JPH01176513A - Porous mold - Google Patents

Abstract

PURPOSE:To obtain excellent air-permeability, superior, rigidity and heat conductivity by providing a permeable backup material constituted of a mutual contact section of a number of metal granular materials bonded with a metal bonding material. CONSTITUTION:A air-permeable backup material 15 of approximately 30mm thickness is provided by having a temperature regulating tube 14 in a manner to be buried on the rear surface of a porous mold main body 6 in a casing 10 and said air-permeable backup material 15 is constituted of a mutual contact section of a number of metal granular materials 16 bonded with a metal bonding material 17. When the metal granular materials 16 are bonded with the similar metal bonding material 17, the metal granular materials 16 are bonded firmly each other, and a breathing backup material 15 of high resistance to degradation is manufactured. As said air-permeable backup material 15 backs up strongly a metal mold main body 6, a porous female mold 1 is of superior rigidity. Also, not only the metal granular material 16 but also the metal bonding material 17 is of high degree of heat conductivity, and the porous female mold 1 is of superior conductivity.

Description

DETAILED DESCRIPTION OF THE INVENTION Purpose of the Invention (Field of Industrial Application) The present invention is directed to concave forming (vacuum forming), pressure forming, concave pressure forming, blow molding, stamping molding, injection molding, This invention relates to an air-permeable porous mold used in reaction injection molding and the like.

(Problems to be solved by the prior art and the invention) This type of porous mold needs to satisfy the following three conditions.

■ Good ventilation. This is to improve the adhesion of the synthetic resin to the mold, improve the shape viscosity and pattern transferability of the molded product, and increase the suction efficiency and compressed air efficiency.

■ High rigidity. This is to prevent the mold from being deformed due to pressure during molding. In particular, molds used for blow molding, stamping molding, injection molding, etc. are required to have high rigidity.

■ Good thermal conductivity. This is to prevent the mold from overheating due to the heat of the synthetic resin and shorten the molding cycle.

Therefore, in conventional general porous molds, the porous mold body is formed into a breathable porous material with a thickness of 2 to 7M to ensure air permeability, and a breathable backup body is provided on the back side of the porous mold body. In addition to providing rigidity, temperature control tubes are also provided to improve thermal conductivity.

As the breathable backup body, there is a groove structure in which the back surface of the porous mold body is supported by a reinforcing member through stud holes 1 to 1 (Japanese Patent Application No. 137072/1984).
. Porous molds using this breathable backup body have the rigidity to be used for everything from concave molding to blow molding. There was still a problem of insufficient rigidity.

There is also an air-permeable back-up body formed by partially bonding numerous steel balls or glass beads with a thermosetting resin (Japanese Patent Application Laid-open No. 106820/1983). This breathable backup body has the feature of backing up the entire back surface of the porous mold body, but since the steel balls or glass beads are partially bonded with different materials using thermosetting resin, the bonding force is weak or the same. Thermosetting resins have problems such as low thermal conductivity and the risk of deterioration due to high heat during molding.

Structure of the Invention (Means for Solving Problems) The present invention provides an air-permeable backup body formed by bonding mutual contact portions of a large number of metal particles with a metal bonding material on the back side of a porous mold body. We adopted the method of

(Function) When the mutual contact portions of a large number of metal particles are bonded using a metal bonding material made of the same material, the metal particles are firmly bonded to each other, and a breathable backup body with high collapse resistance is obtained.

Since this breathable backup body strongly backs up the porous mold body, the porous mold of the present invention has excellent rigidity.

Further, a large number of ventilation paths are formed in the mutually non-contact portions of the metal particles, and a highly breathable backup body is obtained, so that the porous mold of the present invention also has excellent ventilation.

Furthermore, not only the metal granules but also the metal bonding material that joins the mutual contact portions of the metal granules have high thermal conductivity, which is a characteristic of metals. Therefore, the porous mold of the present invention has excellent thermal conductivity, and the heat applied to the porous mold body during synthetic resin molding is quickly transmitted between the metal particles of the breathable backup body and radiated.

