JPH0299301A - Manufacture of inorganic molded product - Google Patents

Abstract

PURPOSE:To improve releasing and prevent the generation of cracks by spraying dry powder composed mainly of a hydraulic inorganic substance on the surface while an extrusion molded material is uncured and then press molding. CONSTITUTION:An extrusion molded material 3 on which dried powder 7 of hydraulic inorganic material composed mainly of Portland cement is piled up one by one on a plurality of stages together with trays 5 on a truck or the like and transferred to the pressing process. The molded material 3 is put into a press mold 1 consisting of a top force 81 and a bottom force 82 together with the trays 5 and press molded to form a pattern surface on the lower surface of the extrusion molded material 3. When the press molding is finished, the top force 81 is moved upward to be released from a press molded material 3a. At that time, the press molded material 3a remains mounted on the tray 5 by its own weight, and the upper surface of the released press molded material 3a is pressed in the state that the powder absorbs the water content of a surface layer of the extrusion molded material to form a pretty surface with little viscosity.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for producing an inorganic molded body suitable for use in producing architectural panels, corner materials, and the like.

(Prior art) Conventionally, extrusion molding materials mainly composed of hydraulic inorganic materials such as cement and gypsum have been extruded into long shapes using an extrusion molding method and then cut into approximately regular lengths in an uncured state. JP-A No. 60-44303 discloses a method of making a molded body, then inserting the molded body into a press mold, press-molding it, and then curing and hardening it to obtain a desired inorganic molded body. The methods described are known.

In this manufacturing method, an extrusion molding material whose main component is a hydraulic inorganic material such as cement is extruded using an extruder using a mold with a cross-sectional shape approximately equal to the final shape of the product, and then the extrusion molded body is shaped into the final shape of the product. Place it on a tray that supports the bottom surface of the
In the pressing process, the molded body is put together with the tray into a mold consisting of an upper mold and a lower mold, and then press-formed, and after press-forming, it is taken out together with the tray and hardened and cured to produce a long architectural accessory. The method is to do so.

(Problem M to be Solved by the Present Invention) However, the above prior art has the following problems.

(2) When the upper mold is removed from the molded body after press molding, the surface portion of the press molded body adheres to the upper mold, making it difficult to release the mold.

This is due to the fact that a thickener such as methyl cellulose is added to the extrusion molding material in order to impart fluidity to it. In other words, an extruded molded product made of a molding material containing a thickener is sticky in an uncured state, and if such a molded product is press-molded and removed from the upper mold before hardening, A part of the extruded molded product adheres to the upper mold surface, causing molding defects. Therefore, the upper mold surface must be cleaned to remove any deposits. Even if a mold release agent is applied to the upper mold to improve mold releasability, the mold release agent adheres to the surface of the molded object, so if paint is applied after curing, it will be difficult for the paint to adhere. , the coating film formed is inferior in durability.

(2) Furthermore, if the press waiting time between extrusion molding and press molding is long, the surface of the extruded product will dry, and cranks will occur during press molding. Therefore, when press-molding an extrusion molded body in a batch process, there is a problem that there is not enough waiting time for pressing.

The present invention has been made in order to solve the above problems, and its purpose is to provide excellent mold release when press-forming an extrusion molded product in a press process, and to avoid a long press waiting time. Another object of the present invention is to provide a method for producing an inorganic molded body that does not generate cranks during press molding.

(Means for Solving the Problems) The present invention uses an extrusion molding material containing a hydraulic inorganic material as a main component, extrudes it into a long shape by an extrusion molding method, and cuts it into approximately regular lengths, and then extrudes the extrusion molding material in an uncured state. In a method for producing an inorganic molded body, which comprises making a molded body, then inserting the molded body into a press mold, press-molding the molded body, and then removing the mold, while the extrusion molded body is in an uncured state. The present invention provides a method for producing an inorganic molded body, which comprises spreading a dry powder material containing a hydraulic inorganic material as a main component onto the surface of the extrusion molded body, followed by press molding.

