JPH0544885B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to a method for drying a ceramic casting body.

(Prior art) Methods for drying a hydrous ceramic molded body formed by cast molding include releasing it from the mold and placing it on a drying table, or casting it in a plaster mold etc. together with the mold. There were methods of natural drying and forced drying using a dryer.

For example, an example schematically shown in FIG. 5 will be explained. That is, as shown in FIG. 5a, air is forced into the porous upper mold 1 and blown to the interface between the porous upper mold 1 and the flat ceramic casting body 3, and as shown in FIG. 5b. As shown in the figure, the porous upper mold 1 is removed from the porous lower mold 2 and the flat ceramic casting body 3, and then, as shown in FIG. Air is pressurized into the porous lower mold 2 as shown in A, and the porous lower mold 2
Air is blown to the interface between the ceramic molded body 3 and the ceramic molded body 3, and the flat ceramic cast molded body 3 is removed from the porous lower mold 2 to form the state shown in FIG. 5d, and air dried or A method of forced drying by placing the material in a drying chamber is being implemented.

(Problem to be Solved by the Invention) However, in such a drying method, the part of the flat ceramic cast body 3 that is in direct contact with the plaster base 5 and the part that is not in direct contact with the plaster table 5 are dried. Cracks occur during the drying process due to differences in speed and stress during drying shrinkage.
Alternatively, distortion may occur after firing due to stress bias during drying. Furthermore, when demolding the flat ceramic casting body 3 from the lower mold 2,
Distortion occurred in this soft molded body 3 due to handling, and furthermore, the flat ceramic cast molded body 3 was sometimes damaged due to the stress at this time. The thinner the molded body 3 becomes, or the larger the area, the more difficult it becomes to handle the molded body 3, and the above-mentioned problem becomes more serious.

The problem of the present invention is to prevent cracks from occurring during the drying process.
It is an object of the present invention to provide a method for drying a ceramic casting body that can prevent distortion due to stress bias during drying, distortion due to handling that occurs when the ceramic casting body is removed from a lower mold, and the like.

(Means for Solving the Problems) The present invention involves adsorbing a ceramic casting body to one of the porous mold parts constituting a casting mold, and transferring the one mold part to the other. a step of separating the ceramic cast molded body from the mold part; a step of transferring the one mold part to a drying processing section with the ceramic casting formed body adsorbed to the one mold part; The method further comprises the steps of releasing the cast body from the one mold part and drying the ceramic cast body while floating the ceramic cast body with blown gas. The present invention relates to a method for drying a ceramic cast body.

Further, the present invention is characterized in that, in the drying processing section, the ceramic casting body is dried by blowing gas onto the upper surface of the ceramic casting body while the ceramic casting body is suspended. The present invention relates to a method for drying the ceramic casting body described above.

Here, "one mold part" may be either the so-called upper mold or the lower mold. Regarding "adsorption",
It is further preferable that one mold part is formed of a porous material and that gas is sucked through the one mold part to vacuum adsorb the ceramic cast body.

(Example) FIGS. 1 to 4 are schematic sectional views schematically showing the procedure of a drying method according to an example of the present invention.

In this embodiment, a flat ceramic cast body is formed by casting, such as pouring or press-fitting, into a pair of upper and lower porous molds. After that, as shown in FIG. 1, the air inside the porous upper mold 1 is sucked from the porous upper mold 1 as shown by arrow B, and at the same time, the air is sucked from the lower mold 2 into the porous mold as shown by arrow A. Press fit into the lower mold 2 and blow air to the interface between the porous lower mold 2 and the flat ceramic casting body 3 to release the flat ceramic casting body 3 from the porous lower mold 2 to form a flat plate. The shaped ceramic casting body 3 is vacuum-adsorbed onto the porous upper mold 1, and the porous lower mold 2 is removed from the porous upper mold 1 and the ceramic casting body 3 to form the state shown in FIG.

Next, the porous upper mold 1 is transferred to the drying processing section 10 by a transfer device (not shown) or by hand, with the flat ceramic casting molded body 3 vacuum-adsorbed onto the porous upper mold 1, and dried. Perform processing. In this embodiment, an air blowing plate 7 made of a porous material is used to constitute the drying processing section, and an air chamber (not shown) is provided below this air blowing plate 7, and pressurized air is fed into this air chamber. is supplied to uniformly blow out air from the surface of the air blowing plate 7 as shown by arrow C.

Next, the air suction shown by arrow B to the porous upper mold 1 is stopped, and air is naturally fed into the porous upper mold 1, thereby creating a vacuum against the porous upper mold 1 of the flat ceramic casting body 3. The suction is released and the molded body 3 is allowed to fall. The molded object 3 that fell instantaneously is levitated as shown in FIG. 4 by the wind pressure of the air flow shown by the arrow C, and in this levitated state is dried by the air blown out from the air blowing plate 7. Ru. At this time, the pressure of the pressurized air sent to the air blowing plate 7 is preferably 1 to 8 kg/cm ² , and the pressure loss in the porous air blowing plate 7 and the weight of the flat ceramic casting body 3 are It is preferable to set it appropriately so that the flat ceramic casting body 3 is slightly lifted from the porous air blowing plate 7. This pressurized air may be heated in advance and supplied to the blowing plate 7 to accelerate drying of the molded body 3.

Further, as shown by arrow D, it is more preferable to blow air or heated air from the upper surface side of the flat ceramic casting body 3 as well, since uniform drying can be quickly achieved.

The porous upper mold 1 separated from the flat ceramic casting body 3 is transferred again to the porous lower mold 2, and then used for manufacturing another flat ceramic casting body.

