JP2010005922A - Manufacturing process of woody core plastic compact, and manufacturing apparatus of woody core plastic compact - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To eliminate defects that bubbles are produced on the inner surface of a plastic, and to finely coat the surface of a woody core material with the plastic and at the same time, closely and solidly conjoin the plastic to the surface of the woody core material. <P>SOLUTION: The manufacturing process of a woody core plastic compact comprises a step of supplying the woody core material 1 in which a shape of the cross section is the same shape to a molding hole 10 of a die 3 to push out, at the same time, of pushing out the thermoplastic plastic 2 in a melting state by heating on the inner surface of the molding hole 10 of the die 3 to allow it to adhere to the surface of the woody core material 1, and of coating the surface of the woody core material 1 pushed out from the molding hole 10 of the die 3 with the thermoplastic plastic 2. Further, the manufacturing process comprises a step of providing a vacuum degassing chamber 6 vacuum-degassing the surface of the woody core material 1 at an inserting side compared with a molding part 11 attaching the melding plastic 2A to the surface in the inner surface of the molding hole 10 of the die 3, and of adhering the thermoplastic plastic 2 in the melting state at the molding part 11 to the surface of the woody core material 1 in which the surface is vacuum-degassed at the vacuum degassing chamber 6. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method and an apparatus for manufacturing a wood core plastic molded body in which the surface of a wood-based core material made of natural wood such as wood or LVL is covered with plastic.

Techniques have been developed for attaching a plastic film to the surface of a wood-based core material or coating the surface with a heat shrink film. A technique called lapping, in which a plastic film is attached to the surface of a wood-based core material, presses and bonds the plastic film coated with an adhesive to the surface of the wood-based core material. As plastic films used for this purpose, polyvinyl chloride film has been the majority, but in recent years olefin-based plastic films have been used due to dioxin problems during combustion, etc. Many interior materials are used. However, this method has the following disadvantages.
(1) It is difficult to attach to the entire circumference of the wood-based core material.
(2) If the surface of the wood-based core material has defects such as chips, holes, and nodes, the surface covered with the plastic film can be uneven.
(3) Thick coating is difficult and the corners cannot be edges smaller than the radius of curvature at which the plastic film can be bent.
(4) There is a VOC problem due to the solvent of the adhesive that bonds the plastic film.

Moreover, the method of coat | covering the surface of a wood type core material with a heat-shrink film inserts a wood type core material in the heat-shrink film currently shape | molded in the cylinder shape, and shrinks a heat-shrink film. In this method, the heat shrink film is generally shrunk by heating with hot air or the like. However, this method has the following drawbacks.
(1) If the surface of the wood-based core material has defects such as chips, holes, and nodes, the surface can be uneven.
(2) Thick coating is difficult, and the corner cannot be processed into an edge smaller than the radius of curvature for bending the heat shrink film.
(3) If there is a groove-shaped corner on the surface of the wood-based core material, the heat shrink film cannot be attached to the inner surface of the corner, and the corner becomes a cavity.

By the way, the surface of the wood-based core material is not covered with plastic, but the surface of wood powder plastic formed by mixing wood powder to 50% by weight or more is formed with wood powder plastic with a low mixing ratio of wood powder. A method for improving the surface performance has also been developed. (See Patent Documents 1 and 2)
In these methods, in order to improve the weather resistance of a plastic molded with a large amount of wood flour, the surface is molded with a plastic of low wood flour. The largest cause of the low weather resistance of high wood powder plastic containing a large amount of wood flour is that the interface with the plastic and the plastic as a binder are destroyed by expansion and contraction due to water absorption and drying of wood flour. This is fatal in the Japanese climate where the difference between temperature and temperature is high and humid, and in order to improve this problem, a plastic mixed material with a low wood powder ratio is used for the skin. The main reason for not reducing the wood flour ratio to the center is that it is classified as wood by mixing wood flour with a weight ratio of 50% or more. However, increasing the amount of plastic reduces rigidity and increases creep. The reason is also great.

  Moreover, when the whole molded object is comprised with a wood powder plastic, there also exists a fault which specific gravity will become large. This is because the true specific gravity of wood powder pulverized in powder form is as high as about 1.5, so even if it is classified into wood while mixed with plastic, it does not float on water. As a countermeasure, hollow molding is generally applied to reduce the apparent specific gravity. Further, the strength of the molded body depends on the strength of the plastic and the adhesion to the wood powder, and the strength per weight is inferior to that of the wood material.

  On the other hand, it is a well-known fact that a wood material made of natural wood has a fine and complex cell structure and is used for various applications including building materials with a light weight and high rigidity. However, wood is a natural material and can only be used for a long time in an ideal environment in a dry state. In particular, material deterioration such as deterioration due to water absorption / drying, UV deterioration, mold, corrosion, and corrosion damage is a major problem when used for a long period of time. There is.

  In general, painting is performed to protect the surface of natural wood, but liquid paints are likely to soak into woody materials and cause dents when cured. In order to prevent this, a process called sealing is carried out, but even if it is possible to improve fine pores on a smooth and even surface, it is like a lightweight early life tree or a medium to low quality engineering wood. Those with poor surface quality are difficult.

  On the other hand, a wide variety of thermoplastic plastics are used by optimizing the types, grades, and blending of resins according to various applications including home appliances and automobiles. However, linear expansion due to temperature changes is generally large, especially in building materials where there are many long objects and board materials, they are used only for special applications such as foam insulation, and when considering replacement of wood In addition to thermal expansion, there are problems such as specific gravity, warping and bending due to creep phenomenon, and its usage is limited.

