JPH0242957B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a method for producing mineral fiberboard used as a ceiling material, wall material, or other panel material for buildings.

(Conventional structure and its problems) Conventionally, in manufacturing mineral fiberboards such as rock wool and slag wool used for ceiling materials, etc., the objective has been to achieve desired insulation properties, weight reduction, or productivity improvement. The main material is mineral fibers with a relatively long fiber length of 4 to 30 m/m, and is wet-formed with a low slurry concentration. However, unlike organic fibers such as wood pulp, mineral fibers are Due to the lack of flexibility, the surface of matte obtained by paper-making mainly from long fibers becomes noticeably uneven, making it impossible to obtain a smooth surface and requiring surface treatment by sanding after drying the matte. Ta.

In addition, even with mineral fiberboard whose surface has been smoothed by sanding, the surface is porous, so paint is absorbed during painting, resulting in poor paintability.
It is necessary to apply an undercoat to suppress variations in absorption before finishing with paint, which poses problems such as reduced productivity.

(Object of the Invention) The present invention has been made in view of the above-mentioned conventional problems, and aims to eliminate the need for sanding treatment and to improve paintability, weight reduction, and productivity of mineral fiberboard. A manufacturing method is provided.

(Structure of the Invention) In order to achieve the above object, the present invention involves adding mineral fibers having an average fiber length of 100 to 2000 μm to a wet mat obtained by paper-making a slurry containing mineral fibers as a main ingredient and adding a binder. High-density wet sheets obtained by paper-making a slurry consisting mainly of fibers and a binder added are layered, dehydrated by applying and/or reducing pressure, and the wet mat and wet sheet are layered together and then dried. It is characterized by the fact that a smooth surface layer with excellent hardness is formed by a wet sheet mainly composed of short mineral fibers, and mineral fiberboard can be manufactured efficiently.

(Explanation of Examples) To explain the examples of the present invention with reference to the drawings, the fiber length of rock wool, slag wool, etc. is 4 to 30 mm.
A slurry is made by using a circular netting machine or a fourdrinier machine to make a slurry, which is mainly made of mineral fiberboard, to which an appropriate amount of inorganic foamed lightweight aggregate such as perlite or shirasu and a binder such as starch is added. A low-density wet mat 1 having a specific gravity of 0.2 to 0.3 after drying is formed. Incidentally, inorganic foamed lightweight aggregate can be added as necessary.

On the other hand, mineral fibers such as rock wool and slag wool are crushed into short fibers with a fiber length of 100 to 2000μ, preferably 100 to 1000μ, and starch, PVA, and phenol are added to the mineral short fibers at a rate of 2 to 20%. , acrylic, acrylic styrene, petroleum resin, etc., and if necessary, organic short fibers such as waste paper pulp, coloring agents such as pigments, calcium carbonate, clay, silica, etc.
Appropriate amounts of inorganic powders such as magnesium carbonate, mineral powder, mica powder, metal powder, aluminum hydroxide, alumina powder, carbon black, and white carbon are added to form a slurry mainly consisting of mineral short fibers, and this slurry is separated. A high-density wet sheet 2, which is thinner than the wet mat 1 and has a specific gravity of 0.3 to 0.5 after drying, is formed by paper-making using a suitable paper-making apparatus.

In this way, wet mats 1 were made separately.
and wet sheet 2. In addition, the wet sheet 2 may be superimposed on the front surface, the back surface, or both surfaces of the wet mat 1, but
It is preferable to arrange the paper sheets so that the mesh side of the paper making machine is located on the outside and overlap them, since the outer surface will be a smooth surface and the mineral fibers on the overlapped surfaces will have good adhesion to each other.

Next, the stacked wet mat 1 and wet sheet 2 are dehydrated under pressure using upper and lower press rolls 3, 4 or a flat plate press, or by suction dehydration 5 from the underside of the wet mat 1 as shown in FIG. 2, or by both dehydrating means. The two are layered together and then dried to form dense and high-density mineral short fibers 12 in which the upper layer is mainly composed of mineral short fibers.
In this way, a mineral fiber board A as shown in FIG. 3 is manufactured, in which the lower layer is a low-density mineral fiber layer 11 formed of mineral fibers having a relatively long fiber length.

In addition, the wet sheet 2 made of mineral short fibers can be dehydrated to a predetermined moisture content at the time of papermaking, so it has good dehydration and drying efficiency after being stacked with the wet mat, and it can also be formed into a sheet and combined with the wet mat 1. It can be provided with a uniform thickness in order to overlap each other, and moreover, it can form a dense layer in which short fibers are evenly intertwined with each other.

In the manufacturing method described above, when the wet mat 1 and the wet sheet 2 are combined, a binder 6 may be applied to the combined surfaces of the wet mat 1 and the wet sheet 2 in order to increase the adhesion between the layers and prevent delamination.

When a liquid binder such as a starch solution, phenol, or a resin solution such as melamine is used as such a binder, it is applied by a flow coater or spray, and the coating liquid is applied to the interface between the wet mat 1 and the wet sheet 2. This is intended to increase the degree of adhesion between layers by partially penetrating it, and to strengthen the interface between each layer to further increase the strength.

