JP5139911B2 - Granule forming method and powder forming apparatus - Google Patents

Description

  The present invention relates to a granular material forming method and a granular material forming apparatus for forming a granular material.

  As a method of forming the granular material, it is put into a storage container and press-molded in a dry or semi-dry method (for example, see Patent Documents 1 and 2), and during or after that, if necessary, heated or dried, or stored at the tip. A method of forming by an extrusion molding machine with a container attached (for example, see Patent Document 3) is known.

However, in these methods, it is difficult to obtain molded bodies having different bulk densities depending on the part of the molded body, and such molded bodies have to be manufactured by joining two types of molded bodies having different bulk densities. It was. In this method, the number of steps is large and time-consuming, and it is difficult to select an adhesive and to optimize the bonding operation in order to maintain the strength of the joint and the original characteristics of the molded body.
JP 2005-146243 A JP 2003-170523 A JP 2003-38628 A

  An object of the present invention is to provide a granular material forming method for manufacturing a granular material molded body having a different bulk density depending on a specified part of the molded body in a small number of steps, and a granular material forming apparatus used for the method. It is.

  The gist of the present invention is a granule molding method comprising a filling step of filling a powder container with a powder body to form a filler, and a solidifying step of solidifying the filler, wherein the mold container Is composed of a non-breathable non-breathable wall portion and a breathable wall portion that does not pass through the granular material and has air permeability, and in the filling step, the granular material is fed into the mold container by air blowing It is that it is the granular material shaping | molding method characterized by this.

In the powder molding method, the powder can include rice husks having polyvinyl alcohol attached to the particle surface,
In the solidification step,
Water or water vapor is introduced into the mold container to make polyvinyl alcohol adhering to the rice husks into an aqueous solution to treat the filler, and the treated filler can be dried.

In the method for forming a granular material, the polyvinyl alcohol that has been made into an aqueous solution can be gelled before the treated filler is dried.

Further, the gist of the present invention is a mold container composed of a non-breathable non-breathable wall portion and a breathable wall portion that does not pass through a granular material and has breathability,
An air feeding means for feeding powder particles into the mold container by air feeding;
The present invention resides in a granular material forming apparatus provided with solidifying means for solidifying a filling material composed of the granular material fed into the mold container.

In the powder and particle molding apparatus, the mold container may be composed of a container having an opening and a lid that covers the opening, and the gap between the periphery of the lid and the opening edge of the container A gap having a size that does not allow passage of powder particles can be formed, and the vicinity of the gap can constitute the breathable wall portion.

In the powder body forming apparatus, the solidifying means may include a fluid introducing means for introducing a fluid into the mold container and a storage container for housing the mold container.

Furthermore, the gist of the present invention resides in a rice husk molded body obtained by the above-mentioned powder body molding method.

  Furthermore, the gist of the present invention resides in an automobile member made of the rice husk molded body.

  ADVANTAGE OF THE INVENTION According to this invention, the granular material shaping | molding method which manufactures the granular material molded object from which bulk density differs with the designated site | part of a molded object in few processes, and the granular material shaping | molding apparatus used for the method are provided.

  The granular material molding method of the present invention is a granular material molding method including a filling step of filling a granular container into a mold container to form a filler, and a solidifying step of solidifying the filler. This type container is constituted by a non-breathable non-breathable wall portion and a breathable wall portion that does not pass through the powder and has air permeability. In the filling step, the granular material is fed into the mold container by air blowing.

An example of the aspect of the granular material forming apparatus used in the present invention will be described. As shown in FIG. 1 (a), the granular material forming apparatus 2 of the present invention has a storage container 8, a fluid introduction means 10 for introducing a fluid into a cavity 9 of the storage container 8, and a breathable wall portion 12. The mold container 14 accommodated in the cavity 9 and the air feeding means 18 for feeding the powder particles 16 into the cavity 9 are provided. The air sending means 18 includes a vacuum duct 34, a vacuum pump 32 that sucks up the powder particles 16 through the vacuum duct 34, and a discharge duct 36 that discharges the sucked up powder particles in an air flow.

