JP5984264B2 - Light weight simple resin mold and manufacturing method thereof - Google Patents

Description

  The present invention relates to a lightweight and simple resin mold mainly used for blow molding of plastic products and a method for producing the same.

The plastic product molding methods include injection molding, extrusion molding, blow molding, and thermoforming. Among them, blow molding is mainly used for molding a product having a hollow portion. The blow molding method includes an extrusion blow molding method in which a tubular parison is extruded from an extruder, the lower part is cut with a split die, and simultaneously fused and blown with compressed air, or a test tube is formed at the core of the molding machine. There is an injection blow molding method in which a parison is molded, moved to a blow mold for each core, and compressed air is blown from the core side. The injection blow molding method has a feature that the production speed is lower than that of the extrusion blow molding method, but the dimensional accuracy is excellent.

Since the metal mold used for these moldings is subjected to a high pressure load, it is generally produced by cutting iron or copper having strength and durability, or casting an alloy of zinc and aluminum. In addition to these machinability and heat treatment properties, the mold requirements include high thermal conductivity to quickly cool and cure the high-temperature resin to be molded, low thermal expansion to increase product accuracy, and contact surface with the molded product. And high corrosion resistance.
However, metal molds for molded products with a three-dimensional curved surface such as a human body model take a long time to manufacture and are expensive. Therefore, although it is suitable for molding a large number of molded products, a variety of molded products can be used. When molding in small quantities, it is often uneconomical, for example, the product price is expensive.
Accordingly, since the wear and damage of the surface increases as the number of uses increases, a resin mold that can be manufactured in a relatively short time and has a low price has been developed. As the resin used for the resin mold, a thermosetting resin that has heat resistance and does not change its shape after curing is used. Thermosetting resins include phenolic resins, epoxy resins, amino resins, polyurethane resins, etc. Epoxy resins have excellent adhesion, mechanical strength, and chemical resistance, so glass fibers, carbon fibers, etc. A material in which various fibers and a metal such as iron and aluminum are combined to increase strength and elastic modulus has been developed (see Patent Document 1, etc.).
Specifically, a base mold is placed in a core box, and metal fibers are impregnated with a thermosetting resin such as epoxy resin, unsaturated polyester resin, urethane resin, and solidified. A method has been proposed in which a resin mold is produced by covering the surface with a surface layer and filling a core box with a sand core (mixture of cinnabar, glass chop and resin) (see Patent Document 2).

On the other hand, when the parison of the blow molding machine is cooled in the atmosphere, a skin layer is formed and the surface transferability deteriorates. In addition, since the pressure of air blown into the parison is relatively low, the transferability of the mold deteriorates unless the air that has entered the mold can be removed. Therefore, when a nickel reduced powder having a particle diameter of 20 to 100 μm is defined as 100, a porous body layer having a pore diameter of 0.3 mm or less formed by filling 5 to 20% by weight of an epoxy resin is formed on the epoxy resin mold. A method has been proposed in which the surface layer is used to remove air that has entered between the mold and the parison (see Patent Document 3).
When molding a hollow plastic product having a mirror surface or a textured surface, it is necessary to improve the transferability of the resin mold so that the mirror surface or the textured surface can be transferred cleanly. Therefore, a method has been proposed in which a plurality of temperature control chambers are provided on the back surface of the resin mold, and a transfer fluid is controlled by supplying a heating fluid and a cooling fluid to each chamber (see Patent Document 4).

On the other hand, the surface layer that is in direct contact with the molded product is formed of a mixture of epoxy resin and metal powder, and the backing layer that supports it is a resin mold formed of metal. Further, delamination and cracks are likely to occur between the surface layer and the backing layer due to expansion and contraction of the mold surface layer due to heating and cooling during use. In view of this, a method has been proposed in which an expansion / contraction prevention portion that prevents expansion / contraction of the surface layer is provided on the surface layer side of the backing layer (see Patent Document 5).