On the other hand, powdered materials such as starch, powdered phenol, and PVA can also be used as a binder.If this is sprinkled on the interface between the wet mat 1 and the wet sheet 2, the powdered binder will not penetrate into the lower layer mat and will remain inside the dryer. After being activated by moisture and heat, it is dried, so it is possible to improve the adhesion between the upper and lower layers with a small amount of spraying.

The binder may be sprayed or applied to either one or both of the wet mat 1 and the wet sheet 2.

Further, when applying the liquid binder, it may be applied to the surface of the wet sheet 2 after the wet mat 1 and the wet sheet 2 are combined.

According to such a treatment, the liquid binder permeates into the underlying wet mat 1 to increase the adhesion between the layers, thereby preventing delamination and at the same time increasing the surface hardness.

In addition, after applying a binder treatment before dehydration,
The binder can also be sucked from the underside of the wet mat 1 or penetrated into the interior during pressurized dehydration.

Application of such a bonding agent is carried out on wet sheet 2.
When papermaking is performed by adding a large amount of binder to the paper, the binder can be used to increase the bonding strength between the layers, and is not necessarily required.

Furthermore, if the surface of the wet sheet is pressed with the pressure roller 6 or a flat press after dehydration, before drying, or simultaneously with dehydration, the surface fluff of the mineral short fiber layer 12 can be almost eliminated and the surface can be made more dense. , the surface properties can be further improved by increasing the density.

Incidentally, when pressing the above-mentioned surface, three-dimensional makeup may be applied at the same time using a pressure roller or a flat press having an uneven pattern on the surface, and in this case, a dense and clear pattern can be provided.

(Effects of the Invention) As described above, according to the present invention, wet matte obtained by paper-making a slurry containing mineral fibers as a main ingredient and a binder added thereto is mainly composed of mineral short fibers and a binder is added thereto. After the wet sheets obtained by paper-making the slurry are stacked together, they are dehydrated in the stacked state and dried in an integrally layered state. Since the sheet is laminated integrally with the pine in a wet state, a surface layer of uniform thickness can be formed, and by dehydrating the sheets while stacked, the adhesion between the fibers between the layers improves, and the surface layer does not peel off. It is difficult to coat and has excellent adhesion, and even if the surface of the wet mat is porous and highly uneven, it will adhere uniformly.

Furthermore, since the wet mat and wet sheet are once dehydrated by suction to a predetermined moisture content during papermaking, the drying load after paper combination is small. As moisture moves during the process, binder migration and intertwining of fibers are promoted between the mineral short fiber layer 2 and the underlying mineral fiber layer 1, increasing adhesion between the layers and preventing delamination. Mineral fiberboard can be obtained through continuous production, and in particular, if suction dehydration is used, the interlayer fiber entanglements and bonded parts will not be broken, and the weight can be reduced by eliminating the increase in the specific gravity of the lower layer wet mat, and it can be made into rolls or flat sheets. By pressurized dehydration, it is possible to create uneven patterns on the surface at the same time as dehydration.
Moreover, it is possible to harden the surface layer without destroying the lower layer.

In addition, since the surface layer is made of a wet sheet mainly composed of short mineral fibers, it is not only non-flammable, but also forms a dense and smooth surface. Because it is dense and has a high density, it absorbs less paint, and can omit the undercoat and form a good film with a small amount of paint.Even when applying adhesive, it absorbs less paint, so it absorbs less paint on the surface. Adhesion of decorative sheets can be easily and reliably performed.

Furthermore, since the surface layer is dense and dense, it is hard and has excellent compression resistance, impact resistance, and bending strength, and a binder such as phenolic resin with excellent water resistance is added to the wet sheet that makes up the surface layer. When formed as a mineral fiberboard, moisture absorption from the surface is suppressed, and a mineral fiberboard with excellent moisture resistance can be obtained with little loss of strength due to moisture absorption.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention; FIG. 1 is a simplified side view, FIG. 2 is a simplified side view of the main parts showing an embodiment of another dehydration method, and FIG. 3 is a diagram showing an embodiment of the present invention. It is a sectional view showing the obtained fiberboard. 1... Wet mat, 2... Wet sheet, 3, 4... Press roll, 5... Suction dehydration,
6...Binding agent.

Claims (1)

[Scope of Claims] 1 Wet mats obtained by paper-making a slurry containing mineral fibers as a main ingredient and a binder added thereto, containing mainly mineral short fibers with an average fiber length of 100 to 2000μ and adding a binder. The wet sheets obtained by paper-making the slurry are stacked one on top of the other, and the wet sheets are dehydrated by pressurizing/reducing the pressure in the stacked state, and the wet mat and the wet sheet are layered together, and then dried. A method for producing mineral fiberboard. 2. The method for manufacturing a mineral fiberboard according to claim 1, characterized in that when the wet mat and the wet sheet are overlapped, a binder is sprinkled on the interface thereof. 3. The method for producing a mineral fiberboard according to claim 1, characterized in that when the wet mat and the wet sheet are layered together, a binder solvent is sprayed onto the surface of the wet sheet. 4. The mineral according to claim 1, 2 or 3, wherein after the wet mat and the wet sheet are integrally layered, the surface of the wet sheet is pressed to make it dense before drying. A method of manufacturing quality fiberboard.