JPH04125106A - Manufacture of light gypsum hardened body - Google Patents

Abstract

PURPOSE:To secure uniformity of thickness of respective layers by driving a body belt and side belts periodically and feeding fiber containing dense gypsum, multi-cellular gypsum and slurry composition of fiber containing dense gypsum successively onto the body belt and laminating thereon. CONSTITUTION:A body belt 1 and side belts 2A and 2B are driven in the same speed, and fiber containing dense gypsum slurry A is fed from a feeding device 4 and smoothened by a forming spatula 7A, and then multi-cellular gypsum slurry B containing fiber or not containing fiber is fed from a feeding device 5 and smoothened by a forming spatula 7B, and lastly slurry A is fed from a feeding device 6, smoothened by a forming spatula 7C and formed. During said process, fiber containing dense gypsum layer 10a and a multi-cellular gypsum layer 10b of a surface layer are hardened to manufacture a light gypsum hardened body 10. Said light gypsum hardened body 10 is composed of the multi-cellular gypsum layer 10b and the dense gypsum layer 10a of total thickness of 10-50% of the thickness of whole layer sandwiching said layer 10b, and slurry A forming the dense gypsum layer 10a is prepared to contain 0.05-5wt.% fiber to semi-fluid gypsum.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for manufacturing a lightweight hardened gypsum body, and in particular, an improved lightweight hardened gypsum body suitable for use in fireproof coating materials for steel frames, fireproof partition materials, etc. The present invention relates to a method for efficiently producing and husking rice.

[Prior Art] A lightweight hardened gypsum body (multicellular gypsum board) manufactured by curing a gypsum slurry containing a large amount of air bubbles is not only lightweight but also has the characteristics of 100% nonflammability and gypsum (Miki gypsum). Due to its excellent fire-resistant properties such as the endothermic reaction caused by dehydration of crystal water when heated above ℃ and the heat insulation effect due to the large amount of air bubbles contained in the hardened body, it is used as a building material such as fire-resistant coating materials for steel frames and fire-resistant partition materials. It has been used more widely than before.

As a method for continuously producing this type of cured product, for example, Japanese Patent Application Laid-Open No. 144749/1984 has been proposed. In this method, cardboard is placed around the outer periphery to allow the gypsum slurry and aerated gypsum slurry to flow onto a belt conveyor, that is, to serve as a formwork. The cardboard on the outer periphery also has a brittle surface and is difficult to handle, due to the fact that the lightweight gypsum hardened material contains a large amount of air bubbles.
It is indispensable to eliminate defects such as difficulty in making the surface smooth, and to achieve smoothness on the surface of the cured product.

However, considering the purpose of using the lightweight hardened gypsum as a fire-resistant material in the event of a fire, using flammable or smoke-emitting substances such as paper or cloth impedes its properties as a fire-resistant material.

In order to solve the problems of the conventional multicellular lightweight gypsum hardened body, we have developed a horizontally installed body heald with corrugated ranges on both sides, and a body belt placed on the sides of the body belt. , the body belt, the side belt, and the leveling belt are driven synchronously using a device equipped with a side belt that is fed along the inside of the ledge and a leveling belt installed horizontally above the body belt. , a method for producing a lightweight hardened gypsum body has been proposed in which dense gypsum slurry, cellular gypsum slurry, and dense gypsum slurry are sequentially supplied and laminated onto a body belt (Japanese Patent Laid-Open No. 63-2425
No. 03).

According to the method of JP-A No. 63-242503, the surface is smooth, hard, and has high bending strength, and it also has sufficient nonflammability as a fireproof material without using flammable or smoke-emitting materials. It is possible to continuously and efficiently manufacture a lightweight gypsum hardened body comprising:

[The invention attempts to solve i! ! However, in the method of JP-A-63-242503, since a leveling belt is used to level the surface of the supplied raw material slurry, the leveling belt takes up a lot of space. Therefore, using multiple leveling belts for each feedstock slurry, i.e.
In order to smooth the surface of each layer, the body belt requires a long belt length, which is industrially disadvantageous. For this reason, in JP-A-63-242503, in practice, one leveling belt is used to level the surface of the laminate after all the raw material slurry has been supplied, so that the thickness of each layer is uniform. There is a problem that the product cannot be obtained.

The present invention solves the problems of the above-mentioned Japanese Patent Application Laid-Open No. 63-242503, and further provides a method for producing a lightweight hardened gypsum body that has excellent uniformity in the thickness of each layer and is therefore of good quality. With the goal.