The above drawbacks can be improved by covering the surface of a wood-based core material made of natural wood with a molded thermoplastic plastic. (See Patent Documents 3 and 4)
The methods described in these publications realize a wood core plastic molded body that covers the size and shape instability and insufficient strength of the wood core material by covering the surface of the wood core material with plastic. It is. In addition, by recycling natural wood waste as a raw material as a wood-based core material, there is also a recycling effect. In addition, it solves the problems of insufficient strength of natural wood and ease of soiling, and has the advantage of realizing VOC-free wood without using paint or adhesive.
Japanese Patent Laid-Open No. 51-67379 JP 2002-338699 A JP 2001-287207 A JP 2003-19703 A

  Patent Document 3 describes a method of forming a coating layer made of an olefin-based synthetic resin having a coating thickness of 3 to 15 mm on the surface of a core material made of thinned wood, and applying a bark-like pattern to the coating layer. ing. The method of extruding wood together with plastic from the molding hole of the mold and covering the surface of the wood with plastic is that the heated and melted plastic heats the wood and expands the air and moisture contained in the wood . The expanded air and moisture move between the plastic covering the surface and generate bubbles. For this reason, bubbles are formed on the inner surface of the plastic covering the wood, and the wood surface cannot be covered cleanly.

  In order to solve this problem, as described in Patent Document 4, in the pre-process of coating with resin, wood is forcibly dried in hot air or a drying furnace, or the surface of the wood is exposed to a flame such as a burner. For example, there is a method of temporarily evaporating moisture from the surface. However, this method has the disadvantages of adding an extra step which is time consuming and consuming a large amount of energy for drying the wood. In addition, this method has the disadvantages that cracks occur in the wood, reducing the strength of the wood and deteriorating the appearance. Further, the method of rubbed the surface with a flame has a drawback that the degree of drying of the wood in each place is likely to vary, and a portion where the drying is insufficient remains.

  In order to avoid this adverse effect, the method of Patent Document 2 covers the surface of wood with a film and the surface of the film with plastic. This method is a film that covers the surface of a wood-based core material, and prevents moisture in the wood from evaporating during extrusion molding. That is, with the film, moisture to be evaporated from the wood is sealed inside the film to prevent bubbles from being generated between the wood and the coating resin.

  This method has a disadvantage that it is necessary to cover the surface of the wood with a film in order to avoid the harmful effects of moisture, and this process is extremely laborious. In addition, since the film is used, there is a disadvantage that the material cost increases. Further, this method has a drawback that the bonding between the plastic and the wood becomes extremely weak because a film is interposed between the plastic covering the surface of the wood and the wood. This disadvantage has the disadvantage that the wood and the plastic move relative to each other so that the wood protrudes from the plastic to the outside at the end, or the plastic protrudes from the wood on the contrary. Furthermore, since the plastic and the wood are not bonded, there is also a drawback that the strength of the plastic is lowered and easily damaged. In addition, the biggest disadvantage of this method is that the surface of the wood is covered with a thin plastic film, so that when heated and molten plastic contacts the surface and vaporizes and expands from the surface of the wood, it is pushed up to the expanded water. And bubbles are generated. For this reason, the film has a drawback that the generation of bubbles cannot be reliably prevented.

  The present inventor has developed a method of applying a sealer having excellent permeability to the surface of wood in order to eliminate the drawbacks of the film. In this method, the surface of the wood is covered with a sealer instead of the film, the wood covered with the sealer is extruded from a mold, and the heated plastic is attached to the surface. Sealer is a highly penetrating paint that improves adhesion to the wood surface compared to film. However, the surface treatment with a sealer cannot provide a sufficient effect when the sealer is made into a thin film, and it takes a long time to dry and cure the sealer with a thick film. In addition, there is a problem that the sealer-treated surface becomes smooth and the adhesive strength of the plastic cannot be increased.

  Furthermore, although the surface treatment with a sealer can suppress the generation of bubbles as compared with a film, it cannot reliably prevent the generation of bubbles in all wood. Wood has a high density of winter eyes and low density summer eyes alternately to form a wood grain, and there are also high density nodes. That is, since the density is in a non-uniform state, the whole cannot be dried uniformly. Also, the state in which moisture is transferred to the surface by heating is not uniform. When the plastic melted by heating is brought into close contact with the uneven surface of wood, a large amount of water is concentrated locally and transferred to the surface, and this water is heated by the molten plastic and vaporized and expanded. To generate bubbles on the inner surface of the plastic. For this reason, bubbles are generated in a concentrated manner along the grain. Although this harmful effect can be prevented by completely drying the wood, it is very impractical to complete the drying of the wood because it takes time and money.

The present invention has been developed for the purpose of solving this drawback. An important object of the present invention is to eliminate the adverse effects caused by moisture contained in the wood-based core material without using a film, that is, the defect that bubbles are formed on the inner surface of the plastic, and the surface of the wood-based core material is made of plastic. An object of the present invention is to provide a manufacturing method and a manufacturing apparatus for a wood core plastic molded body that can be neatly covered.
Another important object of the present invention is to provide a manufacturing method and manufacturing apparatus for a wood core plastic molded body capable of firmly and firmly bonding plastic to the surface of a wood-based core material.
Furthermore, another important object of the present invention is to provide a manufacturing method and manufacturing apparatus for a wood core plastic molded body that can easily and easily prevent bubbles from being generated on the inner surface of the plastic with less energy. It is in.

  The method for producing a wood core plastic molded body of the present invention supplies the wood core material 1 whose cross-sectional shape is processed into the same shape to the insertion side of the molding hole 10 of the mold 3 and extrudes it from the discharge side, The thermoplastic plastic 2 that has been heated and melted is extruded onto the inner surface of the molding hole 10 of the mold 3, adhered to the surface of the wood core 1, and extruded from the molding hole 10 of the mold 3. The surface of the wood-based core material 1 is covered with a thermoplastic plastic 2. Further, in this manufacturing method, a vacuum is used for vacuum degassing the surface of the wood-based core material 1 on the inner side of the molding hole 10 of the mold 3 and on the insertion side of the molding part 11 that adheres the molten plastic 2A to the surface. A deaeration chamber 6 is provided, and a thermoplastic thermoplastic material 2 in a molten state is adhered to the surface of the wood-based core material 1 whose surface has been vacuum deaerated in the vacuum deaeration chamber 6.

