JP2005074950A - Manufacturing process of shaped body - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a shaped body capable of more simply forming a material containing a solid such as fibers or the like or a highly viscous material to a hollow shape. <P>SOLUTION: The method for manufacturing the shaped body comprising a setting step for receiving a shaping material 21, a core material 10 being deformable in a shaping mold 31 such that the shaping material 21 encloses the core material 10 in the shaping mold 31 and a step for shaping them by heating and pressing in the shaping mold 31 is provided. As the core material 10 is deformable it can be followed to be various shapes along with the shaping mold 31. By this way, the shaping material 21 enclosing the core material 10 can be well arranged between the core material 10 and the a shaping face of the mold 31. At the state, by heating and pressing it to shape by the shaping mold 31, the shaping material 21 can be shaped to a shape enclosing the core material 10, namely the hollow shape with the core material 10 so as to be the center part. Therefore, the method is simple because the core material 10 is not necessary to be accurately shaped and the shaped body can be formed keeping well the hollow shape. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method for producing a molded body that can form a material that is not suitable for extrusion molding or blow molding, such as a long fiber-containing material, into a hollow shape.

  In recent years, various structures, particularly moving structures such as vehicles, have been required to be reduced in weight while maintaining strength. In response to this requirement, it is considered that the structural material such as the framework of the structure, the framework, and the exterior plate is changed from a metal to a resin-based material such as fiber-reinforced plastic. However, resin materials with higher strength such as fiber reinforced plastics are often thermosetting, are difficult to remold, and often have high strength between molded bodies. Therefore, it is important for the resin-based material to directly mold the raw material into a final shape, for example, a shape having a curved portion or a bent portion.

  As a method for producing a molded body having a three-dimensional shape and formed hollow in a plastic material, a method using blow molding is known (for example, see Patent Document 1 or 2). In addition, a method is disclosed in which a middle mold made of a water-soluble plastic is placed in an injection mold, and after injection molding, is immersed in water to obtain a hollow molded body (for example, see Patent Document 3). However, a resin-based material in which a fiber, in particular, a fiber containing a longer fiber and a resin is combined to ensure strength is not suitable for extrusion or injection.

  A resin-based material containing relatively long fibers can be preformed into a sheet shape by utilizing the entanglement between the fibers. Therefore, for example, a low melting point alloy or an alkali-soluble metal is molded into a predetermined shape to form a core, a sheet of resin material is wrapped around the outer periphery of the core, and then the core is molded. A method for producing a hollow molded body that is removed by melting or dissolving is disclosed (for example, see Patent Document 4). Alternatively, the material constituting the inner wall of the hollow molded body is formed into a bag shape in advance and filled with fine particles in the hollow portion to create a medium mold that is decompressed, and this resin sheet is heat molded in a state of being wound around the outer periphery of the medium mold Thereafter, a method for producing a hollow molded article by discharging medium-sized fine particles is disclosed (for example, see Patent Document 5).

JP-A-7-164467 Japanese Patent Laid-Open No. 9-70880 JP-A-9-174469 JP-A-6-106632 JP-A-4-294132

However, in these methods, the core or the middle mold must be molded with a predetermined accuracy, and the molding of the core or the middle mold and the molding of the hollow molded body are required twice. Further, in the method using the core, it takes time to remove the core. In the method using the middle mold, the middle mold itself is a hollow molded body, so that it is limited to a shape that can be molded by blow molding or the like. Further, it is difficult to create a middle mold for a hollow body having a plurality of open portions.
Therefore, an object of the present invention is to provide a method for producing a molded body that can more simply form a material containing solids such as fibers or a highly viscous material into a hollow shape.