(First Embodiment) Hereinafter, a first embodiment of the present invention will be described in accordance with FIGS. 1 to 4, in which the present invention is embodied in a secondary mold (here, the female mold side) for stamping the lid of a console box.

This stamping mold is, as shown in Fig. 1,
It consists of a porous female mold 1 and a non-air permeable male mold 2, and a gap 5 is formed between a molding recess 3 of the porous female mold 1 and a molding convex part 4 of the male mold 2.

In the porous female mold 1, a porous mold body 6 forming the cavity 5 is integrally formed by electroforming to a thickness of about 3#, and the porous mold body 6 has a grain pattern as shown in FIG. 8 and a large number of ventilation holes 9 are formed. This vent hole 9 is formed while increasing in diameter from the front side to the back side of the porous mold body 6 at the same time as the electroforming, and its diameter is 50 mm on the surface of the porous mold body 6.
~500 μm 1 It is preferable that it is in the range of 100 to 2000 μm on the back surface, and the distribution density is 5 per 10 cm2.
The number is preferably in the range of 1,000 to 1,000.

The porous mold body 6 is supported by a box 10,
This box body 10 consists of a frame 11 to which the edge of the porous mold body 6 is attached, and a bottom plate 12 attached to the bottom of the frame 11. A suction port 13 for reducing the pressure inside the porous female mold 1 is provided within 30 # from the upper end of the frame portion 11 .

A temperature control pipe 14 is disposed so as to be in contact with the back surface of the porous mold body 6, and a cooling water circulation device (not shown) is connected to the temperature control pipe 14.

In addition, in the box body 10, the temperature control tube] 4 is buried in the back surface of the porous mold body 6 to a thickness of approximately 30 mm.
m air-permeable backup bodies 15 are provided, and the air-permeable backup bodies] 5 are constructed by joining mutually contacting portions of a large number of metal particles 16 with a metal bonding material 17. In this way, when the metal granules 16 are bonded using the metal bonding material 17 which is also metal, the metal granules 16 are firmly bonded to each other, so that a breathable backup body 15 with high collapse resistance is obtained. Since this air-permeable backup body 15 strongly backs up the porous mold body 6, this porous female mold i type 1 has excellent rigidity.

Furthermore, not only the metal particles 16 but also the metal bonding material 17 have high thermal conductivity, which is a characteristic of metal. Therefore, this porous female mold 1 also has excellent thermal conductivity, and the heat applied to the porous mold body 6 during synthetic resin molding is quickly transmitted between the metal particles 16 of the breathable backup body 15 and radiated.

In this embodiment, the metal particles 16 have a particle size of 14 to 2.
Copper metal granules of 4 meshes (average diameter 1250 to 710 .mu.m) are used, and are packed almost densely as shown in FIG. However, a large number of ventilation paths 1B are formed in the non-contact portions of the metal particles 16, and a highly breathable backup body 15 is obtained, so the present porous female mold 1 also has excellent breathability.

Further, the metal bonding material 17 is formed by electroless plating on the back surface of the porous mold body 6 and the metal particles 16, and has a thickness of 20.
As shown in FIG. 3, the nickel plating material with a thickness of .mu.m strongly bonds the porous mold body 6 and the metal granules 16 and the mutual contact portions of the metal granules 16. Note that since the metal bonding material 17 does not fill the ventilation holes 9 and the ventilation paths 18, the air permeability of the porous mold body 6 and the air permeable backup body 15 is not impaired.

Furthermore, in the box body 10, a backup filling body 19 manufactured by Semeni is filled and formed on the back surface of the breathable backup body 15.
The back surface of the breathable backup body 15 is further backed up while saving the metal granules 16 used in the second embodiment.

Next, a method for manufacturing the porous female mold will be described.

First, a master model (not shown) is formed by pasting real leather for the grain pattern onto a wooden mold of the same shape as the lid of the auto operator's console box.Then, the shape of the master model is copied onto a rubber female mold, and the same pattern is created. Inject epoxy resin into the rubber female mold and make the fourth
The mandrel 20 shown in the figure is formed.

Next, a conductive film is formed on the surface of this mandrel 20. This conductive coating can be formed by spraying a mixture of PACE 1 silver lacquer, butyl acetate solution and vinyl chloride lacquer, or by using a silver mirror reaction.