  The method for producing a wood core plastic molded body according to claim 2 of the present invention heats the vacuum deaeration chamber 6 with the mold 3, and vacuums the surface of the woody core material 1 with the heated vacuum deaeration chamber 6. Deaerate.

  According to a third aspect of the present invention, there is provided a method for producing a wood core plastic molded body, wherein the mold 3 is in close contact with the inner surface of the molding hole 10 closer to the insertion side than the vacuum deaeration chamber 6 and the outer surface of the wood-based core material 1. An airtight ring portion 8 is provided for hermetically sealing between the inner surface of the molding hole 10 and the surface of the wood-based core material 1. The airtight ring portion 8 hermetically seals the insertion side of the vacuum deaeration chamber 6. The molten plastic 2A supplied to the forming hole 10 hermetically seals the discharge side of the vacuum deaeration chamber 6 and vacuum deaerates the surface of the wood-based core material 1.

  According to a fourth aspect of the present invention, there is provided a method for producing a wood core plastic molded body, wherein the airtight ring portion 8 of the mold 3 is used as the protrusion 12 protruding from the inner surface of the molding hole 10. Is tightly adhered to the surface of the wooden core 1, the insertion side of the vacuum degassing chamber 6 is hermetically sealed, and the surface of the wooden core 1 is vacuum degassed in the vacuum degassing chamber 6.

  According to a fifth aspect of the present invention, there is provided a method for producing a wood core plastic molded body, wherein the airtight ring portion 8 of the mold 3 is used as the packing 14 provided on the inner surface of the molding hole 10. In close contact with the surface of the wooden core 1, the insertion side of the vacuum degassing chamber 6 is hermetically sealed, and the surface of the wooden core 1 is vacuum degassed in the vacuum degassing chamber 6.

  An apparatus for manufacturing a wood core plastic molded body of the present invention includes a mold 3 having a molding hole 10 for extruding a wood core material 1 whose cross-sectional shape is processed into the same shape, and a molding hole 10 of the mold 3. Extrusion mechanism 4 for extruding the wooden core 1 for extruding the wooden core 1 and a plastic extrusion mechanism for extruding the thermoplastic plastic 2 that has been heated and melted into the inner surface of the molding hole 10 of the mold 3 5. In the manufacturing apparatus, the extrusion mechanism 4 extrudes the wood-based core material 1 from the molding hole 10 of the mold 3, and the heating extrusion mechanism 5 extrudes the molten thermoplastic plastic 2 to the inner surface of the molding hole 10. The surface of the wood-based core material 1 extruded from the 3 molding holes 10 is covered with a thermoplastic plastic 2. The mold 3 includes a vacuum deaeration chamber 6 between the inner surface of the molding hole 10 and the surface of the wood-based core material 1. The manufacturing apparatus connects a vacuum device 7 to the vacuum deaeration chamber 6, and the vacuum device 7 exhausts the air in the vacuum deaeration chamber 6 to vacuum deaerate the surface of the wood-based core material 1. A molten thermoplastic plastic 2 is adhered to the surface of the wood-based core material 1 thus formed.

  According to a seventh aspect of the present invention, there is provided an apparatus for producing a wood core plastic molded body, wherein the mold 3 is in close contact with the inner surface of the molding hole 10 closer to the insertion side than the vacuum deaeration chamber 6 and the outer surface of the wood-based core material 1. Thus, an airtight ring portion 8 that hermetically seals between the inner surface of the molding hole 10 and the surface of the woody core 1 is provided. In this manufacturing apparatus, the hermetic ring portion 8 hermetically seals the insertion side of the vacuum degassing chamber 6, and the molten plastic 2A supplied to the molding hole 10 hermetically seals the discharge side of the vacuum degassing chamber 6. The surface of the wood core 1 is vacuum degassed.

  According to the eighth aspect of the present invention, there is provided an apparatus for producing a wood core plastic molded body, wherein the hermetic ring portion 8 of the mold 3 is used as the projecting portion 12 projecting from the inner surface of the molding hole 10. Is tightly adhered to the surface of the wooden core 1, the insertion side of the vacuum degassing chamber 6 is hermetically sealed, and the surface of the wooden core 1 is vacuum degassed in the vacuum degassing chamber 6.

  According to a ninth aspect of the present invention, there is provided a manufacturing apparatus for a wood core plastic molded body, wherein the airtight ring portion 8 of the mold 3 is used as the packing 14 provided on the inner surface of the molding hole 10. The insertion side of the vacuum degassing chamber 6 is hermetically sealed in close contact with the surface of the wooden core material 1, and the surface of the wooden core material 1 is vacuum degassed in the vacuum degassing chamber 6.

  The present invention has an advantage that the surface of the wood-based core material can be neatly covered with the plastic by eliminating the harmful effect of moisture contained in the wood-based core material, that is, the defect that bubbles are formed on the inner surface of the plastic. This is because the present invention vacuum deaerates the surface of the wood-based core material and coats it with a thermoplastic material in a heated and melted state. In the present invention, the surface of the wood-based core material is vacuum degassed to remove moisture and air from the surface of the wood-based core material, so that it is coated with heated molten plastic. It is possible to reliably prevent the air on the surface of the wood-based core material from expanding due to the heat of the plastic, and the formation of bubbles due to evaporation of water on the surface. In particular, the method of the present invention exhausts the air in the vacuum deaeration chamber to vacuum deaerate the surface of the wood-based core material, so that the surface can be vacuum deaerated efficiently and in a short time with less energy. it can. Therefore, without deteriorating the surface condition of the wood core material, it is possible to reliably prevent bubbles from forming on the plastic inner surface covering the surface of the wood core material, and to clean the surface of the wood core material with plastic. It can be covered neatly.

  Further, the present invention vacuum deaerates the wooden core material and coats the surface with the molten plastic, so that the molten plastic penetrates into the fine irregularities on the surface of the wooden core material, and the thermoplastic plastic is It is possible to cover the core material firmly and firmly on the surface so as not to peel off.