  FIG. 2A shows an example of the mode of the mold container 14. In the mold container 14, the upper wall 15 does not pass the granular material and is the air permeable wall portion 12 having air permeability, and is divided into two vertically by the joint portion 21 of the side wall 17. The breathable wall portion 12 is formed by forming a large number of through holes 19 in the wall. The mold container 14 is composed of a breathable wall portion 12 that does not pass through the granular material and has air permeability and a non-breathable non-breathable wall portion 13.

  The storage container 8 includes a storage container body 4 received by the receiving frame 70, a movable lid body 6 that covers the storage container body 4, and a holding member 76 that holds the periphery of the lid body 6 from above. Is done.

  The fluid introduction means 10 includes a fluid inflow pipe 38. When the fluid is liquid, a liquid feed pump (not shown) is installed upstream of the fluid inflow pipe 38. When the fluid is a gas, a gas pressure source is provided upstream of the fluid inflow pipe 38. The fluid inflow pipe 38 is connected to a through hole 80 that penetrates the lid body 6.

  The mold container 14 is accommodated in the cavity 9. In a state where the mold container 14 is stored in the cavity 9, a gap 25 is provided between the upper edge of the storage container body 4 and the tip of the peripheral rib 78 provided at the peripheral edge of the holding member 76. In addition, there is a gap 27 between the air-permeable wall portion 12 and the inner wall of the cavity 9. That is, the storage container 8 has a cavity capable of forming a hole or a gap that conducts to the outside.

  In the center of the lid body 6, an introduction port 30 is provided for feeding the powder particles 16 into the cavity 9, that is, into the mold container 14. The introduction port 30 is connected to the vacuum pump 32 via the discharge duct 36.

  An inlet 28 for feeding the powder particles 16 is formed on the upper wall of the mold container 14. The granular material 16 is fed into the mold container 14 via the inlet 30 and the inlet 28, and then, if necessary, the movable frame 29 is lowered and the lid body 6 is pressed downward via the holding member 76. The powder container 16 fed into the mold container 14 is pressed downward in the mold container 14. Thereby, a filling body is obtained. At the same time, the gap 25 is sealed by this pressing.

  In order for the air sent into the mold container 14 together with the powder particles to escape from the through holes 19, the powder particles are pressed against the wall by the pressure of the air flow inside the breathable wall portion 12, and the breathable wall portion. While the bulk density of the filler at a position near 12 is increased, the air flow is repelled by the wall inside the non-breathable wall 13 and becomes turbulent, so that the granular material is disturbed by the air flow. The bulk density of the filler at that position is reduced. In this way, as shown in FIG. 3A, a filling body 44 is obtained in which the bulk density of the portion 40 corresponding to the position in the vicinity of the breathable wall portion 12 is larger than the bulk density of the other portions 42.

  The air permeability of the air permeable wall portion 12 is adjusted by the number density of the through holes 19 and the size of each hole. As the air permeability increases, the bulk density of the filler at a position near the air permeable wall portion 12 increases.

  The thus obtained filling body becomes the powder body molded body of the present invention by solidifying the particles of the powder body constituting each other.

  Another embodiment of the present invention may be a granular material forming apparatus 2a shown in FIG. The granular material forming apparatus 2a includes a storage container 8a having a cavity 9 capable of forming a hole or a gap that conducts to the outside, a container 17a that is accommodated in the cavity and opened to one side, and a wind that feeds the granular material into the cavity 9. And a sending means 18. FIG. 2B shows an example of the state of the container 17a opened on one side. The storage container 8a includes a container main body 4a for storing the container 17a and a lid body 6a for covering the container main body 4a. The lid body 6a also serves as a lid body 15a that covers the opening of the container 17a. With the container 17a stored in the container body 4a, the lid body 6a covers the opening of the container 17a with a gap 31 formed between the peripheral edge of the lid body 6a and the opening edge of the container 17a. To be arranged. The container 17a and the lid body 6a (lid body 15a) constitute a mold container 14a.

  The space | interval of the clearance gap 31 is adjusted to the size which does not let a granular material pass. The vicinity of the gap 31 constitutes the breathable wall portion 12a.