[Means for Solving Problem 11] The method for producing a lightweight hardened gypsum body according to claim (1) comprises a porous gypsum layer containing fibers or not containing fibers, and a dense gypsum layer containing fibers sandwiching this layer. The total thickness of the fiber-containing dense gypsum layer is 10 to 50% of the total layer thickness, and the fiber content of the fiber-containing dense gypsum layer is 0.5 to 5% by weight based on the hemihydrate gypsum raw material. A method of manufacturing a lightweight hardened gypsum body, which comprises: a horizontally installed body belt; side belts vertically placed on both sides of the body belt; and a belt guide for holding the side belts. Using a device comprising a forming spatula installed horizontally above the body belt, the body belt and the side belts are driven synchronously to form a fiber-containing dense gypsum slurry, a porous gypsum slurry, and a fiber-containing dense gypsum slurry. The method for manufacturing a lightweight hardened gypsum body according to claim (2), which comprises sequentially supplying and laminating a solid gypsum slurry onto a body belt,
In the method of 1), the device includes a first supply device for supplying fiber-containing dense gypsum slurry, and a second supply device disposed downstream of the first supply device for supplying cellular gypsum slurry. a supply device, a third supply device for supplying fiber-containing dense gypsum slurry, which is disposed downstream of the second supply device in the body belt feeding direction; a first forming spatula disposed between the feeding device, a second forming spatula disposed between the second feeding device and the third feeding device, and a downstream side of the third feeding device; It is characterized by comprising a third forming spatula arranged on the side.

Hereinafter, the present invention will be explained in detail with reference to the drawings.

1 to 4 are diagrams for explaining an embodiment of a manufacturing apparatus suitable for carrying out the method of the present invention, in which FIG. 1 is a side sectional view, and FIG.
The figure is a plan view (however, the feeding device and belt guide are not shown in Fig. 2), and Fig. 3 is an enlarged cross-sectional view taken along line III-III in Fig. 2 (however, the feeding device and belt guide are not shown in Fig. 2).
In the figure, the gypsum hardened body is not shown.
The figure is an enlarged sectional view of the forming spatula.

As shown in the figure, the device of this embodiment has a body belt 1 installed horizontally, and side belts 2A, 2B are vertically arranged on both sides of this body belt, and hold the side belts 2A, 2B. belt guides 3A, 3B
is provided.

In the figure, 11.12 is the driving roller of the body belt 1;
3, 14, 15, and 16 are rollers for driving the side belts 2A and 2B.

A driving device (not shown) such as a variable speed motor is connected to these rollers 11, 12.13, 14.1516, and the body belt 1 and site belts 1-2A and 2B are driven synchronously, that is, at the same speed. It is possible to travel in the same direction. The driving device described above may be provided separately for each of the rollers 11 to 16, or may transmit driving force to the rollers 11 to 16 from a common driving source by a continuous power transmission means such as a chain or a timing belt. It may be.

Above the body belt 1, in order from the upstream side in the belt feeding direction, a first supply device 4 that supplies fiber-containing dense gypsum slurry, a second supply device 5 that supplies porous gypsum slurry, and a fiber-containing The third supplying dense gypsum slurry
A supply device 6 is provided at a position between the first supply device 4 and the second supply device 5, and a position between the second supply device 5 and the third supply device 5.
Forming spatulas 7 (7A, 7B) are located between the third feeding device 6 and downstream of the third feeding device 6, respectively.

7C) is installed horizontally above the body belt 1.

Next, a method for producing a lightweight hardened gypsum body using such an apparatus according to the method of the present invention will be described.

First, the body belt 1 and side belts 2A, 2B of the illustrated device are driven at the same speed, and fiber-containing dense gypsum is applied from the first supply device 4 to the recess formed by the body belt 1 and side belts 2A, 2B. Slurry A is supplied and subjected to break-in molding with a forming spatula 7A, then a fiber-containing or non-fiber-containing porous gypsum slurry B is supplied from the supply device 5 of 342 and subjected to break-in molding with a molding spatula 7A, Finally, the fiber-containing dense gypsum slurry A is supplied from the supplying device 6 of 'f % 3, and the slurry A is smoothed using a shaping tool C. The fiber-containing la dense gypsum slurry A and the fiber-containing or non-fiber-containing foam gypsum slurry B are molded into a molded gypsum slurry A~ It moves 8 times while being molded in 7C. While performing these 8 movements, the surface mm-containing dense gypsum layer 10a and the internal fiber-containing or fiber-free porous gypsum layer 10b harden and become one body, and the lightweight hardened gypsum body 10 is formed. Manufactured. This cured body 10 is then cut into appropriate lengths and dried in a drying process to form a product.

