JP2010005872A - Composite resin molded article and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a composite resin molded article excellent in strength and rigidity by welding and integrating a resin core material and a resin outer skin covering the surface through the intervention of a hot-melt surface material, and to provide its manufacturing method. <P>SOLUTION: The composite resin molded article is composed by covering the resin core material 2 with the resin outer skin. The resin core material 2 and the resin outer skin covering the surface are welded and integrated through the intervention of the hot-melt surface material 13. The outer surface of at least one side wall of the resin outer skin is a rugged surface 12 formed for pressurized fluid passage in blow molding. The resin core material 2 has a honeycomb structure having numerous cavities passing through the thickness direction. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a blow molded composite resin molded article in which a resin core is covered with a resin shell and a method for producing the same.

  The composite resin molded product according to the present invention is used for, for example, a floor panel or a pallet for carrying goods.

A core material is placed between two thermoplastic sheets facing each other at a predetermined interval, and the periphery of the sheet is clamped to form a closed space, which is then sandwiched between a pair of molds to be blow molded and pinched off. A sheet blow molded product and a molding method thereof are disclosed in Japanese Patent Laid-Open No. 8-323842, and a resin panel molding method for manufacturing two resin sheets to be joined using sheet blow molding is disclosed in Japanese Patent Laid-Open No. 2002-2002. 166464 publications respectively.
JP-A-8-323842 JP 2002-166464 A

  In the sheet blow molding disclosed in the above-mentioned Patent Documents 1 and 2, a pair of resin sheets arranged above and below the core material are heat plasticized with the heating means facing the outer surface side to pinch off. The resin sheet containing the core material is molded by joining, blow molding, and heating is performed with the heating means facing the outer surface of the resin sheet. Even when heated to an appropriate temperature, the inner surface does not reach a sufficient temperature. For this reason, even if a pair of resin sheets are pinched off by a mold, the required welding strength cannot be obtained at the portions where the resin sheets are joined to each other, and the inner surface of the low temperature resin sheet is provided on the surface of the core material. Has been pointed out, such as insufficient bonding strength between the core material and the resin sheet.

  Therefore, the present invention is excellent in strength and rigidity by causing the resin core material and the resin outer shell covering the surface thereof to be integrated by welding with a hot-melt surface material interposed therebetween, so that the above-described problems do not occur. A composite resin molded article and a method for producing the same are provided.

  A composite resin molded product according to the present invention that achieves this object is a composite resin molded product in which a resin core is covered with a resin outer shell, and the resin core and the resin outer shell covering the surface thereof are heat-meltable surface materials. The outer surface of at least one of the walls of the resin skin is an uneven surface formed so as to be a pressurized fluid passage during blow molding. It is.

  The method for manufacturing a composite resin molded product according to the present invention that achieves the above object is a method for manufacturing the composite resin molded product, wherein a pressurized fluid passage at the time of blow molding is formed in at least one mold cavity. Between the molding molds of the split type which was an uneven surface for forming, a regular resin core material with a heat-meltable surface material on both sides was placed, and both surfaces of this resin core material were heat plasticized After the pair of resin sheets are opposed to each other in a hanging shape, and then vacuum-molded so that the molding die is clamped to a position where the pinch-off portion is in contact with the resin sheet and the resin sheet is adsorbed to the cavity of the molding die, After completing the mold clamping of the molding die, press the resin sheet against the surface of the fixed resin core material by the cavity of the clamping molding die and weld it with the heat-meltable surface material. Formed with uneven surface Is characterized in that the blow molding for compensation molded by introducing a pressurized fluid between a pair of resin sheets through the pressurized fluid passage.

  In the present invention, the resin core material is preferably a foam or a honeycomb structure having a large number of cavities penetrating in the thickness direction.