According to the drying method of this example as described above,
The flat ceramic cast molded body 3 is floated by the blown air, and dried in this floating state so that it can be freely shrunk.
No external force is applied from the mold or the like, and the product is dried uniformly in a state free from external force. Therefore, cracks due to external forces applied to the molded product during drying shrinkage,
This prevents distortion of the product after firing.

Furthermore, unlike the conventional method in which the flat ceramic casting body 3 is released from the porous lower mold 2 and once placed on a plaster stand or the like to dry, the flat ceramic casting body 3 is removed from the porous upper mold 1. is vacuum-adsorbed, and in this state is transferred to the drying processing section 10, where the vacuum adsorption is canceled and the flat ceramic cast molded product 3 is levitated by the air blown from the air blowing plate. 3 is held and transferred while following the shape of the porous upper mold 1, it is possible to prevent the soft flat ceramic casting body 3 from being distorted or damaged, and it maintains good dimensional accuracy. Can be retained. In this sense, the drying method of the present embodiment is particularly suitable for drying ceramic molded bodies that are difficult to handle, such as thin ceramic cast molded bodies of about 0.5 to 20 mm, and irregularly shaped products with complex shapes.

Furthermore, after the vacuum suction on the flat ceramic casting body 3 is released, the porous upper mold 1 is returned to its original position and used for new casting. It is possible to efficiently rotate and use a certain casting mold, and it is possible to prevent a decrease in the productivity of molded products.

In addition, if the porous upper mold 1 and lower mold 2 are impregnated with a mold release agent prior to cast molding, the mold release agent will leach into the interface between the mold and the molded body 3 along with the blown air during mold release. , is preferable because the molded product can be released from the mold more smoothly.

In addition, as shown in Fig. 4, air or preheated air is also blown from the top side of the flat ceramic casting body 3 to accelerate drying, so that uneven drying can be eliminated. It is even more effective.

Moreover, when releasing the flat ceramic casting body 3 from the porous lower mold 2, air is blown from the porous lower mold 2 side to the interface with the molded body 3, and at the same time, air is blown from the porous upper mold 1 side. Since the molded body 3 is released from the porous lower mold 2 by suctioning air and the molded body 3 is adsorbed to the upper mold 1, the deformation when releasing the lower mold 2 is also very small. It can be suppressed.

The embodiments described above can be modified in various ways.

In the above-described embodiment, the porous upper mold 1 may be removed first, and the flat ceramic casting body 3 may be vacuum-adsorbed onto the porous lower mold 2, and then transferred to the drying section.

Further, although the method for drying a flat plate-shaped ceramic cast body has been described, the present invention can also be applied to drying ceramic bodies of various shapes manufactured by cast molding.

Furthermore, in each of the above embodiments, the ceramic cast body is levitated by air blown out through the porous air blowing plate 7 or by preheated air;
Drying is carried out using this blown air, but on the other hand, an infrared heating device or the like is separately installed on the upper surface side of the molded body to heat the upper surface side of the ceramic cast molded body, and the upper and lower surfaces of the ceramic cast molded body in a floating state are heated. can also be dried at the same time to accelerate drying.

(Effects of the Invention) According to the method for drying a ceramic cast molded body according to the present invention, the ceramic cast molded body is floated by blown air, and in this floating state, the ceramic cast molded body is dried so as to be freely contractible. Because
During drying shrinkage, no external force is applied to the ceramic casting from the mold or drying stand, and the ceramic casting is uniformly dried in a state free from external force.

Therefore, cracks caused by external forces applied to the molded product during drying shrinkage and distortion of the product after firing can be prevented.

In addition, the ceramic casting body is adsorbed onto one of the porous mold parts, and in this state, one of the mold parts is transferred to a drying processing section, and the ceramic casting body is separated from the other mold part. Therefore, the ceramic cast molded body is held and transferred while following the shape of one of the mold parts, and is subjected to a drying process. Therefore, it is possible to prevent the weak flat ceramic casting body 3 from being distorted or damaged.
Good dimensional accuracy can be maintained as is. Therefore,
It is also possible to successfully dry ceramic molded bodies that are difficult to handle, such as extremely thin plate-shaped ceramic cast molded bodies, and irregularly shaped products with complex or special shapes.

Furthermore, when the ceramic casting body is released from the other mold part, since the ceramic casting body is adsorbed to one of the porous mold parts, there is no deformation when the other mold part is released. It can be kept very small.

Moreover, after separating the ceramic casting body from one of the porous mold parts, the ceramic casting body is dried separately in the drying processing section, so that after separation, one of the mold parts can be used for new casting molding. Can be used. Therefore, an expensive casting mold can be efficiently rotated and used, and a decrease in productivity of molded products can be prevented.

[Brief explanation of drawings]

Figures 1, 2, 3, and 4 are schematic sectional views schematically showing the steps of the drying method according to the embodiment of the present invention, and Figures 5a, b, c, and d are for the conventional example. FIG. 3 is a schematic cross-sectional view showing the steps of such a drying method. DESCRIPTION OF SYMBOLS 1... Upper mold, 2... Lower mold, 3... Flat ceramic casting body, 5... Gypsum stand, 7... Air blowing plate, 10... Drying processing section, A, B, C, D …
…the flow of air.

Claims (1)

[Scope of Claims] 1. A step of adsorbing a ceramic casting body to one of the porous mold parts constituting the casting mold and separating said one mold part from the other mold part. and; a step of transferring the one mold part with the ceramic casting molded body adsorbed to the one mold part to a drying processing section; Drying of a ceramic cast molded body, characterized in that the ceramic cast molded body is released from the mold part, and is dried in a state where the ceramic cast molded body is floated by blown gas. Method. 2. The ceramic casting according to claim 1, wherein in the drying processing section, the ceramic casting body is dried by blowing gas onto the upper surface of the ceramic casting body while the ceramic casting body is suspended. Method for drying molded bodies.