In addition, in the apparatus shown in the figure, it is possible to manufacture a cured product with good mold releasability even when the surfaces of the body belt 1 and side belts 2A, 2B are left as they are; By using it as a cured product, adhesion of the cured product can be more reliably prevented, which is extremely advantageous.

A body belt suitable for use in the present invention includes a regular con hair belt manufactured by Band Kagaku Co., Ltd. Further, as the side belt, the Sunline belt made by the same company is suitable.

Further, the shape of the shaping spatula may be a flat plate, but as shown in FIG. 4, by combining a curved surface and a flat surface and having a surface 7a parallel to the body belt 1, the moldability is further improved. As shown in Fig. 1 and Fig. It is preferable to provide the above-mentioned shaping spatula.

Next, the method of manufacturing the lightweight hardened gypsum body of the present invention will be explained.

The lightweight hardened gypsum body of the present invention consists of a fiber-containing or non-fiber-containing multicellular gypsum layer (hereinafter referred to as "second layer J") and a layer thickness of 10 to 50% of the total layer thickness sandwiching this layer. The fiber-containing li!I dense gypsum layer has a total thickness (hereinafter these may be referred to as the "first layer" and the "third layer").

In the present invention, the fiber-containing dense gypsum slurry forming the fiber-containing dense gypsum layers constituting both surfaces of the cured body, that is, the first layer and the third layer, is composed of, for example, hemihydrate gypsum, wood, and hemihydrate. It is prepared by adding a setting regulator as necessary to a paste mainly consisting of reinforcing fibers in an amount of O, S to 5% by weight based on plaster. Here, examples of reinforcing fibers include inorganic fibers such as glass fibers, and natural or synthetic organic polymer fibers.

As the glass fiber, it is preferable to use a weakly convergent fiber that is defibrated into monofilaments during slurry kneading, and specific examples of the organic polymer fiber include vinylon fiber and the like. These can be used alone or in combination of two or more.

In addition, the types of setting regulators include oxycarboxylic acids and their salts, gluconic acid and its salts, phosphoric acid and its salts, amino acids, sugars, etc. as retarders, and calcium sulfate, sodium sulfate, There are sulfates such as aluminum sulfate. The addition rate of the setting modifier is preferably 0.1 to 5.0% by weight based on the gypsum hemihydrate.

In the first and third layers, if the ratio of reinforcing fibers to the raw material gypsum hemihydrate is too small, a sufficient reinforcing effect cannot be obtained, and if it is too large, moldability may be impaired.

Therefore, the amount of reinforcing fibers is within the above range.

On the other hand, the multi-foam gypsum slurry that forms the internal multi-foam gypsum layer, that is, the second layer, is a slurry made of hemihydrate gypsum and water, or a slurry in which reinforcing fibers are further mixed with a known surfactant. It is prepared by adding the agent and introducing a large amount of air bubbles. The slurry may also contain small amounts of known set control agents. When reinforcing fibers are mixed in and used, the amount used is preferably about 0.5 to 5% by weight based on the raw material gypsum hemihydrate. Reinforcing fibers used in the layers can be used.

As is clear from the comparison of the results of Example 1 and Example 2, which will be described later, in the present invention, fibers are mixed into the first layer and the third layer for reinforcement, so that the lightweight hardened gypsum product of the product is The bending strength necessary for this is sufficiently ensured by the first and third layers. Therefore, from the perspective of the bulk specific gravity and bending strength of the car, it is possible to obtain sufficient J characteristics without including fibers in the second layer, and in this case, the amount of fibers used is smaller than the amount of fibers mixed in all layers. Since only a small amount is required, the cost is also low.

However, when taia is not mixed in the second layer, there is a drawback that the cut surface tends to become brittle when the lightweight hardened gypsum body is cut during construction. Therefore, the presence or absence of reinforcing fibers mixed into the multicellular purchased gypsum slurry, and the amount of reinforcing fibers mixed therein, are appropriately determined depending on the purpose of use of the resulting lightweight hardened gypsum body.

The method for introducing air bubbles into the multicellular purchased gypsum slurry may be either the preform method or the mix form method.
In the preform method, first, a known foaming agent such as sodium alkyl sulfate, sodium alkylbenzene sulfonate, polyoxyethylene alkyl sulfate, etc. is added to gypsum hemihydrate in water.
．． Add 02 to 20% by weight and stir vigorously to foam. At this time, PVA (polyvinyl alcohol), MC (
When 0.05 to 3.0% by weight of a polymer thickener such as methyl cellulose is added to hemihydrate gypsum, stable bubbles can be formed. This foamed water and hemihydrate gypsum are mixed to form a slurry. Alternatively, 01 to 10 parts by weight of the foaming agent and 0.2 to 15 parts by weight of the thickener to 100 parts by weight of water;
The richly mixed liquid and air are passed through a so-called foaming machine in which a cylindrical container is filled with beads or mesh to generate foam. This foam, water, and gypsum hemihydrate are mixed to form a slurry. In the mix form method, materials with a similar composition are added at the same time and stirred vigorously to form a slurry. No matter which bubble introduction method is used, the amount of water is 4 to 1
oz amount % is suitable.

