JP5370177B2 - Resin casting equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resin cast molding apparatus capable of stably manufacturing resin cast molded articles such as an artificial marble bathtub and a washstand with constant quality over a long period of time. <P>SOLUTION: The resin cast molding apparatus B includes a nozzle A for injecting thermosetting resin into a cavity of a molding die. A nozzle body 1 of the injection nozzle A is formed of synthetic resin and provided in the die 9, and a die abutting surface 12 at the peripheral edge of a material resin injection port 11 of the nozzle body 1 is protected by a metal cap 2. The metal cap 2 is integrally formed of a protective plate part 21 and a fixing leg piece 22 fixing the protective plate part 21 to the tip part of the nozzle body 1. The metal cap 2 is mounted to the nozzle body 1. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to an apparatus for manufacturing a resin molded product, and more particularly to an apparatus for manufacturing a resin cast molded product such as an artificial marble bathtub or a wash basin used for a system bath by molding.

  Conventionally, a synthetic resin such as a thermosetting resin is injected into a mold and molded to produce a resin cast molded product such as an artificial marble bathtub or a wash basin. For example, in Japanese Patent Application Laid-Open No. 2007-30324, when casting a molding material, the number of work steps can be reduced and the process can be simplified, and the airtightness between members constituting the air supply / exhaust mechanism can be easily and A casting apparatus that can be reliably secured is disclosed.

  That is, as shown in FIG. 1 of the above publication, the casting molding apparatus has a hollow portion that can move forward and backward toward the cavity, has both ends open, and one opening communicates with the cavity. In addition to the provided outer nozzle body and inner nozzle body, the apparatus includes a supply / exhaust nozzle mounted on a molding die.

  The inner nozzle body includes a lower nozzle that is airtightly fitted from the cavity side to the cavity side end of the hollow portion of the outer nozzle body, and a communicating body that is inserted through the hollow portion of the outer nozzle body with a gap. The hollow portion is integrated and has both ends open, and one opening communicates with the cavity. Here, the lower nozzle and the communication body are fused and integrated by rotationally press-fitting one into the other.

  Then, by using the above casting molding apparatus, the gas exhaust from the cavity at the time of injection of the molding material and the gas supply to the cavity for mold release after molding hardening of the molding material are the same. It is described that it can be performed by using an air supply / exhaust nozzle, and it is not necessary to replace the exhaust vent nozzle with an air blow nozzle for air supply, thereby reducing the number of work steps. Further, it is also described that an excellent quality resin cast product can be obtained in order to prevent so-called air traps from occurring in the product.

JP 2007-30324 A

  As described in Patent Document 1, the molding material is injected into the cavity from the nozzle in the mold held at about 50 ° C. at the time of injection, and the mold temperature is about 80 ° C. at the time of thermosetting. The molding material is thermally cured by raising the temperature to about 95 ° C. In this way, because there is a temperature difference between the cavity side and the mold side, the nozzle usually has a low thermal conductivity and is excellent in heat insulation in order to prevent heat transfer to the molding material to be injected. A resin molded product is used.

  Here, when releasing a resin cast molded product that has been cured by heat, the mold contact surface of the nozzle is sandblasted to improve the separation between the synthetic resin nozzle and the resin cast molded product. It has been attempted to improve releasability by reducing the contact area as a rough surface by processing. Alternatively, it is conceivable that the mold contact surface is subjected to fluororesin processing, DLC processing, metal plating processing, or the like, and surface modification is performed to improve the releasability.

  However, when the molding cycle such as injection of molding material and mold release of resin casting is repeated, the surface treatment layer of the nozzle contact surface is peeled off or the contact surface repeatedly pressed is mechanically damaged. There was a problem of durability, and there was a problem with durability.

  The present invention has been made in view of the above-mentioned background art, and its purpose is to improve the mold releasability of the mold contact surface of the nozzle made of synthetic resin and to have excellent durability, and to improve work efficiency. It is an object of the present invention to provide a resin casting apparatus capable of producing a resin casting product stably for a long period of time.

  In order to solve the above-mentioned problem, a resin casting apparatus according to the first aspect of the present invention is a resin casting apparatus having an injection nozzle for injecting a thermosetting resin into a cavity of a molding die. The nozzle body of the injection nozzle is formed of a synthetic resin, and the mold contact surface at the periphery of the material resin injection port of the nozzle body is protected by a metal cap, and the metal cap is a protective plate And a fixed leg piece for fixing the protective plate portion to the tip of the nozzle body, and the metal cap is attached to the nozzle body.

