JP2515450B2 - Method of manufacturing inorganic building board - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a low specific gravity inorganic building board mainly composed of mineral fibers and a starch binder as a main binder.

[0002]

2. Description of the Related Art Conventionally, inorganic building boards mainly composed of mineral fibers have been manufactured by a wet method using a starch-based binder as a main binder.

The reason why a starch-based binder is used as a binder is that it is inexpensive and easy to handle, and also exhibits a binding force in a smaller amount than other binders, so that the amount of the binder used is small. In addition, because the wet method produces a small amount of binder due to the mutual entanglement of mineral fibers, etc., the amount of binder used in combination with the above effects requires a smaller amount of fire protection standards. This is because a satisfying lightweight inorganic building board can be obtained. In addition, according to the wet method, since the water-containing inorganic mat has a certain degree of flexibility, it is easy to convey and the like, and continuous production is easy.

However, among the methods for producing an inorganic building board by the wet method as described above, for example, in the case of cylinder type papermaking, the thickness is adjusted with a brush roll immediately after the papermaking, and the method of the Fourdrinier type papermaking or the paste method In this case, the thickness accuracy is low because the thickness is adjusted by adjusting the pouring amount of the slurry. For this reason, it is necessary to perform sanding after drying in order to make the thickness uniform, which requires a large number of processing steps and material loss.

Further, in the method for producing an inorganic building board as in the conventional example, it is necessary to expose the starch-based binder to saturated steam at 150 to 180 ° C. for a long time in order to gel (gelatinize) the starch-based binder, resulting in low productivity. There is a problem.

In view of the above problems, it is an object of the present invention to provide a method for manufacturing an inorganic building board with high thickness accuracy and high productivity and low specific gravity.

[0007]

[Means for Solving the Problems] In order to achieve the above object, the present invention comprises heating and pressing a hydrous inorganic mat formed by using a starch-based binder as a main binder for a certain period of time with a heated press, Suppressing the springback of the inorganic mat by gelling the starch-based binder,
It is a method for producing an inorganic building board, which comprises drying in a separate step.

Starch-based binders include starch obtained from roots and seed grains of various plants, and examples of starch used in large amounts include corn starch.

Examples of the water-containing inorganic mat are mainly mineral fibers such as rock wool and slag wool, and inorganic fibers such as pearlite and shirasu foam, organic fibers such as pulp and polypropylene fibers, and the above-mentioned mineral fibers. In addition to the starch-based binder, a fixing agent, a sizing agent and the like are added as necessary and kneaded to obtain a slurry, which is obtained by papermaking. The papermaking method is not particularly limited.

An example of the heating press is a continuous belt press, which heats and presses the hydrous inorganic mat for a certain time to gel the starch-based binder as a binder in a short time. It is preferable that the steel belt portion is always heated to 100 ° C to 200 ° C. This is because at 100 ° C or lower, it takes a long time for the binder to gel, and the line speed decreases. At 200 ° C or higher, the water content on the surface of the water-containing inorganic mat in contact with the belt press evaporates abruptly. This is because the gelling of the agent becomes insufficient. The heating temperature of the continuous belt press does not have to be uniform, and may be different depending on the pressing position.For example, by gradually increasing the heating temperature as it goes backward, the rapid temperature in the water-containing inorganic mat is increased. The rise may be prevented.

Further, the pressing force of the continuous belt press needs to be 2 kg / cm ² or more in order to suppress the repulsive force of the mineral fiber board and obtain a high thickness accuracy. However, the pressing force does not have to be constant, and the pressure may be temporarily released during the pressing and repressing. According to such a method, there is an advantage that the internal pressure of the water-containing inorganic mat in the case of manufacturing a thick inorganic building board can be lowered and explosion can be prevented.

