JPH0318805B2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field] The present invention relates to top plates of washstands, wall materials, bathtubs,
Cast molding or FRP for housing and casing etc.
The present invention relates to a molding method that can be manufactured in a short time by hand lay-up molding.

[Background technology] Conventionally, for example, when manufacturing the top plate of a bathroom vanity, an upper mold and a lower mold are made from FRP, etc., and a resin such as polyester called gel coat is applied to the surface of the lower mold. This lower mold is placed in a heating furnace and cured at around 50℃, then molding resin is injected into this lower mold and vibrated to defoam the air in the molding resin, and then the upper mold is molded. After setting it on top of the resin, it is placed in the heating furnace again and cured at around 50℃, then the upper mold is removed, the lower mold and the resin are cooled, and the molded product is removed from the lower mold. The products were produced by finishing the edges of the molded products.

Conventionally, molds made of FRP were used, which meant that the temperature of the mold could only be raised to around 50°C, which meant that it took a long time for the molding resin to harden. , and even when cooling after molding, it takes a long time (for example, conventionally
(about 40 minutes), therefore the molding time was long. In addition, when molding is performed using a thick mold such as a steel material or casting mold, although it is possible to shorten the curing time of the resin by heating the mold to a high temperature, the cost of the mold is high. above,
This method has the disadvantage that it takes a long time for heating and cooling, and it is not possible to significantly shorten the molding time.

[Object of the invention] The present invention has been made in view of the above points, and it is an object of the present invention to provide a molding method that allows a mold to be manufactured at low cost and that can significantly shorten the molding time. The purpose is to

[Disclosure of the Invention] That is, in the molding method according to the present invention, a gel coat 11 is applied to a mold 1 formed of a thin metal plate, and then the gel coat 11 is applied by heating the mold 1.
is heated and cured, and then the gel coat 1 in the mold 1 is
1 is filled with molding resin 2, and then the mold 1 is filled with molding resin 2.
It is characterized by curing the molding resin 2 by heating it, and by forming the mold 1 from a thin metal plate, it is possible to heat to high temperatures, rapidly heat, and cool, thereby significantly shortening the molding time. In addition, the mold 1 can be produced at a lower cost than steel molds or casting molds, and after coating the mold 1 with gel coat 11 and curing it, molding resin 2 can be applied.
By filling and curing the gel coat layer 13 on the surface, a molded product with a beautiful natural marble appearance can be obtained.

The present invention will be described in detail below based on examples. First, FIGS. 1 and 2 show a schematic plan view and a schematic front view of a molding apparatus A used in the present invention. In the figure, 3 is a first chain conveyor 5 that can be rotated freely on the upper surface.
A and a heater 4 are each provided on a frame, and 18 is a cart. Further, 5b is a second chain conveyor on which the lower mold 1a is placed and conveyed, and a resin injection part 19 is provided at the front end of the second chain conveyor 5b. A vibrator (not shown) is disposed in this resin injection part 19 so as to vibrate the lower mold 1a. Further, a plurality of limit switches 16a, 16b, 16c are arranged at the front end of the second chain conveyor 5b, and a stopper 17 is arranged on the conveyance side.
The lower die 1a carried on the second chain conveyor 5b hits this stopper 17 and is temporarily stopped. Also, the second
On the upper surface of the chain conveyor 5b, a plurality of rows of sheet heaters 6a, 6b, and 6c each having heater wires arranged in a sheet are arranged in the conveying direction, and detection means such as the limit switches 16 detect the lower molds 1a and The planar heaters 6a, 6b, and 6c are turned on. That is, projections (not shown) are provided on the lower surface of the lower mold 1a at different positions depending on the length of the lower mold 1a, and when the projections select and contact the limit switch 16, each The planar heater 6 is heated. For example, if the length of the lower mold 1a is short, only one of the planar heaters 6a is turned on and the length of the lower mold 1a is shortened. When the length is long, a plurality of planar heaters 6a, 6b, and 6c can be switched on. Further, a heating furnace 7 heated with steam or the like is provided in the center of the second chain conveyor 5b. Further, at the rear of the second chain conveyor 5b, a cooler 8 for blowing out cold air is disposed at a lower position and a cold air duct 9 is disposed at an upper position. Further, in the figure, 10 is a reverse conveyor for returning the mold, and 20 is a stopper for stopping the lower mold 1b when heating it.