Inorganic molded bodies as used in the present invention are architectural and construction materials used for exterior wall materials such as architectural panels and corner materials, as well as roofing materials, foundation materials, fences, gutters, etc., and include cement, plaster, etc. A molded body made of a material whose main component is a hydraulic inorganic substance.

The extrusion molding material used in the present invention is mainly composed of a hydraulic inorganic material such as cement, silicate, or gypsum, and is used to impart water retention, fluidity, slipperiness, etc. during extrusion molding. This is a mixture in which methyl cellulose and the like are added together with an appropriate amount of water, and if necessary, reinforcing short fibers of organic or inorganic fibers are added and mixed.

In the present invention, the powder substance to be sprinkled on the extrusion molded body is a dry powder mixture in which no fluidity imparting agent such as methyl cellulose and water are added among the above-mentioned extrusion molding material formulations, such as cement-based inorganic substances. and aggregate such as silica beam are mixed in a mixer such as a high-speed blender.

In the present invention, the above-mentioned powder substance is spread on the extruded body before press molding and when it is in an uncured state, using a rotating brush or a vibrating sieve, etc.
If the amount of spraying is too small, the mold release after press molding will be insufficient, and if it is too large, the hydration reaction will not occur sufficiently due to the absorption of water, and the strength of the surface of the press molded product will decrease. ~800 g/rrf is preferred.

(Function) Since the present invention has the above-described structure, when a dry powder substance is sprinkled on an uncured extrusion molded body before press molding, the mixed powder substance adheres to the exposed surface of the extrusion molded body. do. When this powder substance is attached, the surface of the extrusion molded product has reduced adhesiveness, and even when press-molded, the surface of the extrusion molded product does not stick to the press mold surface.

Furthermore, since the extruded body is coated with the adhered powder material, the surface layer of the extruded body is prevented from evaporating moisture and does not dry out.

(Example) Next, an example of a method for manufacturing a long architectural accessory which is an inorganic molded article of the present invention will be described with reference to the drawings.

1 and 2 are schematic explanatory diagrams of an apparatus used in the extrusion process and press process used in the manufacturing method of the present invention. In FIG. 1, 1 includes a hopper 10, a first stage screw part 11, A two-stage vacuum extruder consisting of a stage screw part 12, 14 a mold, 3 an extruded product, 4 a transfer device such as a roll conveyor installed below the extruder 1;
5 is a tray on which the extruded molded body 3 is placed, and 6 is a vibrating sieve on which the mixed powder substance 7 in a dry state is spread. Further, in FIG. 2, reference numeral 8 denotes a press mold consisting of an upper mold 81 and a lower mold 82, and only the upper mold can be moved in the vertical direction by a mechanism not shown.

First, as shown in FIG. 1, a mixed and kneaded extrusion molding material 2 is supplied from a hopper 10 of an extruder 1.

As the molding material 2, for example, one having the following composition was used.

(A) Hydraulic inorganic material Portland cement 100 parts by weight (B) Reinforcing short fiber vinylon short fiber 1 part by weight Polypropylene short fiber 2 parts by weight (C) Water retention agent methylcellulose 2 parts by weight (D) Aggregate fly ash 40 parts by weight Silica hume 5 parts by weight (E) water
35 parts by weight The molding material 2 supplied from the hopper 10 is transferred by the first stage screw 11 to the vacuum chamber 1.
3, after air bubbles drawn in during mixing and kneading are degassed, the mixture is transferred by the second screw 12 and extruded through the mold 14 to form the elongated molded body 3.

Next, this extrusion molded body 3 is cut by a cutter 15 and placed on a tray 5 that is sequentially fed onto a transfer device 4. As shown in FIG. 3, the tray 5 used had a stucco-like pattern 52 formed on the placement surface 51, and further formed with protrusions 53 forming joints in the shape of the final product.

