JPS5833805B2 - Continuous manufacturing method for glass fiber reinforced cement products - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION In the present invention, glass fibers 1 are mixed and dispersed in advance with at least one of aluminum hydroxide or activated alumina, cement, and water, and this fiber-containing slurry 2 is mixed with a large number of linear protrusions 3. Scattered onto the conveying sheet 5 that is continuously transferred by the rotating roll 4, the cement maturo is shaped and adjusted to a predetermined thickness, and then heated at a temperature of 70 to 180°C and a humidity of 90 to 1.
This is a continuous manufacturing method for glass fiber reinforced cement products, which is characterized by curing in a high temperature and humid atmosphere of 0.00 C. The purpose is to achieve a high reinforcing effect with glass fibers, less strength deterioration due to cement alkali, and The object of the present invention is to provide a continuous manufacturing method for glass fiber reinforced cement products that can be easily manufactured continuously.

Traditionally, fiber-reinforced cement products such as pulp cement boards and asbestos cement boards have been manufactured in large quantities, and they have been manufactured continuously and rationally using various methods such as dry and wet methods, but recently, they have received particular attention. Glass fiber reinforced cement products are the most popular.

Glass fiber reinforced cement products are recognized for their excellent mechanical strength, and in terms of resources, unlike naturally occurring asbestos, there are no problems of resource depletion or quality variations; However, it has been attracting a lot of attention recently because it does not have the pollution problems associated with asbestos.

However, despite the significance of glass fiber, it has not yet been put to practical use as a cement reinforcing material. If the cement hardens, it will be attacked over time by the slaked lime that precipitates in large quantities from the cement, and its reinforcing effect will significantly decrease. This is because a rational manufacturing method has not yet been developed.

In order to improve the above-mentioned drawbacks, alkali-resistant glass fibers have been developed, for example, as a means of preventing corrosion by alkalis, but they only deteriorate less over time than ordinary glass fibers, and they also However, a satisfactory method has not yet been developed, and the manufacturing method is also undergoing continuous changes.
Alternatively, a method has been proposed in which cement is slurried and the slurry and glass fibers are simultaneously dispersed and then passed through rollers to continuously manufacture glass fiber reinforced cement products. The adhesion, that is, the adhesion was insufficient, and the reinforcing effect could not be fully exhibited.

The present invention has been made to improve these conventional drawbacks, and will be described in detail below with reference to the accompanying drawings.

In the present invention, ordinary glass fibers 1 such as E-glass and C-glass are first coated with at least 0,000 yen of aluminum hydroxide or activated aluminum, water, and other reinforcements if necessary to prevent the fibers from being cut. A glass fiber-containing slurry 2 is prepared by mixing and dispersing the slurry in agents, fillers, inorganic salts, etc.

Here, the concentration of the fiber-containing slurry 2 is usually 30 to 60 in solids percentage.

This is because if the concentration is less than 30%, the scattering effect will be poor, and the composition of the mixed slurry in the casing and the scattered slurry may change, and if the concentration is more than 60%, the fluidity of the slurry will be lost.
The slurry level becomes uneven in the slurry scattering device,
This is because a cement board with a uniform thickness cannot be obtained.

In addition, to explain the composition of the slurry, the amount of glass fiber mixed in is 30 parts or less per 100 parts by weight (hereinafter referred to as parts), which is preferably 0 for manufacturing purposes, and the amount of glass fiber mixed in is 0. The shape may be a whirl shape or a chopped strand shape of 2 inches or less.

Furthermore, asbestos fibers or the like may be used in combination as a reinforcing material.

The type of cement used is not particularly limited either, and ordinary portland cement, alumina cement, silica cement, etc. can be used.

The amount of aluminum hydroxide or activated alumina added for the purpose of fixing alkali and enhancing adhesion is not particularly limited, but in the case of ordinary Portland cement, it is preferably used in an amount of 5 to 40 parts per 100 parts of cement.

This is because the effect is small if it is less than 5 parts, and if it is used in excess of 40 parts, the effect is already at its upper limit and the strength decreases because the cement component is reduced, which is not very preferable.

In addition, those with a particle size of 150μ or less are Ca(CH)2
Preferable because the fixed effect is dog.

Furthermore, inorganic salts added as necessary have the effect of promoting the reaction between Ca(CH)2 generated during cement hydraulic hardening and amorphous silica, and include alkali metal halides, alkali carbonates, and alkaline earth salts. Metal...logenides,
One or more types selected from the group consisting of water glasses are used, and the amount used is, for example, NaC2 or CaCl2, 3 parts or less per 100 parts of cement to achieve its effect.

The glass fiber-containing slurry 2 prepared as described above is then fed to the first reservoir 8 of the scattering device by any means, for example the supply pipe 1 as shown in FIG. 9.

A rotating roll 4 having a large number of linear protrusions 3 is provided in the second storage part 9.
The bottom part is immersed in the liquid level of slurry 2, and the baffle plate 10 is placed in the top part.
When the rotary roll 4 rotates, the glass fiber-containing slurry 2 adhering to the rotary roll 4 is scattered by the rotational force of the baffle plate 10 and the rotary roll 40, and the conveyance of moving felt, wire mesh, etc. It is placed on the sheet 5.

Here, the amount of scattering of the slurry 2 is determined by the length and rotational speed of the linear protrusions 3 immersed in the slurry 2, the degree of penetration of the baffle plate 10 into the linear protrusions 3, and the speed of the conveyance sheet 5.

The shape and type of the linear protrusions 3 are not particularly limited; in short, it is possible to scoop up the raw material slurry 2 when the rotating roll 4 rotates and scatter it using the rotational force of the rotating roll 4 and the force of the baffle plate 10. That's fine.

Therefore, the material of the linear protrusion 3 is usually metal (for example, stainless steel) or nylon, and the linear protrusion 3 is shaped like a needle with a diameter of 0.1 to 2.0 mm.

The method of transporting the slurry to the scattering device is not particularly limited, but it is preferable to transport the slurry by flowing it in a normal state.

The movable conveyance sheet 5 for receiving the scattered slurry and forming a mat may be a general conveyor, and a sheet of felt or a small wire mesh stretched over the conveyor may be used.

In order to prevent the slurry that has been scattered and formed into a layer from flowing, a suction box 11 is installed on the back of the felt to perform suction dewatering, or a dewatering roll is installed on the top of the felt to squeeze it out.

Next, the cement mat 6 is adjusted to a constant thickness using a pair of leveling rolls 13.

In this case, if you want to increase the thickness of the cement matsuro, you can install multiple scattering devices in a row as shown in Figure 2, or wrap it around a making roll 12 as shown in Figure 3 to keep it at a constant thickness. It is also possible to cut when the target is reached.

The glass fiber-reinforced cement sheet obtained above is made into a predetermined size and shape as is or by pressurization, punching, etc., and then heated to a temperature of 70 to 180°C, preferably 80 to 100°C.
The product is obtained by performing moist heat curing for 2 to 50 hours at a high temperature of 90% to 100% and high humidity of 90% to 100%.

The reason why the curing humidity was set at 70-180℃ is that below 70℃, Ca and CH2 precipitated during cement hydraulic hardening are not sufficiently fixed by activated alumina or aluminum hydroxide. This is inconvenient because the hardened cement product is susceptible to thermal deterioration, and the reason why curing is performed under high humidity is to allow the hydraulic reaction of the cement to occur smoothly.