  In the present invention, the resin core material is a polyolefin (for example, polypropylene, high-density polyethylene), polyamide, polystyrene, poly olefin which is a homopolymer or copolymer of olefins such as ethylene, propylene, butene, isoprene pentene, and methyl pentene. Acrylic derivatives such as vinyl chloride, polyacrylonitrile, ethylene-ethyl acrylate copolymer, polycarbonate, vinyl acetate copolymers such as ethylene-vinyl acetate copolymer, terpolymers such as ionomer, ethylene-propylene-dienes, ABS resin And thermoplastic resins such as polyolefin oxide and polyacetal. In addition, these may be used individually by 1 type, or may mix and use 2 or more types. In particular, among the thermoplastic resins, olefin resins or resins mainly composed of olefin resins, polypropylene resins or resins mainly composed of polypropylene resins have good weldability to the fiber layer, mechanical strength and moldability. It is preferable in terms of excellent balance. The resin core material may contain an additive. Examples of the additive include silica, mica, talc, calcium carbonate, glass fiber, carbon fiber, and other inorganic fillers, plasticizers, stabilizers, colorants, and charging agents. An inhibitor, a flame retardant, a foaming agent, etc. are mentioned.

  In the present invention, the resin shell is composed of a resin sheet formed from a polyolefin resin such as polypropylene or polyethylene, a polyester resin, a polyamide resin, a polycarbonate resin, or a modified polyphenylene ether resin (modified PPE resin). .

  In the present invention, the heat-meltable surface material can interpose a non-woven fabric, a woven fabric, a heat-weldable sheet, or a hot melt type adhesive, and the non-woven fabric or woven fabric is preferably used as the inclusion. In particular, when the resin core material is a honeycomb structure, the nonwoven fabric or woven fabric is welded with at least the same material as the honeycomb structure, or the nonwoven fabric is anchored via a sheet having the same or adhesiveness as the honeycomb structure. Or the like, or bonded to the honeycomb structure with an adhesive. Preferably, the nonwoven fabric or the woven fabric is made of a material having a melting point higher than that of the honeycomb structure and the resin sheet. The non-woven fabric is preferably one having an anchor effect by fusion to the resin sheet or coated fiber covered with the same material as the resin sheet. That is, if the nonwoven fabric or woven fabric remains as a fiber, the overall reinforcement is enhanced. Furthermore, the presence of a fiber layer (nonwoven fabric or fabric) between the resin core material and the resin sheet has an effect of releasing residual air during molding. On the other hand, even when air is blown, It will spread the air. The heat-weldable sheet preferably has a low melting point and has an affinity for the resin core material. When the resin sheet is polypropylene and the resin core material is polyester, the heat-weldable sheet is, for example, a maleic anhydride-modified polypropylene. Use compatible resin.