  In addition, since the method of the present invention does not use a film, the labor involved in manufacturing can be omitted compared with the conventional method of coating with a film, and the material cost can be reduced. It is possible to realize the advantage that the surface can be covered cleanly by firmly and firmly bonding.

  The method for producing a wood core plastic molding of claim 2 of the present invention heats the vacuum deaeration chamber with a mold, and vacuum deaerates the surface of the wood core material with the heated vacuum deaeration chamber. While heating the surface of the wood-based core material in the vacuum degassing chamber, it can be efficiently vacuum degassed, and moisture can be removed. It heats the surface of the wood-based core material to expand the air, lowers the relative humidity to make it easier to vaporize water, and further reduces the boiling point of water by a vacuum degassing chamber, This is because moisture is easily vaporized. In particular, the structure in which the vacuum deaeration chamber is provided in a mold heated by molten plastic does not heat the vacuum deaeration chamber with a dedicated heating mechanism, and the surface of the wood-based core material is heated in the heated vacuum deaeration chamber. Heat and remove air and moisture more efficiently.

  The manufacturing method of claim 3 and the manufacturing apparatus of claim 7 of the present invention are such that the mold is in close contact with the inner surface on the insertion side of the vacuum deaeration chamber of the molding hole and the outer surface of the wood-based core material. Is provided with an airtight ring portion that hermetically seals between the inner surface of the wood and the surface of the wood-based core material, and the airtight ring portion hermetically seals the insertion side of the vacuum degassing chamber and is supplied to the forming hole. Since the molten plastic hermetically seals the discharge side of the vacuum deaeration chamber and vacuum deaerates the surface of the wooden core material, the inner surface of the molding hole is brought into close contact with the surface of the wooden core material, The insertion side of the vacuum deaeration chamber can be hermetically sealed while hermetically sealing the insertion side and inserting the wood core material into the forming hole.

  The manufacturing method according to claim 4 and the manufacturing apparatus according to claim 8 of the present invention are such that the airtight ring portion of the mold is a projecting portion projecting from the inner surface of the molding hole, and the airtight ring portion comprising the projecting portion is a wood-based core material. Adhering to the surface of the wood core, the insertion side of the vacuum deaeration chamber is hermetically sealed, and the surface of the wooden core material is vacuum degassed in the vacuum deaeration chamber, so the protrusions adhere to the surface of the wooden core material Thus, the insertion side of the vacuum degassing chamber can be surely hermetically sealed, and the wood-based core material can be efficiently vacuum degassed.

  The manufacturing method according to claim 5 and the manufacturing apparatus according to claim 9 of the present invention are such that the airtight ring portion of the mold is a packing provided on the inner surface of the molding hole, and the airtight ring portion made of this packing is made of a wood-based core material. Adhering to the surface, the insertion side of the vacuum deaeration chamber is hermetically sealed, and the surface of the wooden core is vacuum degassed in the vacuum deaeration chamber, so the packing is in close contact with the surface of the wooden core In addition, the insertion side of the vacuum degassing chamber can be surely hermetically sealed to efficiently degas the wooden core material.

  Embodiments of the present invention will be described below with reference to the drawings. However, the examples shown below illustrate a manufacturing method and manufacturing apparatus of a wood core plastic molded body for embodying the technical idea of the present invention, and the present invention is a manufacturing method of a wood core plastic molded body. The manufacturing apparatus is not specified as the following method and apparatus.

  Further, in this specification, in order to facilitate understanding of the scope of claims, numbers corresponding to the members shown in the examples are indicated in the “claims” and “means for solving problems” sections. It is added to the members. However, the members shown in the claims are not limited to the members in the embodiments.

  The method and apparatus for producing a wood core plastic molded body of the present invention supplies a wood-based core material whose cross-sectional shape is processed into the same shape to the insertion side of the molding hole of the mold and extrudes it from the discharge side. At the same time, the thermoplastic core that is heated and melted is extruded onto the inner surface of the molding hole of the mold and adhered to the surface of the wooden core material, and the wooden core is extruded from the molding hole of the mold. The surface of the material is coated with a thermoplastic plastic. Furthermore, the manufacturing method and the manufacturing apparatus of the present invention are vacuum degassing for vacuum degassing the surface of the wood-based core material closer to the insertion side than the portion where the molten plastic adheres to the surface, which is the inner surface of the mold hole. An air chamber is provided, and a thermoplastic thermoplastic material in a molten state is attached to the surface of the wood-based core material whose surface is vacuum degassed in the vacuum deaeration chamber.

  FIG. 1 is a schematic plan view showing a manufacturing apparatus used in a method for manufacturing a wood core plastic molded body according to an embodiment of the present invention. A schematic cross-sectional view of the mold 3 of this manufacturing apparatus is shown in FIG. The manufacturing apparatus shown in these drawings extrudes the wood core material 1 together with the plastic 2 from the molding hole 10 of the mold 3 for extruding the plastic 2 so that the surface of the wood core material 1 is thermoplastic plastic. Cover with 2. The manufacturing apparatus shown in the figure includes a mold 3 for covering the surface of a wooden core 1 with a plastic 2, an extrusion mechanism 4 for extruding the wooden core 1 from a molding hole 10 of the mold 3, A vacuum heating apparatus connected to a vacuum deaeration chamber 6 provided in the mold 3 and a plastic heating / extruding mechanism 5 for extruding the molten molten plastic 2A which has been heated and melted to the inner surface of the molding hole 10. 7. In this manufacturing apparatus, the air in the vacuum deaeration chamber 6 is exhausted by the vacuum device 7 to vacuum deaerate the surface of the wood core material 1, and the surface of the wood core material 1 that has been vacuum degassed is in a molten state. Adhere thermoplastic plastic.

  1 and 2 is a wood-based core material 1 whose surface is covered with plastic 2. In addition to solid wood, various kinds of engineering wood such as laminated wood, plywood, LVL, particle board, MDF, OSB, PSL, etc. can do. As the wood, natural wood or waste materials generated in the manufacturing process such as plywood can be used. The wood-based core material 1 is processed into a vertically long shape having the same cross-sectional shape, and the coated surface 1a covered with the plastic 2 is processed into a flat shape, or a curved surface curved with a predetermined radius of curvature. To be processed. The wood-based core material 1 can be cut into a smooth surface by cutting the covering surface 1a, but can also be cut into a flat shape by cutting, for example, with a saw without cutting.