In addition, in the present invention, the gypsum hemihydrate used may be either the α type or the β type.

In the present invention, if the thickness of the porous gypsum layer of the cured product produced is too thick and the thickness of the fiber-containing dense gypsum layer on the outer surface is too thin, sufficient strength will not be obtained; If the thickness of the foamy gypsum layer is too small and the fiber-containing dense gypsum layer on the outer surface is too thick, the specific gravity of the cured product will increase and the lightness will be impaired. For this reason, the fiber-containing dense gypsum layers, ie, the first layer and the third layer, have a total thickness of about 10 to 50% of the total thickness of the lightweight hardened gypsum body.

In the present invention, the specific gravity of the fiber-containing dense gypsum layer of the first and third layers is generally about 0.9 to 11, and the specific gravity of the second porous gypsum layer is generally about 04 to 0.7. It is said that

[Function] The lightweight hardened gypsum body manufactured by the present invention has a structure in which both surfaces of the cellular gypsum layer are covered with fiber-containing dense gypsum layers, and there is no coating with flammable or smoke-emitting substances. ,
The characteristics of the cured gypsum as a fireproof material are not impaired, and the bending strength is higher than that of a cured body of only cellular gypsum having the same bulk specific gravity, and the surface is hard and smooth. For this reason,
It can be painted or finished with wallpaper, etc., and has good adhesion to wallpaper.

Conventionally, it was impossible to directly supply the raw material gypsum slurry onto the belt using only a generally used flat belt, but according to the method of the present invention, the raw material can be directly supplied onto the body belt. I can do it. That is, a recess is formed between the flat plate part of the body belt and the side belts installed on both sides of the body belt, and this recess serves as a movable formwork. , its shape can be stably maintained.

This side belt plays the role of finishing the side surface of the lightweight gypsum hardened product into a smooth plane. Furthermore, the upper surface of the cured product can also be finished smoothly using the upper shaping spatula. In particular, in the present invention, since the surface is level-molded using a forming spatula that takes up relatively little space, this forming spatula is provided for each supply device and the level-forming is performed for each layer. It is possible to produce a lightweight gypsum hardened body in which all of the layers, the second layer to the third layer, have a uniform thickness.

Therefore, according to the method of the present invention, a lightweight hardened gypsum body having a smooth surface can be continuously manufactured without requiring a mold such as cardboard.

Therefore, according to the manufacturing method of the present invention, by casting the slurry of the next layer before the previously cast layer has not yet completely hardened, the adjacent porous gypsum layer (second layer) can be formed. ! # At the interface with the fiber-containing dense gypsum layer (first layer or third layer), two needle-shaped gypsum crystals grow and precipitate from one layer to the other.
A lightweight gypsum cured body with extremely strong bonding between both layers is easily produced.

[Examples] Hereinafter, the present invention will be explained in more detail by giving specific manufacturing examples and comparative examples, but the present invention is not limited to the following examples unless it exceeds the gist thereof. .

Example 1 Slurry A was prepared by kneading 100 parts by weight of β-hemihydrate gypsum, 75 parts by weight of water, and 8 g parts of glass@@O using a Hobart mixer. Separately, 0.015 parts by weight of an anionic surfactant and 0.1 parts by weight of PVA were added to 80 parts by weight of water, stirred at high speed at 600 rpm in a mixer to foam, and added 100 parts by weight of β-hemihydrate gypsum. parts by weight and 1.5 parts by weight of glass fibers were added and mixed to form porous gypsum slurry B.
was prepared.

1J Using the equipment shown in Figures 1 to 4, slurry A was supplied from supply devices 4 and 6, slurry B was supplied from supply device 5, and after curing, it was dried at 80°C for 16 hours to form a lightweight hardened gypsum body with a smooth surface. Manufactured.

The obtained lightweight gypsum hardened body has a lae gypsum layer with a thickness of 5 mm, an internal porous gypsum layer with a thickness of 50 mm, and a width of 6 mm.
When the physical properties of the 00 mm cured product were measured, the bulk specific gravity was 0.72 and the bending strength was 30 kg/am2.

In addition, the surface of this lightweight gypsum cured body is hard and smooth,
Wallpaper adhesion was extremely good.