  In this state, the granular material is fed into the container 17a together with air by the air feeding means 18. Since the air fed into the container 17 a together with the powder particles escapes from the gap 31, the powder particles inside the container 17 a are under the pressure of the air flow, and the inner wall of the container 17 a and the lid body in the vicinity of the gap 31. The bulk density of the filler increases at a position in the vicinity of the opening edge of the container 17a by being pressed against a portion (breathable wall 12a) facing the inside of the container 17a at the peripheral edge of 6a. On the other hand, inside the container 17a excluding this position, the air flow is repelled on the inner wall of the container 17a and becomes a turbulent flow, so that the powder particles are disturbed by the air flow and the bulk density of the filler is reduced. In this way, as shown in FIG. 3B, a filler 44a is obtained in which the bulk density of the portion 40a corresponding to the position near the opening edge of the container 17a is larger than the bulk density of the other portions 42a. When the filler 44a is solidified because the upper edge that goes around the upper side has a bulk density higher than that of the other parts, the filler 44a has a structure that is bulky and strong against external forces, and receives external forces. Even if it becomes a granular material molded object with which an upper edge part does not chip easily.

  As a method of solidifying the filler by bonding the particles constituting the filler to each other, when the powder includes particles composed of at least a thermoplastic resin as constituent particles, the filler is heated to There is a method in which the particle surfaces are melted to fuse the constituent particles of the granular material. Even when the filler is composed of a mixture of particles having at least a surface portion made of a thermoplastic resin and other particles, the particles are heated to melt the surface of the thermoplastic particles so that at least the surface portions are thermoplastic. There is a method of joining through particles made of resin. When a thermosetting adhesive is present on the surface of the particles, there is a method of bonding the particles by heating the filler. The filling body is preferably heated by sending a hot gas such as hot air or water vapor into the inside of the filling body. Alternatively, the filling body may be heated by an oven or induction heating.

  The granular material in the present invention refers to an aggregate of particles having a particle diameter of 1 to 5000 μm. Examples of the granular material used in the present invention include pulverized materials such as wood, paper, cardboard, and straw, cutting waste, sliced materials; okara; coffee and tea extraction residue; fruit cores; cereals; plastic beads; Concrete and rock ground; sand; inorganic hollow bodies such as fly ash balloon, glass balloon, shirasu balloon, pearlite foam; and the like. Two or more of these may be mixed and used. Moreover, the adhesive agent which expresses adhesive force by heating, drying, or time passage may be adhered or coated on the particle surface of these granular materials. Alternatively, particles of an adhesive that develops an adhesive force by heating, drying, or aging may be mixed on the particle surface of these particles.

  When the granular material contains rice husk, the surface of the rice husk particles is coated with polyvinyl alcohol, and the rice husk particles coated with polyvinyl alcohol are used. After the alcohol is dissolved in water, the filler is dried to solidify the filler, thereby obtaining a powder compact. This water is preferably hot water of 50 ° C. or higher.

  As a method for supplying water or water vapor to the inside of the filler, for example, after the filler is formed inside the mold container 14 in the granular material forming apparatus 2, water or water vapor is supplied from the fluid inflow pipe 38 to the cavity 9. The method of supplying is mentioned.

  When the powder includes a rice husk coated with polyvinyl alcohol, before the filler is dried in the above method, gelling the polyvinyl alcohol aqueous solution on the surface of the rice husk is necessary to obtain a high-strength powder molded product. preferable. In some cases, the gelation is performed by cooling the filling body, but the filling body is frozen to form a frozen body and then thawed to obtain a good gelation state. By drying after this gelation, a high-strength powder molded product can be obtained even with a small content of polyvinyl alcohol. Since the functional group of polyvinyl alcohol is directly chemically bonded to silicon in the rice husk, polyvinyl alcohol is preferable as an adhesive for bonding rice husk particles. Furthermore, the adhesive force which joins rice husk | shell_shell particle | grains improves by drying after the above-mentioned freezing and thawing | decompression. Moreover, when the granular material contains crushed rice husk or rice husk charcoal, a high-density and high-strength granular material can be obtained. Furthermore, it is the highest when the granular material contains one or more kinds of fine powders selected from the group of rice husks, colloidal silica, quartz glass powder, and rice husk calcined ash finely pulverized to a particle size of 1 to 100 μm. A strong powder-molded product can be obtained.

