JPH1029215A - Mold for molding plastic product and manufacture of the mold - Google Patents

Abstract

PROBLEM TO BE SOLVED: To contrive improvement of the quick heating and cooling and temperature controllability of a mold by a method wherein an insert piece, which is formed by assembling a temperature-controlling molding surface member, in which a heating medium circulating flow path is formed between a thin plate and a covering layer by eluting cavity molding material, in a packing, is assembled onto the molding surface of the mold. SOLUTION: By eluting wax under heat, a heating medium circulating flow path is formed so as to obtain a temperature controlling molding surface member 1. By assembling the temperature controlling molding surface member 1 in a packing 10, an insert piece 12 is produced. At a cavity 22 side, resin is quickly heated up under high temperature at its charging by the heating medium flowing in the heating medium circulating flow path formed on the rear surface of the thin plate of a mold surface quick heating and cooling insert piece 12. After that, the resin is quickly cooled and solidified under low temperature and finally removed from a mold 20. The heating medium flowing in the heating medium circulating flow path is supplied from a heating medium temperature controller, with which quick heating and cooling can be possible.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mold for obtaining a plastic product having a high quality surface by heating or cooling a mold surface temperature in a short time with high precision during the molding process using a plastic resin as a material. And the manufacturing method of this mold.

[0002]

2. Description of the Related Art In conventional plastic molding in which a mold is used at room temperature, a material resin such as a molten thermoplastic resin rapidly cools, solidifies, and shrinks in the mold. In addition to appearance defects such as welds, flow marks, sink marks, etc., fillers such as glass with small shrinkage included in the resin for reinforcing the mechanical strength of the resin,
Rubber particles such as butadiene are selectively left on the resin surface,
This forms fine irregularities or portions having different optical characteristics on the resin surface, thereby impairing the appearance of a highly glossy product surface. Such poor appearance and poor gloss reduce the value of the product by impairing the appearance of the product, and also impair uniform appearance when painting the product surface, impair the aesthetic appearance, and increase the cost for repair. There is a problem.

[0003] The above-mentioned poor appearance and poor gloss are caused by controlling the resin flow at the time of filling the resin, reducing the amount of fillers and rubber particles contained in the material resin, and reducing the particle size. Although improvement can be made to some extent by the improvement of itself, the most effective means for preventing the appearance defect from occurring is to heat the portion on the visible surface side of the mold where the material resin flows to a high temperature.

[0004] Based on such a concept, there has been proposed a method of heating the mold surface on the visible side of the product by, for example, an electric heater. However, this method has a problem in that it takes a long time for heating, the molding cycle is extended, and the product cost is increased. Therefore, there is a proposal for improving the temperature responsiveness of the mold so as to shorten the time required for heating the mold.

[0005] A mold in which an induction coil is provided on the outer periphery of the mold (Japanese Utility Model Laid-Open No. 62-111182). A high-frequency induction coil made of a copper pipe is provided in a mold so that cooling water flows in the pipe (Japanese Patent Laid-Open No. 63-1).
No. 5707). One in which a movable insert provided with an electric heater can be taken in and out of a mold (JP-A-63-15719). A device for rapidly heating, cooling, or switching between heated and cooled media for supplying the mold temperature adjusting medium to the mold outside the mold, and supplying the supplied heating and cooling medium to the temperature adjusting medium in the mold. A device in which a mold can be heated and cooled by passing through a circulation path (JP-A-62-15707, JP-A-62-15707,
JP-A-2-208918, JP-B-7-25115).

[0006]

As is clear from the above-mentioned known examples, the poor appearance of the product can be improved by heating the surface where the material resin flows on the visible surface side of the mold to a high temperature. This increases the molding cycle, lowers productivity, and raises product costs. In particular, regarding the gloss defect and warpage, when the mold is heated to a high temperature and then rapidly cooled, a molded product with the highest gloss and a molded product without warpage can be obtained. For this purpose, it is necessary to perform not only rapid heating but also rapid cooling. In the improvement of poor gloss, simply heating and molding at a high temperature has a limit on the height of the gloss that can be obtained, and if the temperature control accuracy is insufficient and the temperature becomes too high, the shrinkage of the material resin will increase. And filler particles such as glass and rubber particles such as butadiene are left on the resin surface due to post-shrinkage and the like, which causes a problem of poor gloss again. Therefore, a mold structure capable of rapidly heating and cooling the mold surface is indispensable for improving poor appearance, poor gloss, and warpage of a product.