Japanese Patent No. 2688692 JP-A-1-202407 JP-A-8-72133 Japanese Patent No. 4072840 Japanese Patent Laid-Open No. 10-44161

In view of the above circumstances, the present invention can be easily produced in a relatively short time, has good transferability of a molding surface having a three-dimensional curved surface, is lightweight and easy to mount on a molding machine, and is mainly blown. It aims at providing the resin metal mold | die used for shaping | molding, and its manufacturing method.

The lightweight simple resin mold of the present invention is a pair of lightweight simple resin molds for molding a molded product having a three-dimensional curved surface by sandwiching a parison, and the above-described epoxy resin composition kneaded with metal powder. A surface layer on which a molding surface of a molded product is formed, a reinforcing layer formed by fibers impregnated with the epoxy resin composition, and a space for allowing fluid to flow in and out, and formed by the epoxy resin composition A molded part having a back layer, a frame formed so as to surround a side surface of the molded part, and a plate-like member fixed to the molded part and the frame on the back layer side. It has the housing part which was made.
In that case, the space is formed on the back surface of the molding surface, and it is preferable that the space is provided with a column supporting pressure applied to the molding surface, and a pair of fluids flow into and out of the space from the outside. It is also preferable that the nozzle is provided. Further, the frame preferably has a height at which the surface layer with the molding surface facing upward is hidden or flush with the surface layer, and each of the surface layer and the reinforcing layer is at least 0.5 mm. It is preferable that the frame body has a thickness of at least 10 mm so that the surface layer with the molding surface facing upward is hidden or has a height that is flush.
Thus, since the molding part of a metal mold | die is formed with an epoxy resin composition, it is lightweight and can be easily produced in a comparatively short time. In addition, the side of the molded part is surrounded by a metal frame, etc., and the clamping pressure is received by the frame, and the pressure when the compressed air is sent to the parison is received by the reinforcing layer and the back layer. Enough can be secured. Furthermore, since the metal powder is kneaded in the epoxy resin, the thermal conductivity can be increased to some extent, and the cycle time of the molded product can be shortened by sending a cooling fluid from the outside to the space behind the molding surface. . Moreover, if a support | pillar is provided in the space of a molding surface back surface, the support force with respect to the pressure added to a molding surface will increase.
Here, it is preferable that the molding surface has a plurality of air holes penetrating the surface layer, the reinforcing layer, and the back layer.
In this way, if a plurality of air holes are provided on the molding surface, when the parison is pressed against the molding surface, the air that has entered between the molding surface and the parison can be released to the outside, thereby improving transferability. .

The manufacturing method of the lightweight simple resin mold of this invention is a manufacturing method of a pair of lightweight simple resin mold which shape | molds the molded article which has a three-dimensional curved surface by pinching | interposing a parison, Comprising: The said method accommodated in the mold After the mold release agent is applied to half of the original mold of the molded product, an epoxy resin composition kneaded with metal powder is applied so that the thickness is at least 0.5 mm to form a surface layer having the molding surface of the molded product. A second step of forming a reinforcing layer having a thickness of at least 0.5 mm by laminating and sticking a predetermined size of fiber impregnated with the epoxy resin composition on the surface layer, and the reinforcing step A third step of filling the epoxy resin composition into the mold in which a layer is formed and forming a back surface layer having a space for allowing fluid to flow in and out, and the surface layer on the lid of the mold, Forming the reinforcing layer and the back layer; Each layer formed on the lid is joined to each corresponding layer formed in the mold to form a molded part for molding the molded product, and the formed part is heated for a predetermined time. And the fourth step of curing, removing the lid and the mold, respectively, installing a frame on the side of the molded part, and fixing the molded part and the frame to a plate-like member to form a casing part And a fifth step.
In this way, a molded product having a three-dimensional curved surface is accommodated in a box-shaped mold, and a surface layer, a reinforcing layer, and a back layer are formed with an epoxy resin composition kneaded with metal powder to form a molded part. Further, since it is possible to save labor-intensive processes such as cutting a complicated curved surface or creating a mold by creating a sand mold, it is possible to create it easily in a relatively short time. In addition, the side of the molded part is surrounded by a frame such as metal, the clamping pressure is received by the frame, and the pressure when the compressed air is sent to the parison is received by the reinforcing layer and the back layer, so it is lightweight. Moreover, sufficient durability can be ensured.
In that case, the first step may include a step of housing the whole prototype in the mold and concealing so that half of the contained prototype is buried. In the third step, the epoxy resin composition is placed in a state where a predetermined member is placed on the back surface of the molding surface where the epoxy resin composition is applied to the reinforcing layer so that the thickness is at least 0.5 mm. Forming the back surface layer, and removing the predetermined member from the formed back surface layer to form the space.
In this way, if the entire original mold is accommodated in the mold as it is to form the resin mold, the labor of dividing the original mold can be saved and the original mold can be stored as it is. In addition, if the back surface layer is formed using a member having the same shape and the same size as the predetermined space, the predetermined space can be easily formed.
In addition, the fourth step includes a step of installing a column formed with the epoxy resin composition in the space before each layer of the lid is bonded to each layer in the mold. It can also include a step of forming air holes through which air circulates to the outside at a plurality of locations on the molding surface and holes for allowing fluid to flow into and out of the space from the outside.
In this way, if a support is provided on the back surface of the molding surface in the space of the back surface layer, the pressure applied to the molding surface can be supported more strongly, and if a plurality of air holes are provided on the molding surface, a parison is formed. When pressed against the surface, the air that has entered between the shaping surface and the parison can be released to the outside, so that transferability is improved, and if a hole for sending the cooling fluid from the outside is provided in the specified space, It is also possible to reduce the cycle time of the molded product by installing a nozzle in the fluid and allowing fluid to flow in and out.

