JP3267100B2 - Mold for molding, molding method, molding material, and molded product - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mold for molding a thermoplastic resin, a blow molding method, an injection molding method, a thermoplastic resin material, and a molded product.

[0002]

2. Description of the Related Art As a method for obtaining a resin molded product, there are an injection molding method and a blow molding method. In the injection molding method, the molten resin is placed in a closed mold at a high pressure (200 to 1000 kg / cm).
^In this method, the molding surface of the mold is transferred to resin by injection in ² ). Because of the high pressure, the transfer of the molding surface is performed accurately. Therefore, it is suitable for obtaining a molded product having a mirror surface or a grained surface. However, since a mold that can withstand high pressure is required, the structure of the mold is complicated and the cost is high, which is not suitable for high-mix low-volume production. In addition, since a special device is required for molding a hollow product, the production process is complicated. In the blow molding method, a parison (a hollow cylindrical resin in a melted and softened state) is supplied between molds, the mold is clamped, and a fluid is pressure-fed to the hollow portion so that the outer surface of the parison is a molding surface of the mold. This is a method of transferring the image by pressing it onto Since it is pressed by the pressure of the fluid, the pressure is relatively low (4 to 10 kg / cm ² ), so that the molding surface is not transferred cleanly, which is not suitable for obtaining a molded product having a mirror surface or a grain surface. However, it is widely used because it is suitable for mass production of hollow articles. JP-A-58-102732 discloses a thin inner mold for molding,
A hollow molding die provided with a cooling outer die capable of contacting / isolating the inner molding die is disclosed. In this mold, the inner mold for molding is heated before the parison is supplied for the purpose of improving the surface gloss of the hollow molded article, and after the parison is brought into contact with the molding surface of the inner mold for cooling, it is cooled. By bringing the inner surface of the outer mold into contact with the outer surface of the inner mold for molding, the inner mold for molding is rapidly cooled to obtain a molded product. JP-A-4-77231
In the gazette, when the parison is brought into contact with the molding surface of the mold, the temperature of the mold is maintained between a temperature near the maximum crystallization speed of the parison and a melting point. Blow molding that prevents die lines and weld lines from remaining on the surface of the molded product and circulates refrigerant through the hollow part of the parison during molding to prevent a prolonged molding cycle time. A method is disclosed. In Japanese Patent Publication No. 6-73903,
A lid having good heat conductivity and a large number of through-holes is fixed to a container-like mold frame to form a mold surface area including the lid and an intermediate layer behind the mold, and the intermediate layer is formed. There is disclosed a molding die in which a resin or metal having low heat conductivity is filled, or a reinforcing rib provided with a conduction hole is provided.

[0003]

There is a demand for obtaining a resin molded product having a mirror surface or a grain surface using a mold having a relatively simple structure. There is also a demand for producing a hollow resin molded product having a mirror surface or a grain surface (eg, an air spoiler of an automobile) by a simple process. JP-A-58-1
In the mold for hollow molding disclosed in Japanese Patent No. 027334, the molding surface is clearly transferred by heating the molding inner mold. However, the molding inner mold is relatively displaced and brought into contact with the cooling outer mold. Since the resin is cooled by the method, the structure of the mold may be complicated and weakened, and the cooling time may be prolonged. Further, there is no mention of the optimum range of the heating temperature and the cooling temperature for cleaning the surface of the resin molded product and shortening the entire cycle time of the molding. JP-A-4-77
In the blow molding method of JP-A-231-231, the molding surface is cleaned by heating and maintaining the temperature of the mold at the above-mentioned temperature. The effect is not very large. Further, since the parison is cooled from the inside by circulating the refrigerant, temperature control for heating and maintaining the temperature of the mold at the above-mentioned temperature becomes complicated. In the apparatus disclosed in Japanese Patent Publication No. Hei 6-73903, heating and cooling of a molding surface are performed by heating a large number of conduction holes provided inside or on the back surface of a lid (mold surface area) on which the molding surface is formed.・ It is performed by passing a cooling medium, and also by sending a heating / cooling medium into the intermediate layer behind the molding surface, but in this device, the heat transfer in the intermediate layer is slow. Therefore, it is difficult to shorten the cycle time. An object of the present invention is to produce a resin molded product having a good mirror surface or grain surface in a relatively short cycle time. It is another object of the present invention to produce a resin molded product having a good mirror surface or grain surface in a relatively simple process.

[0004]

