JPH0248413B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to a microwave processing molding machine that heats and melts plastics, wood, foods, etc. using microwaves and molds them. [Prior Art] Generally, wood molding, adhesive processing, plastic molding, etc. are carried out by applying heat while applying pressure with a mold. However, in recent years, with the development and development of microwave engineering, microwave heating and melting can be performed in a short time and is relatively easy to handle, so heating using microwaves has been considered, reducing heating time. - Expected to improve heating efficiency. When considering such a processing and molding machine that uses microwaves, the mold must be made of a material that transmits microwaves, but plastic, for example, cannot be used because it is susceptible to high heat when heated by microwaves. I can't. Other materials such as glass, ceramics, and ceramics may be used, but because machining is difficult, it is not possible to easily create molds of any shape with high precision. For this reason, in the past, when bonding or shaping wood, a wooden mold 1 was used as shown in Figure 1, and the surface of the wooden mold 1 was covered with a thin metal plate 2 to protect it. It's nothing more than that. [Problems to be Solved by the Invention] However, such a conventional device covered with a metal plate had a drawback of poor heating efficiency due to a small amount of microwave transmission. In addition, when performing microwave heating, the electric field becomes zero on the metal surface, the part in contact with the metal is not heated, and at least as shown in Figure 2, from this It is not appropriate to use metal molds because effective heating cannot be obtained unless they are separated by at least the microwave wavelength. Therefore,
Dielectric molds are most suitable, but dielectric materials such as ceramics are difficult to machine, so
The drawback is that it is difficult to create complex shapes with high precision. SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a microwave processing molding machine that can obtain effective heating and can easily and precisely form a mold even if it has a complicated shape during manufacturing. There is something to do. [Means for Solving the Problem] In order to achieve such an object, the present invention has the following features:
In a microwave processing and molding machine that clamps an object to be heated and heats it with microwaves (free space wavelength λ ₀ ) to shape the object, water glass is added to sandwich the object from both directions. It has a mold made of gypsum (relative dielectric constant εr), and each metal pedestal is fixed to the opposite side of the clamping surface of the mold for the object to be heated, and the clamping surface of the mold has a predetermined shape. In addition to forming the shape, the length from the metal pedestal surface of the mold to the surface holding the object to be heated is determined.

[Effect]

As mentioned above, for effective heating, it is necessary for the object to be heated to be at least λ/4 away from the metal plate, but as is well known, when the wavelength in free space is λ ₀ , In a medium with relative permittivity εr, the wavelength is

[Formula] becomes. Therefore, the above λ/4 is

Replaced with [expression]. Therefore, it consists of a mold that clamps the object to be heated from both directions, and each metal pedestal fixed to the opposite side of the clamping surface of the mold for the object to be heated, and The length from the metal pedestal surface to the surface holding the heated object.

[Formula] By doing so, effective heating can be achieved. In addition, the mold can be processed extremely easily and can be formed into complex shapes by adding water glass (sodium silicate) and water to calcined gypsum and heating the solidified product to obtain a fired body. It can be formed with high precision, does not deform even when heated, and acts as a molding machine that is effective against microwaves. (Example) Hereinafter, an example of the microwave processing molding machine according to the present invention will be described using Fig. 3. In the figure, 13 and 14 are molds, and the surfaces for holding the object to be heated (not shown), respectively. A predetermined shape is formed by machining, and a metal pedestal 10, 1 is attached to the other end.
1 is fixed to the metal pedestal 1 of the molds 13 and 14.
0,11 surface, clamping surface and length

[Formula] Above. These molds 13 and 14 are composed of fired bodies obtained by adding water glass (sodium silicate) and water to calcined gypsum and heating the solidified product at about 100 to 150°C, so they can be cast. can be,
In addition, it is not as hard as ordinary ceramics, and can be easily processed by ordinary machining, and can be easily formed into any shape. Furthermore, since the main components of the molds 13 and 14 are calcined gypsum and water glass, their relative permittivity (εr) is 4 to 6, which allows them to sufficiently transmit microwaves. The length from the surface to the surface holding the heated object.

〔Effect of the invention〕

As is clear from the above explanation, the molding machine according to the present invention can be used to bend or bond wood, polymerize and heat plastic (in this case, injecting monomer into a closed mold), or mold food. Molding heating and the like can be performed using microwaves with sufficient heating effects and shortening of working time. In addition, when manufacturing this molding machine, the mold is made of gypsum with water glass added, so pour molding is easy, and the solidified material is also easy to machine, making it easy to process complex shapes. Moreover, it can be formed with high precision.

[Brief explanation of drawings]

Fig. 1 is a structural diagram of a wooden mold of a conventional molding machine, Fig. 2 is an intensity distribution diagram of a microwave electric field near a metal plate, and Fig. 3 is a structure of a mold and a metal pedestal showing an embodiment of the present invention. It is a diagram. 10, 11... Metal pedestal, 13, 14... Molding mold.

Claims (1)

[Scope of Claims] 1. In a microwave processing and molding machine that clamps an object to be heated and heats it with microwaves (free space wavelength λ ₀ ) to shape the object, the object to be heated is heated from both directions. It has a mold made of gypsum (relative permittivity εr) added with water glass to be held, and each metal pedestal fixed to the opposite side of the holding surface of the mold with respect to the object to be heated, A microwave processing molding machine, characterized in that a predetermined shape is formed on the clamping surface of the mold, and the length from the metal pedestal surface of the mold to the clamping surface of the object to be heated is equal to or more than .