JPH0222261Y2 - - Google Patents

Description

[Detailed description of the invention] (Technical field) The present invention is a so-called method in which two or more resin components such as a base resin and a curing agent are mixed and stirred, injected into a cavity such as a rubber mold, and then cured by reaction within the mold. The present invention relates to a casting device for casting synthetic resin.

(Prior art) In the synthetic resin casting method, two or more resin components, such as a base resin and a curing agent, which are liquid at room temperature, are mixed and stirred and then poured into a mold. Since liquid synthetic resin can be supplied to the details inside the cavity with no pressure or only a slight pressure, mold costs are low, and the ratio of equipment costs and energy costs is lower than that of conventional injection molding methods. It is widely used for decorative items and prototypes for high-mix, low-volume production because it is relatively inexpensive and the time required to obtain the product is short. The conventional technology in the above casting method is
To explain with reference to the figure, a mold 2 is set in a vacuum container 1, and a liquid synthetic resin 4 is mixed with a base resin and a curing agent into an injection receiver 3 attached to the mold 2.
After pouring, the lid 5 of the decompression container 1 is closed, the vacuum valve 6 is opened, the leak valve 7 is closed, and the vacuum pump P is used to suction and exhaust. As the pressure inside the vacuum container 1 is reduced, the air in the mold cavity 2a and the air drawn in during mixing and stirring of the base resin and curing agent pass through the injection resin to the outside of the mold, and then through the vacuum pump to the outside of the vacuum container 1. is discharged to. After completing the exhaust inside the mold, close the vacuum pack 6 and close the leak valve 7.
is opened to introduce the atmosphere into the vacuum container 1. Atmospheric pressure pressurizes the injected resin 4, and the resin flows into every corner of the mold cavity 2a, which is in a substantially vacuum state, and hardens within the mold to perform casting.

According to the conventional example, the curing time after mixing the synthetic resin main ingredient and curing agent is relatively long, for example, 5 to 6
Good molded products can be obtained without any problems by casting for materials that take more than a minute or so, but some resins that harden within a short time after mixing, such as urethane resins that harden within about 30 seconds after mixing, may also be used. For this type of resin, the lid 5 of the vacuum container 1 is closed and the air is sucked and discharged to obtain a vacuum degree suitable for casting, for example 5.
In an apparatus that requires more time than the above-mentioned curing time to reduce the pressure to about mmHg, the casting resin hardens during the reduction and loses fluidity, resulting in the inconvenience that a good cast product cannot be obtained. Since the decompression speed is determined by the volume of the space inside the decompression vessel 1 and the displacement per hour of the vacuum pump P, in order to eliminate the above-mentioned disadvantages, it is necessary to reduce the capacity of the decompression vessel and create a vacuum with a large displacement. This can be solved by using a pump, or by preparing a large-capacity decompression tank, depressurizing it in advance, and then operating a valve to rapidly suck the air inside the decompression container, but this is not cost-effective as equipment. It becomes bad. Therefore, it is extremely difficult to apply the conventional apparatus as described above to resins that require a short curing time.

(Purpose) The purpose of the present invention is to vacuum degas and dehydrate two or more resin components such as a base resin and a curing agent set in a vacuum container in an unmixed state, and to remove water from the vacuum container. By providing a casting device that can mix, stir, and inject the two or more resin components into a mold by individual operations from Therefore, it is possible to obtain a good cast product without being influenced in any way by the depressurization speed of a depressurized container.

(Example) The present invention will be explained below with reference to an example. Figure 2,
In FIG. 3, a pipe 11 is connected to the reduced pressure vessel 10, and a leak valve 12 is connected to one side of the pipe.
is connected to the other end, and a vacuum pump P is connected to the other end via a vacuum valve 13. The first storage tank 14 and the second storage tank 15 are supported by one ends of shafts 19 and 20 that pass through vacuum seals 17 and 18 attached to the reduced pressure container 16, respectively, and an operating member 21 and a manipulation member 21 are respectively provided at the other ends of these shafts. 22 is attached, and by operating these operating members, the first storage tank 14 is switched between a liquid storage state and a liquid injection state, and the second storage tank 15 is switched between a liquid storage state and a pouring state, as described later. Can be switched. The reduced pressure container 16 is made of a transparent material such as acrylic resin to facilitate these operations. The operating shaft 23 is inserted through a vacuum seal 25 attached to the lid 24, and can be slid up and down in the axial direction and rotated around the shaft by operating an operating member 26 fixed to the upper end. A stirring blade 27 is fixed near the lower end. 28
is a positioning member that engages with the engagement groove 23a of the operating shaft 23 when the operating shaft 23 is in the raised position. 29 is a casting mold equipped with an injection receiving part 29a and a cavity 29b.