According to the first aspect of the present invention, there is provided a mold having a molding surface (30) for pressing a molten thermoplastic resin against a molding surface (30) so as to be adhered and solidified. Body (3)
Is supported by the mold body (4) while securing a space (B) between the molding surface (30) and the back surface (31): (a) the molding surface (30) is Heating means for heating the resin to a temperature not lower than the Vicat softening temperature (T) ° C; (b) setting the molding surface (30) to (Vicat softening temperature (T) -1);
0) cooling means for cooling to a temperature of not more than 0 ° C .; (c) a fluid regulating mechanism having a function of introducing and / or extracting a fluid into the space and adjusting a pressure in the space ; Pressure and pressure applied to the thermoplastic resin
In blow mold having the configuration requirements; pressure in the space by detecting a force control means for controlling the fluid control mechanism so as to balance the pressure for pressing the thermoplastic resin to said molding surface is there. The heating means (a) can be constituted by, for example, mechanisms 70, 71, 72 for supplying a heating medium (heating oil, heating air, etc.) into the space B on the back side of the molding surface 30. Claim 5
The radiant heating means (i) and other heating means are also included in the heating means (a). By heating the molding surface 30 to the Vicat softening temperature (T) ° C. or higher by the heating means (a), the molding surface 30 is clearly transferred to the surface of the resin, and the transfer of the grained surface and the mirror surface is improved. The cooling means (b) can be constituted by, for example, mechanisms 70, 71, 72 for injecting cooling air or cooling water onto the back surface 31 of the molding surface 30 of the mold 3. The cooling surface (Vicat softening temperature (T)
-10) Since the product is quickly cooled to a temperature of not more than ℃, the molded product can be quickly removed from the mold, and the molding cycle can be shortened. The fluid adjusting mechanism (c) is a mechanism for adjusting the fluid to be introduced / exited into the space B. For example, the fluid adjusting mechanism includes a supply-side valve 72, a pipe 71, and a nozzle 70, and a discharge-side pipe 76 and a valve 77. it can. The control means of the above (d),
Based on the pressure in the space B and the pressure applied to the molding surface 30 from the molten resin, it can be constituted by an electronic circuit for controlling the operation of the opening and closing mechanism of the two valves 72 and 77 or software realizing the function thereof. . The means for detecting the pressure in the space B may be not only means for directly detecting the pressure in the space B, but also means for detecting the pressure of the fluid supplied into the space B. The molding surface 30 from the molten resin
The same applies to the means for detecting the pressure applied to. Also,
Since the molding surface 30 of the molding die may be heated and cooled with a medium containing water as a component, the mold body 4 and the mold 3 are subjected to rust prevention measures as necessary. . As a countermeasure, use of a stainless steel, a copper alloy, a ceramic, an aluminum alloy, or the like, which does not easily rust, as a material of the mold can be cited.
Preferably, stainless steel is used. Other measures include passivation treatment of the metal surface (for example, nitriding treatment), application of a rust preventive paint, and application of a silicone-based sol-gel type paint.

[0005] A second aspect of the present invention is a thermoplastic resin in a molten state.
For pressing and adhering the fat to the molding surface (30)
The mold body (3) having the molding surface (30) is attached to the back surface (3) of the molding surface (30).
A space (B) is secured between the mold and the mold body (4).
Lifting to become: (a) the forming surface (30) of the thermoplastic resin Vicat Soft
Heating means for heating to a temperature (T) ° C. or higher temperatures; (b) the forming surface (30) (Vicat softening temperature (T) -1
0) cooling means for cooling to a temperature of not more than ℃; (c) introducing and / or discharging a fluid into the space ;
Fluid regulator having a function of adjusting the pressure in the space
Structure; (D) the molding pressure in said space is the thermoplastic resin
The fluid adjusting mechanism so as to balance the pressure applied to the surface.
Control means for controlling; (e) a supported portion around the mold body and a supporting portion of the mold body corresponding to the supported portion are loosely fitted with play, and the supported portion is thermally expanded. A fitting member provided on the supported portion and the support portion so that a relative displacement generated between the portion and the support portion is absorbed by the play; (f) a fitting member provided on the play portion of the fitting member. A molding die having the following components: For example, the fitting member (e) may be configured such that the convex portion 36 around the mold body 3 is
4, a mechanism for loosely fitting with a play in the corresponding concave portion 46, or conversely, a concave portion (not shown) around the mold 3
This is a mechanism for loosely fitting a convex portion (not shown) of a corresponding portion of the mold body 4 with play into the inside. This mechanism is
It is provided on the whole area or part of the periphery of the mold 3. Since it is loosely fitted with play, even if relative displacement occurs due to thermal expansion between the mold body 3 and the mold body 4, it is possible to absorb the difference and prevent problems such as distortion and damage. . in this way,
According to the second aspect of the present invention, since the connecting portion between the mold body 3 and the mold body 4 is fitted with play, the control means (d) controls the fluid adjusting mechanism (c) to control the space. In order to balance the pressure of the fluid supplied into B with the pressing force applied to the molding surface 30 by the thermoplastic resin, the connecting portion of the fitting member (e) is securely sealed and It is necessary to prevent the fluid from leaking. Therefore, the seal member (f) is provided. As the sealing member, an O-ring 9, an oil seal, synthetic rubber, metal, felt, leather, cork, or the like can be used. With this sealing member, the mold 3 and the mold body
4 can be sealed, so that the heating oil, the heating steam, the cooling air, the cooling water, etc. filled in the space B can be prevented from leaking out of the connection between the mold 3 and the mold body 4. Further, since the heating oil and the like can be sealed in the space B at a desired pressure, the inside of the space B can be set to a desired pressure. Since the molding surface 30 is heated to the Vicat softening temperature (T) ° C. or higher,
It is required that the material has durability at this temperature.