In the present invention, as described above, glass fibers are mixed in cement and water in advance and dispersed to prepare a glass fiber-containing cement slurry, so that the glass fibers and the cement matrix are compatible, that is, have good adhesion. Moreover, since the slurry contains at least one of activated alumina or aluminum hydroxide and is cured under high temperature and humidity, the slaked lime that precipitates during cement hardening is fixed, and cement products are produced. This not only neutralizes glass fibers and prevents them from being corroded by alkali, but also strengthens the glass surface and cement matte coating by the action of the products produced by blending at least one of activated aluminum and aluminum hydroxide. It prevents the deterioration of the strength of the glass fibers and improves the adhesion between the glass fibers and the cement matrix, resulting in a large reinforcing effect by the glass fibers over a long period of time. This has the advantage of ensuring that the

In addition, by scattering the glass fiber-mixed slurry with a rotating roll having many linear protrusions, the composition of the fiber-mixed slurry does not change from that during kneading, and moreover, it is evenly distributed on the continuously moving conveyor sheet. This has the advantage of providing a continuous and rational manufacturing method for glass fiber-reinforced cement products that have stable strength over a long period of time and also allow for free selection of plate thickness.

In addition, since the slurry is scattered and spread on the conveying sheet by the rotational force of a rotating roll having linear protrusions, there is no bias in the directionality of the glass fibers, making it possible to obtain glass fiber reinforced cement products with less variation in strength. The cement products obtained by this manufacturing method maintain high strength for a long period of time, and are excellent reinforced cement products that prevent the occurrence of whitening phenomenon, that is, efflorescence, which is common in cement products.

The present invention will be specifically explained below based on its implementation.

Examples 1 to 4 and Comparative Examples A glass fiber-containing slurry having the composition shown in the table below was spread using the apparatus shown in FIG. 3, and a sheet having a thickness of 6 mm was wound onto a making roll.

The linear protrusion of the rotating roll of the device used at this time had a diameter of 0.
．． A 5mm stainless steel wire is used, and the rotating roll has a diameter of 200mm and a penetration depth of 15mm into the slurry cylinder.
mm, penetration depth into the baffle plate is 5 mm, rotation speed is 150 r
pm, and also uses Elt for the lower moving conveyor,
The conveyor speed was 20 m/min, and the degree of vacuum in the suction box was 30 K9/crA.

The material wound on the making roll in this way is 20K.
After pressure molding at g/crrf, moist heat curing was performed at 80° C. for 36 hours.

In addition, for the comparative example, natural curing was performed for 3 weeks.

When the bending strength and impact strength of each cured sheet were examined for changes over time, the results shown in FIGS. 4 and 5, respectively, were obtained.

At the same time, these Examples 1 to 4 and Comparative Example 5 were placed outdoors.
The samples were exposed and the occurrence of efflorescence was also investigated.

As a result, whitening occurred in the comparative example in about one month, whereas no efflorescence phenomenon was observed in any of Examples 1 to 4 even after two years had passed.

[Brief explanation of drawings]

Fig. 1 is a schematic sectional view of one embodiment of the slurry scattering process of the present invention, Fig. 2 is a schematic sectional view of another embodiment of the same process, and Fig. 3 is a schematic sectional view of another embodiment of the slurry scattering process of the present invention. The perspective view and FIGS. 4 and 5 are graphs showing the temporal change characteristics of the bending strength and Charpy impact strength of products obtained in Examples 1 to 4 of the present invention and comparative examples, in which 1 is a glass fiber, 2 is a glass fiber, and 2 is a glass fiber. Slurry, 3 is a linear protrusion, 4 is a rotating roll, 5 is a conveyance sheet, and 6 is a cement mat.

Claims (1)

[Claims] 1 Glass fibers are mixed and dispersed in advance with at least one of aluminum hydroxide or activated alumina, cement and water, and this fiber-containing slurry is continuously transferred using a rotating roll having a large number of linear protrusions. After scattering onto a conveyor sheet to form a cement mat and adjusting it to a specified thickness,
A method for continuous production of glass fiber reinforced cement products, characterized by curing in a high temperature and high humidity atmosphere with a temperature of 70 to 180°C and a humidity of 90 to 100°C. 2 The slurry is characterized by containing one or more inorganic salts selected from the group consisting of alkali metal halides, alkali carbonates, alkaline earth metal halogenides, and water glass. A method for continuously manufacturing a glass fiber reinforced cement product according to claim 1.