JPS6298592A - Tray for microwave oven - 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 A) Industrial Application Field The present invention can be placed on a turntable or the like inside a microwave oven, which is popular as a heating cooking appliance in the home, to make it lightweight and easy to handle. And heat resistant.

The present invention relates to a tray for a microwave oven that houses food to be cooked and has improved heat insulation properties.

Conventional technology Conventional microwave oven trays are mainly made of glass and metal, and glass trays are made of ordinary silicate glass with improved heat resistance. The borosilicate glass was molded into a dish shape, while the metal version was made from an iron plate shaped into a dish shape with an enameled surface to make it non-conductive. Although glass trays for microwave ovens satisfy the strength requirements, they have a specific gravity of 2.5, which makes them difficult to handle and meet the demands for compact microwave ovens. Since it is heated to a high temperature, there is a problem that the frozen food placed on the tray is heated unevenly between the upper and lower portions, which may cause a change in quality, especially when the frozen food is thawed and heated.

c) Problems to be solved by the invention The problems which the invention attempts to solve in view of the above-mentioned situation are the requirements originally required for a microwave oven tray;
In other words, we would like to provide a tray for microwave ovens that satisfies the requirements of having a predetermined strength and heat resistance as a non-conductive material, while also providing beneficial effects, namely extremely light weight and high heat insulation properties, thereby solving the above-mentioned problems. The point is that

2) Means for Solving the Problems In order to solve the above-mentioned problems, the present invention forms a tray using an inorganic fired foam mixed with a large number of hollow inorganic foam particles and fired. A microwave oven tray is constructed by imparting water-blocking properties to the surface of the tray. In other words, by using a foam that has a large number of cells formed inside, it is significantly lighter in weight, and also has heat insulation properties, and because it is an inorganic material, it has heat resistance and non-conductivity.
The idea is to provide the surface with water-blocking properties to eliminate the adverse effects of the water-absorbing properties that foams generally have.

e) Examples Preferred examples of the present invention will be described below. The hollow inorganic foamed particles used in the present invention include, for example, those obtained by heat-treating a glassy material at high temperatures to foam the glass particles to form fine hollow foamed glass spheres, which are volcanic eruption deposits. So-called shirasu balloons, which are made by selecting volcanic glass particles from certain shirasu and foaming them by high-temperature heat treatment, can be used as the present inorganic foamed particles. As the inorganic material into which the Shirasu balloons, which are hollow inorganic foamed particles, are mixed, for example, in consideration of economic efficiency, it is desirable to use clay clay, which is used in roof tile manufacturing, and then fire it. That is, to explain one example of the manufacturing process of the tray in the present invention, raw material clay, etc. is crushed, water is added to knead it, and at this time, the above-mentioned whitebait balloon is mixed in, and after adjusting the shape, In order to improve the efficiency of loading, the pieces are dried to the extent that they retain their shape, then loaded onto a trolley, placed in a firing furnace such as a tunnel furnace, and fired for approximately 18 hours. By cooling slowly, an inorganic foam tray can be obtained. As a result, in addition to making the inorganic material porous by firing, the whitebait balloons mixed in the material are melted by firing, leaving the area where the whitebait balloons were as a cavity, resulting in a lightweight tray with many air bubbles. is completed.

Here, since the Shirasu balloon is hollow,
Even if it is not completely melted and remains in the form of a foamed glass bulb, a lightweight L-ray with many bubbles can be realized. Regarding this weight reduction, for example, as in this example, when Shirasu balloons are used as the hollow inorganic fired foam and clayey clay for roof tile manufacturing is used as the inorganic material,
The bulk specific gravity of the inorganic fired body without the addition of whitebait balloons was approximately 2.0 to 2.3 g/cJ, but the bulk specific gravity was approximately 0.
．． 14~0.35g/cn! By mixing in Shirasu balloons, it is possible to form a tray with a weight of approximately 0.5 to 1.5 g/cJ, which is approximately 115 to 1/2 the weight of a conventional glass tray with the same volume. An extremely large weight reduction can be guaranteed. After forming a tray using this foam glass, the tray surface is subjected to a treatment to impart water-blocking properties to complete the microwave tray according to the present invention. In general, there are various treatment methods for imparting water-blocking properties, but the practical requirements for a tray for a microwave oven require at least heat resistance.For this reason, in this example, the surface of the tray is glazed with a glaze, for example, an enamel glaze. A method of imparting water-blocking properties is adopted, such as by firing or coating with ceramics. There are several possible methods for this, depending on the tray to be glazed and the condition of the glaze. As a low-temperature treatment method, there is a method commonly used for pottery, called the cold wet glazing method, in which a sol-like glaze is rubbed onto the surface of a cooled tray and then fired. It is desirable to adopt the so-called hot dry glazing method in consideration of the omission of the manufacturing process and the finish of the surface. That is, in this method, the inorganic fired foam that is being fired in the firing furnace described above is hot and slightly pressure molded to make it smooth, then taken out of the firing furnace, immediately sprinkled with powder glaze, and then returned to the firing furnace. After the glaze is fired, the tray is fired and the water-blocking layer is formed at the same time by cooling slowly as described above. By forming this water-blocking layer, the water absorption of the tray body made of inorganic foam is blocked by the surface, and at the same time, the aesthetic appearance of the tray can be improved.

It should be noted that the tray for microwave ovens according to the present invention can of course be used as a tray for gas ranges, ovens, etc., and a plate made using a similar manufacturing method can also be used as a top plate for an electromagnetic cooker. It is.

f) Effects of the invention According to the tray for a microwave oven of the present invention, the tray is formed using an inorganic foam having a large number of bubbles inside, and the surface of the tray is provided with water-blocking properties. from,
Because it has a large number of air bubbles inside, the tray can be made lighter, making it easier to handle and reducing the weight of the microwave oven itself.As it is made of inorganic material, it is heat resistant.
In addition, it exhibits high insulation properties due to the large number of air bubbles inside it, and it prevents quality problems caused by the difference in heating conditions between the lower and upper parts of the tray that are in contact with the tray, especially when thawing and heating frozen foods. In addition to eliminating non-uniformity, it is also possible to eliminate the negative effects of water absorption that the foam has by adding water-blocking properties to the surface.Also, the zero tray is suitable for production using continuous manufacturing processes. Since it is suitable for mass production, it can be expected to be effective in mass production, and since natural raw materials can be used, it is possible to reduce costs.

Claims (1)

[Claims] 1) A microwave oven in which a tray is formed using an inorganic fired foam fired using an inorganic material mixed with hollow inorganic foamed particles, and a water-blocking property is imparted to the surface of the tray. tray. 2) The tray for a microwave oven according to claim 1, wherein the inorganic foamed particles are microscopic hollow foamed glass spheres. 3) The tray for a microwave oven according to claim 1 or 2, wherein clay is used as the inorganic material. 4) The tray for a microwave oven according to claim 1, 2, or 3, wherein water-blocking properties are imparted by applying a glaze to the surface of the tray and firing the tray.