According to a third aspect of the present invention, there is provided the second aspect of the present invention, further comprising: (g) a heat conductivity provided between the supported portion of the mold body and the support portion of the mold body is zero. .001 to 1 [kcal / mh
° C] and the modulus of longitudinal elasticity is 0.1 × 10 ⁴ -100 ×
It is a molding die having a constitutional requirement of 10 ⁴ [kg / cm ² ] of a heat insulating support member. The heat-insulating support member 1 of the above (g)
The thermal conductivity is 0.001 to 1 [kcal / mh ° C], preferably 0.005 to 0.8 [kcal / mh ° C], and more preferably 0.
0.01 to 0.5 [kcal / mh ° C.] and a modulus of longitudinal elasticity of 0.
1 × 10 ^{4 to} 100 × 10 ⁴ [kg / cm ² ], preferably 0.
2 × 10 ⁴ to 40 × 10 ⁴ [kg / cm ² ], more preferably 1
It may be constituted by using a material of × 10 ^{4 to} 20 × 10 ⁴ [kg / cm ² ] and has a thermal conductivity of 0.001 to 1 [kcal / mh].
C], preferably 0.005 to 0.8 [kcal / mhC], more preferably 0.01 to 0.5 [kcal / mhC].
The longitudinal elastic modulus is 0.1 × 10 ^{4 to} 100 × 10 ⁴ [kg / cm ² ]
, Preferably 0.2 × 10 ⁴ to 40 × 10 ⁴ [kg / cm ² ],
More preferably, it may be constituted as a laminated structure using a material of 1 × 10 ^{4 to} 20 × 10 ⁴ [kg / cm ² ]. That is, the mold 3 and the mold body 4 can be insulated from each other, and the mold 3 can be insulated against the pressing force applied from the mold 3 to the mold body 4.
What is necessary is to be able to securely support without rattling. In addition,
The reason why the above range is indicated as the thermal conductivity of the heat insulating support member is that the thermal conductivity is 0.001 [kcal / mh ° C.]
If it is less than that, special materials are required and it is not practical,
If it exceeds 1 [kcal / mh ° C], the desired heat insulating effect cannot be obtained. Further, the reason why the above range is indicated as the longitudinal elastic modulus of the heat insulating support member is that if the longitudinal elastic modulus is less than 0.1 × 10 ⁴ [kg / cm ² ], the rigidity is insufficient and the seal is sufficient. If it exceeds 100 × 10 ⁴ [kg / cm ² ], it becomes difficult to process the heat insulating support. Thermal conductivity is 0.001 to 1 [kcal / mh ° C] and longitudinal elastic modulus is 0.1 ×
Materials of 10 ^{4 to} 100 × 10 ⁴ [kg / cm ² ] include polyarylate, polyether ether ketone, polyphenylene oxide, modified polyphenylene oxide, polyamide, acetal resin, ethylene tetrafluoride resin, ceramics, PC, phenol Resin, urea, melamine, glass, unsaturated polyester and the like. Preferred are phenol resins, urea resins, melamine, and unsaturated polyesters, and more preferred are phenol resins.

According to a fourth aspect of the present invention, in the second or third aspect, instead of (a) and (c) , (h) the molding surface has a Vicat softening temperature of the thermoplastic resin ( T) a molding die having a component feature of: a fluid adjusting mechanism having a function of introducing and / or extracting a heating fluid into the space so as to be heated to a temperature of not less than ° C and adjusting a pressure in the space. It is. The fluid adjusting mechanism of (h) includes the function of (a) for heating the molding surface 30 and the space.
(B) The function of (c) for adjusting the internal pressure is exhibited. As the heating fluid, heating oil, heating steam, or the like can be used.

[0008] The invention of claim 5 is based on claim 2, claim 3,
Or the space according to claim 4, further comprising: (i) heating the molding surface (30) to a temperature equal to or higher than the Vicat softening temperature (T) ° C. of the thermoplastic resin.
(B) a radiant heating means (5) provided in a position facing the back surface (31) of the molding surface (30) and radiantly heating the back surface (31); Type. The radiant heating means 5 of (i) is, for example, a molding surface 30 of the mold 3.
It can be configured by providing a halogen heater 5 so as to face the back surface 31 of the heater. The molding surface 30 to which the molten resin is pressed and adhered is heated not only by the heating fluid sealed in the space B but also by the heat radiated from the halogen heater 5 to rise to the Vicat softening temperature (T) ° C. or higher. To be heated
The molding surface 30 can be cleanly transferred to the surface of the resin, and the transfer of the textured surface and the mirror surface is improved. The fluid sealed in the space B may be heated by the halogen lamp 5.