In the present invention, in the case of a composite resin molded product having a decorative sheet on the surface, the appearance is improved, the decorative property, and the product that comes into contact with the molded product (for example, in the case of a cargo floor board, placed on the upper surface of the board). Configured for the purpose of protecting the baggage, etc.). As the material of the decorative sheet, a fiber skin material, a sheet-like skin material, a film-like skin material, or the like is applied. As the material of such a fiber skin material, synthetic fibers such as polyester, polypropylene, polyamide, polyurethane, acrylic and vinylon, semi-synthetic fibers such as acetate and rayon, regenerated fibers such as viscose rayon and copper ammonia rayon, cotton, hemp, Examples thereof include natural fibers such as wool and silk, or blended fibers thereof. Among these, polypropylene or polyester is preferable and polyester is more preferable from the viewpoints of touch, durability, and moldability. The yarn used for the fiber skin material 30 is, for example, polyester: (3-5) denier x (50-100) mm, etc., a fineness of 3-15 denier, and a staple spun yarn having a fiber length of about 2-5 inches Polyester in a bundle of thin flexible filaments: multifilaments of about 5 denier × (about 30 to 200) = about 150 to 1000 denier / 1, or thick polyester such as polyester: 400 to 800 denier / 1 -It is preferable to use in combination with a filament. Examples of the structure of the fiber skin material include non-woven fabrics, woven fabrics, knitted fabrics, and fabrics obtained by raising them. The woven fabric includes not only a plain structure in which the woven structure is tangled up and down in order, but also various changed woven forms in which some yarns are entangled and jumped. Among these, since there is no directionality with respect to elongation, a non-woven fabric is preferable because it can be easily formed into a three-dimensional shape and has excellent surface feel and texture. Here, the non-woven fabric means a cloth-like product in which fibers are stacked in parallel or alternately or are randomly dispersed to form a web, and then the fibers that become the web are joined. Among these, it is preferable that it is a nonwoven fabric manufactured by the needle punch method from a viewpoint of the three-dimensional shape reproducibility of a molded article, and an external appearance characteristic. In addition, since the nonwoven fabric obtained by the needle punch method has lower strength and higher elongation than the woven fabric and has a large degree of deformation in any direction, it improves the strength of the nonwoven fabric and stabilizes its dimensions. Therefore, it is more preferable that a binder is attached to the nonwoven fabric, or the web and the nonwoven fabric are punched with overlapping needles. For these reasons, the fiber skin material is more preferably a polypropylene nonwoven fabric or a polyester nonwoven fabric. In this case, since the fiber skin material itself is thermoplastic, it can be used for another purpose by being heated and deformed after separation and collection. For example, when the main resin layer is made of polypropylene and the fiber skin material is made of polypropylene nonwoven fabric, the main resin layer and the fiber skin material of the molded product are the same material, which facilitates recycling. On the other hand, if the fiber skin material is a polyester nonwoven fabric, the melting point of the main resin layer composed of polypropylene and the fiber skin material is different, so when the fiber skin material is bonded to the molded product, it is altered or deformed by heat, Generation | occurrence | production of malfunctions, such as being unable to adhere | attach on the correct position, can be suppressed. In this case, the moldability, rigidity, appearance and durability are also excellent. The tensile strength of the fiber skin material is preferably 15 kg / cm ² or more, and the elongation is preferably 30% or more, from the viewpoint of three-dimensional shape reproducibility and moldability. In addition, the value of this tensile strength and elongation is measured based on JIS-K-7113 at the temperature of 20 degreeC. As the sheet-like skin material and film-like skin material, thermoplastic elastomer, embossed resin layer, resin layer with printed layer attached to the outer surface, synthetic leather, non-slip mesh-shaped skin layer, etc. can be used. .

  In the present invention, the composite resin molded product is mainly a floor panel or a pallet for carrying goods, but a car floor board, a footrest, a side door trim, a seat back, a rear parcel shelf, a door panel, a seat for a vehicle interior such as a seat, Carrying case for machinery, parts for light electrical appliances, wall materials, interior materials for partitions such as partitions, furniture such as chairs, etc. Besides, it is suitable for applications such as tanks, dust, cases, housings, trays, containers, etc. . For example, when a laminated resin molded product is applied to a cargo floor board for automobiles, a fiber skin material is pasted on the front wall of the board, and a fiber skin material is not pasted on the back wall of the board. Consists of faces. Moreover, a part of the front wall of the board can be covered with a fiber skin material. Since the laminated resin molded product of the present invention is lightweight and has an effect of exhibiting high rigidity, some load acts on the upper surface, and is used by being installed on a plane that requires flexural strength, for example, cargo floor Suitable for board-like products such as boards.

  According to the present invention, the resin core material and the resin outer shell covering the surface thereof are welded and integrated with a hot-melt surface material interposed therebetween, so that the above-described problems do not occur and the strength and rigidity are excellent. A composite resin molded product can be obtained.

  1 and 2 illustrate a floor panel as a composite resin molded article of the present invention. FIG. 1 is a perspective view of the floor panel, and FIG. 3 to 5 illustrate a pallet for carrying goods as a composite resin molded article of the present invention, FIG. 3 is a sectional view showing a part of the pallet, and FIG. 4 is a perspective view showing a part of the core material. FIG. 5 is a perspective view showing an embodiment in which a hot-melt surface material is pasted on both surfaces of the core material shown in FIG. FIGS. 6 to 8 show the molding mode of the floor panel as the composite resin molded article of the present invention in the order of steps, and FIG. 6 shows the mode in which the resin core material and a pair of resin sheets are arranged between the molding dies. FIG. 7 is a cross-sectional view of an embodiment in which the molding die is clamped to a position where the pinch-off portion is in contact with the resin sheet, and the resin sheet is vacuum-molded so as to be adsorbed in the cavity of the molding die, and FIG. It is sectional drawing of the aspect which completed fastening and was blow-molded.