According to the lightweight simple resin mold and the manufacturing method thereof of the present invention, the molding part of the mold is formed of a lightweight epoxy resin composition, while the mold clamping pressure of the molding machine is a frame made of metal or the like around the molding part. Since it is received by the body, the weight can be halved compared to a metal mold. In addition, since the molded part is created directly from the original without passing through a cutting process or a casting process, it can be created in a relatively short time and at a low cost.
In addition, by creating a cavity inside the molded part, cooling the molding surface, and providing many air vents on the molding surface, the transferability of the molding surface with a three-dimensional curved surface is improved and cycle time is shortened. Can be achieved.

FIG. 1 is a front view of a molding surface of a pair of lightweight simple resin molds according to the present embodiment. FIG. 2 is a side sectional view showing a state in which the pair of lightweight simple resin molds of the present embodiment is closed. FIG. 3 is a plan view showing a state in which the pair of lightweight simple resin molds of the present embodiment is closed. FIG. 4 is a side cross-sectional view of a state in which a lightweight simple resin mold formed with a molded product is opened. Drawing 5 is a figure showing an example of the 1st process of a manufacturing method of a pair of lightweight simple resin metallic molds of this embodiment. Drawing 6 is a figure showing other examples of the 1st process of a manufacturing method of a pair of lightweight simple resin metallic molds of this embodiment. FIG. 7 is a diagram showing a second step of the present embodiment. FIG. 8 is a diagram showing a third step of the present embodiment. FIG. 9 is a diagram showing a third step of the present embodiment. FIG. 10 is a diagram showing a third step of the present embodiment. FIG. 11 is a diagram illustrating a fourth step of the present embodiment. FIG. 12 is a diagram showing a fourth step of the present embodiment. FIG. 13 is a diagram illustrating a fourth step of the present embodiment. FIG. 14 is a diagram showing a fifth step of the present embodiment. FIG. 15 is a diagram illustrating an example of a molded product formed using the pair of lightweight simple resin molds of the present embodiment or the pair of lightweight simple resin molds manufactured in the manufacturing process of the present embodiment.

