JPS61256184A - Shelf plate for baking ceramic - 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 [Field of Industrial Application] The present invention relates to a shelf board used for firing ceramic products, particularly clay molded products such as tea bowls, tiles, fmm, cups, and the like.

The following will be described based on an example in which a trinket is fired.

[Conventional technology]

FIG. 5 is a partial vertical sectional view of the thread kiln 1, which is an example of a firing furnace. As shown in the figure, the thread kiln 1 has an eight carriage 3 that can slide on a guide rail 2.2 that passes through a kiln (not shown). It consists of a base plate 9 placed on the base plate 4.2 via a slide plate 4.4, and fireproof insulation bricks 5 laid out on the base plate 9. When the tile is a normal flat tile 6, the firing of the tile in the thread kiln 1 is carried out by placing the flat tile 6 as it is on the fireproof insulation brick 5 and passing it through the furnace. ing. In addition, when the tiles are accessory tiles 7, a shelf board 8 is placed on the fireproof insulation brick 5, and the accessory tile 7 is placed on the shelf board 8 and passed through the furnace. . This is because if the accessory tile 7 is placed directly on the fireproof insulation brick 5 and fired, it will soften during firing and deform due to its own weight.

The shelf board 8 is usually manufactured by forming a powder of a heat-resistant raw material whose main component is a mixture of silicon carbide, silicon nitride, alumina, etc. with lpl or 2f1' or more into a plate shape and firing it at a high temperature. . Further, 0.5 to 4% by volume of stainless steel fibers are mixed into the powder of the heat-resistant raw material and formed into a plate shape.
Some are baked.

Furthermore, the heat-resistant, lightweight, and high-strength shelf board 8 may be made by molding heat-resistant inorganic fibers (generally ceramic fibers) together with an inorganic binder.

[Problem that the invention seeks to solve]

However, the shelf board 8 whose main component is IN or a mixture of silicon carbide, silicon nitride, alumina, etc. with a length of 2 m or more cannot be said to have excellent heat resistance, and has the drawbacks of cracking during firing and short life. was there.

Also, silicon carbide, silicon nitride, alumina, etc. II! or 2
The shelf board 8, which is made by mixing stainless steel m fibers into a heat-resistant raw material powder whose main component is a mixture of three or more species, has a bulk density of 1.0 g/c+J or more, and is quite heavy, making it inconvenient to handle. However, there were drawbacks such as the need for larger transport equipment. In addition, because the bulk density is large, the amount of heat stored becomes large, which takes away the firing heat from the back side 7b of the tile during firing, causing uneven firing between it and the front side 7a, and causing warping of the tile itself. there were. Furthermore, in the shelf board 8 manufactured from a mixture mainly composed of heat-resistant inorganic fibers, the front surface of the cough shelf board 8 is vitrified, but the degree of vitrification is small on the back surface, so the front surface 8a side and the back surface are The degree of thermal expansion and contraction from the 8b side is greatly different, causing large deformations such as warping,
This has a drawback in that it affects the softened accessory tile 7, causing deformation such as warping of the cough accessory tile 7.

Further, in the conventional shelf board 8, since the upper surface 8a is flat, there is a problem that it comes into close contact with the back surface 7b of the accessory tile 7, making it difficult for the firing heat to be transmitted to the back surface 7b. For this reason, the firing temperature between the front surface 7a and the back surface 7b of the accessory tile 7 was uneven, causing uneven firing. The uneven firing causes the accessory tile 7 to be warped or otherwise deformed.

In short, the conventional shelf board 8 has problems of deformation due to its own thermal expansion and contraction during firing, problems in handling, and problems with the accessory tile 7.
There was a problem in that the firing caused unevenness between the surfaces 7a and 7b, and the accessory tile 7 was deformed due to warping or the like.

The present invention improves and eliminates the above-mentioned drawbacks of conventional shelf boards, and makes it possible to make the firing temperature on the front and back surfaces of ceramic products as uniform as possible, and to make the shelf board itself as uniform as possible. The aim is to provide products that do not undergo deformation.

[Means for solving problems]

Means for solving the problems of the present invention consists essentially of heat-resistant inorganic fibers and an inorganic binder, and has a bulk density of 0.2 to 0.
．． It is a 5 g/d fibrous molded plate, and at least one surface is coated with an inorganic coating agent mainly composed of alumina, silica, alumina-silica, zirconia, etc., and a plurality of grooves are provided. The depth of the groove is 5 to 50% relative to the dimension of the fibrous molded plate in the direction perpendicular to the groove forming surface.
50% range, and the interval between each groove is 20 to 50 m in the orientation direction of the heat-resistant inorganic fibers, and 50 to 1 m in the direction orthogonal to the orientation direction of the heat-resistant inorganic fibers.
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[For production]

As is clear from the embodiments shown in Figs.
By forming the grooves 11 and 12, the thermal expansion and contraction that occurs in the shelf board 10 during firing is dispersed by the grooves 11 and 12 in both the orientation direction of the heat-resistant inorganic fibers and the direction orthogonal to the orientation direction, thereby preventing warping of the shelf board 10, etc. deformation is prevented. In addition, the shelf board 10 has a low bulk density, making it convenient to handle, and furthermore, heat can pass through more easily, and firing heat is efficiently transferred to the back surface of the accessory tile 15 through heat conduction of the shelf board 10. Moreover, through the grooves 11 and 12 with a predetermined depth h, the back surface 1 of the accessory tile 15 is
5b The furnace atmosphere is efficiently transmitted to the OFI, and the front surface 15a and back surface 15b of the accessory tile 5 can be fired uniformly. Therefore, the firing of the accessory tile 15 itself is uniform, and there is no deformation such as warping caused by this.

The configuration of the present invention will be explained below based on the embodiments shown in the drawings.

〔Example〕

1 to 4 show an embodiment of a shelf board 10 according to the present invention. This shelf board 10 has four linear grooves 11 on its surface 10a side, which are parallel to the short side direction of the shelf board 10 in the direction in which the heat-resistant inorganic fibers are arranged. One linear groove 12 parallel to the long side direction of the shelf board 10 is formed in the orthogonal direction.

By the way, in order to make the firing temperature of the back surface 15b of the accessory tile as equal as possible to the firing temperature of the front surface 15a, the raw material of the accessory tile 15 and the shape and spacing of the grooves 11 and 12 are as follows. It is selected as follows. That is, the raw materials are mainly heat-resistant inorganic fibers and inorganic binders, and their bulk density is kept low to make them porous. The appropriate bulk density range is 0.2 to 0.5 g/d. Suitable heat-resistant inorganic fibers include ceramic fibers, silica fibers, alumina, mullite crystalline fibers, etc., and at least one of them is used. Inorganic binders include silica sol, alumina sol, and bentonite.

Commonly used materials such as kaolin and montmorillonite can be used.

The reason why the bulk density is limited is that if it is less than 0.2 g/-, the strength of the shelf board 10 itself becomes weak and cannot withstand use as a platform for placing relatively heavy tiles. Also, the bulk density is 0.5g/a! When it exceeds the shelf lO
The weight of the product itself becomes too heavy, making it inconvenient to handle.
Furthermore, the amount of N heat in the shelf board 10 itself increases, resulting in poor thermal efficiency.

When the bulk density is within the above range, the shelf board 10 has excellent strength and thermal efficiency, and is convenient to handle. In addition, it is porous and allows good heat to pass through.As a result, during firing, the heat passes from the shelf board 10 to the back surface 15b of the accessory tile 15. It works to make it as uniform as possible.

