JPH0510457B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a ceiling material made of mineral fiberboard that prevents sagging when moisture is absorbed.

(Conventional structure and its problems) Conventionally, ceiling materials made of fiberboard made from mineral fiberboard such as rock wool have poor heat insulating properties,
It is widely used as a ceiling material for buildings and other structures due to its excellent fireproofing and sound absorption properties.

However, ceiling panels made of mineral fiberboard have difficulty in moisture resistance because they use a binder mainly consisting of starch, which can achieve a large bonding effect with a small amount of addition. If it is formed into a board, the central part tends to sag due to its own weight as it absorbs moisture, and this is especially true when a ceiling board is erected and supported between T-shaped bars using the drop-in method, since the central part is not supported at all. The disadvantage was that large sag occurred.

In order to eliminate these drawbacks, ceiling panels made of mineral fiberboard have been proposed, which use a large amount of a highly water-resistant binder such as phenolic resin to increase moisture resistance. There is a problem that if it is contained in a large amount, the fire retardant properties will be inferior.

(Purpose of the Invention) The present disclosure was made in view of the above-mentioned conventional problems, and the purpose is to provide a mineral fiber that has good fire resistance and prevents the occurrence of sagging due to its own weight when installed. The company provides ceiling materials made of wood.

(Structure of the Invention) In order to achieve the above object, the mineral fiberboard ceiling material of the present invention is a mineral fiberboard ceiling material formed by integrally layering two mineral fiber layers, upper and lower. , the upper mineral fiber layer has a higher hygroscopic expansion coefficient than that of the lower mineral fiber layer, and when moisture is absorbed, the upper mineral fiber layer expands greatly in the plane direction. In this way, an acting force is generated that causes the central portion to warp upward, and this acting force absorbs and offsets the amount of sagging due to its own weight, thereby preventing the occurrence of sag.

In the present invention, in order to increase the elongation of the upper mineral fiber layer by changing the hygroscopic expansion coefficient of the upper and lower mineral fiber layers, a material that swells and expands due to moisture absorption is added to the upper mineral fiber layer. Mix a lot.

Specifically, in the composition of the upper and lower mineral fiber layers, the amount of vegetable fibers such as waste paper pipes, which tend to absorb moisture and cause volume expansion, and the amount of organic binders such as starch and poval can be adjusted. The number may be adjusted so that the number in the upper layer is larger than that in the lower layer.

For example, if inorganic fibers such as rock wool and inorganic aggregates such as perlite and shirasu added to these inorganic fibers are 100 parts by weight, the organic content consisting of waste paper pipes and binders such as starch is added to the upper layer by 20 to 30 parts by weight. , the lower layer may contain 5 to 15 parts by weight, and each layer may be formed and integrated.

The coefficient of hygroscopic expansion of a ceiling material made of mineral fiberboard with such a structure is as follows: When the temperature is changed from 50% humidity at 30°C to 90% humidity at the same temperature, the upper layer 1
is 0.1 to 0.2%, the lower layer 2 has an elongation rate of 0.04 to 0.07%, and the upper layer 1 elongates significantly, causing the central part of the ceiling material to curve upward as shown in FIG. The upper and lower mineral fiber layers are closely integrated to prevent separation between the two layers due to the difference in elongation rate due to moisture absorption, and the lower layer follows the deformation of the upper layer due to moisture absorption and expansion. It is formed into a layer that has sufficient rigidity to prevent damage. If the ceiling material formed in this way is a flat plate of 2 shaku (606 mm width), for example, the height of the warp at the center of the ceiling material will be 2 to 5 mm when it is placed vertically and no weight is applied. This warping alleviates sagging due to its own weight, which is caused by a decrease in strength when moisture is absorbed in the installed state.

In addition, when forming the mineral fiber layer of the lower layer (surface side layer), a thin layer mainly composed of short rock wool fibers with a fiber length of 100 to 2000 μm, which is obtained by crushing rock wool, is integrally formed on the surface layer. Good too.