The extrusion molded body 3 placed on this tray 5 is conveyed together with the tray 5 to the exit side (right side in FIG. 1) of the transfer device 4,
A vibrating sieve 6 placed above the outlet side spreads a dry powder substance 7 onto the upper surface of the extruded body 3 .

As the powder substance 7, for example, the following composition was mixed in a high-speed blender.

(A) Hydraulic inorganic material Portland cement 100 parts by weight (B) Aggregate fly ash 40 parts by weight Silica hume 5 parts by weight As described above, extruded molded body 3 on which dry powder substance 7 mainly composed of Portland cement is spread The trays 5 are sequentially loaded in multiple stages on a cart (not shown) or the like and transported to a pressing process. In the pressing process, as shown in FIG. 2, the molded body 3 is charged together with the tray 5 into the press mold 1 of an upper mold 81 and a lower mold 82 and press-molded, and a patterned surface is formed on the lower surface of the extruded molded body 3. form. When the press molding is completed, the upper mold 81 is moved upward and removed from the press molded body 3a. At this time, the press molded body 3
a remains placed on the tray 5 due to its own weight, and the upper surface of the demolded press-formed body 3a is pressed with the powder absorbing the moisture in the surface layer of the extrusion-molded body, making it sticky. It is formed on a beautiful surface with few scratches.

The press molded body 3a is taken out from the press die 8 along with the tray 5, and sequentially loaded in multiple stages onto another truck (not shown) or the like.
The material is transported to a curing process and hardened by causing a hydration reaction by steam heating. After curing and curing, the press molded body 3a is removed from the tray 5 to obtain a molded body of a blood vessel product having a pattern on the lower surface.

The patterned architectural accessory molded object thus obtained is the fourth
As shown in the figure, it is used as a corner material A at a projecting corner B of a building.

In the pressing process, it is preferable to interpose an elastic rubber sheet 83 such as urethane rubber between the lower mold 82 and the tray 5 to perform press molding. With this elastic rubber sheet 83, even if the press molding time is short, it is possible to form a clearer pattern and improve the molding cycle.

(Effects of the Invention) Since the method for manufacturing an inorganic molded body of the present invention is configured as described above, when a dry powder substance is sprinkled on an uneffected extrusion molded body before press molding, The powder substance adheres to the surface exposed from the tray, and the surface of the extrusion molded product becomes less sticky, so that the upper surface of the molded product does not stick to the upper mold even when press molding is performed. Therefore, when the upper mold is removed from the press-formed body after press molding, a part of the molded body does not adhere to the upper mold, resulting in excellent mold releasability and a gradual reduction in the molding defect rate.

In addition, since the extruded body is coated with the attached powder substance, the surface layer of the extruded body is prevented from evaporating moisture, and the occurrence of cranks during press molding due to natural drying is reduced.
You will have more time to wait for the press. Therefore, when performing the process in batch mode, it is efficient because it enables large-volume processing.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of the apparatus used in the extrusion process used in the method for producing inorganic molded bodies of the present invention, FIG. 2 is a cross-sectional perspective view showing the state of press forming in the press process, and FIG. FIG. 4 is a perspective view showing a state in which an example corner material obtained by the manufacturing method of the present invention is used. Explanation of symbols l...Extruder, 2...Extruded material, 3...Extruded body, 3a...Pressed body, 4...Transfer device, 5...Tray 7...Powder material, 8...Press Mold, 81...upper die, 82...lower die.

Claims (1)

[Claims] 1. Using extrusion molding material whose main component is hydraulic inorganic material,
An extrusion molded product in an uncured state is produced by extruding it into a long shape and cutting it into approximately regular lengths using an extrusion molding method, and then the molded product is placed in a press mold and press-molded. In a method for producing an inorganic molded body to be demolded, while the extruded body is in an uncured state, a dry powder substance containing a hydraulic inorganic substance as a main component is sprinkled on the surface of the extruded body, and A method for producing an inorganic molded article, the method comprising: