JPS59106943A - Fabrication of super-hard resin product such as industrial trial manufacture model - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method and apparatus for manufacturing resin products such as industrial prototype models and denture models.

Conventionally, all resin products such as industrial prototype models and denture models have been manufactured using molds.

That is, a method has been adopted in which upper and lower molds are prepared that match the shape of the product to be manufactured, and a plastic material is poured between the molds and pressed into the desired shape.

However, manufacturing methods using these molds have drawbacks such as being expensive and difficult to modify.

Therefore, for a long time there has been a need for simpler and more precise manufacturing methods and devices to replace these known means.

The main object of the present invention is to provide an economical and highly sophisticated method for manufacturing resin products for models.

Furthermore, a second object of the present invention is to provide a method for manufacturing a resin product that allows the shape to be modified very easily by using a wax model.

A third object is to provide an apparatus specially adapted for use in the manufacturing method of the invention.

Finally, the objective is to provide a device with the most suitable resin injection speed, pressure, temperature, sprue runner diameter, etc. in the manufacturing process.g.

The method and apparatus of this invention can be used for a wide variety of purposes including industrial sampling models, dentures, trays, kitchen utensils, and the like.

The technical means to realize the idea of this invention are to place a wax model in a flask, inject plaster into the flask, heat the wax model until the wax model melts after the plaster hardens, and the melted wax. It is formed by a special process of draining the model out of the flask, injecting resin into the space created by the flow of the wax model, and cooling the resin until it hardens.

The structure of the present invention will be explained in detail with reference to the accompanying drawings as follows.

1 to 3 are drawings showing embodiments of the apparatus of the present invention.

First, a wax model 1 and upper and lower parts 2a that match the dimensions and shape of the resin product to be manufactured are prepared.

A flask 2 divided into 2b is prepared.

The flask 2 is divided into an upper and lower lid 11 and a side body 12.

These parts are typically fully joined by joining means 8, such as bolts 13 and nuts 14.

A hole 4 for press-fitting resin injection is formed in the side body 12 so that melted wax can flow out from the injection hole 4.

The number of injection holes 4 is not limited.

However, when two or more holes 4 are formed, all holes 4 except for one hole 4 into which the resin is injected and press-fit must be tightly sealed with a plug 15 when the resin is injected and press-fitted.

A gypsum injection port 9 is formed in the upper lid of the upper flask.

The stopper 16 is removably fitted into the injection port 9.

The wax model 1 is placed inside the bottom of the lower flask 2b.

The resin press-fitting gate 5 is formed by connecting the wax model 1 to the resin press-fitting hole 4 with wax.

The cooling vibro is housed inside the lower flask 2b so that both ends thereof are connected to openings 7 formed in the sides of the flask 2.

The upper flask 2a is placed on the upper surface of the lower flask 2b, and the two upper and lower flasks 2a and 2b are joined together by a joining means 8 as shown in Figure i2.

As shown in FIG. 4, the wax model 1 has a lower flask 2.
It is embedded and fixed in the cemented carbide gypsum floor 3 formed on the inner bottom surface of b. This wax model 1 may be a composite of wax and soft resin.

The upper flask 2 is placed on the upper surface of the lower flask 2b.
A is placed on the flask 2, and the upper and lower parts are tightly joined by a joining means so that the flasks 2 can be brought into close contact with each other as shown in FIG.

However, as shown in FIG. 3, a resin injection press-fit gate 5 is formed with the wax pattern 1 housed in the lower flask 2b, and this gate 5 is inserted into the resin injection press-fit gate 5 from the wax pattern 1 formed on one side of the flask 2. It is connected up to hole 4.

Both ends of the cooling vibro are opened to the outside air through holes 7 provided at the upper end of the frame of the lower flask 2b, and are provided inside the flask 2. It is desirable that this cooling vibro has as much pressure resistance and heat resistance as possible.

Of course, it is also possible to have more than one cooling pipe in the flask 2.

Next, FIGS. 4 to 7 are detailed explanatory diagrams of the present invention, showing the steps used in this method.

First, the wax pattern 1 is placed in a flask 2 and the flask 2 is tightly joined by the means described above. Gypsum is poured into the flask 2 through the open lower part until the inside of the flask 2 is filled, and the cooling vibro and the gate 5 are embedded in the plaster 10 as shown in Figure '5. After the plaster 10 has hardened, the flask 2 is heated until the wax inside it melts. This condition is shown in FIG.

This melted wax is then allowed to flow out through the holes 4 and is flushed out of the flask 2 with hot water.

Note that the flask 2 may be heated by circulating hot water or steam through a cooling vibro.

Flask 2 is cooled by circulating cold water through a cold vibro.

Referring to FIG. 7, one of the two resin injection press-fit holes is tightly sealed and the flask 2 is turned over so that the injection hole 4 is on top. Then Aksilik. Resin, polycarbonate, polynate resin, styrene, resin and porsentan.

A soft resin material such as resin, polyester, or resin is injected and press-fitted through the injection press-fitting opening 4 using an injection molding machine.

At this time, it is desirable to apply a resin mold release agent to the flask before injection and press-fitting the soft resin material, because by applying it, the process of removing the resin product 1 from the plaster 10 can be quickly carried out. be. After the resin material has hardened until it is molded into resin product a, the flask 2 is separated and the plaster 10 is
is removed to obtain product 1. The resulting product is polished and finished in the usual manner.

FIGS. 8 to 10 show a second embodiment of the present invention, in which a matched row of teeth is produced according to the idea of the present invention. The wax model 21 of the dentition is housed in a lower flask 22 consisting of a bottom plate 22a and a lower collar 22b. As shown in FIG. 8, the wax pattern 21 includes an injection gate 26 that connects the injection port 24 and the wax pattern 21, and a pouring gate 27.
6.27 is made of wax.

Further, the upper flask 23 is composed of the upper collar 23b and the upper plate 23a, and the upper flask 23 and the lower flask are placed so as to constitute a complete flask, and are tightly connected by joining means as shown in FIGS. 9 and 10. is joined to.

Such a flask is 1000-1500 9/cI/
It is desirable that the capacitor be designed to have a breakdown voltage of 1. The upper and lower collars 23b, 22b are provided with a pouring port 25 on the opposite side of the pouring port 24. A stopper 31 is fitted into the spout 25 to hold the resin material that is injected and press-fitted into the flask. This stopper 31 has an energizing port 32 so that air can be removed if air remains in the flask.
It is desirable to have the following. Once the flasks are connected together, gypsum is poured into the flask through opening 29.

This opening 29 is then sealed with a stopper 30. The gypsum is filled into flasks using vacuum devesuring or vibration methods or commonly known injection methods. The plaster poured into the flask waits until it hardens, and once it hardens, it is heated until the wax model 21 melts. Then, in order to facilitate removal of the resin product made from the plaster mold, a resin mold release agent is injected through the injection port 24 so as to evenly cover the inner surface of the plaster.

Before injecting the resin liquid, the flask is turned over on its side so that the injection IE port 24 is located above and the spout ports 25 each having a stopper 31 at the bottom. Then, the resin liquid is injected into the flask.

This injection molding (required condition is injection speed of resin liquid 0.0
It is desirable that the injection pressure is 30-1200 and the holding pressure time is 0.05-60/sec. Furthermore, the diameter of the injection gate or the same circumferential diameter is between 0.5 and 20
Y! Me, the diameter of the air deaeration hole or the same circumferential diameter is 0.1 to 5.
．． gwnR is desirable, and injection molding of the resin liquid cannot be carried out satisfactorily under or above this condition.

The resin product can be removed from the plaster after the resin liquid has hardened.

Since this invention consists of a method including the above-mentioned steps, the conventional manufacturing method for dental prostheses is simply a pouring method, that is, an inner wax molding method. In addition, the teeth that are temporarily fixed in the hardened plaster tend to become misaligned, and the process of removing and polishing is not only time-consuming but also poor in accuracy. This problem was solved by injection molding a super hard resin liquid into the plaster cavity.

Furthermore, if conventional industrial sampling is used, it becomes a simple plaster mold, which can be produced at a lower cost and with greater precision than when using a conventional real mold. In addition, for medical purposes other than dentistry, for example, when creating a prosthetic joint due to a bone defect in the foot joint, it is possible to manufacture a resin prosthetic limb using the same method as this method. The uses are wide-ranging.