[0007] Also, regarding the method of heating the mold surface, the above-mentioned known examples have the following problems. In the case where the induction coil is provided, there are many restrictions on the incorporation into the mold, and the mold becomes large. When the movable insert having the electric heater is provided, the mold must be provided with an insertion portion for the movable insert, and the mold structure becomes complicated. In addition, the heating means is not versatile, and the cooling is performed by natural cooling, so that the molding cycle becomes longer. Heating from an external device,
Heating and cooling the mold surface by passing the cooling medium through the temperature control medium circulation path in the mold has the versatility and the mold structure does not require special processing, but on the other hand, However, when a temperature control medium circulation path in a mold in a normally provided category is used, the heat capacity of a mold portion to be heated and cooled is large, causing a temperature loss, and it takes time for heating and cooling. In addition, since the temperature response of the mold surface is finally slow, there is a problem that the temperature control accuracy is deteriorated. The present invention has been made in view of the above circumstances. In molding plastic products, by improving rapid heating, cooling and temperature controllability, high quality, high gloss, and warpage without poor appearance are provided. It is an object of the present invention to provide a mold capable of molding a plastic product having no resin and a method of manufacturing the mold.

[0008]

The configuration of the present invention is as follows. 1. On the back surface of the molding surface forming thin plate according to the surface shape of the product, to form a circulation channel with a cavity molding material that can be melted later, then form a coating layer on the surface of the circulation channel, Thereafter, the cavity molding material is melted out to form a heat medium circulating flow path between the thin plate and the coating layer to produce a temperature control molding surface member. Next, the temperature control molding surface member is formed into a molding surface of a mold. A method for manufacturing a mold for molding plastic products, which is incorporated in a mold. 2. 2. The method for producing a plastic product molding die as described in 1 above, wherein wax is used as the cavity molding material. 3. 3. The method for producing a plastic product molding die according to the above 1 or 2, wherein a metal coating layer is formed on the surface of the circulation channel by electroforming. 4. 3. The method for producing a metal mold for forming a plastic product according to the above item 1 or 2, wherein a metal coating layer is formed on the surface of the circulation channel by a plating method.

[0009] 5. Close the front side of the master having the same shape as the product surface, form a circulation channel with a cavity molding material so that it has the same three-dimensional shape and high density with respect to the product surface, and immerse it in the electroforming tank 3. The method for producing a plastic product molding die according to the above item 1 or 2, wherein the thin plate and the coating layer are integrally molded at the same time. 6. After forming a circulation channel with a cavity molding material that can be melted later on the back surface of the thin plate according to the surface shape of the product, a metal coating layer is formed on the surface of the circulation channel, and then the cavity molding material is formed. To form a molding surface member for temperature control in which a heat medium circulation channel is formed between the thin plate and the coating layer, and this is incorporated into a backing to form a insert. Mold for molding plastic products, which is built into the product.

[0010] 7. 7. The plastic product mold according to the above item 6, wherein a planar heat medium circulation channel is formed on the back surface of the thin plate so as to have the same three-dimensional shape and high density with respect to the product surface. 8. 8. The mold for molding a plastic product according to 6 or 7, wherein the turbulence generating member is incorporated in the heat medium circulation channel. 9. 9. The plastic product molding die as set forth in 6 or 7 or 8, wherein a temperature control molding surface member is incorporated only on the visible surface side of the product. 10. 10. The mold for molding a plastic product according to the above 6 or 7, or 8 or 9, wherein the molding surface member for temperature control is incorporated only in a part of the molding surface in contact with the product. 11. 6 or 7 or 8 or 9 or 10 or 10 wherein a heat insulating layer is formed between the back surface of the temperature control forming surface member and the backing mounting surface when incorporating the temperature control forming surface member into the backing.
The mold for molding plastic products as described.

[0011]