  As the nozzle body made of synthetic resin, a nozzle body made of an engineering plastic excellent in heat resistance, durability, and heat insulation is used. For example, a nozzle made of polyamideimide resin is used.

  As the metal constituting the metal cap, a metal having excellent rigidity such as stainless steel or steel plate is used, and the thickness thereof does not hinder the heat insulating property of the injection nozzle, and is 0.5 to 2 mm. Is appropriate. In addition, it is preferable to finish the surface of the protective plate portion of the metal cap so as to have a smooth surface from the viewpoint of preventing adhesion of the thermosetting resin as a molding material.

  As the mold, a lower mold that constitutes the core and an upper mold that covers the lower mold are used. A cavity is provided between the upper and lower molds, and a thermosetting resin is placed in the cavity forming the product. After filling and heating, after completion of the curing reaction, the lower mold and the upper mold are divided to obtain a product such as an artificial marble bathtub or a washstand.

  In the resin casting apparatus according to the first aspect of the present invention, the mold contact surface at the periphery of the resin injection port of the material of the nozzle body made of a synthetic resin, for example, a polyamide-imide resin, which constitutes the injection nozzle is made of metal Because it is protected by a cap, it can be stably produced over a long period of time without damage even if molding cycles such as injection of molding material and mold release of resin casting are repeated. it can.

  In addition, since the mold contact surface is covered with a protective plate made of a metal having physical properties different from that of the resin, there is little adhesion between the cast resin molded product and the mold release property is improved. Moreover, since the durability is high, a product of a certain quality can be produced with high production efficiency.

(A) is a cross-sectional view showing the injection nozzle, (b) is a front view showing the injection nozzle. Partial cross-sectional explanatory drawing which shows schematic structure of the resin casting molding apparatus which comprised the injection nozzle inside.

  Hereinafter, embodiments of a resin casting apparatus according to the present invention will be described in detail with reference to the drawings. In the present embodiment, first, an injection nozzle constituting the main part of the present invention will be described with reference to the drawings. FIG. 1A is a cross-sectional view showing the injection nozzle A. FIG. FIG. 1B is a front view showing the injection nozzle A. FIG. As shown in FIG. 1A, the injection nozzle A is composed of a nozzle body 1 and a metal cap 2 attached to the nozzle body 1. For example, the interior of the nozzle body 1 made of polyamideimide resin is tapered. A molding material flow path is formed in a cavity formed between the upper mold and the lower mold by being cut out in a tapered shape.

  Further, the front end opening of the nozzle body 1 serves as a material resin injection port 11 into the cavity, and the periphery thereof constitutes a mold contact surface 12 of the nozzle body 1 and is protected by a metal cap 2. The metal cap 2 includes a protection plate portion 21 and a fixed leg piece 22 that fixes the protection plate portion 21 to the tip end portion of the nozzle body 1, and is integrally formed of, for example, stainless steel (SUS304). . It is appropriate from the viewpoint of durability that the metal cap 2 has a thickness of 0.5 to 2 mm.

  As shown in FIG. 1B, the fixed leg piece 22 and the nozzle body 1 are provided with a screw hole 3 into which a stator for mounting a metal cap 2, for example, a screw or the like, is screwed. The cap 2 is firmly fixed to the tip of the nozzle body 1 by screwing four fixing screws 4 into the screw holes 3.

  FIG. 2 is a partial cross-sectional explanatory view showing a schematic configuration of a resin casting apparatus B provided with the injection nozzle A inside the mold 9. As shown in FIG. 2, the resin casting apparatus B is provided with a material resin charging port 5, and from the material resin charging port 5, for example, when manufacturing an artificial marble bathtub, the above-described polyester resin is used as a main raw material. And a thermosetting material resin 51 containing aluminum hydroxide, calcium carbonate or the like as a filler is charged.

  Here, hot water of about 100 ° C. is circulated through the hot water circulation pipe 6 to heat the mold 9 and the material resin 51 is kept in a fluid state. The material resin 51 heated as described above is poured from the injection nozzle A into the cavity of the mold 9 and further heated to about 130 ° C. by the heating means 7 such as an electric heater to accelerate the curing reaction. Complete molding. The mold temperature condition at this time is appropriately set depending on the composition of the material resin 51.