(Operation) Next, the operation of the embodiment configured as described above will be explained. To perform casting, first place the vacuum container 1
0, then the vacuum container 16 is closely placed on the vacuum container, and the first storage tank 14 and the second storage tank 14 are
The storage tanks 15 are each set in a liquid storage state as shown in FIG. 2, and in this example, the first liquid resin component is
A curing agent 30 is placed in the storage tank 14, and a base agent 31 is placed in the second storage tank 15.
Then, the lid 24 is closely placed on the vacuum container 16, and the operating shaft 23 and the blade 27 are placed in the required amount.
is in the state shown in FIG. In this state, the vacuum chamber 32 surrounded by the vacuum vessels 10 and 16 and the lid 24
is formed. Next, close the leak valve 12, open the vacuum pump 13, and suck and exhaust with the vacuum pump P.
The entire interior of the decompression chamber 32 and the cavity 29 of the mold 29
The air in b is discharged, and the curing agent 30 and main agent 31
After sufficient vacuum degassing and dehydration are performed, the operating member 21 is rotated to change the first storage tank 14 from the liquid storage state to the liquid injection state shown in FIG. is injected into the second storage tank 15. After the injection, the first storage tank may be left as it is as shown by the solid line in FIG. 5, or it may be returned to the state shown by the two-dot chain line in the figure by rotating the operating member 21. Next, by operating the operating member 26, the blade 2
7 to uniformly mix the two liquids, the curing agent 30 and the base agent 31, in the second storage tank. After sufficient mixing is performed, the operating shaft 23 is pulled up together with the blade 27 by operating the operating member 26, and the engagement groove 23a is engaged with the positioning member 28 (FIG. 2). 2 storage tank 15 from the liquid storage state to the 5th storage tank 15
In the casting state shown in the figure, the liquid mixed resin 33 in the second storage tank 15 is injected into the cavity 29b of the mold 29 via the injection receiving part 29a. Next, the operation of the vacuum pump P is stopped, the vacuum valve 13 is closed, and the leak valve 12 is opened to introduce the atmosphere into the decompression chamber 32. The atmospheric pressure pressurizes the injected resin, and every corner of the cavity 29b, which is in a substantially vacuum state, is The resin wraps around until the mold cavity hardens within the mold cavity, and casting is performed. In this casting, mixing and stirring of the base material 31 and the curing agent 30 is performed after the pressure in the vacuum chamber 32 is reduced, so that casting can be performed without being affected by the pressure reduction speed by the vacuum pump P. Therefore, good cast products can be obtained even when using resins that require a short curing time after mixing. In addition, in this implementation, the first storage tank 14
The second storage tank 15 and the blade 27 are connected to the operating member 2, respectively.
1, 22, and 26, and since the reduced pressure container 16 is made of a transparent material, the operation can be carried out while checking the operation status, so there is no need to worry about erroneous operation. Furthermore, in this embodiment, the case where the casting resin is a mixture of two types, the base resin 31 and the curing agent 30, has been described, but the piping inside the decompression chamber 32 has been devised, and the resin corresponding to the first storage tank 14 has been If the number is increased, it is possible to cast molds containing more than the above two types of ingredients.

(Effects) As described above, the present invention is capable of vacuum defoaming and dehydration of two or more resin components such as a base resin and a curing agent set in a vacuum container in an unmixed state, and allows The present invention provides a casting device that enables mixing and agitating the two or more resin components and injecting them into a mold by individual operations, and there is no need to worry about these operations, and it is suitable for resins with a high curing speed. This method has the remarkable effect that a good cast product can be obtained without being affected by the decompression rate of the depressurized container.

[Brief explanation of drawings]

FIG. 1 is a vertical cross-sectional view of a conventional casting device, FIGS. 2 to 5 are examples of the present invention, and FIG. 2 is a vertical cross-section of the casting device showing vacuum defoaming and dewatering states. Fig. 3 is a view showing the main part in the direction of arrow A in Fig. 2, Fig. 4 is a vertical sectional view showing the main part of the casting device showing the process of mixing the curing agent with the main ingredient, and Fig. 5 is a view showing the main part of the casting device. FIG. 3 is a longitudinal cross-sectional view of the casting device showing the forming process. 14 is the first storage tank, 15 is the second storage tank, 21, 2
2 and 26 are operating members, 23 is an operating shaft, 27 is a blade, 29 is a mold, and 32 is a decompression chamber.

Claims (1)

[Scope of utility model registration request] In the casting method, in which a liquid synthetic resin made by mixing two or more components such as a base resin and a curing agent is injected into a mold and hardened, the operation member 26 is inserted through the inside and outside of the decompression chamber 32 and placed near the upper end. A stirring blade 27 is attached to the lower end of the operating shaft 23 and can be slid in the axial direction and rotated about the shaft by the operating member, and a stirring blade 27 is disposed in the decompression chamber 32. A first storage tank 14 that is switched from a liquid storage state in which liquid can be stored to a liquid injection state by an operating member 21 arranged outside the decompression chamber, and a second storage tank 15 arranged below the first storage tank. The decompression chamber is changed from a liquid storage state in which liquid can be stored and the liquid poured from the first storage tank 14 can be mixed and stirred with the liquid in the second storage tank by rotating the blade 27. 3. A casting device comprising: a second storage tank 15 which can be switched to a casting state into a mold 29 by rotating an operating member 22 disposed outside of the second storage tank 15;