Below, embodiment of a pair of lightweight simple resin metal mold | die of this invention is described.
1 to 4 are diagrams showing a pair of lightweight simple resin molds according to this embodiment. FIG. 1 is a front view of a molding surface of the lightweight simple resin mold. FIG. FIG. 3 is a side cross-sectional view of the closed state, FIG. 3 is a plan view of the light weight simple resin mold in a closed state, and FIG. 4 is a side cross sectional view of the light weight simple resin mold in which a molded product is molded.
Each of the pair of lightweight simple resin molds 1 of the present embodiment shown in FIGS. 1 to 4 forms a parting line 10 by a mold part 2 and a casing part 3 that are freely openable and symmetric. The casing 3 is a metal frame (corresponding to the “frame” of the present invention) 3 a that surrounds the side surface of the molded part 2, and a metal back plate (corresponding to the “plate member” of the present invention) 11. The metal frame 3a has a large number of bolt holes 24 and is fixed to the back plate 11 with bolts. Further, the molding portion 2 and the back plate 11 have screw holes 8 and 9 for bolts at corresponding positions, and the molding portion 2 is also fixed to the back plate 11 with bolts. Accordingly, by fixing the back plate 11 to the blow molding machine, each of the pair of lightweight simple resin molds 1 can be installed on the blow molding machine.
Each of the pair of lightweight simple resin molds 1 installed in the blow molding machine sandwiches a parison made of a thermoplastic resin, and then press-fits air from the air insertion port 25 to the parison at the molding surface 22 of each molding part 2. Mold the parison. Then, for example, cooling water is allowed to flow from the nozzle 14 into the annular spaces 13 (corresponding to the “space” of the present invention) formed in each of the molding parts 2, thereby cooling the molded product 19 molded by the molding surface 22. Thereafter, each of the pair of lightweight simple resin molds 1 is opened, and the molded product 19 is dropped to obtain a desired molded product 19.
Here, although a pair of lightweight simple resin metal mold | die 1 of this embodiment is comprised by the two split molds which form the parting line 10, since both are the same structures except the molding surface 22, about one side explain.

Each of the molded portions 2 includes a surface layer 5 on which a molded surface 22 having a three-dimensional curved surface is formed, a reinforcing layer 6 that reinforces the surface layer, and the surface layer and the reinforcing layer 6 at the same time as the appearance of the molded portion 2. The molding surface 22 is provided with a plurality of air vent holes 15 that pass through the surface layer 5, the reinforcing layer 6, and the back surface layer 7, and allow air to flow outside. Further, an annular space 13 through which a cooling liquid or gas flows in and out from the outside is provided inside the back surface layer 7, and the molding surface 22 of the surface layer 5 can be cooled via the reinforcing layer 6. Further, four support columns 23 are provided in the annular space 13 to support the pressure applied to the molding surface 22 on the back side. On the other hand, there is a cutout 16 that cuts the parison on the lower side of each molding surface 22 forming the parting line 10.
Moreover, the through-hole to the annular space 13 is provided in the side surface or bottom surface of the shaping | molding part 2, and a pair of nozzle 14 which makes fluid flow in / out from the exterior is installed in the through-hole. The nozzle 14 is connected to a hose connected to a pump.
Here, the fluid flowing into and out of the annular space 13 from the nozzle 14 may be a liquid such as water or a gas such as cooling air. Further, the annular space 13 provided in the back surface layer 7 is not necessarily formed in an annular shape, and may have any shape as long as the molding surface 22 can be efficiently cooled. Furthermore, in this embodiment, four support columns 23 are provided inside the annular space 13, but the support columns 23 are not necessarily provided depending on the size of the molding surface 22 and the size of the annular space 13, and the number of support columns There is no need to limit the number to four. Further, the pair of nozzles 14 that allow the fluid to flow into and out of the annular space 13 may be provided on the side surface of the molding portion 2 as long as the fluid that flows in and out can be circulated in the annular space 13. Either one may be provided on the side surface, and the other may be provided on the bottom surface.

