JPS61191583A - Method of sealing air flow-out pore of ceramic double structure vessel - 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 (Industrial Application Field) The present invention relates to a method for sealing an air outflow hole formed in a ceramic double structure container.

(Prior Art) Conventionally, there are ceramic containers such as coffee cups, mugs, teacups, and tokkuri that have a double structure to enhance their heat-retaining and cold-retaining functions. When manufacturing this type of double-layered ceramic container, the inner and outer walls of the container are usually molded by casting or using a potter's wheel, and then combined and bonded with slurry. Air vents must be left open. This allows the expanded air to escape to the outside in order to prevent the container from being destroyed by the expansion of the air in the void surrounded by the double walls when firing at high temperatures after molding and drying. It's h.

As described above, air outflow holes are essential in manufacturing double-layered ceramic containers.

By the way, such double-walled ceramic containers have better heat and cold retention functions than single-walled containers, but on the other hand, when washing the container, water gets into the double wall through the air outlet holes, making cleaning difficult. Even after wiping off water droplets on the surface of the rear container, the water remaining inside the double wall may unexpectedly drip to the outside, so care must be taken when cleaning. However, the air outflow holes reduced the commercial value of the double-walled container.

Therefore, in the past, when manufacturing this type of double-layered container, the air outflow hole was not sealed with an adhesive such as epoxy resin after the overlay was finished.

(Problems to be Solved by the Invention) The above-mentioned method of V-closing the air outflow hole with adhesive takes a long time because there is a considerable temperature difference between when the container is used to hold hot or cold drinks and when it is not in use. The disadvantage is that the adhesive will peel off if used repeatedly over a period of time.

Furthermore, the sealing method using adhesive is carried out after the overglaze printing operation, which is the final step in ordinary ceramic manufacturing, but the increase in the number of steps results in an increase in manufacturing costs.

In view of these drawbacks, the present invention provides a method for sealing the air outlet hole of a ceramic double-layered container, which allows the air outlet hole to remain sealed even during long-term use and does not require any special process. It is about providing.

(Means for Solving the Problems) The present invention provides a method in which a glaze made by mixing coarse ceramic particles with a medium for overglaze is applied to a ceramic double-structured container during overglaze painting. The glaze is applied to the air outflow holes, and when the overglaze is fired, the glaze is melted to intimately contact the air outflow holes.

(Example) As shown in Fig. 1, a ceramic mug with a double structure 1
The mug is composed of an outer wall portion 2 and an inner wall portion 3 which have been separately molded in advance, and are joined together with slurry to form a double-layered mug. During molding of the first outer wall portion 2, air outflow holes 4 are bored.

After that, the mug goes through the drying, glazing, and firing processes, and then the overglaze painting process.

However, according to the present invention, during this overglaze painting process, as shown in FIG. Apply the glaze 6 using a brush.

In this example, lead oxide (P b
O) 30.8wt 1%, sodium oxide (NatO)
28°5% by weight, boron oxide (B20.) 21.
9% by weight and 18.8% by weight of silicic acid (SiO2) was used, and for the coarse ceramic particles, firebrick scraps, broken saggers, etc. were crushed to 0.5111111.
The particles with the same particle size were used. Coarse ceramic particles were mixed with these 7 liters, and 15% of tin oxide (SnOz) was added as a color base to 75% of the 7 liters. The glaze prepared in this way can be used as a white glaze overlay.

After applying glaze 4, the glaze is fired at a low temperature of about 750°C.As the temperature in the void 7 surrounded by the outer wall and inner wall gradually rises, the air in the void 7 expands and the applied glaze is heated. 6 and flows out to the outside, resulting in a reduced pressure state. Furthermore, when the temperature inside the void increases and reaches the same temperature as the temperature inside the kiln, the air within the void no longer flows out to the outside (the applied glaze 6 continues to be fired at this temperature until it completely melts). The melted glaze has fluidity and if left as it is, it would drip down into the voids 7 through the air outflow holes 4, but according to the present invention, since the coarse ceramic particles 5 are mixed in the glaze 6, the voids will flow. It accumulates in the air outlet hole 4 without dripping into the air outlet hole 7 and blocks the air outlet hole 4.
In this embodiment, the air outflow hole 6 is formed into a funnel shape in order to make it easier for the glaze 6 to accumulate inside the air outflow hole 6. After firing, when cooled, the glaze 6 remains vitreous and forms the outer wall r! 1 will be given.

In this example, the composition described above was used as a medium for overpainting, and tin oxide was added as a pigment to prepare a white overpainting, but when used on white ceramics, This is because the sealing of the air outlet holes becomes less noticeable.

The composition of the 7 liters is not limited to this example, and other compositions may be used as long as the medium melts at low temperatures for overpaints. If it is applied to the air outflow hole when painting the painting side, the air outflow hole can be sealed.

Further, the particle size of the ceramic should be appropriately selected depending on the diameter of the air outflow hole so that the molten glaze accumulates in the air outflow hole, and is not limited to the particle size described in the examples. .

(Effects of the Invention) According to the present invention, a glaze for blocking the air outflow holes is applied at the same time as the overglaze is applied, and this glaze melts at the firing temperature during the overglaze firing. If you print the image, the air outflow hole will be closed naturally, and the air outflow hole formed in the double-layered ceramic container can be closed without the need for any special process, thereby reducing the increase in manufacturing costs. It never comes.

In addition, the glaze used to seal the air outflow holes does not require any special raw materials or composition; instead, it is made from ceramic waste such as bricks and fragments of saggers in addition to the glaze used when preparing the overglaze. Only one crushed and granulated grain is mixed, and it can be easily procured.

Furthermore, since the air outlet holes are sealed with glaze, it will not peel off even after repeated use over a long period of time.

[Brief explanation of the drawing]

FIG. 1 shows a sectional view of a ceramic mug with a double structure, and FIGS. 2 and 3 are partially enlarged sectional views thereof.

Claims (1)

[Claims] A glaze made by mixing coarse ceramic grains with a medium for overglaze is applied to the air outlet hole bored in a double-layered ceramic container during overglaze painting, and the glaze is applied during overglaze firing. 1. A method for sealing an air outflow hole in a ceramic double-structured container, the method comprising melting the air outflow hole to seal the air outflow hole.