[Function] A high-temperature heat medium is supplied and circulated in the heat medium circulation channel of the temperature control molding surface member incorporated in the molding surface of the mold at the time of molding, and the molding surface of the resin-filled product is rapidly cooled. Heat. Then, when the filling is completed, the medium is switched to a low-temperature heat medium, and the low-temperature heat medium circulates in the heat medium circulation channel, thereby rapidly cooling the molding surface of the molded article. The turbulence generating member incorporated in the heat medium circulation flow channel generates turbulence such as contraction, expansion, and swirling flow in the circulating heat medium to increase heat transfer efficiency.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION A thin plate of a molding surface member for temperature adjustment incorporated in a molding surface of a mold and a heat medium circulation channel on the back surface thereof are formed, for example, in a three-dimensional shape along the product shape. The temperature control molding surface member may be directly incorporated into the mold, but it is difficult to assemble the mold and to reduce the heat capacity of the surface of the mold to reduce the heat response of the mold surface, the responsiveness during cooling, and the temperature control. To improve moldability and thereby control the mold surface temperature to a high temperature in a short time without extending the molding cycle, or to control a low temperature to produce a high-quality, high-gloss and warp-free product without poor appearance In this case, it is preferable that a temperature control molding surface member is incorporated into a backing via a heat insulating layer to produce an insert, which is incorporated into all or a part of the molding surface of a mold (cavity).

A feature of the mold is that a heat medium circulating flow path is formed on the molding surface of the mold along the molding surface. In particular, the flow path is not limited to the case where a hole is formed in the mold material, but also has a limitation on the bending radius when formed near the mold surface using a metal tube such as copper. Particularly, in the case of a three-dimensional mold, it was difficult, but in the case of the present invention, firstly, a circulation channel is formed on the back surface of the thin plate with wax or the like, and the surface is coated by electroforming or plating.
Since the wax or the like is dissolved to form the flow path, the flow path can be formed at an arbitrary position and with an arbitrary shape and diameter. Therefore, there is no limitation on the flow path and the shape, and it can be arranged at a high density at a position close to the mold surface, and there is no problem even if it has a three-dimensional complicated shape.

As the cavity molding material for forming the flow path, aluminum, a low melting point alloy or compound, a water-soluble polymer, or the like can be used other than wax as long as it can be eluted later. As a method for dissolving these materials, there is a method of immersing in an alkaline solution, heating, or the like.

The thinner the space between the thin plate (molding surface of the mold) and the heat medium circulation flow path, the thinner it is better in consideration of the mold temperature responsiveness. However, 5 mm is sufficient to withstand the mold internal pressure during molding. The above is desirable. However, even if the plate thickness is small, if the required strength can be obtained by forming the heat insulating layer on the back surface side of the heat medium circulating channel with a resin type material or the like, the heat conduction can be immediately reduced to 5 mm or less to enhance the immediate effect. Good.

The diameter of the heat medium circulating flow path is preferably smaller in order to increase the Reynolds number and increase the heat exchange effect by utilizing high density in the mold and increasing the flow rate of the internal fluid. It is desirable that the diameter is about 5 mm or less. When silicone oil or the like is used as a heat medium for temperature adjustment when molding at a high mold temperature, the Reynolds number is small and a laminar flow is often used. For example, it is desirable to disturb the flow of the fluid by inserting a baffle plate or to form a protrusion in the flow path to form a turbulent flow in order to increase the heat transfer rate. Also, if it is difficult to insert a baffle plate or the like into the flow path, a baffle plate or the like may be placed at the entrance and exit of the flow path and a part of the way, or a projection may be put in advance in wax or the like. , The flow contracts through the shape of wax, etc.
It is also possible to adopt a method of forming a heat medium circulation channel in a complicated shape so as to form a diverging or swirling flow.

Next, the cross section of the heat medium circulating channel is circular,
Any shape such as a square, an irregular shape, or a flat surface may be used, but a trapezoidal shape is preferable in consideration of heat transfer and the throwing power of the electroformed layer or the plated layer.

On the back side of the heat medium circulating flow path, a heat insulating layer is formed of a resin material or the like to reduce the heat capacity of the mold portion for controlling the temperature and to improve the controllability and response of the mold surface temperature. good. As the heat insulating layer, a polymer material such as a plastic having low thermal conductivity, a ceramic or a material obtained by mixing a filler for reinforcement, a porous metal such as a foamed metal, or the like can be used.

The resin that can be molded using the mold according to the present invention includes polyolefin resin, polystyrene resin, ABS
Not only general-purpose resins such as resins, industrial resins such as polycarbonate resins and polyamide resins, but also those obtained by mixing various resins and those obtained by mixing reinforcing agents can be used.