Note that the term "soft resin" used in this text refers to a resin liquid that has become a soft liquid, and after hardening, it becomes a "super hard resin."

In addition, as described in Patent No. 100331, a female plaster mold is imprinted with a plastic material obtained by adding water to a mixture of gypsum starch and common salt and kneading, and this female plaster mold is filled with ordinary gypsum and solidified. A method for manufacturing male molds for plaster molding has been proposed.

However, the purpose of the above-mentioned product is to fill plaster with a stable cooling and solidification reaction, and because it is a plaster female mold formed by an impression, it cannot be used for manufacturing resin products that easily lose their properties and change their condition greatly. It is not durable, and it cannot be manufactured into a product with a shape that can be pulled out, so its uses are extremely limited.

Furthermore, since the plaster female mold formed by the impression has a large opening, the cooling and hardening reaction of the resin varies, resulting in unevenness of the product, and the surface becomes rough and flakes are likely to form. In addition, a mixture of gypsum starch and common salt mixed with water and kneaded will easily fracture, and the injection pressure of the resin will be limited to a very small one, and the resin will not be able to flow into the fine details, resulting in a poor surface condition. Become.

However, in the present invention, a model made of a material such as wax that can be melted and discharged is housed in a pressure flask, and the opening provided on the side of the pressure flask is connected by a gate made of the same material as the model. The model and gate are buried by injecting plaster, and after the plaster hardens, the model and gate are melted and discharged to form a plaster mold that surrounds the cavity of the model space. When resin is injected into the mold through a narrow vent hole, the cooling and hardening reaction of the resin becomes stable, the resin spreads to every corner of the cavity, and the surface becomes dense and highly accurate. Since the resin product is obtained by crushing the plaster after the resin has hardened, high-quality products such as dentures, prosthetic joints, prosthetic limbs, etc., can be obtained in any shape or made to order.

Furthermore, in the present invention, the softened synthetic resin is injected from the opening of the pressure flask through the gate hole of the plaster into the cavity of the model space, and after the resin hardens, the pressure flask is divided and the plaster is crushed to obtain the resin product. Therefore, the female plaster mold will match the flask and be able to withstand high resin injection pressure. Since the resin is injected under high pressure into the female plaster mold that surrounds the cavity of the model space through the narrow gate hole, the conditions for resin injection are favorable, and the resin is distributed to every detail, making it possible to improve the surface condition. This will result in dense, high-precision resin products.

In addition, in the present invention, the resin injection conditions are set to an injection speed of 0.01 to 1.
0 seconds, injection pressure 30-1200KP/cf/, holding pressure time 0.05-60 seconds, injection gate diameter or same circumference diameter 0
．． 5-2 (lyIm, the diameter of the air degassing hole or the same circumference 0.1 to 5 times, air is removed from the flask's △ and thin air degassing hole, so the injected resin liquid is air-filled in a short time in the plaster mold. It is molded at the same time as it is molded, resulting in a resin product with a fine and clean surface.

In other words, with values other than the above-mentioned values, it is difficult to manufacture a plaster molded resin product due to the deterioration and loss of resin properties and fluctuations in the condition, and even if it is possible, it will be of extremely poor quality.

In the case of plaster, it is difficult to apply high injection pressure like a mold even if it is supported by a pressure flask, but if the injection speed is increased, the plaster mold can withstand high pressure for a very short time. This was confirmed through experiments.

For example, if the injection speed is 1 to 5 seconds, the injection speed will be 250 to 300 Ky.
/cl, 700-900Ky / for 0.1 seconds or less
Can withstand pressure of d. Therefore, by increasing the injection speed, plaster mold resin products can be manufactured with even better quality.

Furthermore, Japanese Patent Application Laid-Open No. 53-61194 proposes a method for manufacturing dentures using a single-implantation method, which uses a plunger that moves up and down by rotating a handle, and allows insertion of the tip of the plunger. It consists of a rice cake-shaped resin storage cylinder and one part, and without rotating the handle, the resin was slowly injected under pressure into the plaster mold of the flask, and during this pressurized injection process, it was confirmed that the resin was poured out from the vent. After that, the resin is heated and polymerized according to legal methods. That is, the vessel is moored at 60°C for 30 minutes and then at 100°C for 30 minutes.