  A floor panel 1 which is an example of a composite resin molded article according to the present invention has a monolithic laminated structure in which the surface of a regular resin core material 2 is covered with resin outer skins 3 and 3. The resin core material 2 has a preformed honeycomb structure (see FIGS. 4 and 5), but may be a resin core material having another structure. The back wall 4 of the floor panel 1 has an uneven surface formed to be a pressurized fluid passage during blow molding, and 5 is the pressurized fluid passage. The honeycomb structure forming the resin core material 2 has many cavities penetrating in the thickness direction. A is the floor base of the building. Although not shown, a plurality of ribs can be formed from the resin skins 3 and 3 so that the resin core material 2 is floated in the hollow portion. It becomes possible.

  The floor panel 1 shown in FIGS. 1 and 2 is formed in the manner shown in FIGS. As shown in FIG. 6 to FIG. 8, a resin core 3 having a pre-shaped fixed resin core material 2 is disposed between divided molding dies 7 and 8 and is opposed to the resin core material 2. The resin sheets 6 and 6 to be 3 are extruded from the extrusion heads 9 and 9 and are suspended. Reference numerals 10 and 11 denote mold cavities, and the cavity 10 of one mold 7 is formed as an uneven surface 12 for forming the pressurized fluid passage 5 during blow molding. On both surfaces of the resin core material 2, a heat-meltable surface material 13 is applied by applying a heat-weldable sheet or applying a hot-melt adhesive.

  Next, as shown in FIG. 7, the molding dies 7, 8 are clamped until the pinch-off portions 14, 15 are in contact with the resin sheet, and the resin sheets 6, 6 are then cavities 10, 11 of the molding dies 7, 8. After the vacuum molding is performed so as to adsorb to the resin core material 2, as shown in FIG. 8, the mold dies 7, 8 are finished to be clamped, and the resin core material 2 is pressed by the pressing action of the cavities 10, 11 of the clamped molding dies. The resin sheets 6 and 6 are welded to each other surface with the hot-melt surface material 13 interposed. Next, a pressurized fluid is introduced between the pair of resin sheets 6 and 6 through the pressurized fluid passage 5 formed by the concave and convex surfaces of the molding dies 7 and 8 to perform blow molding for correction molding.

  The resin sheets 6 and 6 extruded from the extrusion heads 9 and 9 are in a state where the entire resin sheet 6 and 6 are heat-plasticized substantially uniformly. However, the resin sheets 6 and 6 are formed in a cavity 10 of the molding dies 7 and 8 by vacuum forming. Even if the resin sheets 6 and 6 are cooled from the outer surface side in contact with the resin sheet 11, the inner surfaces of the resin sheets 6 and 6 are kept in a plasticized state. When the resin sheets 6 and 6 are pressed on both sides, the resin sheets 6 and 6 are strongly welded to the resin core material 2 by a synergistic effect by the intervening hot-melt surface material 13. Moreover, since the inner surfaces of the resin sheets 6 and 6 compressed by the pinch-off portions 14 and 15 are kept in a plasticized state, the welding strength is high and the strength is excellent. In addition, the resin core material 2 is disposed between the pair of resin sheets 6 and 6 as described above, and is disposed along the resin sheet 4 adsorbed by the cavity 8 of the molding die 5 by the vacuum forming. Such aspects are possible.