  The granular material molded body of the present invention achieves both shock absorption due to plastic deformation and crushing of the low density portion when subjected to external force, and high strength at the high density portion. It is suitably used as a member for a portion that receives an impact. For example, as shown in FIG. 4, it is used for a side collision pad 60 of an automobile. As shown in the sectional view shown by the arrow in FIG. 4, the side impact pad 60 attached to the door 59 has a high density at the armrest portion 62 and a low density at the outer side portion 64 of the upper door for shock absorption. Excellent. At the initial stage of the impact, the upper portion 64 adjacent to the door 59 is first compressed and deformed to absorb the impact, and then the impact is absorbed by the upper deformed portion 64 and the armrest 62. Since the impact is absorbed in two stages as described above, the entire impact pad 60 is excellent in impact absorption.

  Such a molded body may be obtained by joining two types of molded bodies having different bulk densities, but the two types of molded bodies are both porous and have a rough structure compared to a molded body made of a dense substance. And has a low bonding strength. In addition, two types of molded bodies having different bulk densities are manufactured and matched, and an extra effort is required to apply and bond the adhesive to the joint portion. This effort increases as the shape of the molded body becomes more complex.

  In addition, the present invention can be carried out in a mode in which various improvements, modifications, and changes are added based on the knowledge of those skilled in the art without departing from the gist.

It is a cross-sectional schematic diagram which shows an example of the aspect of the granular material shaping | molding apparatus of this invention. It is a cross-sectional schematic diagram which shows another example of the aspect of the granular material shaping | molding apparatus of this invention. It is a perspective view which shows an example of the aspect of the type | mold container used for the granular material shaping | molding apparatus of this invention. It is sectional explanatory drawing which shows an example of the structure of the filler obtained by the granular material shaping | molding apparatus of this invention. It is a perspective schematic diagram which shows the side collision pad obtained by the granular material shaping | molding apparatus of this invention.

Explanation of symbols

2, 2a: Powder body forming apparatus 4: Storage container body 6: Cover body 8: Storage container 9: Cavity 10: Fluid introducing means 12: Breathable wall 13: Non-breathable wall 14, 14a: Mold container 15a: Lid 16: Granule 17a: Container 18: Air sending means 19: Through hole 25: Gap 32: Vacuum pump 36: Discharge duct 38: Fluid inflow pipe 44: Filler 70: Receiving frame 76: Holding member 59 : Door 60: Side impact pad 62: Armrest part 64: Outside part of the door

Claims (8)

A method for forming a granular material, comprising: a filling step of filling a powder container into a mold container to form a filling body; and a solidifying process for solidifying the filling body, wherein the mold container is a non-breathable non-breathable wall And a gas permeable wall part that does not pass through the powder and has air permeability, and the powder is fed into the mold container by air blowing in the filling step Method. The powder includes a rice husk having polyvinyl alcohol attached to the particle surface,
In the said solidification process, water or water vapor | steam is introduce | transduced in the said type | mold container, the polyvinyl alcohol adhering to the rice husk is made into aqueous solution, the said filling body is processed, The said processed filling body is dried. The granular material forming method as described. The granular material forming method according to claim 2, wherein the polyvinyl alcohol that has been made into an aqueous solution is gelled before the treated filler is dried. A mold container composed of a non-breathable non-breathable wall portion and a breathable wall portion that does not pass through the powder and has breathability;
An air feeding means for feeding powder particles into the mold container by air feeding;
A granular material forming apparatus comprising: a solidifying means for solidifying a filling material composed of the granular material that has been fed into the mold container and filled. The mold container includes a container having an opening and a lid that covers the opening, and a gap having a size that does not allow the granular material to pass between a peripheral edge of the lid and an opening edge of the container. The granular material forming apparatus according to claim 4, wherein the apparatus is formed, and the vicinity of the gap constitutes the breathable wall portion. The granular material forming apparatus according to claim 4 or 5, wherein the solidifying means includes a fluid introducing means for introducing a fluid into the mold container and a storage container for housing the mold container. A rice husk molded body obtained by the method for molding a granular material according to claim 2 or 3. The member for motor vehicles which consists of a rice husk molded object of Claim 7.

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