The surface layer 5 is formed by applying an epoxy resin composition obtained by kneading 5 wt% to 98 wt% of metal powder so that the thickness is 0.5 mm or more.
The reinforcing layer 6 is impregnated with an epoxy resin composition in which glass fiber, carbon fiber, felt, non-woven fabric, or other sheet is cut into 5 to 30 cm squares and kneaded with 5 to 98% by weight of metal powder. The surface layer 3 is laminated and pasted without gaps until the thickness is about 0.5 mm to 10 mm.
For the back surface layer 7, an epoxy resin composition obtained by kneading 5 wt% to 98 wt% of metal powder is applied over the reinforcing layer 6 so that the annular space 13 is formed inside. And it shapes so that an external appearance may become a rectangular parallelepiped.
Here, the annular space 13 of the present embodiment can be formed by placing clay or polystyrene foam shaped to the same size as the annular space 13 on the back surface of the molding surface 22 when the back surface layer 7 is applied. it can. At that time, through holes may be provided in the clay or the polystyrene foam, and the through holes may be filled with the epoxy resin composition to provide the support pillars 23 in the annular space 13. You may install the support | pillar 23 previously shape | molded with the epoxy resin composition in the annular space 13. FIG.
The size of the annular space 13 is adjusted so that the thickness of the back surface layer 7 is 10 mm or more even at the thinnest part.
Moreover, the epoxy resin composition of this embodiment can be comprised with an epoxy resin, a hardening | curing agent, and metal powder.
Examples of epoxy resins include glycidyl ethers of various phenols such as bisphenol A, bisphenol F, nobonec resin, and brominated bisphenol A, cyclic aliphatic epoxy resins, glycidyl ester resins, glycidyl amine resins, and heterocyclic epoxy resins. Can be mentioned.
Examples of the curing agent include amines and acid anhydrides.
Furthermore, examples of the metal powder include aluminum, iron, copper, nickel, and tin.
In addition, if necessary, fillers such as silica, alumina, magnesium, and carbon black, various additives, and solvents other than curing accelerators, diluents, flexibility imparting agents, and metal powders can be added.
In the epoxy resin composition of the present embodiment, the metal powder is kneaded in the range of 5% by weight to 98% by weight. However, when the amount exceeds 98% by weight, the bonding state of the metal powder is deteriorated, resulting in a problem in strength. When the content is less than 5% by weight, the thermal conductivity is extremely lowered, the temperature of the molded product is slowly lowered, and the molding cycle time is prolonged.

The housing part 3 is comprised by the metal frame 3a surrounding the side surface of the shaping | molding part 2, and the metal back plate 11, and aluminum and stainless steel are mentioned, for example as a metal used for them.
There are a large number of bolt holes 24 at corresponding positions of the metal frame 3a and the back plate 11, and the metal frame 3a is fixed to the back plate 11 with bolts.
The height of the metal frame 3a is set so that the upper surface of the surface layer 5 when the molding surface 22 faces upward is slightly hidden or flush with the surface layer 5.
Accordingly, each of the housing portions 3 is tightly joined at the joining surface of the pair of lightweight simple resin molds 1 on which the parting line 10 is formed, but each molding portion 2 has a gap of about 0.05 mm to 5 mm. As a result, the mold clamping pressure of the blow molding machine is not directly applied to the molding part 2. Further, since the metal frame 3a is fixed to the back plate 11 having a larger size than that, the nozzles 14 protruding outside the metal frame 3a are also protected by the back plate 11.
Here, the housing portion 3 of the present embodiment is formed by the metal frame 3a and the metal back plate 11. However, these are not necessarily made of metal, and may be ceramics or CFRP. It may be a highly rigid plastic.

Next, an embodiment of a method for producing a pair of lightweight simple resin molds of the present invention will be described.
5-13 is a figure which shows each process of the manufacturing method of a pair of lightweight simple resin metal mold | die of this embodiment.
Here, the pair of lightweight simple resin molds manufactured through the respective steps of the present embodiment is composed of two split molds that form the parting line 10, but since the manufacturing processes of both are the same, The manufacturing process will be described.
FIG. 5 is a diagram illustrating an example of the first step of the present embodiment.
The first step shown as an example in FIG. 5 is to divide the prototype 4 of the molded product into halves while paying attention to undercuts. One of the divided prototypes is made of plastic, wood, or metal with the molding surface facing upward. It puts in the created box-shaped formwork 12. At that time, the clay 17 is pasted in a region of 5 mm to 40 mm around which the prototype 4 is in contact with the bottom of the mold 12 so that the thickness is 5 mm to 30 mm. When the clay 17 is dried, an epoxy resin mold release agent is applied to the inside of the box-shaped mold 12 containing the clay 17 and the original mold 4. Then, an epoxy resin composition obtained by kneading 5 wt% to 98 wt% of a metal powder on the epoxy resin mold release agent is applied so as to have a thickness of at least 0.5 mm, and is cured at a low temperature. The surface layer 5 having 22 is formed.
Here, the portion to which the clay 17 is attached is for forming a burr cut-off portion 16 attached to a parison or a molded product.