According to a sixth aspect of the present invention, there is provided a method according to any one of the first to fifth aspects of the present invention, which comprises the steps of:
+100) The modulus of longitudinal elasticity at ℃ is 0.01 to 10 [kg /
cm ² ], preferably in the range of 0.05 to 2 [kg / cm ² ],
More preferably, a hollow parison using a thermoplastic resin in the range of 0.1 to 1 [kg / cm ² ] is supplied, and the pressure in the space is reduced.
Detecting a force and a pressure applied to the thermoplastic resin , pressing the outer surface of the hollow parison against the molding surface with a pressure of 100 kg / cm ² or less so that the outer surface is in close contact with the molding surface and balancing the pressing force. Adjust the pressure in the space, preferably at this time, the air between the parison and the molding surface for the purpose of further improving the transferability by further improving the close contact of the parison outer surface and the molding surface, for example, the air It is discharged to the outside by vacuum suction or the like through a fine gap provided in the molding surface, and the molding surface is heated to Vicat softening temperature (T) ° C. or higher, preferably (Vicat softening temperature (T) +10) ° C. or higher, more preferably (Vicat Heating to softening temperature (T) +20) ℃ or more,
Thereafter, the molding surface is set to (Vicat softening temperature (T) -1).
0) C. or lower, preferably (Vicat softening temperature (T) -2)
0) ° C. or lower, more preferably (Vicat softening temperature (T)
-40) A blow molding method in which a molded product is obtained by cooling to a temperature of not more than ℃. The reason that the above range is indicated as the longitudinal elastic modulus at (Vicat softening temperature (T) +100) ° C. of the thermoplastic resin is that the longitudinal elastic modulus is less than 0.01 [kg / cm ² ]. In the case of (1), drawdown of the parison occurs and stable molding cannot be performed. On the other hand, if the longitudinal elastic modulus exceeds 10 [kg / cm ² ], a large molding pressure is required for forming the parison. This is because a very large blow pressure is required to inflate the parison and press it against the molding surface. As a molding material suitable for this molding method, that is, as a thermoplastic resin having a modulus of longitudinal elasticity at (Vicat softening temperature + 100) ° C. in a range of 0.01 to 10 [kg / cm ² ], for example, AS resin, Graft copolymer (ABS resin) composed of polystyrene, high-impact polystyrene, acrylonitrile-butadiene rubber-styrene, graft copolymer composed of acrylonitrile-butadiene rubber-styrene-α-methylstyrene (heat-resistant A
(BS resin), acrylonitrile-ethylene-propylene rubber-graft copolymer composed of styrene and / or methyl methacrylate (AES resin), acrylonitrile-hydrogenated diene rubber-graft copolymer composed of styrene and / or methyl methacrylate Coalescence, acrylonitrile-
A graft copolymer comprising silicone rubber-styrene and / or methyl methacrylate, polyethylene, polypropylene, polycarbonate, polyphenylene ether,
Polyoxymethylene, nylon, methyl methacrylate-based polymer, polyethersulfone, polyarylate, vinyl chloride, maleimide compound-copolymer of styrene and / or acrylonitrile and / or α-methylstyrene, rubbery polymer- Maleimide compounds-graft copolymers composed of styrene and / or acrylonitrile and / or methyl methacrylate and / or α-methylstyrene, and the like, and composites thereof, and resins obtained by adding fillers to these composites. Examples of molded articles suitably molded by this molding method include housing, sports products, playground equipment, vehicle products, furniture products, sanitary products, building material products, kitchen products, and the molded articles. Are molded articles having a foamed layer in a hollow portion, molded articles produced by a multilayer blow molding method, and molded articles plated, sputtered, vapor-deposited, and painted. As specific examples of these molded articles, as the housing, for example, a cooler box, a TV, an audio device, a printer, a fax, a copier, a game machine, a washing machine, an air conditioner,
There are refrigerators, vacuum cleaners, attache cases, musical instrument cases, tool boxes, containers, camera cases, and the like. Sports products include, for example, swimming boards, surfboards,
Windsurfing, skiing, snowboarding, skateboarding, ice hockey stick, curling ball, gateball racket, tennis racket, canoe,
There are boats. Examples of the playground equipment include a bat, a block, a building block, a fishing gear case, a pachinko underframe, and the like. Products for vehicles include, for example, air spoilers, doors, bumpers, fenders, bonnets, sunroofs,
There are rear gate, wheel cap, instrument panel, glove box, console box, armrest, headrest, fuel tank, driver's seat cover, trunk tool box, etc. Furniture products include, for example, drawers,
Desk top plate, bed top plate / bottom plate, mirror base frame plate, grated box plate / front door, chair back plate / bottom plate, tray / tray, umbrella stand, vase, medicine box, hanger, makeup box, storage box board, book stand, office work There are a desk top plate, an OA desk top plate, and an OA rack. Sanitary products include, for example, shower heads, toilet seats, toilet plates, drain pans, water tank lids, vanity doors, bathroom doors, and the like. Examples of building material products include ceiling boards, floor boards, wall boards, window frames, doors, benches, and the like. Examples of kitchen products include cutting boards and kitchen doors. Examples of the molded article having the foam layer in the hollow portion include a refrigerator front door and a cooler box. Examples of the molded article manufactured by the multilayer blow molding method include a fuel tank and the like. Examples of the molded product on which the molded product is plated, sputtered, vapor-deposited, and painted include, for example, vehicle exterior parts and electronic equipment soldering. In addition, these are illustrations, and molded articles other than these can also be suitably molded.