  The wood-based core material 1 is processed into a shape optimal for the application. The wood core plastic molded body manufactured by coating the surface of the wood-based core material 1 with the thermoplastic plastic 2 is currently used for building materials such as interior materials, exterior materials, exterior materials, and civil engineering materials. For example, a wood-based core material used for a concrete formwork is processed into a flat shape, and a wood-based core material used for a chamfering material for a concrete formwork is The cross-sectional shape is a right triangle. Further, the wood-based core material used for the blind is processed into a thin plate shape, and further, the wood-based core material used for the interior and exterior materials is processed into various shapes such as a plate shape.

  A mold 3 for covering the surface of the wood-based core material 1 with a plastic 2 is connected to a plastic heating extrusion mechanism 5 for supplying a molten plastic 2A that has been heated and melted. The heating extrusion mechanism 5 heats the thermoplastic plastic 2 to be in a molten state, and supplies the molten plastic 2A in a molten state to the molding hole 10 of the mold 3 in a pressurized state.

  The thermoplastic plastic 2 includes PP, HDPE, LDPE, LLDPE, EVA, EEA, EMMA, EVOH, PVC, VDC, ABS, AS, PS, GPPS, HIPS, PMMA, MS, SBR, PC, PET, PA, POM, PPE, PPS, PBT, etc. can be used singly or as a mixture of plural kinds. In addition, as the thermoplastic plastic, various TPE (thermoplastic elastomer) and biomass-derived plastics such as polylactic acid can also be used. Therefore, the present invention does not limit the types and blends of plastics used as thermoplastic plastics.

  The mold 3 is provided with a molding hole 10 for transferring the wood core material 1 so as to penetrate the mold 3. The molding hole 10 is provided with a molding part 11 on the discharge side for adhering and covering the molten plastic 2A on the surface of the wooden core material 1, and the surface of the wooden core material 1 is closer to the insertion side than the molding part 11 is. A vacuum degassing chamber 6 is provided for vacuum degassing. The wood-based core material 1 passing through the molding hole 10 is vacuum deaerated on the surface in the vacuum deaeration chamber 6, and then the molten thermoplastic 2 is attached to the molding unit 11 to cover the surface.

  The molding part 11 provided on the discharge side of the molding hole 10 has an inner shape larger than the outer shape of the woody core material 1. FIG. 3 is a cross-sectional view showing the relative positions of the molding part 11 of the mold 3 and the wood-based core material 1. As shown in this figure, the plastic 2 is pushed out into the gap (d) between the inner surface of the molded part 11 and the outer surface of the wooden core 1, and the surface of the wooden core 1 is covered with the plastic 2. The gap (d) specifies the thickness of the plastic 2 that covers the surface of the woody core material 1. Accordingly, the gap (d) can be widened to increase the thickness of the plastic 2 that covers the surface of the woody core 1, and conversely, it can be decreased to decrease the thickness of the plastic 2. The thickness of the plastic 2 that covers the surface of the woody core 1 can be 0.1 to 10 mm, preferably 0.5 to 3 mm. Accordingly, the gap (d) between the inner surface of the molded part 11 and the outer surface of the wood-based core material 1 is designed so as to be optimally spaced in consideration of the thickness of the plastic 2. As shown in FIG. 3, the wood-based core material 1 is covered with a plastic 2 on the entire circumference. The wood core material 1 whose entire circumference is covered with the plastic 2 prevents the wood core material 1 from being dried and absorbed by the surface plastic 2, thereby preventing shrinkage and distortion. The wood-based core material does not need to be coated with the same thickness of plastic. For example, indoor and outdoor flooring can be made thicker than the lower surface plastic to improve durability and wear resistance.

  The vacuum deaeration chamber 6 is sealed with a molten plastic 2 </ b> A that covers the surface of the wooden core 1 and the wooden core 1 inserted into the molding hole 10. In order to seal the insertion side of the vacuum deaeration chamber 6, the molding hole 10 is in close contact with the inner surface of the insertion side of the vacuum deaeration chamber 6 and the outer surface of the wooden core 1, and the inner surface of the molding hole 10. And an airtight ring portion 8 that hermetically seals between the surface of the wood-based core material 1.

  The mold 3 shown in FIG. 4 is provided with a projecting portion 12 projecting to the inner surface on the insertion side of the molding hole 10, and the projecting portion 12 serves as an airtight ring portion 8. The protruding portion 12 is an inclined surface 13 that is inclined in the direction of decreasing the inner shape toward the insertion direction of the woody core material 1. The protrusion 12 can smoothly insert the wood core material 1. The airtight ring portion 8 including the projecting portion 12 has its inner surface in close contact with the surface of the woody core 1 and hermetically seals the insertion side of the vacuum deaeration chamber 6. The hermetic ring portion 8 formed of the protruding portion 12 has an inner shape smaller than the outer shape of the wooden core material 1. For example, the inner shape in which the protruding portion 12 is press-fitted into the surface of the wooden core material 1 by 0.1 mm to 5 mm. As a result, the insertion side of the vacuum deaeration chamber 6 can be sealed more reliably. This is because the insertion side of the vacuum deaeration chamber 6 is sealed while the protrusion 12 is pushed into the surface of the woody core 1. However, if the depth by which the protruding portion is pushed into the surface of the wooden core material is increased, the frictional resistance between the wooden core material and the protruding portion increases, and the wooden core material cannot be smoothly inserted into the molding hole. Therefore, the inner shape of the projecting portion is such that the insertion side of the vacuum deaeration chamber can be sealed and the wood-based core material can be smoothly inserted into the molding hole. Even if the protruding portion is pushed into the surface of the wooden core, the frictional resistance between the protruding portion and the wooden core varies depending on the hardness of the wooden core. A hard wooden core material has a high frictional resistance, and a soft wooden core material is easily deformed. Therefore, the pressure with which the protruding portion presses the surface of the wooden core material decreases, and the frictional resistance decreases. Therefore, the depth at which the protruding portion is pushed into the surface of the wooden core material is set to an optimum value depending on the type of the wooden core material, the hard wooden core material is shallow, and the flexible wooden core material is deepened.