Subsequently, S2M is performed using the mandrel 20 as a cathode in a plating solution (not shown) containing nickel sulfamate and boric acid as main components, and electricity is applied between the mandrel 20 and the nickel anode. After performing electroforming in this way for 10 to 15 days, the mandrel 2
A porous mold body 6 with a thickness of about 3 m is formed on the surface of the mold 0, and at the same time, a ventilation hole 9 is formed.

This vent hole 9 is caused by factors such as the fact that the conductive film contains vinyl chloride, the plating solution does not contain a surfactant that suppresses the formation of pinholes, and the current at the initial stage of electroforming is large. It is generated and grown simultaneously with electroforming. Therefore, since there is no need to mechanically knead the vent holes after electroforming, a high quality porous mold body 6 can be manufactured easily and at low cost. Further, the diameter and number of the ventilation holes 9 can be freely controlled by changing and adjusting each of the above-mentioned factors.

In general, even if the vent holes 9 are formed with a small diameter on the surface of the porous mold body 6, they grow with electroforming and expand in diameter as described above, so they have excellent ventilation.

Next, as shown in FIG.
Connect the opening. In addition, the delivery pipe 2 of the same pump 21
3 is connected to a heating device 24 of a type that heats the plating solution to 90 to 100°C via boiling water.
The outlet pipe 25 is opened at the upper part of the frame part 11.

Subsequently, the metal particles 16 which have been pickled, neutralized, washed with water and hot water are applied to the back surface of the porous mold body 6 from the -F side of the frame part 11 to a thickness of 1 to 3 #. Sprinkle.

Then, a nickel electroless plating solution 26 is injected into the frame 11, and while circulating the plating solution 26 in the order of the frame 11 → pump 21 → heating device 24 → frame 11, the porous mold body 6 and metal particles are Electroless nickel plating is applied to the body 16, and the areas between the porous mold body 6 and the metal granules 16 and the mutual contact portions of the metal granules 16 are bonded with a metal bonding material 17.

Furthermore, the electroless plating is continued while the metal particles 1-6 are gradually piled up on the back surface of the porous mold body 6, thereby forming a breathable backup body 15 with a thickness of about 30 m. .

Next, the nickel electroless plating solution 26 inside the frame portion 11 is removed, and the breathable backup body 15 is washed with water and dried. Then, cement 1 to 1 is poured onto the back surface of the breathable backup body 15 and hardened to form the backup filling body 19.

Finally, by attaching the suction port 13 and the bottom plate 12 to the frame 11, the porous female mold 1 is completed.

A method of stamping molding the lid of a console box using the porous female mold 1 and male mold 2 configured as described above will be described.

First, a heated and plasticized synthetic resin sheet 27 is stretched between the porous female mold 1 and the male mold 2, cooling water is flowed through the temperature control pipe 14, and a vacuum pump connected to the suction port 13 is used. 29 to drive. Then, the pressure inside the box 10 is reduced,
Since the air on the surface side of the porous mold body 6 is sucked into the breathable backup body 15 through the ventilation holes 9, the synthetic resin sheets 1 to 27 are adsorbed to the surface of the porous mold body 6.

In this way, the synthetic resin sheets 1 to 27 are shaped into a lid shape, and the grain pattern 8 on the surface of the porous mold body 6 is accurately transferred to the synthetic resin sheet 27.

Here, since the porous mold main body 6 and the air permeable backup body 15 have high air permeability as described above, the above-mentioned suction can be performed strongly.

Subsequently, a fixed amount of synthetic resin material 28 that has been heated and plasticized is injected onto the synthetic resin sheet 27, and then the male mold 2 is moved to the porous female mold 1 and the synthetic resin material 28 is strongly pressed. Move and fill the cavity 5 (stamping molding). Here, since the porous female mold 1 has high rigidity due to the breathable backup body 15 having high collapse resistance as described above, it can sufficiently withstand high pressure during stamping molding.