As described above, the mold surface temperature can be accurately determined.
Using a mold for plastic product molding that can heat and cool effectively in a short period of time, after rapidly heating the surface temperature of the mold on the visible side of the product to near the glass transfer temperature of the resin when filling the resin, quenching and cooling the mold temperature When injection molding is performed, a solidified layer hardly develops on the resin surface in contact with the mold surface on the visible surface side of the high-temperature product, and is easily deformed, so it solidifies on the resin surface at the usual low mold surface temperature. Layers develop and form rapidly,
Product appearance defects such as flow marks and welds to be stored do not occur. In addition, the release of the resin is delayed because the resin is sufficiently adhered to the mold surface and the transferability is good. During this time, the solidified layer develops to a sufficient strength, so that the influence of the heat shrinkage of the resin is small. Appearance defects caused on the product surface due to, for example, dent-like sink marks, or poor gloss due to selective residual of rubber particles such as butadiene or fillers such as glass or glass filler with small shrinkage in the resin material. And a high-quality product without appearance defects can be obtained.

In particular, regarding gloss, when the mold temperature control accuracy is insufficient and the temperature is too high, the amount of shrinkage of the material resin further increases, and filler such as glass due to post-shrinkage, etc.
Rubber particles such as butadiene may remain on the resin surface and cause poor gloss again.However, since this mold has good responsiveness and controllability of surface temperature, a stable and high-gloss product can be obtained. . Furthermore, when the mold surface is formed at a high temperature, if the cooling is slow, the product is likely to be warped or deformed. However, in the present mold, the mold surface can be rapidly cooled, so that the product does not warp or deform. In addition, since the heating and cooling of the mold surface can be accurately achieved in a short time, the molding cycle is not extended and the mass productivity is not impaired, and high-quality molding can be performed at low cost.

[0022]

Embodiment 1 A member for forming a heat medium circulation channel on a molding surface of a mold is manufactured through the steps shown in FIG. First,
As shown in FIG. 1A, a thin plate 2 made of nickel and having a thickness of about 2 mm is formed on the surface of the master 7 by electroforming.
Next, as shown in (B), a flow path strip 4 for forming a temperature control heat medium circulation flow path is formed of wax 3 on the back surface of the formed thin plate 2. Next, as shown in (C), the thin plate 2 is immersed together with the master 7 in an electroforming tank 8 filled with an electroforming solution 8 ′ to form a nickel coating layer 5 on the surface of the wax 3. 9 is an electrode in the figure. Next, a heat is applied to the wax 3 to melt it, thereby forming a cavity between the thin plate 2 and the coating layer 5,
In other words, after forming the heat medium circulating flow path 6, the molding surface member 1 for temperature control is obtained without removing the master 7. Next, as shown in (E), the temperature control molding surface member 1 is inserted into the backing 10 with the heat insulating layer 11 inserted therebetween to produce the insert piece 12, and the insert piece 12 is attached to the molding surface of the mold. Incorporate within.

[0023]

Embodiment 2 This embodiment is an embodiment in which the insert piece 12 manufactured in Embodiment 1 is integrated into the molding surface of the mold 20. FIG. 2 is an overall view of the mold, and FIG. Is an explanatory view of the insert 12, FIG. 4 is a sectional view taken along the line AA ', and FIG. 5 is an explanatory view of a heat medium inlet and an outlet of a mold. The plastic injection mold 20 shown in FIG. 2 is roughly divided into a core 21 (product invisible surface side) and a cavity 22 (product visible surface side), and both are connected to an injection molding machine (not shown). , Core 21
And the cavity 22 can be opened and closed. Core 2
1 and a cavity 22 corresponding to the outer shape of the product are formed in the cavity 22, and molten plastic is injected into the recess 23 from an injection molding machine (not shown) through a sprue 24 provided at a predetermined position of the cavity 22. It is poured and the product is shaped. On the product visible surface side (the cavity 22 side) of this product, the inside of the insert 12 for rapid heating and cooling of the mold surface is incorporated.
The resin is heated rapidly at a high temperature at the time of filling by the heat medium flowing in the heat medium circulation flow path 6 formed on the back surface of the resin, then rapidly cooled at a low temperature to be solidified, and thereafter taken out from the mold 20. . The heat medium flowing in the heat medium circulation flow path 6 includes a high-frequency heater and a cooler (not shown),
It is supplied from a heat medium temperature controller capable of cooling.