As means for solving the above-mentioned problems, the first invention of the present invention is a method for producing a molded body as described in claim 1, wherein a molding material and a deformable core material are molded. A molding step in which the molding material surrounds the core material in a molding die and a molding step in which the molding die is heated and pressed.
Further, according to a second invention of the present invention, as described in claim 2, the core material is composed of a sheet member constituting the outer surface and a small piece material accommodated inside the sheet member. Item 2. A method for producing a molded article according to Item 1.
Further, according to a third aspect of the present invention, as described in the third aspect, in the setting step, the molding material formed on the sheet containing the fiber and the resin is wound around the core material. It is a manufacturing method of the molded object as described above.
Further, according to a fourth aspect of the present invention, as described in the fourth aspect, the amount of compressive deformation in the core material molding process and the perpendicular to the surface of the core material are set in the setting process using a molding material containing fibers and resin. It is a manufacturing method of the molded object of Claim 1 which adjusts the quantity of the fiber in the said molding material in a direction.
According to a fifth aspect of the present invention, as described in claim 5, the molding material formed on the sheet is wound around the surface of the core material by adjusting the number of windings, and the perpendicular direction of the surface of the core material is measured. The method for producing a molded body according to claim 4, wherein the amount of fibers in the molding material is adjusted.

According to the present invention, a material that is difficult to extrude or inject, such as fiber, is provided by providing a method for producing a molded body that can more simply form a solid-containing material such as fiber or a highly viscous material into a hollow shape. A molded body having various complicated shapes can be manufactured using a material mainly composed of reinforced plastic or fiber.
In the method for producing a molded body according to claim 1, a deformable core material is prepared and accommodated in a molding die so that the core material is surrounded by the molding material in the setting step. Since the core material is deformable, it can follow various shapes along the mold. Thereby, the molding material surrounding the core material can be favorably disposed between the core material and the mold surface of the mold. In this state, the molding material can be molded into a shape that surrounds the core material, that is, a hollow shape having the core material as a central portion, by heat and pressure molding using a molding die. Therefore, the manufacturing method of the present invention is simple because it is not necessary to precisely mold the core material, and a molded body having a hollow shape can be molded well.
According to the method for manufacturing a molded article according to claim 2, since the core material has a sheet member as an outer surface and contains a small piece material therein, the small piece material imparts good deformability. The core material can be easily handled. In addition, the deformation capacity and rigidity of the core material can be adjusted by selecting the material (hardness) and amount of the small piece material. Moreover, the rough external shape of a core material can also be set by giving a shape to a sheet | seat member. The sheet member may be integrated with the inner surface of the molding material in the molding process, or may be peeled off from the molding material side after the molding process.
In addition, according to the method for manufacturing a molded body according to claim 3, since the molding material formed on the sheet is wound around the core material, the core material can be surrounded easily and reliably. In addition, the amount of the molding material at each part of the molded body can be controlled more accurately.

According to the method for producing a molded body according to claim 4, the distance between the mold and the core material, that is, the thickness of the molding material is controlled by adjusting the amount of compression during the molding process of the core material. Can do. Furthermore, by adjusting the amount (weight per unit area) of the molding material in the perpendicular direction from the surface of the core material, the amount of fibers existing in a predetermined part of the molded body can be controlled, and by combining these, The fiber density at the predetermined site can be controlled.
Moreover, according to the manufacturing method of the molded object of Claim 5, the quantity of the fiber of the perpendicular direction on the surface of a core material can be adjusted easily. For example, a sheet with a single basis weight can be created and used as a raw material for molded articles having various densities.

  The molded body that can be manufactured by the manufacturing method of the present invention is a molded body that includes at least an outer shape formed in a hollow shape. Typically, it is a hollow molded body whose outer portion is the entire molded body, such as a tubular member as shown in FIG. 1, various containers not shown, and a housing. Moreover, the molded object (refer FIG. 7) which has the external shape part formed in the hollow shape, and the core part (filler) which consists of another member and another material in the inside can also be manufactured. As such a molded body, for example, a molded body that is used for applications that do not use a hollow internal space such as a pipe as a structural material, and additional properties such as strength, rigidity, and sound absorption properties of a tubular member , Molded articles to which hygroscopicity, deodorizing property, fragrance and the like have been imparted. The molded body 1 in FIG. 1 is a tubular member having a curved portion 1a and having both ends open.

  Hereinafter, an embodiment of a method for producing a molded body according to the present invention will be described with reference to the molded body 1 shown in FIG. The manufacturing method of the molded object of this embodiment is provided with the setting process and the shaping | molding process.

(Set process)
In the setting step, the core material 10 and the molding material 21 are accommodated in the molding die 31 so that the molding material 21 surrounds the core material 10. First, the core material 10 and the molding material 21 will be described.