Example 2 0.015 parts by weight of an anionic surfactant and 0.01 parts by weight of PVA were added to 80 parts by weight of water, and the mixture was heated to 600 parts by weight in a mixer.
The foam was stirred at high speed using an Orpm, and 100 parts by weight of β-hemihydrate gypsum and 1.0 parts by weight of glass fibers were added and mixed to prepare a multicellular gypsum slurry 〇. A lightweight gypsum hardened body was obtained in the same manner as in Example 1 except that Slurry C was used instead of Slurry B. When the physical properties of this cured product were measured, the bulk specific gravity was 068 and the bending strength was 27 kg.
/cm2.

In addition, the surface of this lightweight gypsum cured body is hard and smooth,
Wallpaper adhesion was extremely good.

Example 3 The thickness of the dense gypsum layer was set to 8 in the same manner as in Example 1.
mm, internal porous gypsum layer thickness 44mm, width 600m
When a cured product with m was produced and its physical properties were measured, the bulk specific gravity was 0.80 and the bending strength was 38 kg/am2.

The surface of this lightweight cured gypsum body was hard and smooth, and the wallpaper adhesiveness was extremely good.

Comparative Example 1 Slurry D was prepared by kneading 100 parts by weight of β-hemihydrate gypsum and 75 parts by weight of water using a Hobart mixer. A lightweight gypsum hardened body was obtained in the same manner as in Example 1 except that slurry D was used instead of slurry A. When the physical properties of this cured product were measured, the bulk specific gravity was 0.70 and the bending strength was 17 kg/cm'.

From the above results, it is clear that according to the present invention, it is possible to continuously produce a lightweight hardened gypsum body with extremely high bending strength and a hard and smooth surface due to the reinforcing effect of the fibers contained in the first and second layers. It is.

[Effects of the Invention] As detailed above, according to the method for producing a lightweight hardened gypsum body of the present invention, the outer surface layer is a 1aaa-containing dense layer without using flammable or smoke-emitting storage such as cardboard. , it is possible to easily and efficiently continuously produce a lightweight gypsum hardened body whose interior consists of a porous gypsum layer with excellent glabellar adhesion.

The lightweight hardened gypsum body produced according to the method and apparatus of the present invention is lightweight, has excellent heat insulation and sound insulation properties, and also has (1) extremely high bending strength and excellent mechanical properties.

■ The surface is hard and smooth.

■ Therefore, it has excellent workability and can be applied well to painting and wallpaper finishing.

■ Since there is no flammable or smoke-emitting coating on the shed, the fire resistance of the plaster is not compromised.

It has excellent characteristics such as, and is extremely useful as a fire-resistant building material.

[Brief explanation of the drawing]

Figures 1 to 4 are diagrams illustrating a manufacturing apparatus suitable for carrying out the present invention, in which Figure %1 is a side sectional view, Figure 2 is a plan view, and Figure 3 is I■ in Figure 2. FIG. 4 is an enlarged cross-sectional view of the forming spatula along line -m. 1... Body belt, 2A, 2B... Side belt, 3A, 3B... Belt guide, 4.5.6... Supply device, (7A 7B. 7C)... Forming spatula, 0.・Lightweight gypsum hardened body.

Claims (2)

[Claims] (1) Consisting of a cellular gypsum layer containing or not containing fibers and a dense gypsum layer containing fibers sandwiching this layer, the total thickness of the dense gypsum layer containing fibers is 10 to 50% of the total layer thickness.
and the fiber content of the fiber-containing dense gypsum layer is 0.5 to 5 parts by weight based on the hemihydrate gypsum raw material, the method comprising: a horizontally installed body belt; and a side belt arranged vertically on both sides of the body belt, a belt guide for holding the side belt, and a shaping spatula installed horizontally above the body belt. Lightweight gypsum curing characterized by synchronously driving a body belt and side belts and sequentially supplying and laminating fiber-containing dense gypsum slurry, multicellular gypsum slurry, and fiber-containing dense gypsum slurry onto the body belt. How the body is manufactured. (2) The device includes a first supply device that supplies fiber-containing dense gypsum slurry, and a second supply device that supplies porous gypsum slurry, which is disposed downstream of the first supply device in the body belt feeding direction. a second supply device, a third supply device disposed downstream of the second supply device and supplying the fiber-containing dense gypsum slurry, the first supply device and the second supply device; a first forming spatula disposed between the second forming spatula, a second forming spatula disposed between the second feeding device and the third feeding device, and a forming spatula disposed downstream of the third feeding device; Claim characterized in that it comprises a third shaping spatula (
The method described in 1).