JP3530974B2 - Manufacturing method of inorganic plate - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an autoclave curing method used when manufacturing an inorganic board such as a cement board.

[0002]

2. Description of the Related Art When an inorganic plate such as a cement plate is manufactured by high-pressure steam curing in an autoclave with a curing plate loaded, it is necessary to reduce the pressure in the autoclave from high pressure to atmospheric pressure before the completion of high-pressure steam curing. is there. At this time, water evaporates from the inside of the inorganic plate, and especially the amount of water evaporation at each end of the plurality of inorganic plates and the surface of the uppermost inorganic plate becomes larger than that in the core due to the effect of radiant heat of the inner wall of the autoclave, The difference in water content becomes severe. As a result, the water content of each end of the plurality of inorganic plates and the uppermost inorganic plate becomes lower than that of the other parts, and cracks are more likely to occur.

As a countermeasure against this, conventionally, autoclave curing is performed by a method such as slowing down the pressure reduction rate.

[0004]

However, in the conventional technique described above, the difference in water content still occurs in the inorganic plate, which is insufficient as a countermeasure. The present invention has been made in view of the above points, when a curing plate is subjected to high-pressure steam curing in an autoclave to produce an inorganic plate,
It is an object of the present invention to provide a method for producing an inorganic plate, which does not cause a difference in water content in the inorganic plate and can make the water content of the inorganic plate uniform and prevent the occurrence of cracks.

[0005]

The method for producing an inorganic plate according to the first aspect of the present invention is characterized in that when a plurality of curing plates 3 are introduced into the autoclave 1 for high pressure steam curing, the autoclave 1 is used. The heat-reflecting plate 2 having a mirror-finished surface is disposed between the inner wall and the curing plate 3.

The method for producing an inorganic plate according to a second aspect of the present invention is characterized in that, in addition to the structure of the first aspect, a heat-reflecting plate 2 made of stainless steel is used.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below. When the inorganic plate 4 is manufactured by autoclave curing, cement, fly ash, silica stone powder, pulp, etc. are mixed at a predetermined ratio, and then water is added to form a slurry, which is then press-molded and cured. The plate 3 is formed. Then, a plurality of the curing plates 3 stacked on the pallet 6 is introduced into the autoclave 1, and high-pressure steam curing is performed to form the inorganic plate 4.

In the present invention, the curing plate 3 is attached to the autoclave 1.
When curing inside, the inner wall of autoclave 1 and curing plate 3
The heat reflection plate 2 is arranged between the two. When arranging the heat reflection plate 2 between the inner wall of the autoclave 1 and the curing plate 3, as shown in FIG. 1, a plurality of heat reflection plates 2 formed in a box shape with an opened lower surface are stacked on a pallet 6. The protective plate 3 can be placed by covering it from above. Here, it is preferable to provide a gap 5 between the inner surface of the heat reflection plate 2 and the end portion 7 of the curing plate 3. By passing high-pressure steam through the autoclave 1 in this state, the hydration reaction of the cement proceeds and the curing plate 3
Is cured and cured to form the inorganic plate 4. When the curing plate 3 is sufficiently cured to form the inorganic plate 4, the pressure inside the autoclave 1 is reduced to atmospheric pressure, and then the inorganic plate 4 is taken out from the autoclave 1.

In the process of manufacturing the inorganic plate 4 described above, when the pressure in the autoclave 1 is reduced, water is likely to evaporate from the inorganic plate 4, and the autoclave 1 is further reduced.
The inner wall of is heated by water vapor during the curing process to store heat, and radiant heat is emitted from the inner wall of the heat reflecting plate 2
If not arranged, the respective end portions 7 of the plurality of inorganic plates 4 formed from the plurality of laminated curing plates 3 and the uppermost curing plate 3 of the laminated curing plates 3 are formed. The surface of the inorganic plate 4 is heated to promote the evaporation of water in this portion, and as a result, the water content of each of the end portions 7 of the plurality of inorganic plates 4 and the uppermost inorganic plate 4 becomes lower than that in other portions. The water content difference in the inorganic plate 4 becomes severe,
Moreover, the unevenness of the water content tends to cause cracks in the inorganic plate 4. However, since the heat reflecting plate 2 is arranged between the inner wall of the autoclave 1 and the curing plate 3 as described above, the radiant heat from the inner wall is blocked by the heat reflecting plate 2 and the radiant heat is reduced. To prevent the moisture from evaporating from the inorganic plate 4 due to radiant heat from the inner wall, prevent the difference in water content in the inorganic plate 4 from increasing, and improve the water content of the inorganic plate 4 throughout. In addition, it is possible to prevent the occurrence of cracks due to uneven water content of the inorganic plate 4. Here, a gap 5 is provided between the heat reflection plate 2 and the curing plate 3.
As a result, the heat conduction from the heat reflection plate 2 to the curing plate 3 can be suppressed.

When a stainless steel plate is used as the material of the heat reflecting plate 2, the heat reflecting plate 2 has good durability and the life of the heat reflecting plate 2 can be maintained for a long period of time. Preferably, if the thickness is made thin, the amount of heat stored in the heat reflecting plate 2 at the time of curing the curing plate 3 with pressurized steam can be reduced, and the radiant heat from the heat reflecting plate 2 to the curing plate 3 can be reduced. it can.