According to a seventh aspect of the present invention, the longitudinal elastic modulus at (Vicat softening temperature (T) +100) ° C. is set in a closed mold surrounded by the molding surface of the molding die of the second to fifth aspects. A thermoplastic resin of 0.01 to 10 [kg / cm ² ] is injected in a molten state, and the pressure in the space is adjusted so as to be balanced with the pressing force, and the molding surface is vicat softening temperature (T) ° C. Above, preferably (Vicat softening temperature (T) +
10) C. or higher, more preferably to (Vicat softening temperature (T) +20) .degree. C. or higher, and thereafter, the molding surface is heated to Vicat softening temperature ((T) -10) .degree. C. or lower, preferably (Vicat softening temperature (T) This is an injection molding method in which a molded product is obtained by cooling to a temperature of -20) C or lower, more preferably (Vicat softening temperature (T) -40) C or lower. In the above, as the thermoplastic resin having a longitudinal elastic modulus at (Vicat softening temperature + 100) ° C. in the range of 0.01 to 10 [kg / cm ² ], for example, AS resin, polystyrene, high-impact polystyrene, Graft copolymer (ABS resin) composed of acrylonitrile-butadiene rubber-styrene, graft copolymer composed of acrylonitrile-butadiene rubber-styrene-α-methylstyrene (heat-resistant A
(BS resin), acrylonitrile-ethylene-propylene rubber-graft copolymer composed of styrene and / or methyl methacrylate (AES resin), acrylonitrile-hydrogenated diene rubber-graft copolymer composed of styrene and / or methyl methacrylate Coalesced, SX, polyethylene, polypropylene, polycarbonate, polyphenylene ether, polyoxymethylene, nylon, methyl methacrylate polymer, polyether sulfone, polyarylate, vinyl chloride, maleimide compound-styrene and / or Copolymer of Acrylonitrile and / or α-Methylstyrene, Rubbery Polymer-Maleimide Compound-
Examples include graft copolymers of styrene and / or acrylonitrile and / or methyl methacrylate and / or α-methylstyrene, and composites thereof, and resins obtained by adding fillers to these.

[0011]

【Example】

First Embodiment FIG. 1 shows an entire configuration of a first embodiment, and FIG. 2A shows a mold of the first embodiment. FIG. 3 shows a mounting structure of a corner portion of a molding die common to each embodiment. As shown in FIG. 3, each molding die is a mold 3 having a molding surface 30.
And a mold body 4 for supporting the mold body 3. The mold 3 and the mold body 4 are both made of stainless steel. As shown in FIG. 3, a supported plate 36 projecting around the periphery of the mold body 3 has a play A in a groove 46 provided in the mold body 4 so as to correspond to the supported plate 36. , So that the mold 3 is supported by the mold body 4. The groove 46 is formed by attaching a main body plate 400 having an overhang 400a to a main body 401 with bolts 403. Also, as shown in FIG. 3A, four main body plates 400 arranged in a square shape when viewed from above the molding surface 30.
Is approximately 0.1 [m
m]. Further, a heat insulating layer (heat insulating support member) 1 made of a phenol resin having a thickness of 10 [mm] is provided on the surfaces of both opposing walls of the groove 46. An O-ring 9 is fitted in the gap. For this reason, heat during molding of the molten resin
4 is thermally expanded and a relative misalignment occurs between the supported plate 36 and the groove 46, the misalignment is absorbed by the play A and adversely affects (bending, distortion, and life of the mold 3). Is shortened). Moreover, a precise molded product can be obtained. Further, the mold body 3 is attached to the mold body via a heat insulating layer 1 of a phenol resin which satisfies the conditions of the present invention (material having a longitudinal elastic modulus of 0.1 × 10 ^{4 to} 100 × 10 ⁴ [kg / cm ² ]). Since it is supported, problems such as rattling are prevented. Further, since the space B formed between the back side of the mold 3 and the mold body 4 is sealed by the O-ring 9, the valve
The heating steam supplied to and enclosed in the space B during heating through the piping 72, the pipe 71, and the nozzle 70, and the cooling air similarly enclosed in the space B during cooling, form a connection between the mold 3 and the mold body 4. (The portion where the mold body 3 is supported by the mold 4 = the portion of the supported plate 36 and the groove 46), a decrease in the pressure in the space B generated at that time, and a molding caused by the decrease. surface
30 bending is prevented. The heated steam / cooled air injected into the space B is discharged through the pipe 76 and the valve 77. As shown in FIG. 3B, a phenol resin layer 22 having a thickness of 10 [mm] and an asbestos layer 21 having a thickness of 2 [mm] are provided on the inner surface of the mold body 4 facing the space B. Is provided, the heat of the heating medium in the space B escapes through the mold body 4 and the external heat passes through the mold body 4 The problem of being transmitted to the cooling water is prevented. Therefore, a decrease in the temperature of the heated steam supplied into the space B is prevented, and the transferability and the dimensional stability of the molding surface are improved. In the first embodiment, ABS45A (Nippon Synthetic Rubber Co., Ltd.) was used as the thermoplastic resin material.
IPB-EP-55 (manufactured by Ishikawajima-Harima Heavy Industries, Ltd.) as a blow molding machine using a Vicat softening temperature of 105 ° C) and a modulus of longitudinal elasticity at 205 ° C of 0.3 [kg / cm ² ]). And blow molding was performed at the timing of FIG. 4 under the following conditions. That is, the conditions are as follows: (1) Extruder temperature: 220 ° C. (2) Mold clamping force: 15 ton (3) Blow pressure of parison P: 6 kg / cm ² (4) Heating steam supplied to heating space B of molding surface 30 Pressure: 6 kg / cm ² Final temperature of molding surface 30: 140-150 ° C Heating and holding time of molding surface 30: 10 sec (5) Cooling of molding surface 30 Pressure of cooling water and air supplied to space B: 6 kg / cm ² Final cooling temperature of the molding surface 30: 70 ° C. Cooling holding time of the molding surface 30: 60 seconds Total process time: 150 seconds. In the above, the pressure of the heated steam and the blow pressure of the parison P were balanced by controlling the opening degrees of the valves 72 and 77 by a controller based on the detection values of the pressure sensors 61 and 62. The details will be described later. Comparing the molded product (Example product) molded in this way with the molded product (Comparative product) molded without heating (4) heating to supply the heating steam into the space B as described above, Has a surface gloss of 9
At 5%, the R of the corner portion was 0.5 or less and there was no deformation, whereas the surface gloss of the comparative example product was 20% or less and the R of the corner portion was 0.5 or more and deformed. In other words, the example product had a better transfer of the molding surface, was able to accurately mold a molded product having a small R at the corners which could not be obtained by conventional blow molding, and had excellent dimensional stability. The outside dimensions of the mold: 460 (L) x 560 (W) x 720
(H) [mm] Molded product size: 120 (L) x 40 (W) x 480 (H) [mm].

