JPH04168001A - Manufacture of thin inorganic board - Google Patents

Abstract

PURPOSE:To obtain a thin inorganic board without causing longitudinal cracks thereon by extrusion-molding a kneaded substance made by applying and then kneading an inorganic material, aggregate, fiber material, admixture, additive, and water into a continuous board, and cutting it into predetermined dimensions, and thereafter rolling the board by pressing rolls and thus forming it into a thin board. CONSTITUTION:A kneaded substance is put into an extruding machine, which is made by employing mainly an inorganic material such as cement, gypsum, slag, and the like and mixing appropriately an aggregate, fiber material, admixture, expanding agent, and the like, and applying a suitable quantity of water thereto and then kneading it by a kneading machine, and it is extrusion-molded into an arbitrary thickness continuous board. The continuous board obtained is served at every tentatively predetermined length by a cutting device so as to make a dimensionally fixed board, after that, it is rolled by pressing rolls in order to be a thin board. The pressing rolls are arranged such that the axial centers are parallel to the particle orientating direction of the dimensionally fixed board. The thin board obtained herein is cut into article predetermined dimensions, and as required, a surface recession and protrusion treatment is given by means of an embossing device for forming a desired patterns thereon.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a method for manufacturing a thin inorganic plate by extrusion molding.

<Prior art> Conventional inorganic plates have been manufactured using the batch method in which an inorganic kneaded material is poured into a mold, the papermaking method in which the kneaded material is scooped out or dehydrated, the press method in which the kneaded material is pressed to dehydrate it, and the extrusion method in which the kneaded material is extruded and molded. It is manufactured by various methods such as Among these methods, the extrusion molding method in particular has less raw material loss.
It has been widely adopted in recent years due to its excellent production efficiency.

<Problem to be solved by the invention> Since the extrusion molding method extrudes the kneaded material from a cylinder through a die of a predetermined shape, when trying to manufacture a thin inorganic plate by this method, it is necessary to narrow the die opening. need to be formed.

However, as the die opening becomes narrower, the extrusion resistance increases, so higher extrusion pressure is required.
The extrusion speed decreases and the back spring after extrusion increases, which tends to cause thickness unevenness and causes clogging at the die opening. Due to these problems, although extrusion molding is suitable for producing medium to thick inorganic plates, it cannot currently be used as a method for producing thin inorganic plates.

<Means for Solving the Problems> Accordingly, an object of the present invention is to provide a novel method capable of producing a thin inorganic plate, which has been conventionally considered impossible, even though it uses an extrusion method.

The purpose is to extrude a kneaded product obtained by adding and kneading inorganic materials, aggregates, fiber materials, admixtures, additives, and water into an extruder into a continuous plate-like body, By the method for producing a thin inorganic plate of the present invention, which comprises the steps of: cutting the body into a predetermined size; and rolling the cut plate body with a rolling roll to form a thin plate body. achieved. The above-mentioned rolling process is performed by inserting the plate-shaped body into the rolling roll so that the axis of the roll and the direction of grain orientation of the plate-shaped body are parallel to each other.

<Operation> A thin inorganic plate having a predetermined thickness is obtained by rolling the extruded plate-shaped body. A thin inorganic plate without longitudinal cracks can be obtained by inserting the plate into a rolling roll and rolling the plate so that the grain orientation direction is parallel to the axis of the rolling roll.

Description of specific composition> Mainly made of inorganic materials such as cement gypsum and slag, silica sand, perlite, calcium carbonate, clay, and synthetic resin particles 1
Aggregates such as synthetic resin foam granules, incinerated ash and sand, fiber materials such as wood fibers, valves, synthetic fibers, glass fibers and carbon fibers, admixtures such as methylcellulose, synthetic resin 1 synthetic rubber, etc.
Additives such as an expanding material and a shrinkage reducing material are appropriately mixed, an appropriate amount of water is added thereto, and the mixture is kneaded in a mixer to obtain a kneaded product.

The obtained kneaded material is put into an extruder. As is well known, the extruder is equipped with a cylinder and a fla-soto die at the tip of the cylinder, and extrudes the kneaded material into a continuous plate-like body of arbitrary thickness.

The obtained continuous plate-like body is cut into a fixed-size plate-like body by cutting the obtained continuous plate-like body into a predetermined length using a cutting device, and then rolled with a rolling roll to form a thin plate-like body. This rolling roll is, for example, one that is equipped with one or more rolls on a conveying device, and when a plurality of rolls are provided, the height of the roll is gradually lowered in the conveying direction. The shaped body can be rolled to a predetermined thickness. A plurality of rolls may be provided on the upper and lower sides of the plate-like body being transported, and the plate-like body may be rolled to a predetermined thickness while being passed between these rolls in a press-contact state. Note that instead of the rolling rolls, the plate-shaped body may be rolled using an endless belt provided so that the intervals between the rolling rolls become gradually narrower.