The heat reflecting plate 2 is not limited to the one described above, and a cylindrical heat reflecting plate 2 made of a stainless steel plate or the like may be arranged inside the inner wall of the autoclave 1. In this case, a plurality of curing plates 3 loaded as described above are introduced into the inside of the heat reflecting plate 2, and high-pressure steam is passed through the inside of the heat reflecting plate 2 to cure the curing plate 3.
The high pressure steam curing is performed to form the inorganic plate 4.

[0012]

EXAMPLES The present invention will be described in detail below with reference to examples. (Example 1) Cement 41.5 wt%, fly ash 40 wt%, silica stone powder 15 wt%, pulp 3.5 wt% were mixed, and water was added to form a slurry, which was then press-molded. 1000 mm x 3000 mm x
A plate-shaped curing plate 3 of 18 mmt was formed, and 100 curing plates 3 were stacked on the pallet 5.

On the other hand, a stainless steel material (SU
S304) is formed in the shape of a box with an open lower surface, and the surface thereof is mirror-finished to form the heat reflection plate 2, and the heat reflection plate 2 is covered from above the laminated curing plate 3. Placed. Here, a gap 5 of 50 mm was provided between the inner surface of the heat reflection plate 2 and the end portion 7 of the curing plate 3. In this state, as shown in FIG. 4, the curing plate 3 and the heat reflection plate 2 are introduced into the autoclave 1 together with the pallet 6,
Pressurized steam curing was performed under the conditions shown in FIG. 3 to form the inorganic plate 4.

After decompressing the inside of the autoclave 1, the inorganic plate 4 is taken out from the autoclave 1, and the inorganic plate 4 formed from the 50th curing plate 3 from the bottom of the laminated curing plates 3 is taken out and shown in FIG. As shown, the core portion 8 and the end portion 7 of the inorganic plate 4 are cut off, the core portion 8 and the end portion 7 are dried at 105 ° C. respectively, and the weight loss before and after the drying is measured to measure the core portion 8 and the end portion. The respective moisture contents of 7 were derived. (Comparative Example 1) The same procedure as in Example 1 was carried out except that the heat reflection plate 2 was not placed on the curing plate 3, and as shown in FIG. 4, pressure steam curing was carried out simultaneously with the curing plate of Example 1. An inorganic plate was formed.

The water content of the formed inorganic plate was derived in the same manner as in Example 1. The above results are shown in Table 1.

[0016]

[Table 1]

As can be seen from Table 1, in Comparative Example 1, the water content of the end portion 7 of the inorganic plate 4 is about ½ of that of the core portion 8, whereas in Example 1, the inorganic plate 4 formed. It was confirmed that the difference in water content between the core portion 8 and the end portion 7 was small and that the heat reflecting plate 2 could suppress the evaporation of water due to the radiant heat from the inner wall of the autoclave 1.

[0018]

As described above, in the method for producing an inorganic plate according to the first aspect of the present invention, in introducing a stack of a plurality of curing plates into an autoclave for high-pressure steam curing, the inner wall of the autoclave is Between the curing plate and the surface
Since a heat-reflecting plate with a mirror finish is placed, the radiant heat from the inner wall of the autoclave is heat-reflected when the autoclave is depressurized to atmospheric pressure after high-pressure steam curing of the autoclave to form an inorganic plate. It is possible to prevent radiant heat from being conducted to the inorganic plate by blocking with a plate, each end of a plurality of inorganic plates formed from a plurality of laminated curing plates, and among the laminated curing plates. The amount of water evaporation on the surface of the inorganic plate formed from the uppermost curing plate becomes larger than the amount of water evaporation on other parts due to the radiant heat from the inner wall of the autoclave, and the water content difference in the inorganic plate becomes severe. It is possible to prevent, the water content of the inorganic plate can be made uniform throughout, it is also possible to prevent the occurrence of cracks due to uneven water content of the inorganic plate. It is intended.

Further, in the method for producing an inorganic plate according to a second aspect of the present invention, in addition to the structure of the first aspect, since the heat reflecting plate made of stainless steel is used, the durability of the heat reflecting plate is good. In addition, the life of the heat reflection plate can be maintained for a long period of time.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an example of an embodiment of the present invention.

2 is a plan view showing an inorganic plate formed in Example 1 and Comparative Example 1. FIG.

FIG. 3 is a graph showing curing conditions for autoclaving the curing plates in Example 1 and Comparative Example 1.

FIG. 4 is a cross-sectional view showing a curing step of the curing plate in the autoclave in Example 1 and Comparative Example 1.

[Explanation of symbols]

1 autoclave 2 heat reflector 3 curing board 4 Inorganic board

Claims (2)

(57) [Claims] 1. When introducing a stack of a plurality of curing plates into an autoclave for high-pressure steam curing, a mirror-finished surface is provided between the inner wall of the autoclave and the curing plate.
A method for manufacturing an inorganic plate, which comprises disposing a raised heat reflection plate. 2. The method for producing an inorganic plate according to claim 1, wherein a heat reflecting plate made of stainless steel is used.