Next, the control of the mold according to the first embodiment will be described with reference to FIGS. Extruder 100
When a signal indicating that the injection of the parison P has been completed is sent (S11; YES), the mold opening / closing mechanism is driven to start mold clamping (S13). When the mold clamping is completed (S14; YES), the parison blowing mechanism is driven to start blowing air into the parison P, the parison suction mechanism is driven to start parison suction, and the valve 72 is opened and heated. The introduction of steam is started (S15). When the blowing pressure detecting sensor 61 detects that the blowing pressure in the parison P has reached a predetermined set value (in this case, 6 [kg / cm ² ]) (S1).
6; YES), control for maintaining the blow pressure in the parison P at the set value is started (S19). This control monitors the detection value of the blow pressure detection sensor 61 and
In order to keep the blow pressure in P at the above set value,
This is a control for fine adjustment of the blowing pressure into the parison P. That is, when the blow pressure in the parison P deviates from the above set value by more than a certain value, the parison P
In this control, the pressure in the parison P is increased or decreased by driving the blowing mechanism. If the blow pressure in the parison P does not reach the set value even after a sufficient time has elapsed for the blow pressure in the parison P to reach the set value (S16; NO, and, S17; YES ), It is considered that some abnormality has occurred on the blowing side, and a warning or the like is given to that effect. Next, the pressure detection sensor 62 in the space B
The pressure of the heated steam inside the tank is set to a predetermined value (in this case, 6 [kg /
cm ² ]) (S21; YES), the space B
The control for maintaining the heating steam pressure in the chamber at the set value is started (S25), and a timer for managing the heating continuation time (10 [sec]) is started (S27). The control in step S25 is a control for monitoring the detection value of the pressure detection sensor 62 in the space B and finely adjusting the opening of the valve 72 so that the heating steam pressure in the space B is maintained at the set value. It is. That is, when the pressure in the space B deviates from the set value by more than a certain value, the opening and closing mechanism of the valve 72 is driven in response to the pressure to increase or decrease the pressure in the space B. If the heating steam pressure in the space B does not reach the set value even after a sufficient time has elapsed for the heated steam pressure in the space B to reach the set value (S21; NO, and, S23 ; YES), it is considered that some abnormality has occurred in the heating steam supply system, and a warning or the like is given to that effect. When the time managed by the heating timer started in step S27 elapses (S
29; YES), the control for maintaining the pressure of the heated steam in the space B at the set value is terminated, and the valve 77 is opened to open the space B.
The steam in B is discharged (S31). In addition, steam / cooling water
When the air switching mechanism is driven and the valve 72 is opened, the cooling water is injected to the molding surface back surface 31 and the cooling air space B
Is started (S33). When the pressure detection sensor 62 in the space B detects that the pressure of the cooling air in the space B has reached a predetermined set value (in this case, 6 kg / cm ² ) (S35; YES) At the same time, the control for maintaining the cooling air pressure in the space B at the set value is started (S39), and the timer for managing the cooling continuation time (60 [sec]) is started (S41). . The control in step S39 is a control for monitoring the detection value of the pressure detection sensor 62 in the space B and finely adjusting the opening degree of the valve 72 so that the cooling air pressure in the space B is maintained at the set value. It is. That is, when the pressure in the space B deviates from the set value by more than a certain value, the opening and closing mechanism of the valve 72 is driven in response to the pressure to increase or decrease the pressure in the space B. If the cooling air pressure in the space B does not reach the above set value even after a sufficient time has elapsed for the cooling air pressure in the space B to reach the above set value,
(S35; NO, and, S37; YES), it is considered that some abnormality has occurred in the cooling air supply system, and a warning to that effect is issued. When the time managed by the cooling timer started in step S41 has elapsed (S43; YES), the control for maintaining the pressure of the cooling air in the space B at the set value is terminated, and the valve 77 is opened. The cooling air in the space B is discharged (S45). Thereafter, when the pressure detection sensor 62 in the space B detects that the pressure in the space B has decreased to the set value (S47; YES), the blowing into the parison P is terminated (S4).
9) Further, the adsorption of parison P is terminated (S51). The control of the mold according to the first embodiment is performed as described above. In the above description, an example of a control method in which blow blowing into the parison is performed by side blowing is described. That is, the control of the type in which the blowing into the parison is started (S15) after the mold clamping is completed (S14; YES) is described as an example. However, the invention is not limited to this type of control. That is, it is naturally applicable to a control method in which blow-in to the parison is performed by blow-up or blow-down. In this case, for example, after the injection from the extruder is completed, the lower end of the parison is sealed by pre-pinch, and then the blowing into the parison (upward blowing) may be started.