FIG. 6 is a diagram illustrating another example of the first step of the present embodiment.
In the first step shown in FIG. 6, the entire original mold 4 having a three-dimensional curved surface is placed in a box-shaped large frame 12 a, the lower half is concealed, and the upper half is exposed. The clay 17 is packed in the large frame 12a so that the boundary surface becomes flat. Then, clay 17 for forming the biting portion 16 is placed in a range of 5 mm to 40 mm around the exposed prototype 4 until the thickness becomes 5 mm to 30 mm. Then, when the clay 17 is dried, an epoxy resin mold release agent is applied to the inner surface of the large frame 12 a including the clay 17 and the original mold 4. Then, an epoxy resin composition in which 5% to 98% by weight of metal powder is kneaded on the mold release agent for epoxy resin is applied so as to have a thickness of 0.5 mm or more, and is cured at a low temperature. A surface layer 5 having a surface 22 is formed.
Here, as a molded article having a three-dimensional curved surface, for example, a human body model such as a mannequin or a doll, a toy including a figure, a prototype of a part having a complicated shape such as an automobile or an industrial machine, or the like can be given.
Further, the epoxy resin composition used in the present embodiment is also composed of an epoxy resin, a curing agent, and metal powder as in the description of FIGS. 1 to 4, and the metal powder is 5% by weight to 98%. It is kneaded in the range of% by weight.

FIG. 7 is a diagram showing a second step of the present embodiment.
In the second step shown in FIG. 7, an epoxy resin composition in which 5% to 98% by weight of metal powder is kneaded with glass fiber, carbon fiber, felt, non-woven fabric, or other sheet that has been cut into 5 to 30 cm squares in advance. An impregnated section is prepared, and the section is laminated and pasted on the surface layer 5 formed in the first step until the thickness becomes at least about 0.5 mm, and cured at low temperature to form the reinforcing layer 6. .

8-10 is a figure which shows the 3rd process of this embodiment.
As shown in FIG. 8, the third step is an epoxy resin composition in which 5% to 98% by weight of metal powder is kneaded on the bottom surface of the mold 4 and the mold 12 in the reinforcing layer 6 formed in the second step. An object is applied so as to have a thickness of about 0.5 mm to 50 mm and cured at a low temperature to form a part of the back layer 7.
Next, as shown in FIG. 9, an annular member 18 formed by shaping clay or styrene foam is placed on the back surface layer 7 formed on the prototype 4. Then, the mold 12 on which the annular member 18 is placed is filled with an epoxy resin composition in which 5% to 98% by weight of metal powder is kneaded until it is flush with the mold 12, and is cured.
Then, as shown in FIG. 10, the annular member 18 is removed, and a region that becomes the annular space 13 is provided on the prototype 4.
Here, in the present embodiment, the annular space 13 is formed inside the back surface layer 7 using the annular member 18, but the space formed inside the back surface layer 7 does not necessarily need to be the annular space 13. Any shape can be used as long as the surface 22 can be cooled.