Now, in the above-mentioned molding apparatus A, when manufacturing a top plate of a washstand or the like after cooling, a lower mold 1 formed of a thin metal plate such as stainless steel or steel plate is used.
A and an upper mold 1b are used. Although the thickness of each mold 1 is not limited in any way,
For example, a metal plate of about 0.3 mm (preferably about 1.2 to 1.5 mm) is used (the 0.3 mm or more here is for strength reasons;
Also, the reason why it is set to 10 mm or less is because the limit for sheet metal production is about 10 mm, so it is set to 10 mm or less so that sheet metal production can be made.)

First, the lower mold 1a is placed on the upper surface of the cart 18, and after coating the inner surface of the lower mold 1a with the gel coat 11 made of polyester resin or the like, the lower mold 1a is transferred to the upper surface of the pedestal 3 by spraying or the like. Next, the heater 4 arranged on the top surface of the pedestal 3 is
The lower mold 1a is heated to about 100° C. to harden the gel coat 11. Here, the lower surface of the lower mold 1a is coated with a black absorption film that particularly absorbs far infrared rays, so that even if the lower mold 1a is formed of a highly reflective metal plate such as stainless steel, it can be efficiently It is capable of absorbing far infrared rays. Next, from the first chain conveyor 5a to the second
The lower mold 1a is transferred to the chain conveyor 5b, the lower mold 1a is brought into contact with the stopper 17, the lower mold 1a is temporarily stopped at the resin injection part 19, and the molding material is placed on the upper surface of the lower mold 1a as shown in FIG. 4b. Inject resin 2.
The composition of the molding resin 2 is, for example, one obtained by kneading a polyester resin, calcium carbonate, a curing agent, and a mold release agent.
This molding resin 2 contains a curing agent that causes a radical reaction at about 60°C, and heating it to 60°C or higher will rapidly increase the reaction rate. Furthermore, the amount of mold release agent blended is smaller than that of conventional molding resins.

The lower mold 1a into which the molding resin 2 has been injected is then vibrated to remove air from the molding resin 2. Next, after the upper mold 1b is set on the upper surface of the molding resin 2, the stopper 17 is released and the lower mold 1a is conveyed by the drive of the second chain conveyor 5b. At this time, as described above, the limit switch 16 is activated and the planar heater 6 is heated, and the planar heater 6 heats the molding resin 2 at a temperature of about 100° C. from the bottom surface of the lower mold 1a. The molding resin 2 gradually hardens from the bottom, and when the upper molding resin 2 is in an uncured state, the upper mold 1 is heated as shown in FIGS. 3 and 4 d.
The uncured resin on the outside of b is removed using a spatula 14 or the like, and the surface is leveled. In this way, by smoothing out the resin overflowing from between the upper mold 1b and the lower mold 1a with the spatula 14, the number of man-hours in the finishing process can be reduced. next,
This material is transported into a heating furnace 7 and heated at about 50° C. to completely cure the molding resin 2. Thereafter, the upper mold 1b is released and then cooled in a cooler 8. Since the lower mold 1a is formed of a thin metal plate, the cooling can be performed rapidly by blowing cold air onto the lower surface of the lower mold 1a, for example.
It can be cooled to room temperature within 10 minutes.
Thereafter, the molded product is removed from the lower mold 1a, and the end face is finished to form a product B as shown in FIG. A cross-sectional view of this top plate is shown in FIG. 6. A gel coat layer 13 is formed on the surface of the casting layer 12, and by using calcium carbonate and mica as fillers in the molding resin 2, white marble is formed. By using aluminum hydroxide as a filler, a top plate with an onyx pattern can be obtained.