  In the mold 3 of FIG. 5, a packing 14 such as an O-ring is provided on the inner surface of the molding hole 10 on the insertion side from the vacuum deaeration chamber 6, and this packing 14 is used as an airtight ring portion 8. The hermetic ring portion 8 made of the packing 14 is in close contact with the surface of the woody core 1 and hermetically seals the insertion side of the vacuum degassing chamber 6. The inner shape of the packing 14 is smaller than the outer shape of the wood-based core material 1 and elastically deforms to hermetically seal the insertion side of the vacuum deaeration chamber 6. With this structure, the packing 14 can be elastically deformed and adhered to the surface of the wooden core 1 regardless of the hardness of the wooden core 1.

  Further, the mold 3 is provided with a partition wall 15 that prevents the molten plastic 2 </ b> A from flowing into the vacuum degassing chamber 6 between the vacuum degassing chamber 6 and the molding portion 11. The partition wall 15 has an inner shape equal to the outer shape of the wooden core material 1 or smaller than the outer shape of the wooden core material 1, and has an inner surface in close contact with the wooden core material 1. The molding hole 10 can hermetically seal the discharge side of the vacuum deaeration chamber 6 with a partition wall 15. The mold 3 can securely and hermetically seal the discharge side of the vacuum deaeration chamber 6 with both the partition wall 15 and the molten plastic 2A. Since this mold 3 seals the discharge side of the vacuum deaeration chamber 6 with the molten plastic 2A in addition to the partition wall 15, it is not necessary to completely seal the discharge side of the vacuum deaeration chamber 6 with the partition wall 15.

  Further, the partition wall 15 for bringing the inner surface into close contact with the outer surface of the wooden core material 1 places the wooden core material 1 in a fixed position and pushes it out to the molding part 11. If the relative position of the molding part 11 and the wood core material 1 is shifted, the film thickness of the plastic 2 provided on the surface of the wood core material 1 changes. In order to coat the surface of the wood core 1 with the plastic 2 having a predetermined film thickness, it is important that the wood core 1 is extruded at a fixed position of the molding part 11. The partition wall 15 is configured such that the wood-based core material 1 is disposed at a fixed position of the molding part 11 and is inserted into the fixed position of the molding part 11. The wood-based core material 1 is pushed out from the molding part 11 while sliding on the inner surface of the partition wall 15.

  The vacuum deaeration chamber 6 is connected to a vacuum device 7. The vacuum device 7 is a vacuum pump that depressurizes the vacuum deaeration chamber 6 and vacuum deaerates the surface of the wooden core 1. The vacuum device 7 reduces the vacuum deaeration chamber 6 to 50 Torr, for example. The degree of vacuum of the vacuum deaeration chamber 6 evacuated by the vacuum device 7 can be increased so that the surface of the wood-based core material 1 can be vacuum deaerated more reliably. However, when the degree of vacuum in the vacuum deaeration chamber 6 is increased, the power consumption of the vacuum device 7 is increased and the running cost is increased. This is because it is necessary to increase the capacity of the vacuum pump and the motor that drives the vacuum pump. The reason why the surface of the wood core 1 is vacuum degassed in the vacuum deaeration chamber 6 is that the molten plastic 2A covering the surface heats the wood core 1 and the contained moisture and air expand to expand locally. This is to prevent this. The extent to which the molten plastic 2A swells varies depending on the type of the wood core 1, and the wood core of natural cedar has a low density and easily contains moisture and air, and local swelling of the molten plastic tends to occur. Thus, in the wood type core material in which local swelling is likely to occur, the degree of vacuum of the vacuum deaeration chamber is increased, and the surface of the wood type core material is more completely vacuum degassed. Therefore, the degree of vacuum in the vacuum deaeration chamber 6 is controlled to an optimum value within a range of 5 to 100 torr, for example, in consideration of the degree of vacuum deaeration and power consumption required for the wood-based core material 1. .

  The extrusion mechanism 4 supplies the wooden core material 1 to the molding hole 10 of the mold 3. The extrusion mechanism 4 in FIGS. 1 and 2 includes a transfer roll 16 that extrudes and transfers the surface of the woody core material 1. The transfer roll 16 is rotated in the transfer direction of the woody core 1 by a rotating mechanism (not shown) such as a motor. The extruding mechanism 4 shown in the figure transfers the wooden core material 1 by pressing with a pair of transfer rolls 16 sandwiching the opposing surface of the wooden core material 1. Further, in the manufacturing apparatus shown in FIG. 1, on the discharge side of the mold 3, a drawer mechanism 9 that pulls out the wood core plastic molded body discharged from the mold 3 from the mold 3 is disposed. The drawing mechanism 9 in FIG. 1 includes a transfer roll 17 that transfers while pressing the surface of the wood core plastic molded body. The drawing mechanism 9 is also pressed by a pair of transfer rolls 17 so as to sandwich the opposing surface of the wood core plastic molded body, and the wood core plastic molded body is pulled out from the mold 3. The drawer mechanism 9 can reliably pull out the end of the wood core material 1 supplied to the mold 3 from the mold 3 and discharge the wood core plastic molded body.

