JP2501433B2 - Mineral fiber board manufacturing method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for producing a mineral fiber board in which cutting powder of a mineral fiber board such as rock wool board is reused.

BACKGROUND ART Mineral fiber boards such as rock wool boards are formed by aggregating and binding mineral fibers such as rock wool with a binder such as starch, but a large amount of cutting powder is generated during the processing. Therefore, the cutting powder of mineral fiber board such as rock wool board is recycled. That is, the cutting powder is mixed with water to form a water-kneaded product, which is regenerated as a mineral fiber board by molding, and in this case, the binder contained in the cutting powder acts as a binder of the mineral fiber board. . However, the mineral fiber board thus regenerated has a dense structure because it is formed by the cutting powder of the mineral fiber board, the specific gravity becomes very high, and the properties such as heat insulating property and sound absorbing property become low. Therefore, a foaming agent was added to the water-kneaded material of cutting powder to knead it to foam the water-kneaded material. By molding the water-kneaded material in such a foamed state, the foam was contained. A mineral fiber board with a low specific gravity is obtained.

However, when manufacturing mineral fiber boards,
First, a water-kneaded mixture of cutting powder is mixed with a foaming agent to foam, and the mixture is poured into a mold or the like to form a mat 1, and the mat 1 is heated at 150 ° C. for about 2 hours. Although it is carried out by drying, the foam 2 in the mat 1 will escape with the passage of time as shown in FIG. 2 (a) when it is poured into the mold, while it will be heated while it is being dried. As shown in FIG. 2 (b), the bubbles 2 in the mat 1 are heated and expanded, and the mat 1 expands so as to increase the thickness as a whole, and some of the bubbles 2 are destroyed. And after drying mat 1
As the foam cools, the foam 2 contracts and breaks back to its original state, and the volume of the mat 1 decreases by the volume of the broken foam 2, and the mat 1 becomes a reduced state as shown in FIG. 2 (c). The surface is deformed and the distribution of the bubbles 2 becomes uneven. Therefore, it is very difficult to manufacture a mineral fiber board having a uniform thickness and properties. Further, since this mineral fiber board is formed of cutting powder, there is almost no binding effect by the fibers, and there is a problem that bending strength is weak and chips and cracks are very likely to occur.

[Object of the Invention] The present invention has been made in view of the above points, and it is possible to uniformly form bubbles to obtain a mineral fiber plate having a uniform thickness and properties, and further, excellent strength. It is an object of the present invention to provide a method for producing a mineral fiber board that can obtain the mineral fiber board.

DISCLOSURE OF THE INVENTION However, in the method for producing a mineral fiber board according to the present invention, a cutting powder of a mineral fiber board containing a binder and a foaming agent are blended, and further fibers are blended to prepare a water-kneaded product. The present invention is described in detail below.

The water kneaded product is prepared by mixing cutting powder of a mineral fiber plate such as rock wool plate, a foaming agent, fibers, and other aggregates and kneading the mixture with water. Here, the cutting powder of a mineral fiber board such as a rock wool board contains a binder such as starch used in manufacturing the mineral fiber board. As the foaming agent, a surfactant such as an anionic surfactant, a polyethylene ether type nonionic surfactant, or an aliphatic ester type nonionic surfactant can be used. Further, as the fibers, inorganic fibers such as rock wool and organic fibers such as pulp can be used,
These can also be used together. When a water kneaded product is prepared, it is foamed by the action of a foaming agent when kneading with a stirring device, and the water kneaded product contains bubbles. Then, the water-kneaded product thus prepared is poured into a mold, introduced into a dryer and heated to be dried to obtain a mineral fiber board.

Here, the mat 1 molded by pouring the water-kneaded material into the mold contains the foam 2 foamed by the foaming agent. The foam 2 is a water-mixed material as shown in FIG. It is held between the fibers 3 by being entangled with the fibers 3 mixed in. Therefore, the foam 2 is difficult to be removed from the mat 1, and the foam 2 is not easily broken. Therefore, even if the foam 2 is expanded and contracted by heating and drying and subsequent cooling, the foam 2 is retained between the fibers 3 and It is difficult to be affected, and prevents the mat 1 from being lost due to the breakage or dropout of bubbles 2 as in the case of FIG.
It is possible to reduce the unevenness of the thickness due to the deformation and the unevenness of the distribution of the bubbles 2. And the mineral fiber board obtained as described above, since the cutting powder of the mineral fiber board such as rock wool board which is normally discarded is the main raw material, it can be manufactured at low cost, and By containing the foam 2 by the foaming agent, it is possible to manufacture a plate having a low specific gravity. Further, the reinforcing effect of the fibers mixed in the mineral fiber board can improve the strength of the mineral fiber board during bending and the like, and prevent the occurrence of chipping or cracking.

 Next, the present invention will be described with reference to examples.

Example 1 A water-kneaded product was prepared by using rock wool as a fiber to be compounded and kneading with the compounding in Table 1. Next, this was poured into a mold and dried by a dryer at 150 ° C. for 2 hours to obtain a 300 mm × 600 mm × 12 mm mineral fiber board.

Example 2 A water-kneaded product was prepared by using pulp as a fiber to be mixed, and a mineral fiber board was obtained in the same manner as in Example 1.

Comparative Example A water-kneaded product was prepared without blending fibers, and the other example was used.
A mineral fiber board was obtained in the same manner as.

The specific gravity (apparent specific gravity), bending strength, and thickness variation of the mineral fiber boards obtained in Examples 1 and 2 and Comparative Example were measured. The results are shown in Table 1. In addition, "thickness change amount" in Table 1 is + when the surface of the mineral fiber board is swollen
In the above, the case where the surface of the mineral fiber board is dented is shown by 1.

From the results shown in Table 1, it is confirmed that, in each of the examples in which the fibers are mixed, the change in thickness can be reduced and the bending strength can be further increased as compared with the comparative example.

[Effects of the Invention] As described above, in the present invention, the water-kneaded product is prepared by blending the cutting powder of the mineral fiber plate containing the binder and the foaming agent, and further blending the fibers. Since it is configured to be molded, the foam foamed by the foaming agent is entangled with the fibers and held between the fibers,
It is possible to reduce the loss and destruction of bubbles, and to prevent the loss due to the destruction and loss of bubbles to obtain a mineral fiber board with a uniform thickness and a uniform distribution of bubbles. By the reinforcing action of this fiber, the strength of the mineral fiber board such as bending can be improved and the occurrence of chipping or cracking can be prevented. Moreover, the binder and the fiber powder contained in the cutting powder of the mineral fiber board, which is normally discarded, can be reused as the main raw materials, and the manufacturing cost can be suppressed.

[Brief description of drawings]

FIG. 1 is a front view of an embodiment of the present invention, and FIG. 2 (a).
(B) and (c) are front views of a conventional example, 1 is a mat of a water-kneaded material, 2 is a foam, and 3 is a fiber.

Claims (1)

(57) [Claims] 1. A mineral fiber board characterized in that a water-kneaded product is prepared by blending cutting powder of a mineral fiber board containing a binder and a foaming agent, and further blending fibers, and molding the mixture. Production method.