FIGS. 3 and 4 are explanatory views of the insert 12 to which the temperature-adjusting molding surface member 1 in which the heat medium circulation channel 6 for rapid heating and cooling of the mold surface is formed is fixed. Is formed of Ni—Cr, and a heat medium circulation channel 6 connected to a heat medium inlet 13 and an outlet 14 is formed therein. The heat medium circulating flow path 6 is formed by forming a pipe on the inner surface of the mold of the thin plate 2 with the wax 3 and then forming the coating layer 5 on the surface in an electroforming tank. 2 and one. The cross-sectional shape of the heat medium circulation channel 6 is a square of 5 mm × 5 mm, and the pitch is 12 mm. The distance between the surfaces of the mold 12 for heating and cooling the mold surface in contact with the heat medium circulation channel 6 and the product is 2 mm.
And In addition, a heat insulating layer 11 made of epoxy and reinforcing material having a thickness of about 2 mm is provided on the back surface of the heat medium circulating flow path 6, and a heat capacity is achieved by thermally isolating a mold portion for performing rapid heating and cooling. It was made small.

Using the molds shown in FIGS. 2 to 5, an ABS resin (15G20, glass transition temperature 98 ° C., Japan Synthetic Rubber) containing 20% glass filler was used to fill the mold surface temperature on the visible side of the product with the resin. Injection molding was performed by rapidly heating and cooling to 100 ° C. and 60 ° C. during cooling. The molding cycle (injection-holding pressure-cooling-unloading, mold opening / closing) at this time was 50 seconds, the time required for heating was 13 seconds, and the time required for cooling was 20 seconds. As a result of measuring the glossiness of the visible surface of the product, a product with a high glossiness was obtained despite having a glossiness of 92 and containing a glass filler. Further, at the time of taking out the product, the product was sufficiently solidified, and there was no problem of deformation and release of the product.

[0026]

Example 3 Using the same apparatus as in Example 2 and impact-resistant polystyrene (400, glass transition temperature 97 ° C., Asahi Kasei Kogyo), the surface temperature of the mold on the visible side of the product was set at 100 ° C. when the resin was filled.
Upon cooling, the mixture was rapidly heated to 60 ° C. and cooled to perform injection molding.
The molding cycle (injection-holding pressure-cooling-unloading, mold opening / closing) at this time is 50 seconds, and the time required for heating is 13 seconds.
Seconds and the time required for cooling was 20 seconds.

The mold surface on the product invisible surface side is provided with a boss, a rib-shaped engraving, and a push-out protrusion with the product visible surface side mold so as to easily cause appearance defects such as sink marks and welds on the molded product. And molding was performed. On the visible surface of the obtained molded product, there were no appearance defects such as sink marks, welds, and flow marks, and a high-quality product having a gloss of 96 and a high gloss was obtained. No deformation such as warpage was observed in the product.

[0028]

Embodiment 4 FIG. 6 shows that a baffle plate 16 as a turbulent flow generating member is inserted into a heat medium circulating flow path 6 so that the heat medium circulates through the heat medium.
This is an embodiment in which a swirling flow is generated to increase the heat transfer rate. In addition, instead of the baffle plate 16, as shown in FIG.
A protrusion 15 that disturbs the flow may be formed in the heat medium circulation channel 6.

Fifth Embodiment In the molding surface member 1 for temperature control of the first to fourth embodiments, the heat medium circulation flow path 6 is formed on the back surface of the thin plate 2 using the wax 3. It is also possible to simultaneously form the path 6 integrally by electroforming. This method
The heating medium circulation flow path 4 is arranged with wax 3 on the surface side of the master 7 at an interval corresponding to the thin plate 2, and is immersed in the electroforming tank 8 in this state, and the molding surface corresponding to the thin plate 2 is heated. The medium circulation channel 6 is formed integrally.

[0029]

Comparative Example 1 Insert 1 for Rapid Heating and Cooling of Mold Surface of Example
The same apparatus and resin as in Example 2 were used, except that S2C was replaced with an insert that simulated a normal mold structure in which two heat medium circulation channels 6 were machined in a horizontal hole shape using S55C. The same mold surface temperature at the visible side of the product at the time of filling is 100 ° C, and at the time of cooling 6
The molding was performed under the temperature condition of 0 ° C. At this time, the molding cycle (injection-holding pressure-cooling-unloading, mold opening / closing) was 84 seconds, the time required for heating was 39 seconds, the time required for cooling was 40 seconds, and the molding cycle was 68% longer. . Also, the gloss measurement result of the visible surface of the product was 88, which was lower than that of the product of Example 2. Conversely, when the molding cycle was set to 50 seconds, the same as in Example 2, the product gloss was extremely low, and the product temperature at the time of removal was high and the product was easily deformed.