  First, the core material 10 will be described with reference to FIG. The core material 10 has a deformable configuration. Specifically, the core material 10 can be deformed into a shape in which the molding material can be easily disposed so as to surround the core material 10 and a molded shape in the molding process. The core material 10 can be formed to have a fluid material, for example, a gas, a viscous fluid, or a small solid (small piece material). Further, these fluid materials are appropriately formed on the core material 10 by being covered with a flexible sheet member 11.

  The small piece material 13 can use solids of various materials and shapes within a range that does not adversely affect the molding in the molding process. Examples of the shape of the small piece material 13 include a granular shape, a sand shape, a fiber shape, and a long axis shape. Specific examples of the small piece material 13 include sand, activated carbon, pulverized coal, various fibers, and resin beads. Moreover, you may utilize small pieces scrap materials, such as dust, the skin which comes out at the time of natural fiber collection, a core, and sawdust. The small piece material 13 is preferably a material capable of controlling the rigidity and the amount of compressive deformation of the core material. Typically, a material having a relatively low friction coefficient and a high hardness is used. Further, as shown in FIG. 7, in the case of forming a molded body without removing the core material 10 in particular, when a material similar to the molding material is used, the used molded body is regenerated, reused, etc. It is preferable because the molding material portion and the core material do not have to be separated.

The sheet member 11 is made of various materials that can ensure the deformability of the core material 10. The sheet member 11 that is removed from the molded body 1 after the molding process to be described later has an outer surface that has good peelability for the molding material 21. For example, a sheet whose outer surface is coated with a fluororesin can be suitably used. After the molding step, the sheet member 11 that does not need to be removed from the molded body 1 has at least an outer surface with good adhesion to the molding material 21. This fixing is not limited to a form in which the sheet member 11 (or its surface) is melted and compatible with a binder resin of a molding material described later. For example, the adhesion is physically performed by the impregnation of the binder resin of the molding material. Also included is a form fixed to.
In the form in which the molded body holds the core material, for example, the form shown in FIG. 7, the core material 10 may be impregnated with the resin of the molding material 21. In this case, the core material 10 can be stably fixed to a predetermined part. Moreover, when it is not necessary to remove | exclude a small piece material, a sheet | seat member, etc. from a hollow part exactly | strictly, even when manufacturing the molded object 1 provided with a hollow, using the core material of the structure impregnated or the structure which is hard to peel. Also good.

  The core material 10 of this embodiment is comprised from the rectangular sheet member 11 and the small piece material 13, as shown in the lower part of FIG. As shown in FIG. 2, the core material 10 is formed by rolling a sheet member 11 on a sheet member 11 so as to wrap the small piece material 13 on a predetermined amount and squeezing both ends. It is obtained by sealing with a string or adhesive.

In addition, as another form of the core material 10, it is comprised from the sheet | seat member 41 previously sewn in the bag shape as shown to Fig.8 (a), and the small piece material 43 with which the sheet | seat member 41 is filled. There is a core material 40. In this case, an approximate shape can be given to the bag-like sheet member 41 as appropriate. Further, a core material 45 made of a flexible rubber having elasticity having a predetermined length and shape as shown in FIG. The core material 45 made of flexible rubber can be easily given a shape roughly or precisely to the shape of the hollow portion as appropriate. A core material 47 formed of a rope having a predetermined thickness as shown in FIG. Further, as shown in FIG. 8 (d), a core material 49 in which a fiber material 51 such as a flexible long-axis-shaped wall is bound with a string 53 formed of fibers or the like to stabilize the aggregate state may be used.
Furthermore, the core material 10 may be brought into direct contact with the forming raw material without particularly wrapping small piece materials such as sand, flakes and fibers. In this case, by surrounding with the molding material 21, the core material 10 is formed into a shape that allows easy molding of the molding material 21, and can be deformed along the molding shape by being housed in the molding die 31.