Second Embodiment FIG. 2B shows a mold according to a second embodiment. The overall configuration is the same as in the first embodiment (see FIG. 1). Hereinafter, the first
The configuration different from that of the first embodiment will be described, and the description of the same configuration as the first embodiment will be omitted. In the second embodiment, the space B
A configuration was used in which heating was performed by a halogen lamp 5 provided inside. The total output of the halogen lamp 5 is 60 [kW] (30
[kW]), and the final temperature of the molding surface 30 is the same as that of the first embodiment. Also in the case of the second embodiment, the same effects as in the case of the first embodiment were obtained with respect to the surface glossiness and the R of the corner portion. Regarding the dimensional accuracy,
Although the product of the example was 5/1000, the product of the comparative example was 10/1000 or more, and the accuracy of the product of the example was excellent.

Third Embodiment Injection molding was carried out using a molding die represented as a schematic diagram equivalent to FIG. 1A. That is, as a thermoplastic resin material, ABS15 (Vicat softening temperature of 100 ° C. manufactured by Japan Synthetic Rubber Co., Ltd.) and a longitudinal elastic modulus at 200 ° C. of 0.2 [k]
g / cm ² ]) and the injection molding machine IS170FA3-
Using 5A (manufactured by Toshiba Corporation), injection molding was performed under the following conditions. That is, the conditions are as follows: (1) Cylinder temperature: 210 ° C. (2) Gate: Two places of side gates (3) Heating of forming surface 30 Pressure of heated steam supplied to space B: 6 kg / cm ² Final arrival of forming surface 30 Temperature: 140-150 ° C. (4) Cooling of molding surface 30 Pressure of cooling water and air supplied to space B: 6 kg / cm ² Final cooling temperature of molding surface 30: 50 ° C. In the above, the pressure of the heated steam and the blow pressure of the parison P were balanced by controlling the opening degrees of the valves 72 and 77 by a controller based on the detection values of the pressure sensors 61 and 62. The details will be described later. The molded product (Example product) molded in this manner is used in combination with (3) molding surface 30
In comparison with the molded product (comparative example product) molded without heating by enclosing the heating oil, the surface glossiness of the example product was 95%, no weld was observed, and no deformation was observed. The surface gloss of the example product was 85%, and a weld was observed and deformation occurred. That is, the example product had better transfer of the molding surface, was superior in preventing weld, and had good dimensional stability. The outside dimensions of the mold: 400 (L) x 400 (W) x 350
(H) [mm] Molded product dimensions: 50 (L) x 3.2 (W) x 80 (H) [mm].

[0015] The (a) another embodiment Figure 9 In the structure of FIG. 2 (a), the mold body
A plurality of rod-shaped reinforcing ribs 6 are provided between the back side of the mold body 3 and the inner surface of the mold body 4 (the surface facing the back surface 31 of the mold body 3). It is a supporting structure. 9 (b) shows the structure between the back side of the mold 3 and the inner surface of the mold body 4 (the surface facing the back 31 of the mold 3) in the structure of FIG. 2 (b). Multiple bar-shaped reinforcing ribs 6
The reinforcing rib 6 is used to support the back side of the mold 3. Thus, in the other embodiment, the reinforcing rib
6, the pressure of the heating steam or cooling water supplied to the space B while being pressure-controlled through the valve 72, the pipe 71, and the nozzle 70 is applied to the pressure applied from the molding surface 30 side of the mold 3 (Parison Even when the pressure is smaller than (blow pressure / injection pressure), the mold body 3 can be supported, and the deformation of the molded product due to the bending of the molding surface 30 can be prevented.

[0016]

According to the present invention, since the molding surface is relatively thin and has good heat conductivity and can be quickly heated to a desired temperature, a resin molded product having a good mirror surface or grain surface and excellent dimensional accuracy can be obtained. It can be produced with a relatively short cycle time and a relatively simple process. Despite the fact that the molding surface is relatively thin and the mechanical strength is not very large, the pressure in the space on the back side of the molding surface can be adjusted so as to balance the pressure from the molten resin side. Can be prevented,
The mold has excellent durability and long life.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing an overall configuration of an apparatus including a mold according to a first embodiment.

FIGS. 2A and 2B are schematic diagrams illustrating a mold according to an embodiment, in which FIG. 2A illustrates a first embodiment and FIG. 2B illustrates a second embodiment.

3A and 3B show a mounting structure of a corner portion of each molding die of the embodiment, wherein FIG. 3A is a view as viewed from the molding surface 30 side, and FIG. 3B is a sectional view taken along the line II of FIG.

FIG. 4 is a timing chart showing steps of a blow molding method according to an embodiment.

FIG. 5 is a flowchart showing a part of control of the mold according to the first embodiment;
Chart.

FIG. 6 is a flowchart showing a part of control of the mold according to the first embodiment.
Chart.

FIG. 7 is a flowchart showing the rest of the control of the mold according to the first embodiment.
Chart.

FIG. 8 is a block diagram showing signals input to and output from the controller according to the first embodiment.