[0030]

Comparative Example 2 Insert 1 for Rapid Heating and Cooling of Mold Surface of Example
2 was replaced with an insert that simulates a normal mold structure made of S55C and having two heat medium circulation channels 6 in a horizontal hole shape. Molding was performed under the same temperature conditions of the visible surface side mold surface of 100 ° C. and cooling at 60 ° C. At this time, the molding cycle (injection-holding pressure-cooling-unloading, mold opening / closing) was 84 seconds, the time required for heating was 39 seconds, the time required for cooling was 40 seconds, and the molding cycle was 68% longer. . In addition, the measurement result of the glossiness of the visible surface of the product also showed that the glossiness 91 was lower than the glossiness of the product of Example 2 and that the warpage of the product was large.

[0031]

According to the above-mentioned mold, not only general-purpose resins but also resin moldings containing fillers such as glass and rubber particles such as butadiene, which have conventionally been considered difficult to obtain a high-gloss product surface. In addition, a high gloss, high quality, and non-warped product having no defective appearance can be obtained, the merits are great in terms of quality and cost, and the effect of reducing product defects is extremely large (claims 1 to 11). Next, by incorporating a turbulence generating member into the heat medium circulation flow path, the heat transfer rate can be improved (claim 8). Further, according to the present invention, by forming a heat insulating layer on the back side of the heat medium circulating flow path, the heat capacity on the mold side is reduced, so that rapid heating and rapid cooling can be performed immediately. .

[Brief description of the drawings]

FIG. 1 is an explanatory view of a method for manufacturing a mold according to the present invention.

FIG. 2 is a cross-sectional view showing an example of an injection mold according to an embodiment of the present invention.

FIG. 3 is an explanatory view of a heat medium circulating flow path and an insertion piece.

FIG. 4 is a sectional view taken along line AA ′.

FIG. 5 is an explanatory view of a heat medium inlet and an outlet in a mold.

FIG. 6 is an explanatory view of an embodiment in which a baffle plate is placed in a heat medium circulation channel.

FIG. 7 is an explanatory view of an embodiment in which a protrusion is formed in a heat medium circulation channel.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Molding surface member for temperature control 2 Thin plate 3 Wax 4 Heat medium circulation channel 5 Coating layer 6 Heat medium circulation channel 7 Master 8 Electroforming tank 9 Electrode 11 Heat insulation layer 12 Insert 13 Heat medium inlet 14 Heat medium outlet 15 Projection 16 Baffle plate 20 Mold

Claims (11)

[Claims] 1. A circulating channel is formed on a back surface of a forming surface forming thin plate according to a surface shape of a product by a cavity molding material that can be melted later. Next, the surface of the circulating channel is coated. Forming a layer, and then extruding the cavity molding material to form a heat medium circulating flow path between the thin plate and the coating layer to produce a temperature control molding surface member. A method for producing a mold for molding plastic products, which is incorporated into a molding surface of the mold. 2. The method according to claim 1, wherein wax is used as the cavity molding material. 3. The method according to claim 1, wherein a metal coating layer is formed on the surface of the circulation channel by electroforming. 4. The method according to claim 1, wherein a metal coating layer is formed on the surface of the circulation channel by plating. 5. A circulating flow path is formed from a cavity molding material so as to approach the front side of a master having the same shape as the product surface so as to have the same three-dimensional shape and high density with respect to the product surface. 3. The method for manufacturing a plastic product molding die according to claim 1, wherein the thin plate and the coating layer are integrally molded simultaneously by dipping in a casting tank. 6. After forming a circulation channel with a cavity molding material that can be melted later on the back surface of the thin plate according to the surface shape of the product, a metal coating layer is formed on the surface of the circulation channel. Then, by extruding the cavity molding material,
A temperature control molding surface member with a heat medium circulation channel formed between the thin plate and the coating layer is manufactured, this is incorporated into a backing to make a insert, and this insert is incorporated into the molding surface of a mold to form a plastic product. Mold. 7. A plastic product molding die according to claim 6, wherein a planar heat medium circulation channel is formed on the back surface of the thin plate so as to have the same three-dimensional shape and high density with respect to the product surface. 8. The plastic product molding die according to claim 6, wherein a turbulence generating member is incorporated in the heat medium circulating flow path. 9. The mold for molding a plastic product according to claim 6, wherein a molding surface member for temperature control is incorporated only on the visible surface side of the product. 10. A temperature control molding surface member is incorporated only in a part of a molding surface in contact with a product.
Or a mold for molding a plastic product according to 9 above. 11. A heat insulating layer is formed between the back surface of the temperature control forming surface member and the backing mounting surface when the temperature control forming surface member is incorporated in the backing. Mold for plastic products molding.