Further, in this embodiment, the depth h of the grooves 11 and 12 is limited as follows. That is, the depth h of the cough grooves 11.12 is set in a range of 5 to 50%, preferably 25 to 40%, of the height H of the shelf board 10. If it is less than 5%, the direct objective of the present invention is to prevent the shelf board 10 itself from deforming due to thermal expansion and contraction during firing, and to prevent the accessory tile 1 from being deformed due to thermal expansion and contraction.
This is because the effect of eliminating non-uniformity in firing temperature between the front surface 15a and the back surface 15b of No. 5 cannot be obtained. This will be discussed later. Furthermore, if the ratio of the depth h exceeds 50%,
This is because the strength of the shelf board 10 itself is weak, and chipping, cracking, etc. occur.

Furthermore, the distance g between the linear grooves 11 and 12
, L is 20 to 50 Tsuru in the orientation direction of the heat resistant inorganic fibers, and L is 50 to 100 Tsuru in the direction perpendicular to the orientation direction of the heat resistant inorganic fibers. In the orientation direction and in the direction perpendicular to the orientation direction,
Distance E between valley grooves 11 and grooves 12.

The reason for changing L is that the shrinkage rate of the shelf board 10 is different in both directions, and by shortening the interval i in the orientation direction where the shrinkage ratio is large, deformation such as warping of the shelf board 10 can be efficiently (dispersed) Let it absorb and relax.

Therefore, l in the orientation direction is set in the range of 20 to 50 because if it is less than 200, the unevenness of the surface may affect the softened accessory tile and cause deformation of the accessory tile. This is because, if it exceeds 50 cranes, the shrinkage of the shelf board 10 itself cannot be alleviated. The reason for limiting the numerical values is the same for the direction perpendicular to the orientation direction.

The shelf board 10 may be manufactured by selecting an appropriate material from the above-mentioned materials and forming it into a predetermined shape by a known paper forming method, pressing method, or the like. In this case, organic binders (*powder,
latex, acrylic resin, etc.), organic fibers (pulp, etc.)
and thickener (CMC).

(sodium alginate, etc.). The purpose of the organic binder is to ensure shape retention of the shelf board 10 from the time of molding to the time of firing.

The method of using the shelf board 10 manufactured in this way is as follows.
As shown in the figure, accessory tiles 15 are placed and prepared for firing. This placement condition is no different from the conventional one. Then,
The shelf board 10 in the state shown in FIG. 2 is placed on the trolley 3 in the thread kiln 1 (see FIG. 5), and the accessory tile 1
5, the front surface 10a of the shelf board 10 is exposed to the furnace atmosphere, and the back surface 10b rM is connected to the refractory insulation brick 5, so the front surface 10δ side and the back surface 10b
(A temperature difference occurs between the surface i0
a 0111 contracts more than the back surface 10b ill and tends to deform. However, in the bookshelf board 10, the grooves 11 and 12 in both directions form the surface 10a.
As shown in Figure 3, the political situation 1
] and 12 themselves increase in groove width, thereby absorbing and alleviating the shrinkage. Here, in the orientation direction of heat-resistant inorganic fibers with a large shrinkage rate, four grooves 1
1 shares this, so that the degree of contraction shared by each *ii is equal to the degree of contraction shared by the groove 12 in the direction orthogonal to the orientation direction where the shrinkage rate is small. Therefore, the degree of shrinkage of the entire surface 10a side of the shelf board 10 is significantly reduced compared to the conventional case, and the flatness of the surface 1.0a remains almost unchanged. It is possible to prevent the board 10 itself from being deformed during firing, and the softened accessory tile 15 is not subjected to deformation such as warping.

Further, as shown in FIG. 4, the grooves 11 and 12 act as passages that directly guide the atmosphere inside the furnace to the back surface 15b (III) of the accessory tile 15, and can control the firing temperature of the tile surfaces 15a and 15b during firing. In other words, it is possible to prevent uneven firing between the front surface 15a side and the back surface 15b (all) of the accessory tile 15.