  Next, the molding material will be described. The molding material 21 is a material that constitutes the molded body 1 (outer part), can be arranged so as to surround the core material 10, and is a material that can continue to surround the core material 10 in the molding process. Typically, it is a highly viscous material or a solid material that can hold a predetermined shape. A solid material is preferable, and a solid material that maintains a solid state even during heat and pressure molding is preferable. As such a molding material, a material containing fibers is preferable, and a material in which the fibers are molded into a predetermined shape such as a sheet shape or a rope shape is more preferable. In particular, those in which fibers remain after molding are preferred, and for example, inorganic fibers such as glass wool and rock wool, animal hair, high-melting synthetic fibers, and vegetable fibers are preferred. Of these, natural materials such as animal hair and plant fibers are preferred because they can reduce the use of petroleum resources and can reduce the burden on the natural environment in the regeneration and disposal of used molded bodies. Plant fibers are various fibers derived from woods or herbs, and resources that can be cultivated are preferable. Plants that can be cultivated and grow relatively fast include sisal, jute, and kenaf. Kenaf is particularly preferred because it is easy to grow and high quality long fibers are easily obtained. Fibers can be formed into sheets (including mats) and ropes by known spinning methods, spinning methods, web manufacturing methods, nonwoven fabric manufacturing methods, or various woven and knitted fabric manufacturing methods.

  A molding material containing solids such as fibers contains a thermoplastic or thermosetting binder resin. Examples of the thermoplastic binder resin include polyolefins such as polypropylene and polyesters such as polylactic acid. Moreover, as thermosetting binder resin, resin utilized as adhesives, such as a phenol resin and urethane, can be used, for example. In a fiber molding material that retains a predetermined shape such as a sheet or a rope, a contraction of the molding material is satisfactorily suppressed by the fibers, and a molded body having a predetermined size is obtained. For this reason, it is preferable to use a thermosetting resin that easily contracts as the binder resin because a molded body with high accuracy and high strength can be obtained.

  The ratio of the fiber to the binder resin is not particularly limited. For example, the weight ratio of fiber: binder resin = 7: 3 is preferable. The addition of the binder resin to the fibers can be performed satisfactorily by applying the fibers formed in a predetermined shape such as a sheet or a rope with a spray or a roller or immersing the fibers in a binder resin bath. Further, the fibers before being formed into a predetermined shape may be immersed in a binder resin bath, and particularly in the case of a thermoplastic resin, the binder resin is formed into a fiber shape and mixed with the above-described fibers to obtain a predetermined shape. It can also be added by forming. In the present embodiment, as shown in FIG. 3, the molding material 21 is formed into a belt-like sheet having a certain width.

  In the setting step, the molding material 21 surrounding the core material 10 may be accommodated in the molding die 31, or the molding material 21 is accommodated in the molding die 31, and then the core material 10 is molded in the molding die 31. You may arrange | position in the shaping | molding die 31 in the state enclosed by the material 21. FIG. In the present embodiment, after the molding material 21 is wound around the core material 10 as shown in FIG. 3, the molding material 21 and the core material 10 are accommodated in the molding die 31 shown in FIG. 4, and the set state shown in FIG. And

  As shown in FIG. 3, the molding material 21 formed on a sheet or rope can be easily disposed so as to surround the outer periphery of the core material 10 by being wound around the outer periphery of the core material 10. In winding, in particular, since the surrounding state of the core material 10 is stable, storage in this state is also possible. The winding method is not particularly limited, and it may be formed equal to the length of the molded body 1 from which a sheet is to be obtained and rounded in a direction perpendicular to the length, or wound in a spiral shape as shown in FIG. May be. In plant-derived fibers, depending on the method of producing the sheet or the like, the spiral load at the same angle as when present in the plant reduces the load on the fibers, and a higher strength molded body 1 Is also expected to be obtained. The number of molding materials 21 is not limited to one (one), and a plurality of molding materials 21 may be used. Moreover, you may use different types, for example, the molding material from which fiber and the fabric weight of a fiber differ. The winding amount (number of stacked layers) may be increased or decreased by a predetermined portion, whereby a high density portion or a low density portion can be formed.

  Further, the molding material 21 may be provided at a predetermined portion so as to bite into the core material 10, that is, so as to deform the core material 10. For example, a rope-shaped molding material may be wound so that the core material 10 becomes concave so as to form an outer peripheral circle of the core material 10 at a spiral shape or at a predetermined interval. Thereafter, for example, by winding the sheet-shaped molding material uniformly, the rope-shaped molding material has a shape protruding inward. Thereby, it can be expected that a rib for reinforcing the outer peripheral portion of the obtained molded body 1 can be formed. When the molding material that protrudes inward as described above is prepared as a molding material that is separate from the outer peripheral body, it may be a disk-like member or a shaft-like member made of only a binder resin. In any case, the molding material constituting the portion to be protruded inward in this way is fixed in a state where the predetermined outer surface of the core member 10 is pressed so as to be concave.