This is an attempt to manufacture acrylic resin dentures, which have been used for a long time in the dental industry, in a single implantation, but such acrylic resin products are so weak that they can be damaged by fly-metal work inside the oral cavity. It is of low quality and has many drawbacks, such as hygienic disadvantages as residual monomers elute from the top and cause allergies, and the surface texture is rough and lacks aesthetics due to uneven polymerization, which requires long heating polymerization. However, productivity is poor and costs are high.

The present invention completely eliminates the above-mentioned drawbacks that have not been overcome for many years, and uses an injection molding machine capable of super high-speed injection into a plaster mold to inject ultra-hard resin such as polycarbonate resin with a high viscosity of 0.01 to 0.0. A completely new method that allows ultra-high-speed injection in about 5 seconds, and an injection pressure of 30 to 1200 with 9/Cr11
Holding pressure time 0.05-60 seconds, injection gate diameter 0.5
~2001 flask pressure resistance 1000~1500Ky/a
Under the setting conditions d, injection molding was carried out at an extremely high speed of about 0.01 to 0.5 seconds while removing air from the air degassing hole cut by 0.1 to 1, so there was no residual monomer and no variation in heating polymerization. , ultra-high-strength resin products with high strength and excellent aesthetics are highly precise, and the surface is dense and the interior is molded into a single layer, making them very suitable as resin molded products using plaster molds. Excellent products can be obtained efficiently.

In this case, the plaster mold is brittle and will break immediately if the injection pressure is increased. Moreover, unlike molds, plaster molds cannot be formed into mirror-like surfaces, and the inner surface of the cavity is soft, and they also have many disadvantages, such as low thermal conductivity. It was believed that it was impossible to obtain high-quality resin products by molding with a mold, but in the present invention, under the above setting conditions, air is removed from the air degassing hole of 0.1 to 1 dag for about 0.001 to 0.5 seconds. This has been made possible by injection molding at ultra-high speeds, resulting in great effects.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a resin product made according to this invention;
FIG. 2 is a perspective view of a flask in an embodiment of the apparatus of this invention;
Fig. 3 is a cross-sectional view of the lower flask of the embodiment in which the wax pattern is stored, Figs. A plan view showing the wax pattern of the second embodiment stored in the lower flask, FIG. 9 a perspective view showing the assembled state of all the parts of the second embodiment, and FIG. 10 the second embodiment. FIG. 2 is an exploded view of the device. 1.21...Wax prototype 2 ” 'Flask 2a+
23... Upper flask 2b, 22... Lower flask
4, 24... Inlet 5... Injection gate 6... Cooling pipe 10... Plaster 22a... Bottom plate 22b... Lower collar 238... Top lid 23b... Upper collar 25.
・Pour spout 31... Plug patent application person Kogure Yamahito J)

Claims (1)

[Claims] A model of the desired product shape made of a material that can be melted and discharged, such as wax, is placed in a pressure flask, and the model and a plurality of holes provided on the side of the flask are laterally connected by a gate formed of the material that can be melted and discharged. Pour plaster into the flask until the model and gate are buried.
After the plaster hardens, the model and gate are melted and discharged to form a plaster mold that surrounds the cavity of the model space, and the holes other than the resin injection holes are used as air degassing holes, and the gate is formed in the space previously formed by the model. In the resin product manufacturing method, the softened resin is injected and press-fitted through the resin injection hole in the flask and the resin hardens, and then the plaster is crushed to obtain the resin product.
An ultra-hard resin such as polycarbonate resin is injected into the plaster mold using an injection molding machine capable of ultra-high-speed injection at an injection pressure of 30 to 12
00 K9/cd, holding pressure time 0.05-60 seconds, injection gate diameter 0.5-2011 flask pressure resistance 1000
It is made of ultra-hard resin by injection molding at an extremely high speed of about 0.01-0.5 seconds under the setting conditions of ~1500 to 9/crl while removing air from the air degassing hole of 0.1-1g. A method for producing ultra-hard resin products such as industrial prototype models, characterized by molding prototype models, prosthetic joints, prosthetic limbs, etc.