FIG. 9 is a schematic view showing a mold according to another embodiment, and FIG.
Shows another embodiment corresponding to the first embodiment, and (b) shows another embodiment corresponding to the second embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Heat insulation layer (heat insulation support member) 2 Heat insulation layer (heat insulation member) 3 Mold 30 Molding surface 4 Mold main body 5 Halogen lamp 6 Bar-shaped reinforcing rib 61 Pressure sensor (in parison P) 62 Pressure sensor (in space B)

────────────────────────────────────────────────── ─── Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI B29C 49/64 B29C 49/64 // B29L 22:00 B29L 22:00 (72) Inventor Fumio Kurihara 2-chome Tsukiji, Chuo-ku, Tokyo No. 11-24 Japan Synthetic Rubber Co., Ltd. (56) References JP-A-1-285322 (JP, A) JP-A-7-1459 (JP, A) JP-A-7-297004 (JP, A) JP 58-38126 (JP, A) JP-A-5-177540 (JP, A) JP 2-40498 (JP, B2) (58) Fields investigated (Int. Cl. ⁷ , DB name) B29C 33 / 02 B29C 33/38 B29C 45/26 B29C 45/73 B29C 49/48 B29C 49/64

Claims (7)

(57) [Claims] 1. A mold provided with a molding surface for pressing and adhering a molten thermoplastic resin to a molding surface so as to be adhered and solidified, and a mold is provided by securing a space between the molding surface and the back surface of the molding surface. A blow molding mold having the following components (a), (b), (c) and (d) supported by a main body: (a) The molding surface is a Vicat softening temperature (T) of the thermoplastic resin. Heating means for heating to a temperature of not less than ℃; (b) the molding surface (Vicat softening temperature (T) -10)
(C) a fluid adjusting mechanism having a function of introducing and / or extracting a fluid into and from the space and adjusting a pressure in the space; (d) a pressure in the space. Control means for detecting the pressure applied to the thermoplastic resin and controlling the fluid adjusting mechanism so that the pressure in the space is balanced with the pressure pressing the thermoplastic resin against the molding surface. 2. A mold provided with a molding surface for pressing and adhering a molten thermoplastic resin to a molding surface so as to be adhered and solidified, and a mold is provided by securing a space between the molding surface and the back surface of the molding surface. (A) (b) (c) (D)
(E) a molding die having the respective constituent requirements of (f): (a) heating means for heating the molding surface to a temperature equal to or higher than the Vicat softening temperature (T) ° C. of the thermoplastic resin; (b) the molding Surface (Vicat softening temperature (T) -10)
(C) a fluid adjusting mechanism having a function of introducing and / or taking out a fluid into the space and adjusting a pressure in the space; (D) a pressure in the space. Means for controlling the fluid adjusting mechanism so as to balance the pressure with which the thermoplastic resin is pressed against the molding surface; and (e) a supported portion around the mold and the mold corresponding to the supported portion. The supporting portion of the main body is loosely fitted with play, and the relative displacement generated in the supported portion and the supporting portion due to thermal expansion is absorbed by the play, so that the supported portion and the supporting portion are connected to each other. (F) A sealing member provided at the play portion of the fitting member. 3. The method according to claim 2, further comprising:
(G) a thermal conductivity provided between the supported portion of the mold body and the support portion of the mold body, having a thermal conductivity of 0.001 to 1 [kcal / mh]
° C] and the modulus of longitudinal elasticity is 0.1 × 10 ⁴ -100 ×
10 ⁴ [kg / cm ² ] heat insulating support member. 4. A molding die according to claim 2 or 3, wherein said molding die has the following constitutional requirements instead of said (a) and (c): (h) said molding surface A fluid regulating mechanism having a function of introducing and / or extracting a heating fluid into the space so as to heat the thermoplastic resin to a temperature equal to or higher than the Vicat softening temperature (T) ° C. and adjusting a pressure in the space. 5. The molding die according to claim 2, further comprising: (i) a vicat of the thermoplastic resin, wherein the molding surface is formed of the thermoplastic resin. Radiation heating means provided in the space and at a position facing the back surface of the molding surface to heat the back surface to a temperature equal to or higher than the softening temperature (T) ° C. for radiantly heating the back surface. 6. A modulus of longitudinal elasticity at (Vicat softening temperature (T) +100) ° C. between the molding surfaces of the molding die according to claim 1 to 0.01 [kg / cm ^2]. A hollow parison made of a thermoplastic resin of the type described above, and detecting the pressure in the space and the pressure applied to the thermoplastic resin so that the outer surface of the hollow parison is placed on the molding surface by 10%.
It is pressed with a pressure of 0 [kg / cm ² ] or less to make it adhere, and the pressure in the space is adjusted so as to balance the pressing force, and the molding surface is heated to a Vicat softening temperature (T) ° C. or higher, and thereafter , And the molding surface is (Vicat softening temperature (T) -1)
0) A blow molding method in which a molded product is obtained by cooling to a temperature of not more than ° C. 7. The method according to claim 2, wherein the molding die (Vicat softening temperature (T)) is enclosed in a closed mold surrounded by the molding surface.
+100) The modulus of longitudinal elasticity at ℃ is 0.01 to 10 [kg /
cm ² ] of a thermoplastic resin in a molten state, and the pressure in the space is adjusted so as to be balanced with the pressing force. The molding surface is heated to a Vicat softening temperature (T) ° C. or higher. Vicat softening temperature ((T) -1)
0) An injection molding method in which a molded product is obtained by cooling to a temperature of not more than ° C.