Then, the core material 10 in which the molding material 21 is wound around the molding die 31 shown in FIG. 4 is accommodated. Here, the forming die 31 is one of press molds made of a known pair of split dies, and is formed in a concave shape similar to the outer shape of the formed body 1 so as to form the formed body 1 shown in FIG. A surface 31a is provided.
Since the core material 10 is deformable, it can be accommodated by being pushed along the molding surface 31 a of the molding die 31. Further, in this embodiment in which the molding material 21 surrounds the core material 10 by winding, the molding material 21 is positioned with the core material 10 even if it is rubbed against the molding surface 31 a when being accommodated in the molding die 31. Is stable and can be accommodated in the molding die 31 in a state where the molding material 21 surrounds the core material 10 by a simple operation.

(Molding process)
FIG. 6 shows a state of heat and pressure molding. The heat and pressure molding is performed by closing the mold 31 that forms a pair with the mold 31 shown in FIG. In the present embodiment, the molds 31 and 32 are molds that can be heated to predetermined temperatures, respectively. In the molding step, molding is performed by setting the desired temperature in accordance with the curing temperature of the thermosetting resin in the molding material 21 and holding the heated and pressurized state until the binder resin is completely cured. At this time, as shown in FIG. 6, the molding material 21 is sandwiched between the core material 10 located on the inner peripheral side and the molding surface 31a of the molding die 31 located on the outer peripheral side, and is pressed. And is molded to a predetermined thickness. Specific conditions for heating and pressurization in the molding step can be set by a technique known to those skilled in the art depending on the thickness of the thermosetting resin, the molding material 21, and the like, and thus detailed description thereof is omitted.

After the thermosetting resin in the molding material 21 is completely cured, the mold is opened and the molded body 1 is removed. FIG. 7 shows the molded body 1 immediately after being removed from the mold. At this time, the hollow portion of the molded body 1 is filled with the core material 10. In the configuration in which the core material 10 is held as it is, a product can be obtained by appropriately processing the end of the core material 10 and the like.
When obtaining the hollow molded body 1 from which the core material 10 is removed, the core material 10 is removed. The method for removing the core material 10 is not particularly limited, and various methods may be used. In the present embodiment, for example, the narrowed portions at both ends of the sheet member 11 are opened, the internal small piece material is collected from the molded body 1, and then the sheet member 11 is pulled to be peeled off and pulled out. 10 can be removed from the molded body 1.

  In this manufacturing method, by forming the core material 10 so as to be deformable, the molding material 21 is accommodated in the molding die 31 so as to surround the core material 10, whereby the molding material 21 is heated and pressed by a normal method. The molding material 21 can be formed into a hollow shape by the same molding as the molding. Moreover, it can be set by accommodating the core material 10 and the molding material 21 in a deformable state even for a complicated shape such as a three-dimensional shape, for example, using three or more split molds, and is good. Can be molded.

  Moreover, by using what is comprised with a small piece material as the core material 10, it can draw out from a hollow part easily after shaping | molding. That is, the small pieces can be taken out little by little because there is no connection between them in the assembled state, and the shape of the core can be easily changed by this, and can be taken out from the opening of the molded body. . Therefore, it is possible to satisfactorily manufacture a molded body having a complicated hollow shape such as a hollow portion having a larger diameter and shape at the center than the end portion.

  In this manufacturing method, the amount of compressive deformation in the core material molding step and the amount of fibers in the molding material in the direction perpendicular to the surface of the core material can be adjusted in the setting step. Thereby, the density and wall thickness of the molded object obtained, especially an outer shape part are controllable. For example, by adjusting the amount of compressive deformation in the molding process of the core material, the distance from the molding surface of the molding die 31 to the surface of the core material 10 in the molding process can be controlled, and the thickness of the molding material can be controlled. In this case, furthermore, the amount of fibers per unit volume in the molded body (outer portion thereof) obtained by adjusting the amount of the molding material corresponding to the predetermined thickness portion, that is, the amount of fibers in the direction perpendicular to the surface of the core material That is, the fiber density can be controlled. That is, when the amount of compressive deformation of the core material 10 is constant in the entire core material, the fiber density of the portion can be increased and obtained by partially increasing the amount of fibers in the molding material. The intensity | strength of the said part of a molded object can be improved.