As described above, in this embodiment, by providing the grooves 11 and 12, deformation of the shelf board 10 itself is prevented, and by making the firing temperature uniform on the front and back surfaces of the accessory tile 15, uneven firing is prevented. This also prevents deformation of the tile itself. This is also clear from the experimental results described below. In the experiment, 85 wt% of ceramic fiber (trade name: Ibiwool) as a heat-resistant inorganic fiber was prepared, and 10 wt% of silica sol as an inorganic binder and 51% of starch as an organic binder were mixed therein. The mixture was made into a size of 200 mm x 100 fl x 30 f by a papermaking method.
A shelf board 10 having a bulk density of 0.38/cd is formed by using a commercially available band saw on the surface 10a side. Grooves 11 and 12 with a low depth were formed and fired at a temperature of 1300 to 1400°C. The interval l between the grooves 11 is 40f1. The width L from the side surface of the shelf to 1li12 (if a plurality of grooves 12 are provided, the distance between each groove 12) is 50 mm. In an experiment in which accessory tiles 15 were fired at 1200° C. using shelf boards 10 for ceramic firing manufactured in this way, no deformation such as warping was observed in both the shelf boards 10 and accessory tiles 15. There wasn't.

By the way, the present invention is not limited to the above embodiments, and can be modified as appropriate.For example, the grooves 11 and 12
may be formed on the side and back surfaces of the shelf board 10 within the range permitted by the strength of the shelf board 10, and the number of grooves 11 and 12, etc.
The shrinkage rate in each direction of the shelf board 10 may be taken into consideration and the setting may be made appropriately.Furthermore, although the above-mentioned embodiment describes a shelf for firing accessory tiles, it may also be used for firing other ceramic products. Needless to say, it can be used.

〔Effect of the invention〕

As explained above, in the present invention, by forming grooves on the surface of the shelf board, the difference in thermal expansion and contraction between the front and back surfaces of the shelf board during firing can be absorbed and alleviated, thereby preventing deformation such as warping. be able to. For this reason, the shelves do not have any negative effects such as deforming the ceramic fired product, and the furnace atmosphere is introduced to the back side of the ceramic fired product through the grooves on the surface of the shelf, and the atmosphere inside the furnace and the shelf are introduced to the political situation. Since the back surface of the fired ceramic product can be heated and fired through heat conduction of the plate itself, it is possible to make the firing temperature on the front and back surfaces of the fired ceramic product as uniform as possible. Therefore, there is no unevenness in firing, and ceramic products of excellent quality can be fired. Furthermore, since the shelf board of the present invention has a low bulk density and is lightweight, it is very convenient to handle, and it is possible to downsize the transportation device.

[Brief explanation of the drawing]

Figures 1 to 4 show an embodiment of the present invention applicable to a shelf board for baking accessory tiles. Figure 3 is a side view showing the thermal deformation of the shelf board during firing. Figure 4 is a perspective view showing the state in which the accessory tile is placed on the shelf board. Figure 4 is a side view showing the thermal deformation of the shelf board during firing. a perspective view showing a state in which it is introduced into the
FIG. 5 is a longitudinal sectional view of the thread kiln. 15... Accessory tiles 10... Shelf board 11.12
···groove

Claims (1)

[Claims] 1. A fibrous molded plate consisting essentially of heat-resistant inorganic fibers and an inorganic binder and having a bulk density of 0.2 to 0.5 g/cm^2, with a plurality of linear grooves on at least one surface. The depth of the groove is in the range of 5 to 50% of the dimension of the fibrous molded plate in the direction perpendicular to the groove forming surface, and the interval between each groove is the same as that of the heat-resistant inorganic fiber. A shelf board for ceramic firing, characterized in that the orientation direction of the heat-resistant inorganic fibers is 20 to 50 mm, and the orientation direction of the heat-resistant inorganic fibers is 50 to 100 mm.