The hydrated inorganic mat has a thickness of 4 to 5 mm.
However, the gelling of the binder requires heating and pressing time of 2 seconds or more, and the longer the pressing time is, the more preferable. Heating by continuous belt press as above,
Clamping can significantly reduce the time required for the subsequent drying process. However, the drying method in the subsequent drying step is not particularly limited and can be arbitrarily selected from existing drying methods.

[0013]

EXAMPLES Next, examples according to the present invention will be described. (Example) Rockwool 60% by weight, perlite 24% by weight, cellulose fiber 10% by weight, starch-based binder 5
By weight, 1% by weight of a fixing agent and a sizing agent were suspended in clear water to obtain a slurry having a solid content concentration of 2 to 3% by weight. Then, as shown in FIG.
To obtain a water-containing inorganic mat 2a, the surface of which is scratched by a brush roll 3 and dehydrated by a roll press 4 to a water content of 80 to 100%, and a water-containing inorganic mat 2b having a thickness of 14 mm. Got Then, the entrance spacing is 1
The water-containing inorganic mat 2b is placed in a continuous belt press 5 heated to 180 ° C.
Is fed, heated at a pressure of 5 kg / cm ² for 1 minute and clamped, then cut to an appropriate length with CUTTER 6, and then 1
Specific gravity of 0.36 after drying for 30 minutes at 80 ° C DRIER7
The mineral fiber board 8 was obtained as a sample.

(Comparative Example) Heating with a continuous belt press,
The hydrated inorganic mat with a thickness of 11 mm, which was dehydrated by roll press without compression, was saturated with saturated steam at 150 ° C to 180 ° C.
A mineral fiber board having a specific gravity of 0.36 was obtained by performing the same operation as in the above-mentioned example except that it was exposed to a DRIER at 180 ° C. for 1 hour after being exposed for a minute, and this was used as a sample.

The various measurement results of the samples according to the above-mentioned Examples and Comparative Examples are as follows. Example Comparative example Thickness accuracy (mm) 12 ± 0.5 12 ± 1 Specific gravity 0.36 0.36 Bending strength (kg / cm ² ) 34 32

The measurement result of the bending strength is JIS-59.
It is based on 07-1977.

As is clear from the above measurement results, it was found that the thickness accuracy of this example is higher than that of the comparative example. It is considered that this is because the pressure is applied during the gelation of the starch-based binder, so that the spring back of the hydrous inorganic mat can be regulated. Moreover, it was found that this example is substantially equivalent to the comparative example in specific gravity and bending strength.

Therefore, according to the present embodiment, it is possible to produce a material having the same performance as the mineral fiber board according to the comparative example in a shorter time than the comparative example. Therefore, the productivity of the embodiment is higher than that of the comparative example. Was found to be high.

[0019]

As is apparent from the above description, according to the method for producing an inorganic building board of the present invention, the starch-based binder is gelated under heating and compression conditions, and thus the heating efficiency is high. The starch-based binder can be gelled in a short time. Moreover, since it is not necessary to expose the hydrated inorganic mat to saturated steam and the passage time of the dryer can be shortened, high-speed continuous production of low-density inorganic building boards is possible, and productivity is dramatically improved.

Furthermore, since pressure is applied when the starch-based binder is gelled, springback of the hydrous inorganic mat is eliminated, and higher thickness accuracy can be obtained. For this reason,
There is an effect that the amount of sanding for making the thickness uniform is reduced and material loss is eliminated.

[Brief description of drawings]

FIG. 1 is a process drawing showing an example according to the present invention.

[Explanation of symbols]

1 ... Cylinder type paper making machine, 2 ... Hydrous inorganic matte, 5 ... Continuous belt press, 6 ... DRIER.

Claims (1)

(57) [Claims] 1. A spring back of an inorganic mat by gelling the starch-based binder by heating and pressing a hydrous inorganic mat formed by using a starch-based binder as a main binder for a certain period of time with a heated press. And a method of manufacturing an inorganic building board, which comprises drying in a separate process.