  The wood-based core material 1 transferred by the extrusion mechanism 4 passes through the vacuum deaeration chamber 6 and is supplied to the molding unit 11. The vacuum deaeration chamber 6 evacuates the surface of the wooden core 1. The illustrated mold 3 is provided with a vacuum deaeration chamber 6 and a molding portion 11 on the inner surface of the molding hole 10. The plastic 2 press-fitted into the molding part 11 is heated and in a molten state. Therefore, the molten plastic 2A heats the mold 3. The mold 3 heated by the molten plastic 2A heats the inner surface of the vacuum deaeration chamber 6. The heated vacuum deaeration chamber 6 heats the surface of the wood-based core material 1 by heat conduction by bringing the airtight ring portion 8 formed of the protruding portion 12 on the insertion side into contact with the wood-based core material 1. In particular, the protruding portion 12 of the airtight ring portion 8 is strongly pressed against the wooden core material 1 in order to hermetically seal the gap with the wooden core material 1, so that the wooden core material 1 from the protruding portion 12. The surface of the wood-based core material 1 is heated by conducting heat efficiently. Further, the heated vacuum deaeration chamber 6 irradiates the surface of the wooden core 1 with infrared rays radiated from the inner surface of the mold 3 and heats the surface of the wooden core 1 with radiant heat.

  The air in the surface layer portion 1 b of the wood core 1 heated in the vacuum deaeration chamber 6 expands and is efficiently exhausted by the vacuum device 7. Furthermore, the surface layer portion 1b of the woody core material 1 reduces the relative humidity by heating to facilitate vaporization of moisture. Since the amount of water that can be contained in air increases as the temperature rises, the relative humidity decreases as the temperature increases, and the moisture tends to vaporize as the relative humidity decreases. The vaporized water is degassed from the surface of the woody core 1 and exhausted by the vacuum device 7. Further, the reduced vacuum degassing chamber 6 lowers the boiling point of moisture contained in the surface layer portion 1b of the woody core 1, and is further heated in the vacuum degassing chamber 6 to thereby cause moisture in the surface layer portion 1b. Evaporates easily and is efficiently exhausted.

  The wood-based core material 1 in which the moisture and air in the surface layer portion 1b are vacuum-degassed in the vacuum degassing chamber 6 is expanded when air is covered with the molten plastic 2A, and when the moisture evaporates and expands, Is prevented from occurring. Furthermore, the wood-based core material 1 that has been vacuum degassed in the vacuum degassing chamber 6 has a reduced pressure in the space of the surface layer portion 1 b while passing through the molding portion 11. This wood-based core material 1 is transferred to the molding part 11 and, as shown in FIG. 6, the molten plastic 2A in contact with the surface is sucked into the voids 18 in the surface layer part 1b to enter the fine irregularities on the surface. For this reason, the wood-based core material 1 extruded from the molding part 11 is such that the plastic 2 is sucked into the fine irregularities on the surface and the wood-based core material 1 and the plastic 2 are not peeled off by the throwing effect of the plastic 2. Bonded firmly. In particular, the wood-based core material, which is natural wood, has an excellent deaeration effect even in the portion inserted into the molded part due to the air permeability of the layered conduit in the surface layer part, and the molten plastic that contacts the surface becomes the surface layer part. It can be effectively inhaled into the voids and penetrated into fine irregularities on the surface.

The manufacturing apparatus shown in FIGS. 1 to 4 coats the surface of the wood core 1 with the thermoplastic plastic 2 by the following method. For the thermoplastic plastic 2, for example, polyethylene resin, polypropylene resin, acrylic resin or the like is used. For the woody core material 1, a plate material that is LVL and has a cross-sectional shape of length × width of 1 cm × 5 cm is used. This wood-based core material 1 has a smooth surface by machining a plate material having a rectangular cross-sectional shape with a saw. Since the surface of the wood-based core material 1 is covered with a plastic 2 having a thickness of 1 mm, the molding part 11 of the mold 3 has a rectangular shape of 12 mm × 52 mm. In a state where the molten plastic 2A is supplied to the molding part 11 of the mold 3, the extrusion mechanism 4 transfers the wood core material 1 from the vacuum deaeration chamber 6 toward the molding part 11. The extrusion mechanism 4 transfers the woody core material 1 at a transfer speed of 5 m / min. The vacuum deaeration chamber 6 evacuates the surface layer portion 1b of the wooden core 1 with a degree of vacuum of 50 Torr. The wood-based core material 1 evacuated in the vacuum deaeration chamber 6 is transferred to the molding part 11 of the molding hole 10. The woody core 1 passing through the molding part 11 of the mold 3 has a molten plastic 2A attached to the surface. As shown in FIG. 6, the molten plastic 2 </ b> A is attached in a state of entering the void 18 in the surface layer portion 1 b of the woody core material 1 in a decompressed state. Further, the wood-based core material 1 is covered with the plastic 2 with the plastic 2 attached to the surface to a thickness of 1 mm while being extruded from the molding part 11.

  The plastic that covers the surface of the wood-based core material by the above method is wood cutting powder, antibacterial agent, fragrance, etc. alone or mixed together to antibacterialize the surface of the wood-based core material Alternatively, it can be coated in a scented state. It is also possible to mix a powder obtained by pulverizing stone with plastic and coat the surface of the wood-based core material with plastic similar to artificial marble. Furthermore, use a wood-based core material with natural wood grain on the surface, coat the surface of this wood-based core material with translucent plastic, and decorate the surface cleanly with the wood-based core material Can do. In addition, pigments and dyes can be added to plastics to decorate the surface of the wood-based core material. Furthermore, the present invention is a plate-like thickness that can bend the wood-based core material, and this wood-based core material is extruded from a curved-shaped molding hole, and the wooden core material is held in a shape that curves with the plastic on the surface. However, the surface can also be coated. This method is suitable, for example, for producing blind plates.

It is a schematic plan view of the manufacturing apparatus of the wood core plastic molding concerning one Example of this invention. It is a schematic sectional drawing of the metal mold | die of the manufacturing apparatus of the wood core plastic molding shown in FIG. It is the sectional view on the AA line of the metal mold | die shown in FIG. It is an expanded sectional view of the metal mold | die shown in FIG. It is an expanded sectional view showing other examples of a metallic mold. It is an expanded sectional view showing the state where plastic adheres to the surface of the woody core material.