The rolling rolls are arranged so that their axes are parallel to the grain orientation direction of the sizing plate. The reason for this is as follows.

Since the plate-shaped body is extruded by an extruder, there is particle orientation inside it (direction in the same direction as the extrusion direction).
occurs. In other words, since the kneaded material is fed by a screw in the cylinder of an extruder and extruded from a flat die under high extrusion pressure, the inorganic material particles and aggregate particles constituting the kneaded material are ,
There is a tendency for granular or linear materials such as fibrous materials to be filled in a state substantially aligned in the extrusion direction. In addition, due to frictional resistance with the flat die during extrusion, the flow velocity of the kneaded material on the four circumferential surfaces of the front and back parts and the end part becomes lower than that inside, so that the filling of the above-mentioned granules, etc. is caused by this difference in flow velocity. The particles are formed densely on the four circumferential surfaces of the front and back parts and the butt end, and become coarser toward the inside, so the particle orientation in the extruded product is particularly noticeable on the four circumferential surfaces of the front and back parts and the butt end, and in the center. Although it becomes weaker toward the center, in the case of thin to medium-thick objects, a fairly strong grain orientation can be seen even in the center.

By the way, when a plate-like body is rolled by a rolling roll or the like, a force that tends to spread the plate-like body in a direction transverse to the direction of insertion into the rolling roll acts on the plate-like body. Therefore, when attempting to roll a plate-shaped body made to have the above-mentioned particle orientation by extrusion using a rolling roll having an axis perpendicular to the direction of particle orientation,
Since the grain orientation within the plate-shaped body is further spread out in a fan shape in the transverse direction during rolling, not only a high pressing force is required, but also vertical cracks are likely to occur along the grain orientation direction. On the other hand, when rolling is performed by inserting the plate into a rolling roll so that the particle orientation direction of the plate is parallel to the axis of the rolling roll, the overall length of the cut plate is Since they are rolled at the same time, no force is applied to spread the grain orientation into a fan shape, and rolling can be carried out with a relatively small pressing force without causing longitudinal cracks.

According to the experiments conducted by the present inventors, a plate-shaped body discharged from an extruder with a thickness of 7 mm can be reduced to a thickness of 4 mm using one rolling roll whose axis is parallel to the direction of grain orientation. The thickness could be easily reduced, and no vertical cracks occurred in the obtained thin plate-like body.

The specific configuration for rolling the plate-like material so that the grain orientation direction and the axis of the rolling roll are parallel is not limited, but for example, rolling the plate-like material discharged from an extruder along the extrusion direction is not limited. After cutting the plate-shaped body into a predetermined length using the overculm conveyed by the culm, the plate-shaped body is transferred onto a second conveyor having a width sufficiently larger than the length, and is placed approximately perpendicular to the extrusion direction. A rolling roll having an axial length sufficiently longer than the length dimension is pressed against the plate-shaped object conveyed on the second conveyor from above or from above and below. This can be done by Alternatively, instead of the second conveyor being a lateral conveyor,
A turning means for changing the direction of the cut plate-shaped body by approximately 90° may be provided, and this turning means may be connected to a second conveyor that moves straight in the same direction as the extrusion direction.

In this way, the plate-like body is rolled a plurality of times by rolling rolls whose axes are parallel to the grain orientation direction, and is made into a thin plate-like body having a predetermined thickness. The obtained thin plate-like material is cut into a predetermined product size, and if necessary, the surface is textured using an embossing device such as an embossing roll or an embossing press to form a desired pattern, or it can be colored or painted. Pattern printing etc. are applied to improve the design.

<Effects of the Invention> According to the present invention, it is possible to obtain a thin plate-like body, which was conventionally considered impossible by extrusion molding, and vertical cracks do not occur.

Claims (3)

[Claims] (1) A step in which a kneaded material obtained by adding and kneading inorganic materials, aggregates, fibrous materials, admixtures, additives, and water is fed into an extruder and extruded into a continuous plate-shaped body, and the continuous plate-shaped body is 1. A method for producing a thin inorganic board, comprising the steps of: cutting the inorganic material into a predetermined size; and rolling the cut plate using a rolling roll to form a thin plate. (2) In the rolling step, rolling is performed by inserting the plate-like body into the roll so that the axis of the roll and the direction of grain orientation of the plate-like body are parallel to each other. A method for manufacturing thin inorganic plates. (3) The method for producing a thin inorganic plate according to claim 1, wherein an embossing process for forming irregularities on the surface of the plate-shaped body is added after the rolling process.