core 3 is disposed in the cavity using the guide cover 34 in the fiber slurry, but the core 3 is disposed in the cavity outside the fiber slurry. It may be provided.
[0111]
In the second embodiment, the flange is formed by rounding the opening end after the drying step. However, the flange is formed in advance on the forming surface of the cavity of the split mold constituting the papermaking mold. A concave portion may be formed, and a flange portion may be formed during papermaking.
Further, a flange member can be attached to an end of the tubular molded body after forming the tubular molded body without forming the flange portion.
[0112]
In addition, the present invention can be applied to the manufacture of a hollow fiber molded body having a twisted portion and a hollow fiber molded body having a twisted portion and a bent portion in addition to the bent portion.
[0113]
Further, the cross-sectional form of the fiber molded body manufactured in the present invention can be appropriately changed according to the form of the bent portion or the twisted portion. In addition, for example, the diameter of the body and the end of the molded body may be different from each other so as to enable connection by insertion fitting, or the end of the molded body may be tapered.
[0114]
Although the use of the hollow fiber molded article of the present invention is not particularly limited, for example, it can be preferably used for a hollow molded article such as a hollow container having a small diameter or an irregular shape.
[0115]
【The invention's effect】
According to the present invention, a hollow fiber molded body having various forms including a complicated bent form such as being bent at two or more places, and a plurality of fiber laminates being firmly integrated and having a uniform wall thickness, Provided are a method and apparatus for manufacturing a hollow fiber molded body that can suitably produce a molded body.
[Brief description of the drawings]
FIGS. 1 (a) and 1 (b) schematically show a papermaking process in a first embodiment in which a method for producing a hollow fiber molded article of the present invention is applied to production of the tubular molded article. I have. FIG. 1A is a partial cross-sectional view illustrating a papermaking process using a part of a split mold. FIG. 2B is a plan view of FIG.
FIGS. 2A to 2C are partial cross-sectional views schematically showing a procedure of a papermaking / dewatering step in the first embodiment. FIG. 2A shows a state in which a core is arranged on a fiber molded body. FIG. 2B shows a papermaking process using a set of split dies. FIG. 2C shows a dehydration molding step.
FIGS. 3A to 3D are partial cross-sectional views schematically showing a procedure of a manufacturing process in the first embodiment. FIG. 3A shows a transition from the dehydration molding process to the dry molding process. 3 (b) and 3 (c) show a dry molding process using a core. FIG. 3D is a diagram showing a fiber molded body and a core taken out from the drying mold.
FIG. 4 is a perspective view schematically showing an embodiment in which the hollow fiber molded article of the present invention is applied to a tubular molded article having two openings.
FIGS. 5A to 5D schematically show a procedure of a papermaking / dewatering step in a second embodiment in which the method for producing a hollow fiber molded article of the present invention is applied to production of a tubular molded article. It is a perspective view. FIG. 5A shows a papermaking process. FIG. 5B shows a state before the core is provided. FIG. 5C shows a dehydration step. FIG. 5D shows a state where the split mold is separated.
FIGS. 6A to 6C schematically show a procedure of a drying step in the second embodiment. FIG. 6A shows a state before the molded body and the core are disposed in the drying mold. FIG. 6B shows a state in which the molded body and the core are disposed in a drying mold. FIG. 6C shows a state in which the molded body and the core are separated.
7 (a) to 7 (f) schematically show a manufacturing process of a hollow fiber molded body using a fiber laminate of another embodiment according to the present invention. FIGS. 7A and 7B show a manufacturing process of a hollow fiber molded body having a joining flange portion. FIGS. 7 (c) and 7 (d) and FIGS. 7 (e) and 7 (f) show a manufacturing process of a hollow fiber molded body having a mounting flange portion.
[Explanation of symbols]
1 tubular molded product (hollow fiber molded product)
1a, 1b Opening portion 10 Fiber slurry 10a, 10b Fiber laminate 11 Bent portion 100 Manufacturing apparatus for hollow fiber molded body 2 Papermaking mold 20 Cavities 20a, 20b Openings 21, 22 Split molds 21a, 22a Cavity forming surfaces 21b, 22b Flow passage 21c Joining surface 3 Core 30 Hollow pressing portion 31 Pressing portion 32 Weight 33 Head 34 Guide cover 4 Drying mold 40 Cavities 40a, 40b Opening 40
41, 42 Split molds 41a, 42a Cavity forming surfaces 41b, 42b Flow passage 100 Hollow fiber molded body manufacturing apparatus

Claims (4)

A hollow fiber molded body formed by integrating a plurality of fiber laminates and having a bent portion or a twisted portion, wherein a seam of the plurality of fiber laminates is closed. The hollow fiber molded article according to claim 1, wherein the seam is closed with a new fiber laminate formed on the inner surface. The hollow fiber molded article according to claim 1, wherein the hollow fiber molded body has two or more openings, and is formed such that at least one of the other openings cannot be seen through one of the openings. A hollow fiber molded article using a papermaking mold in which a pair of split molds are combined to form a cavity having two or more openings communicating with the outside, and an expandable / contractible core provided in the cavity. The method of manufacturing
Before combining the split mold, the split mold is immersed in a fiber slurry to form a fiber laminate on the surface where the cavity is formed, and the fiber laminate is mixed in the fiber slurry before the split mold is formed. After arranging the core on the fiber laminate formed in any of the split molds and combining the split molds, after forming a new fiber laminate on the surface of each of the formed fiber laminates And a method for producing a hollow fiber molded body in which the core is expanded to form a hollow fiber molded body in the papermaking mold.

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