Explanation of symbols

1 ... Wood-based core material 1a ... Coating surface
DESCRIPTION OF SYMBOLS 1b ... Surface layer part 2 ... Plastic 2A ... Molten plastic 3 ... Mold 4 ... Extrusion mechanism 5 ... Heating extrusion mechanism 6 ... Vacuum deaeration chamber 7 ... Vacuum apparatus 8 ... Airtight ring part 9 ... Drawer 10 ... Molding hole 11 ... Molding Part 12 ... Projection part 13 ... Inclined surface 14 ... Packing 15 ... Partition 16 ... Transfer roll 17 ... Transfer roll 18 ... Air gap

Claims (9)

Supply the wooden core material (1) whose cross-sectional shape is the same shape to the insertion side (10) of the molding hole (10) of the mold (3) and extrude it from the discharge side, and mold the mold (3) On the inner surface of the hole (10), the thermoplastic plastic (2) that has been heated and melted is extruded and adhered to the surface of the wood-based core material (1). A method for producing a wood core plastic molded body in which the surface of the wood core (1) extruded from 10) is coated with a thermoplastic plastic (2),
The inner surface of the molding hole (10) of the mold (3), and the surface of the wood-based core material (1) is vacuumed more on the insertion side than the molding part (11) that adheres the molten plastic (2A) to the surface. A vacuum deaeration chamber (6) for deaeration is provided, and the thermoplastic resin in the molten state is formed on the surface of the wood-based core material (1) whose surface has been vacuum degassed in this vacuum deaeration chamber (6). A method for producing a wood core plastic molding, characterized by adhering plastic (2).   The vacuum degassing chamber (6) is heated with the mold (3), and the surface of the wood core (1) is vacuum degassed with the heated vacuum degassing chamber (6). Manufacturing method of a wood core plastic molded body.   The mold (3) is in close contact with the inner surface of the molding hole (10) closer to the insertion side than the vacuum deaeration chamber (6), and the outer surface of the wood core (1), and the molding hole (10) There is an airtight ring (8) that hermetically seals between the inner surface and the surface of the wood-based core (1), and this airtight ring (8) is airtight on the insertion side of the vacuum deaeration chamber (6). The molten plastic (2A) supplied to the molding hole (10) is hermetically sealed on the discharge side of the vacuum deaeration chamber (6) to vacuum deaerate the surface of the wood-based core material (1) Item 2. A method for producing a wood core plastic molded article according to Item 1.   The hermetic ring portion (8) of the mold (3) is a projecting portion (12) projecting to the inner surface of the molding hole (10), and the hermetic ring portion (8) comprising the projecting portion (12) is replaced with a wood core. Adhering closely to the surface of the material (1), hermetically sealing the insertion side of the vacuum degassing chamber (6), and vacuum degassing the surface of the wood core (1) in the vacuum degassing chamber (6) A method for producing a wood core plastic molded product according to claim 3.   The airtight ring portion (8) of the mold (3) is a packing provided on the inner surface of the molding hole (10), and the airtight ring portion (8) made of this packing is formed on the surface of the wood-based core material (1). The surface of the wood-based core material (1) is vacuum degassed in a vacuum degassing chamber (6) by tightly sealing and hermetically sealing the insertion side of the vacuum degassing chamber (6). A method for producing a wood core plastic molding. A mold core (3) having a molding hole (10) for extruding a wooden core material (1) whose cross-sectional shape is processed into the same shape, and a wooden core from the molding hole (10) of this mold (3) The extrusion mechanism (4) of the wood-based core material (1) that extrudes the material (1), and the inner surface of the molding hole (10) of the mold (3), a thermoplastic plastic that is heated and melted ( 2) a heating extrusion mechanism (5) of plastic (2) for extruding,
The extrusion mechanism (4) extrudes the wood core (1) from the molding hole (10) of the mold (3), and the heating extrusion mechanism (5) forms the molten thermoplastic plastic (2) into the molding hole. A wood core plastic molded body that is extruded on the inner surface of (10) and covers the surface of the wood-based core material (1) extruded from the molding hole (10) of the mold (3) with the thermoplastic plastic (2). Manufacturing equipment,
The mold (3) is provided with a vacuum deaeration chamber (6) between the inner surface of the molding hole (10) and the surface of the wood-based core material (1), and the vacuum deaeration chamber (6) has a vacuum. The device (7) is connected, the vacuum device (7) exhausts the air in the vacuum degassing chamber (6), the surface of the wood core (1) is vacuum degassed, and the vacuum degassed wood An apparatus for producing a wood core plastic molding, characterized in that a molten thermoplastic plastic (2) is adhered to the surface of a system core material (1).   The mold (3) is in close contact with the inner surface of the molding hole (10) closer to the insertion side than the vacuum deaeration chamber (6), and the outer surface of the wood core (1), and the molding hole (10) There is an airtight ring (8) that hermetically seals between the inner surface and the surface of the wood-based core (1), and this airtight ring (8) is airtight on the insertion side of the vacuum deaeration chamber (6). The molten plastic (2A) supplied to the molding hole (10) is hermetically sealed at the discharge side of the vacuum deaeration chamber (6) to vacuum deaerate the surface of the wooden core (1). An apparatus for producing a wood core plastic molded body according to claim 6.   The hermetic ring part (8) of the mold (3) is a projecting part (12) projecting from the inner surface of the molding hole (10), and the hermetic ring part (8) comprising the projecting part (12) is a wood core. So that the insertion side of the vacuum degassing chamber (6) is hermetically sealed, and the surface of the wood-based core material (1) is vacuum degassed in the vacuum degassing chamber (6). An apparatus for manufacturing a wood core plastic molded body according to claim 7.   The hermetic ring portion (8) of the mold (3) is a packing (14) provided on the inner surface of the molding hole (10), and the hermetic ring portion (8) comprising the packing (14) is replaced with a wood-based core material. Adhering closely to the surface of (1), the insertion side of the vacuum deaeration chamber (6) is hermetically sealed, and the surface of the wood core (1) is vacuum degassed in the vacuum deaeration chamber (6). The manufacturing apparatus of the wood core plastic molded object described in Claim 7.

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