On the other hand, when a liquid or fluid (including gas) is used as the fluid material contained in the core material 10, the internal pressure of the entire core material 10 can be made uniform. can do. Thereby, for example, when the amount of fibers in the molding material is increased at a predetermined site, the molding material is molded so as to protrude inward, and a molded body or a thick part having ribs and protrusions inside. It is also possible to mold a molded body comprising
Thus, in the method for producing a molded body according to the present invention, it is possible to provide portions with different thicknesses and portions with different densities (strength and hardness) in a single molding, and various performances according to complex shapes. Can be produced.

Fibers (average fiber length 70 mm) that can be collected from kenaf were formed into a mat shape with a basis weight of 350 g / m ² by needle punching. Subsequently, a phenol resin adhesive was spray-applied to the mat so that the weight ratio of kenaf fiber mat: adhesive solid content = 7: 3 was obtained, thereby obtaining a molding material.
After placing sand at a rate of 1300 g / m ² along one side of one surface of the mat-shaped molding material, the molding material was wound using sand as a core material. At this time, the mat-shaped molding material was made to be three layers or four layers. The amount of fibers in the direction perpendicular to the core surface in the three-layer portion is about 1500 g / m ² , and the amount of fibers in the direction perpendicular to the core surface in the four-layer portion is about 2000 g / m ² .
Next, the rolled molding material was accommodated together with the sand along the concave portion of the lower mold, and the upper mold was closed and hot pressed at 200 ° C. for 10 minutes. After cooling, the molded product was taken out from the mold together with the sand, and the core was removed to obtain a hollow molded body. The density of the substantial part excluding the hollow part of the molded body was about 0.9 g / cm ³ . The wall thickness was 1 to 5 mm.

It is a perspective view of one embodiment of a molded object manufactured by a manufacturing method of a molded object concerning the present invention. It is a schematic diagram which shows the procedure which produces a core material in one Embodiment of the manufacturing method of the molded object which concerns on this invention. FIG. 3 is a perspective view showing a state in which the core material of FIG. 2 is surrounded by a molding material in an embodiment of the method for producing a molded body according to the present invention. It is a perspective view which shows one side of the shaping | molding die used in one Embodiment of the manufacturing method of the molded object which concerns on this invention. FIG. 5 is a perspective view showing a state in which a molding material surrounding the core material of FIG. 3 is accommodated in the molding die of FIG. 4. FIG. 6 is a cross-sectional view showing a state where heating and pressing are performed after FIG. 5. It is a perspective view which shows the molding material after completion | finish of shaping | molding, and the appearance of a core material. It is a perspective view which shows other embodiment of the core material utilized with the manufacturing method of the molded object which concerns on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Molded object 1a Bending part 10 Core material 11 Sheet member 13 Small piece material 21 Molding material 31 Mold

Claims (5)

A method for producing a molded body, comprising:
A setting step of accommodating the molding material and the deformable core material in the molding die so that the molding material surrounds the core material in the molding die;
The manufacturing method of a molded object provided with the shaping | molding process which heat-press molds with the said shaping | molding die.   The core material is a method for producing a molded body according to claim 1, wherein the core material is composed of a sheet member constituting an outer surface and a small piece material accommodated inside the sheet member.   The manufacturing method of the molded object in any one of Claim 1 or 2 which winds around the core material the molding material formed in the sheet | seat containing a fiber and resin in a setting process.   The molding material containing fibers and resin is used, and in the setting step, the amount of compressive deformation in the core material molding step and the amount of fibers in the molding material in the direction perpendicular to the surface of the core material are adjusted. The manufacturing method of the molded object of description. The amount of fibers in the molding material in the perpendicular direction of the core material surface is adjusted by adjusting the number of windings of the molding material formed on the sheet and adjusting the number of windings around the surface of the core material. Manufacturing method of a molded object.

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