11-13 is a figure which shows the 4th process of this embodiment.
As shown in FIG. 11, an epoxy resin composition in which a metal powder is kneaded with 5 wt% to 98 wt% of an epoxy resin mold release agent is applied to the lid portion 12 b of the mold 12. The surface layer 5 having the molding surface 22 is formed by applying and curing so as to be at least 0.5 mm.
Next, on the formed surface layer 5, the same section impregnated with the epoxy resin composition as that used in the second step is overlapped and pasted until it has a thickness of at least about 0.5 mm and cured. Thus, the reinforcing layer 6 is formed. Further, an epoxy resin composition obtained by kneading 5% to 98% by weight of metal powder on the reinforcing layer 6 is applied to a thickness of about 0.5 mm to 50 mm and cured at a low temperature to form the back layer 7. To do.
Then, both edges are polished and cut obliquely so that the lid 12b fits snugly into the mold 12.
Moreover, the support | pillar 23 standing in the cyclic | annular space 13 is shape | molded previously with an epoxy resin composition, the hardened thing is adhere | attached on the formed back layer 7, and it stands. In addition, the position which becomes the back surface of a molding surface is selected as the position which raises the support | pillar 23. FIG.
Here, the column 23 according to the present embodiment uses a method of bonding the preformed column 23 in the annular space 13 in the fourth step after forming the annular space 13 in the third step. As explained in 0014,
A through hole may be provided in the annular member 18, and the through hole may be filled with the epoxy resin composition so that the support column 23 is provided simultaneously with the annular space 13.
As shown in FIG. 12, an epoxy resin composition in which metal powder is kneaded in an amount of 5 wt% to 98 wt% is applied to the edges of the mold 12 and the lid 12 b, and the both sides are pressure-bonded. Then, the annular space 13 supported by the support pillars 23 is provided in the back layer 7 to form the molding part 2.
As shown in FIG. 13, the mold 12 and the lid 12 b are removed from the molding portion 2 to expose the molding surface 22, and are distributed outside the molding surface 22 at a plurality of locations (here, two locations are displayed). The air holes 15 of about 0.1 mm to 10 mm are opened with about 1 to 10 places with a drill. Furthermore, a through hole for installing a pair of nozzles 14 for allowing fluid to flow into and out of the annular space 13 from the outside is drilled.
Note that the pair of through holes for installing the pair of nozzles 14 may be both installed on the bottom surface of the molding unit 2, or both may be installed on the side surface of the molding unit 2, or either one of them. May be placed on the bottom and the other on the side. Moreover, when the molding surface 22 of the molding part 2 is turned upward, the edge of the molding surface 22 is higher than the peripheral part thereof, and the burr cutout part 16 is formed.
Next, the completed molding part 2 is put into a thermostat and heated at 80 to 300 degrees Celsius to cure the epoxy resin at a high temperature.
Here, the time for heating in the thermostat varies depending on the overall size of the molded part 2 and the thickness of the surface layer 5, the reinforcing layer 6, and the back layer 7 to be formed, but for example, polymerization takes about 2 to 8 hours. Accelerate reaction and cure completely.
In the present embodiment, the molding part 2 is hardened at a high temperature in a thermostatic chamber after a through-hole for installing the air hole 15 and the pair of nozzles 14 is drilled in the molding part 2. High temperature curing may be performed before opening.

FIG. 14 is a diagram showing a fifth step of the present embodiment.
As shown in FIG. 14, a metal frame 3 a made of aluminum or stainless steel having a thickness of 0.5 cm to 5 cm is installed in the molding portion 2 so as to surround the side surface. The metal frame 3a is fixed with bolts and nuts to a metal back plate 11 such as aluminum or stainless steel through a large number of bolt holes 24 provided in the metal frame 3a, whereby the housing part 3 is formed.
On the other hand, through holes 8 and 9 for bolts are drilled in the molded part 2 and the back plate 11, and the molded part 2 is fixed to the back plate 11 with bolts and nuts using the through holes 8 and 9. .
Here, the height of the metal frame 3a is set so that the upper surface of the molding part 2 when the molding surface 22 faces upward is slightly lower than or flush with the upper surface of the housing part 3. Accordingly, each of the pair of lightweight simple resin molds 1 is mounted on a blow molding machine, and the mold clamping pressure of the blow molding machine when molding a molded product is received by the housing part 3, so that the molding part 2 is press-fitted into the parison. The required strength and durability can be kept small as long as it can withstand the air pressure.
Here, the housing portion 3 of the present embodiment is formed by the metal frame 3a and the metal back plate 11. However, these are not necessarily made of metal, and may be ceramics or CFRP. It may be a highly rigid plastic.
FIG. 15 is a diagram illustrating an example of a molded product formed using the pair of lightweight simple resin molds of the present embodiment or the pair of lightweight simple resin molds manufactured in the manufacturing process of the present embodiment.
As shown in FIG. 15, a molded product (a symmetrical heart-shaped three-dimensional image) 19 blow-molded using a pair of lightweight simple resin molds of this embodiment is attached to a support base 20 using a connector 21. Fixed.