By providing a lower layer of mineral fibers mainly consisting of short rock wool fibers, it is possible to increase the surface density of the ceiling material and obtain a ceiling material with excellent surface smoothness, cosmetic properties, and surface hardness. back side layer)
Since defects such as surface roughness of the mineral fiber layer are hidden, the weight of the entire ceiling board can be reduced by making the upper mineral fiber layer a porous layer with a low specific gravity.

Furthermore, a colored decorative surface may be formed by adding various inorganic or organic colorants to the lower mineral fiber layer within a range that does not exceed the coefficient of hygroscopic linear expansion of the upper mineral fiber layer.

As such a coloring agent, for example, inorganic powder such as mica or red iron, pigments, dyes, etc. can be used.

Further, a binder may be applied to the interface between the upper and lower mineral fiber layers within a range that does not significantly reduce fire protection.

In addition, a known decoration such as a travertine pattern may be applied to the surface of the ceiling material, especially on the lower layer (surface side).
If the mineral fiber layer is formed mainly from short rock wool fibers, the surface is dense, so the travertine pattern becomes clear, and the upper layer is formed of a porous mineral fiber layer, which makes the travertine pattern more clear. This makes it possible to improve sound absorption in the concave pattern portion.

(Explanation of Examples) Example The composition for forming the lower (surface side) mineral fiber layer was adjusted to 90% short rock wool fibers, mainly fibers with a length of 300 to 1000μ, 6% waste paper pulp, and 4% starch. Using a slurry with a low organic content ratio, the composition for forming the upper layer (surface side) mineral fiber layer is 73% rock wool, which mainly consists of fibers with a length of 4 to 10 mm, and lightweight aggregate (perlite) 7 % Waste paper pulp 10% Starch 4% A slurry with a large organic proportion was used, and each slurry was made into paper to form a wet mat, which was then combined and dried with a dryer until the upper layer was 11 mm thick. A ceiling material was obtained in which upper and lower mineral fiber layers with a lower layer thickness of 1 mm were integrated.

As a comparative example with this ceiling material, a ceiling material consisting only of the composition of the upper layer was formed, and after applying the same travertine pattern to both ceiling materials, the moisture absorption and sagging were compared. The results are shown in FIG.

In addition, 2 shaku wide test pieces were used as ceiling material test pieces, and the amount of sagging in the center over time was measured under conditions of a temperature of 30° C. and a humidity of 90%.

As is clear from the figure, in the comparative example, sagging occurred over 3 mm after 24 hours and reached 4.5 mm after 120 hours, but in the example of the present invention, sagging did not occur even after 120 hours. It was less than 3 mm, hardly noticeable, and had excellent sag resistance.

(Effects of the Invention) As described above, according to the mineral fiberboard ceiling material of the present invention, the mineral fiberboard ceiling material has two upper and lower layers layered together, and when moisture is absorbed, the central part of the ceiling material Since it is formed to curve upward, even if it is used in a humid room, the sagging due to its own weight is absorbed by the amount of upward curvature due to the difference in expansion rate, and even if sag occurs, it is small and stable. In addition, by reducing the blending ratio of organic components in the lower layer, the coefficient of hygroscopic expansion can be reduced, which significantly improves the fire protection of the surface of the lower layer. It is something that can be done.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIG. 1 is a simplified side view showing an upwardly warped state, and FIG. 2 is a comparison diagram of the amount of sagging. 1... Upper mineral fiber layer, 2... Lower mineral fiber layer.

Claims (1)

[Scope of Claims] 1. A ceiling material made of mineral fiberboard formed by integrally layering two upper and lower mineral fiber layers, in which the coefficient of hygroscopic linear expansion of the upper mineral fiber layer is determined by the coefficient of hygroscopic expansion of the mineral fiber layer of the lower layer. A ceiling material made of mineral fiberboard, characterized in that the material is formed to have a coefficient of expansion greater than the hygroscopic linear expansion coefficient of the layer so that the central portion warps upward when moisture is absorbed. 2. A ceiling material made of mineral fiberboard according to claim 1, characterized in that two upper and lower mineral fiber layers are laminated and integrated by lamination.