  On the other hand, a cooling water channel 8 is provided in the mold 9, and when it is necessary to adjust the holding temperature of the mold 9 with hot water depending on the composition of the material resin 51, or when the mold 9 is cooled to room temperature. The temperature is adjusted by flowing cold water as appropriate.

  The molding pressure conditions are, for example, that the casting pressure from the injection nozzle A is 0.15 MPa, the holding pressure is 0.4 MPa, the clamping pressure is 0.6 MP, and the above-mentioned pressure conditions are maintained for 30 to 60 minutes. 51 is shaped into an artificial marble bathtub.

  After the curing molding is completed, the resin cast molded product P, that is, the artificial marble bathtub is released from the mold 9. At this time, as shown in FIG. 1 (a), the mold contact surface 12 at the periphery of the material resin inlet 11 of the nozzle body 1 is protected by a metal cap 2, and has a physical property different from that of the resin. Therefore, the resin cast molded product P is excellent in releasability without adhering to the protective plate portion 21. In addition, since it is made of metal, it can be stably obtained over a long period of time without being damaged even if a molding cycle such as injection of molding material and mold release of a resin cast molding is repeated. .

  In this embodiment, the metal cap 2 is fixed to the tip of the nozzle body 1 by screwing the fixing screw 4 into the screw hole 3. However, the present invention is not limited to this. A female screw may be cut on the inner peripheral surface of the fixed leg piece 22, and a male screw may be cut and screwed on the outer peripheral surface of the tip of the nozzle body 1. Alternatively, the metal cap 2 may be embedded in the mold contact surface 12 and fixed, or may be fitted. The fixed leg piece 22 is suspended from the protective plate portion 21. When the fixed leg piece 22 is fixed from the side surface of the nozzle body 1, an influence of external force (pressure applied to the injection nozzle A during injection) is exerted on the fixed portion. There are few things, and there is little possibility that a fixed part will loosen. Further, when an insertion groove is formed on the side surface of the nozzle body 1 and the fixed leg piece 22 is inserted and fixed in the insertion groove, there is an advantage that positioning can be performed accurately.

  As the thermosetting resin used as the molding material, a polyester resin, a vinyl ester resin, a thermosetting acrylic resin can be used alone, or a mixture of two or more of these can be used.

  Polyester resins are thermosetting and synthesized by the condensation reaction of unsaturated dibasic acids such as maleic anhydride and saturated dibasic acids such as phthalic anhydride and glycols, and unsaturated in the molecule. It has a bond and an ester bond. Usually, this resin is blended with a styrene monomer, an acrylic monomer, or the like as a crosslinking agent, and what is called an unsaturated polyester resin is used, but the form is not particularly limited.

  As the vinyl ester resin, a bisphenol type vinyl ester resin or a novolac type vinyl ester resin or a mixture of both can be used. Here, the bisphenol-type vinyl ester resin is an addition reaction product of a bisphenol-type epoxy resin and an acid, and both have reactive unsaturated groups only at both ends. As the bisphenol type epoxy resin, various types such as a bisphenol A type, a bisphenol AD type, a bisphenol S type, and a bisphenol F type can be used. Usually, this vinyl ester resin is blended with a styrene monomer, an acrylic monomer or the like as a crosslinking agent, but the form is not particularly limited.

  As the thermosetting acrylic resin, what is called an acrylic syrup composed of a mixture of two or more of methyl methacrylate monomer, polyfunctional acrylic monomer or prepolymer, or polymer is usually used as thermosetting type. Although used, the form is not particularly limited.

  As described above, the resin casting apparatus according to the present invention can be changed in design, and all cases belong to the technical scope of the present invention unless departing from the scope of the claims.

A Injection nozzle B Resin casting molding device P Resin casting molding product 1 Nozzle body 11 Material resin injection port 12 Mold contact surface 2 Metal cap 21 Protection plate 22 Fixing leg piece 3 Screw hole 4 Fixing screw 5 Material Resin inlet 51 Material resin 6 Hot water circulation pipe 7 Heating means 8 Cooling water channel 9 Mold

Claims (1)

  A resin casting apparatus having a nozzle for injecting a thermosetting resin into a cavity of a molding die, wherein the nozzle body of the injection nozzle is formed of a synthetic resin and provided in the die, The metal abutment surface at the periphery of the material resin injection port of the nozzle body is protected by a metal cap, and the metal cap is fixed to fix the protection plate portion and the protection plate portion to the tip portion of the nozzle body. A resin casting apparatus, wherein the apparatus is integrally formed with a leg piece and the metal cap is attached to a nozzle body.

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