By using the lightweight simple resin mold manufactured according to the present invention, it can be used for the production of a human body model such as a mannequin doll, the production of a toy model, a prototype of an electric / mechanical part having a curved surface, and the like.

1 Lightweight simple resin mold 2 Molded part 3 Housing part
3a
Metal frame 4 Prototype 5 Surface layer 6 Reinforcing layer 7 Back surface layer 8 and 9 Through hole 10 Parting line 11 Back plate 12 Mold frame 12a Large frame 12b Lid 13 Annular space 14 Nozzle 15 Air vent 16 Chamfer 17 Clay 18 Annular Member 19 Molded product 20 Support base 21 Connector 22 Molding surface
23 Post 24 Bolt hole 25 Air inlet

Claims (8)

A pair of lightweight simple resin molds for molding a molded product having a three-dimensional curved surface by sandwiching a parison,
A surface layer in which a molding surface of the molded product is formed by an epoxy resin composition in which metal powder is kneaded, a reinforcing layer formed by fibers impregnated with the epoxy resin composition, and a space through which fluid flows in and out. Having a back layer formed of the epoxy resin composition, a frame formed so as to surround a side surface of the molded portion, and the molded portion and the frame on the back layer side a plate member fixed to the body, the skeleton portion provided with the possess,
The lightweight simple resin mold , wherein the molding surface is formed with a plurality of air holes penetrating the surface layer, the reinforcing layer, and the back surface layer . The lightweight simple resin mold according to claim 1, wherein the space is formed on a back surface of the molding surface and includes a support column for supporting pressure applied to the molding surface. The lightweight simple resin mold according to claim 1 or 2, wherein the frame body has a height at which the surface layer with the molding surface facing upward is hidden or flush. A method of manufacturing a pair of lightweight simple resin molds for molding a molded product having a three-dimensional curved surface by sandwiching a parison,
First, a release agent is applied to half of the original mold of the molded product housed in a mold, and then an epoxy resin composition kneaded with metal powder is applied to form a surface layer having a molded surface of the molded product. One process,
A second step of forming a reinforcing layer by laminating and sticking a predetermined size of fibers impregnated with the epoxy resin composition on the surface layer;
A third step of forming a back surface layer having a space in which the epoxy resin composition is filled and the fluid is allowed to flow in and out of the mold in which the reinforcing layer is formed;
The front surface layer, the reinforcing layer, and the back surface layer are formed on the lid portion of the mold, and each of the layers formed on the lid portion is joined to each corresponding layer formed in the mold frame. A fourth step of forming a molded part for molding the molded product, and heating and curing the formed molded part for a predetermined time;
A fifth step of removing each of the lid and the mold, installing a frame on a side surface of the molded part, and fixing the molded part and the frame to a plate-like member to form a housing part. A method for producing a lightweight and simple resin mold. 5. The lightweight simple resin mold manufacturing method according to claim 4 , wherein the first step includes a step of housing the whole prototype in the mold and concealing the half of the contained prototype so as to be buried. Method. In the third step, the epoxy resin composition is filled in a state where a predetermined member is placed on the back surface of the molding surface on which the epoxy resin composition is applied to the reinforcing layer so that the thickness is at least 0.5 mm. The method of manufacturing a lightweight simple resin mold according to claim 4 , further comprising: forming the back surface layer and removing the predetermined member from the formed back surface layer to form the space. Method. The fourth step includes a step of placing a column formed of the epoxy resin composition in the space before bonding each layer of the lid to each layer in the mold. The method for producing a lightweight simple resin mold according to any one of claims 4 to 6 . The fourth step, claim characterized in that it comprises a step of forming the air holes of the air in a plurality of locations of said forming surface flows with the outside, and a hole for the flow and out the fluid from the outside into the space 4 8. A method for producing a lightweight simple resin mold according to any one of items 1 to 7 .

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