  According to the experiment, the welding strength of the pinch-off part according to the present invention is the above value because the welded part of the pinch-off part was not broken although the resin core material was broken at 20 kgf / cm to 35 kgf / cm. On the other hand, since the pinch-off portion was broken at 8 kgf / cm in the conventional example, the superiority of the present invention is clear. In addition, the resin sheet in a state of being heat plasticized substantially uniformly is a sheet immediately after being extruded through a die from an extruder, and the extruded sheet is extruded using a die on a flat plate, or blow molding There is a sheet separating the parison. And if it is a sheet immediately after being extruded through a die from an extruder, it is possible to adjust the drawdown etc. by controlling the extrusion, but when heating a cooled sheet, it is heated uniformly to the inside of the sheet Even if it tries to plasticize to the inside of the sheet during heating, it takes a very long time, the surface temperature becomes too high, drawdown or surface sagging occurs, the entire sheet is distorted, etc. Uniform plasticization is impossible.

  As the composite resin molded product of the present invention, a transportation pallet 16 can be configured as shown in FIG. The pallet 16 shown in FIG. 3 has a pressurized fluid passage 5 formed in the front wall 17 at the time of blow molding, and the uneven surface thereby serves as a slip stopper for the front wall 17. Reference numeral 18 denotes a leg portion. In the pallet 16 shown in FIG. 3, it is preferable that the core material 2 has a honeycomb structure as shown in FIGS. 4 and 5 in order to provide strength and appropriate buffering properties. A heat-meltable surface material 13 is stuck on both surfaces of the core material 2 having a honeycomb structure. The pallet 16 shown in FIG. 3 is also formed in the manner shown in FIGS.

It is a perspective view of the floor panel illustrated as a composite resin molding of this invention. It is a back view which fractures | ruptures and shows a part same as the above. It is sectional drawing which shows a part of pallet which illustrated the pallet for cargo transportation as the composite resin molded product of this invention. It is a perspective view which shows a part of core material same as the above. It is a perspective view which shows the aspect which stuck the heat-meltable surface material on both surfaces of the core material shown in FIG. It is sectional drawing of the aspect which showed the shaping | molding aspect of the floor panel as a composite resin molded article of this invention, and has arrange | positioned a resin core material and a pair of resin sheet on both sides of it. It is sectional drawing of the aspect which vacuum-molded so that a molding die may be clamped to the position where the pinch-off part touches a resin sheet, and a resin sheet is adsorb | sucked to the cavity of a molding die. It is sectional drawing of the aspect which completed mold clamping and was blow-molded.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Floor panel 2 Resin core material 3, 3 Resin outer skin 4 Back wall 5 Pressurized fluid passage 6, 6 Resin sheet 7, 8 Molding die 9, 9 Extrusion head 10, 11 Cavity 12 Uneven surface 13 Heat-meltable surface material 14 , 15 Pinch-off part 16 Pallet 17 Front wall 18 Leg part A Building floor base

Claims (4)

A composite resin molded product in which a resin core is covered with a resin shell,
The resin core material and the resin outer shell covering the surface are integrated by interposing a hot-melt surface material,
A composite resin molded product, wherein an outer surface of at least one of the walls of the resin skin is an uneven surface formed to be a pressurized fluid passage during blow molding.   The composite resin molded article according to claim 1, wherein the resin core material is a foam or a honeycomb structure having a large number of cavities penetrating in the thickness direction thereof. A method for producing a composite resin molded article according to claim 1,
A fixed resin core material with a heat-meltable surface material on both sides is formed between the molding molds of the split type in which the cavity of at least one mold is formed as an uneven surface for forming a pressurized fluid passage during blow molding. Along with the arrangement, on both sides of the resin core material, a pair of heat-plasticized resin sheets are opposed in a suspended manner,
Next, the mold is clamped to a position where its pinch-off part is in contact with the resin sheet, and the resin sheet is vacuum-molded so that it is adsorbed by the cavity of the mold, and then the mold is clamped. The resin sheet is pressed against the surface of the fixed resin core material by the cavity of the mold that has been clamped and welded with the heat-meltable surface material.
Next, the composite resin molded product is characterized in that a pressurized fluid is introduced between a pair of resin sheets through a pressurized fluid passage formed by the uneven surface of the molding die to perform blow molding for correction molding. Production method.   The method for producing a laminated resin molded product according to claim 3, wherein the resin core material is a foam or a honeycomb structure having a large number of cavities penetrating in the thickness direction thereof.

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