By forming the lower mold 1a from a thin metal plate as described above, it is possible to heat the mold to a high temperature of, for example, about 100°C, thereby accelerating the reaction rate of the molding resin 2 and shortening the curing time. Moreover, since rapid heating and cooling are possible, heating time and cooling time can be significantly shortened. In addition, during cooling, the shrinkage rate between the metal lower mold 1a and the molded product is significantly different, so rapid cooling will cause a misalignment between the lower mold 1a and the molded product, making demolding easier. It becomes like this. Also,
By forming the lower mold 1a from stainless steel, the mirror surface formed on the inner surface can be transferred to the molded product, and a product B with a beautiful surface can be obtained. There is no need to finish by plating, and a smooth mirror surface can be formed by simply polishing and finishing the surface of the lower mold 1a. For example, when the lower mold 1a is made with brass, etc. It is necessary to apply a plating finish to the inner surface, and if the plating layer peels off, it is necessary to apply plating again, but with the stainless steel lower mold 1a, such trouble is unnecessary. It is something.

Furthermore, the heat distribution of the lower mold 1a has a difference of about ±5°C between the center and the edges, and areas that harden quickly tend to release from the mold quickly, creating a step between the areas that harden slowly. As mentioned above, by reducing the amount of mold release agent in the molding resin 2, the mold release properties in the areas that harden quickly are deteriorated, resulting in lower mold 1a.
It is possible to reduce the difference in level between the molded product and the molded product. In addition, by using a curing agent that starts the reaction at high temperatures as a catalyst for the molding resin, it is possible to leave the molding resin mixed with the catalyst at room temperature, allowing the resin to be mixed each time it is molded. This can save you such trouble. In addition, as mentioned above, by using the spatula 14 to scrape off the burr parts during hardening, so-called wet trimming, the finish can be completed by just scraping once or twice with sandpaper after hardening, and the finishing process can be completed easily. Man-hours can be significantly reduced.

In the above embodiment, the lower mold 1b was heated from the lower surface side, but after the upper mold 1a is set on the lower mold 1b, the upper mold 1b is also heated to harden the molding resin 2 from both the upper and lower surfaces. In the above embodiment, after the upper mold 1b is set on the upper surface of the molding resin 2, the uncured resin 2 is removed with the spatula 14, and then the resin 2 is completely cured. It is also possible to heat and harden the resin 2 without performing the trimming operation, and then finish it.

[Effects of the Invention] As described above, in the present invention, since the mold is formed of a thin metal plate, high temperature heating, rapid heating, and rapid cooling are possible, and the molding time can be significantly shortened, thereby increasing productivity. This has the advantage that the mold can be made at a lower cost than steel molds, casting molds, etc. In addition, since gel coat is first applied to the mold and cured, then molding resin is filled and cured, a gel coat layer is formed on the surface and a beautiful molded product with a natural marble-like appearance can be obtained. There are advantages.

[Brief explanation of the drawing]

FIG. 1 is a plan view of a molding apparatus according to an embodiment of the present invention;
Figure 2 is a front view of the same as above, Figures 3a and b are perspective views and sectional views of essential parts of the same as above, Figures 4 a to d are sectional views showing the manufacturing method of the same as above, and Figure 5 is as above. A perspective view of the obtained top plate, FIG. 6 is a sectional view of the main part of the same as above,
FIG. 7 is a perspective view of the bathroom vanity. 1 is a mold, 2 is a molding resin, and 11 is a gel coat.

Claims (1)

[Claims] 1 Apply gel coat to a mold made of a thin metal plate, then heat the mold to harden the gel coat, fill the gel coat in the mold with molding resin, and then remove the mold. A molding method characterized by curing a molding resin by heating.