In addition, since the breathable backup body 15 has high thermal conductivity as described above, the heat applied to the porous mold body 6 during the molding is efficiently transferred to the breathable backup body 15 and the temperature control tube 14. heat is transmitted and radiated. Since the porous mold body 6 is thus quickly cooled, the molding cycle can also be shortened.

Next, the male mold 2 is opened to take out the molded product, and the excess synthetic resin sheets 1 to 27 are removed to complete the console box lid with the textured skin.

(Second Embodiment) Next, a twenty-sixth embodiment of the present invention will be described with reference to FIGS. 5 and 6.

This embodiment has the following features: (1) the metal bonding material 17 that joins the mutual contact portions of the metal particles 16 is a plating material formed by electroplating, (2) the backup filler 19 is formed of epoxy resin, and (2) ventilation. This embodiment differs from the first embodiment in that the temperature control pipe 14 is omitted by directly circulating cooling water within the temperature backup body 15.

A method of manufacturing this porous female mold 1 will be explained.

First, the steps up to electroforming the porous mold body 6 on the surface of the mandrel 20 are the same as in the first embodiment.

Next, as shown in FIG. 6, a synthetic resin frame 30 is attached to the porous mold body 6, and the metal granules 16 are pickled, neutralized, washed with water and hot water, and then placed on the back side of the porous mold body 6. 1~
Sprinkle it to a thickness of 3m. Plating tank 31
The porous mold body 6 is immersed in an electroplating solution 32 containing nickel sulfamate as a main component to serve as a cathode.
A current is applied between the nickel anode 39 and the nickel anode 39 at a current density of about 5 A/dm2. When electroplating is performed for 1 to 2 hours in this manner, 50 μm thick nickel as the metal bonding material 17 is deposited between the porous mold body 6 and the metal granules 16 and at the mutual contact portions of the metal granules 16. They are firmly joined.

Furthermore, by continuing the electroplating while gradually overlapping the metal particles 16 on the back surface of the porous mold body 6, an air-permeable back-up layer 15 with a thickness of about 30M is formed.

Next, the electroplating liquid 32 inside the synthetic resin frame 30 is removed,
The breathable backup body 15 is washed with water and dried. Then, the frame portion 11 is attached or replaced, and an epoxy resin is poured onto the back surface of the breathable backup body 15 to avoid hardening, thereby forming one backup filling body. Epoxy resins are characterized by low shrinkage during curing and are lightweight.

Finally, the suction port 13 and the base of the bottom plate 12 are attached to the frame 11.
If the cooling water inlet 33, which is unique to this embodiment, is placed on the claw side, the porous female mold 1 is completed.

The stamping method using the porous female mold 1 is almost the same as in the first embodiment, but the cooling method of the porous female mold 1 is completely different.

That is, as shown in FIG. 5, the suction port 13 and the injection port 33 are equipped with a suction pump manufactured by Gifu Seiki Kogyo Co., Ltd., which functions as both a cooling liquid supply device and a vacuum pump. A suction pump 34 with the trade name "Logic Seal" is connected.

Further, cooling water at a constant temperature is supplied to the suction pump 34, and cooling water at a constant temperature is supplied to the suction pump 34.
Temperature controller 35.3 as a cooling device that collects cooling water from
Connect 6. One temperature regulator 35 supplies high temperature cooling water of 90 to 100'C, and the other temperature regulator 36 supplies low temperature cooling water of 0 to 20C to the suction pump 34.

The timing of starting and stopping the supply of the cooling water to the suction pump 34 is controlled by opening and closing the valve 37 provided between the temperature controller 35, 36 and the suction pump 34 in accordance with the molding timing. Specifically, when adsorbing the synthetic resin sheet 27, the valve 37 of the temperature regulator 35 is opened to supply high-temperature cooling water in order to facilitate the transfer of the striped pattern 8. Further, when stamping the synthetic resin material 28, in order to rapidly cool the porous mold body 6, the valve 37 of the temperature regulator 36 is opened to supply cold cooling water. closes.

When the suction pump 34 is activated, the air on the surface side of the porous mold body 6 is sucked into the breathable backup body 15 through the ventilation holes 9, and the cooling water of the temperature controllers 35 and 36 is sucked through the inlet 33. The air and cooling water are circulated within the breathable backup body 15 and discharged from the suction port 13 at the same time.

