JPS5819450B2 - Plastic Sekimen Cement Banno Seizouhouhou - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of manufacturing a plastic coated asbestos cement board.

Asbestos cement boards are widely used as boards for various constructions, but because of their poor water resistance, when used as roofing materials, for example, the surfaces must be coated with plastic.

This plastic-coated asbestos cement board is usually manufactured as follows.

That is, the raw asbestos cement board is made strong enough to withstand cutting during natural curing, and this natural curing board is cut into a product shape.

Next, a resin paint is applied to the surface of this cut plate material, and this applied layer is blown into hot air and dried.

Several resin-coated plates are stacked one on top of the other, placed in an autoclave, and heated with high-temperature, high-pressure steam.

Through this heat treatment, the asbestos cement board is finally cured and the resin is baked onto the asbestos cement board.

Various coating methods are used to apply the above-mentioned wood paint.
However, when using the flow coater method, the resin paint drips onto the peripheral end surface of the board material and even the peripheral end surface of the board material is covered with a resin film, which is advantageous because it prevents water from entering the board material from the same end surface. be.

However, in this case, as shown in Fig. 2, the resin C cannot be avoided to get around the back side of the plate material P, and when the plate materials are stacked and cured in an autoclave, the above-mentioned excess resin and When the resin on the surface of the board is completely welded and the board is separated one by one after curing.

A problem occurs in that the resin that goes around is transferred to the surface of another plate material.

This transfer occurs because the coating area of the wrapping resin 1 on the back side of the board is smaller than the coating area of the resin on the surface of the plate, and the surface of the transferred wrapping resin layer is asbestos cement. Whitening due to particle adhesion.

Therefore, the resulting plastic-coated asbestos cement board has a white peripheral area on its surface, and this white area is easily mistaken for so-called efflorescence, which inevitably lowers the product value.

Curing of asbestos-cement boards can be effectively promoted only when excess moisture in asbestos cement is appropriately evaporated while maintaining equilibrium with water vapor, which is a heat medium for curing.

However, if the above-mentioned wrap-around resin is present, as shown in FIG. 4, the asbestos cement plates Po, P.

The overlapping seams m, m, etc. of... are tightly sealed, and as a result of this strict sealing, the evaporation of the above-mentioned excess moisture is undeniably disadvantageous in terms of curing. .

Although the method for producing a plastic-coated asbestos cement board according to the present invention employs a flow coater method, it can overcome the above-mentioned difficulties.

That is, the present invention applies a resin paint to the surface of an asbestos cement board using a flow coater method, then removes the paint that has gotten around the back side of the board during this application, and then stacks these boards. In addition, when curing by heating, it is necessary to touch the paint wiping member on both sides of the back side of the board while supporting the middle part of the back side with a transfer roll, and to dry the board while supporting both sides of the back side of the board with a transfer roll. Continuously apply the middle part of the back side to the paint wiping member, and then apply the upper part.

This method is characterized by removing paint that has entered the recording area.

The present invention will be explained below with reference to the drawings.

In Figure 1, 1 and 2 are belt conveyors, 3 is a resin flow device installed in the space above these conveyors 1 and 2, and a naturally cured asbestos cement board P (hereinafter referred to as a semi-hardened board) ) is coated with a resin paint from the resin flow device 3, for example an aqueous emulsion solution, while passing between the belt conveyors 1 and 2.

In this case, due to its low viscosity, the resin paint that has been poured onto the surface of the semi-cured board P is not only cast onto the surface of the board and the edges around the board, but also onto the back surface of the board P as shown in Figure 2. peripheral area C
Hamo goes around.

4 is a drying oven, and the semi-cured board after the above coating is placed in this drying oven 4.
While passing through, the resin paint is dried.

Reference numeral A denotes a wiping device for removing the resin paint that has gone around the back surface of the semi-cured board, and is provided between the belt conveyors 2 and 5.

This wiping device A coats resin on both sides of a drive transfer roll 610 that comes into contact with the middle part of the back surface of the semi-cured board.

The second half A1 is provided with wiping pads 62, 62.

Drive transfer rolls 71.7 that are in contact with both sides of the semi-cured board
The first half A2 has a resin paint wiping pad 72 between 1 and 1.
The wiping pad 622.62 is composed of the wiping pad 7 so that the gold mine in the middle of the plate P can be wiped.
It goes a little inside than both ends of 2.

These wiping pads 62, 62, and 72 are made by moistening a sponge with a resin paint solvent (for example, water if the resin paint is an emulsion aqueous solution).

While the semi-cured board from the drying oven 4 passes through the resin paint wiping device A, the metal peaks on the back of the board are rubbed by the wiping pad 72 and 62, 62, so the resin paint ( C) in FIG. 2 is wiped with these wiping pads.

At this time, the semi-cured board is forcibly fed by the drive transfer rolls 71, 71 and 61, so despite the friction with the wiping pad 72 and 61, 61, the semi-cured board is transferred at a reduced speed. Transferred smoothly without any problems.

The resin-coated semi-cured plates sent to the end of the belt conveyor 5 are taken out from the belt conveyor 5, stacked, and the stacked plates are carried into an autoclave.

The backside of each board in this stacked board is not resistant to adhesion of resin paint, and as mentioned above, the overflowing resin paint transfers to the board surface, and curing is poor due to strict sealing of the overlapped boards with the overflowing resin paint. etc., can be resolved by themselves.

FIG. 3 shows the plastic-coated asbestos cement board obtained as described above, which has excellent water resistance because not only the surface but also the surrounding end faces are covered with the plastic coating d.

As described above, according to the present invention, when applying a resin paint to improve the water resistance of an asbestos cement board, the edge surfaces around the board can also be coated, which is advantageous in improving the water resistance. The appearance and the curing condition of the asbestos cement board will not be impaired.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram showing the outline of the manufacturing equipment used in the present invention, Fig. 2 is an explanatory diagram showing the back side of the board when paint is applied to the board surface by the flow coater method, and Fig. 3 is an explanatory diagram showing the outline of the manufacturing equipment used in the present invention. FIG. 4 is an explanatory diagram showing a plastic-coated asbestos-cement board obtained by the above method, and FIG. 4 is an explanatory diagram showing the state during curing in the production of a conventional plastic-coated asbestos-cement board. In the figure, P is an asbestos cement board, C is resin that has gone around the back of the board P, 1 and 2 are conveyors, 3 is a flow coater,
4 is a drying oven, 5 is a conveyor, 61 is a driving roll, 62.
62 is a resin wiping pad, 71.71 is a drive roll, 7
2 is a resin wiping parapet.

Claims (1)

[Claims] 1. Apply resin paint to the surface of asbestos cement boards using the procoater method, then remove the paint that has gotten around the back of the board during application, and then stack these boards and cure them by heating. In this case, the middle part of the back side of the board should be supported by a transfer roll while both tracks on the back side of the board should be brought into contact with the paint wiping member, and the middle part of the back side of the board should be supported by a transfer roll and the middle part of the back side of the board should be wiped with paint. A method for producing a plastic-coated asbestos cement board, characterized in that the coating material is removed by continuously contacting the board with a removal member.