Therefore, the porous mold body 6 and the breathable buffer tube body 15 are efficiently and uniformly cooled by direct contact with the cooling water, which has the effect of further shortening the molding cycle.

(Third Embodiment) Next, a third embodiment of the present invention will be described with reference to FIGS. 7 and 8.

The third embodiment of the present invention differs from the first embodiment only in that the metal bonding material 17 for bonding the mutually contacting portions of the metal particles 16 is a brazing material.

A method of manufacturing this porous female mold 1 will be explained.

First, the porous mold body 6 electroformed as in the first embodiment is removed from the mandrel 20, and the porous mold body 6 is removed from the mandrel 20.
There are several examples of frame parts 11 (vines).

Next, as shown in FIG. 7, copper metal particles 16 coated in advance with tin-lead solder as a brazing material 38 to a thickness of 50 μm are placed on the back surface of the porous mold body 6 to a thickness of about 30 m. Sprinkle until smooth. When these are placed in a heating furnace (not shown) and heated to about 2oo'c, they are taken out.
Only the brazing material 38 of the metal granules 16 melts and solidifies to become the metal bonding material 17, which joins the porous mold body 6 and the metal granules 16 and the mutual contact portions of the metal granules 16. The subsequent method of forming the backup filling body 19 and the like are the same as in the first embodiment.

In this way, according to this embodiment, the porous female mold 1 can be manufactured very easily.

It should be noted that the present invention is not limited to the configuration of the above-mentioned embodiments, and may be modified and embodied as desired without departing from the spirit of the invention, for example, as described below.

(1) Metal granules] In addition to copper, any solid metals and alloys such as iron, nickel, zinc, aluminum, and alloys thereof can be used as the material for the metal granules 6.

(2) Metal bonding material 1 in the above-mentioned first and second embodiments
In addition to nickel, any metal or alloy that can be plated, such as zinc, chromium, silver, etc., can be used as the material for the plate 7. As the material for the metal bonding material 17 in the third embodiment, any brazing material can be used in addition to tin-lead solder.

(3) The backup filler 19 may be of any material as long as it has high rigidity (and machinability in some cases), and does not require thermal conductivity or air permeability.

Therefore, ZAS (zinc alloy), a low melting point metal, a large number of large diameter spherical bodies, etc. can also be applied.

(4) Since the porous mold of the present invention has particularly high rigidity,
It can also be embodied as molds for various moldings (particularly injection molding) described in the field of industrial application.

Effects of the Invention As detailed above, the porous mold of the present invention satisfies all three requirements of the mold at a high level: air permeability, rigidity, and thermal conductivity, so it is suitable for stamping molding and injection molding. It also has the excellent effect of shortening the molding cycle.

[Brief explanation of the drawing]

Figure 1 is a sectional view showing the porous mold of the first embodiment,
FIG. 3 is a partially enlarged cross-sectional view of the porous mold, and FIG. 4 is a schematic diagram showing a method of manufacturing the porous mold. Fig. 5 is a cross-sectional view showing the porous mold of the second embodiment, Fig. 6 is a schematic diagram showing the manufacturing method of the same porous mold, and Fig. 7 is a cross-sectional view of the porous mold of the third embodiment before joining. FIG. 8 is a partially enlarged sectional view showing the state after bonding. 6...Porous mold body, 15...Air permeable backup body, 16...Metal granules, 17...Metal bonding material.

Claims (1)

[Claims] 1. A breathable backup body (15) formed by bonding the mutual contact portions of a large number of metal particles (16) to the back surface of a porous mold body (6) with a metal bonding material (17). A porous mold characterized by having a. 2. The porous mold according to claim 1, wherein the metal bonding material (17) is a plating material formed by electroless plating on mutual contact portions of the metal particles (16). 3. The porous mold according to claim 1, wherein the metal bonding material (17) is a plating material formed by electroplating the mutual contact portions of the metal particles (16). 4. The porous mold according to claim 1, wherein the metal bonding material (17) is a brazing material for bonding the mutual contact portions of the metal particles (16).