JPH06234108A - Pressing of cement product with embossed pattern - Google Patents

Abstract

PURPOSE:To obtain a method of pressing a cement product with an embossed pattern which can be impressed well linearly and easily, if the embossed pattern is deep. CONSTITUTION:When impressing an embossed pattern on the surface of a cement product by a press immediately after molding, a hermetically sealed space S is provided between a die 1 and the surface of a molding C, then the die 1 is lowered to press the surface of the molding G after making an internal pressure of the hermetically sealed space negative. This creation of the negative pressure in the space prevents an impediment attributed to the entrapping of air from occurring. Further, it prevents a suction hole from becoming plugged due to the suction of air in a non-contact condition with the surface of the molding.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for pressing a concavo-convex pattern on a cement product. It relates to the improvement of the press mold for adding patterns.

[0002]

2. Description of the Related Art Heretofore, it has been widely practiced to extrude cement-kneaded products to produce extruded products having various cross-sectional shapes. This molding method has an advantage that a product having an arbitrary cross section can be continuously molded by changing the cross-sectional shape of a molding die for extrusion molding, and various products with excellent design characteristics can be mass-produced. However, this cross-sectional shape is a uniform shape that is continuous in the extrusion direction, and if you want to add an uneven pattern that is not continuous in the extrusion direction, contact the extruded product surface with, for example, an uneven roll, and synchronize with the extrusion speed. It must be rotated by, or by means of patterning with an uneven patterning press.

[0003]

[Problems of the prior art] However, when an uneven pattern is formed by a roll, in the case of a deep uneven pattern, the interference of a convex type with a concave pattern occurs, and a sharp uneven pattern is not formed. In this case, since the molded product has a fluidity due to the addition of methyl cellulose or the like immediately after extrusion and thus has a deep uneven pattern, even if the press is pressed with a strong compressive force,
The material flows in the width direction and escapes, and since air is trapped inside the inner surface of the mold recess, it is impossible to form a deep uneven pattern. In particular, when an uneven pattern like brickwork is applied, the linearity of the groove portion cannot be obtained due to the escape of these materials, and it is difficult to obtain a product with a sharp uneven pattern of uniform appearance. It was

Further, in the case of the above-mentioned pressing, depressurizing holes may be provided on the pressing surface so that the air trapped in the inner surface of the mold is discharged to the outside. In this case, cement particles and the like are degassed depending on the pressing pressure. However, there is a problem in that the manufacturing efficiency is very poor, because it causes clogging and causes clogging and requires the removal work of these.

[0005]

SUMMARY OF THE INVENTION In view of the above problems, the present invention has been made for the purpose of providing a method for pressing a concavo-convex pattern of a cement product which can easily form a deep concavo-convex pattern.

[0006]

[Means for Solving the Problems] That is, the method for pressing the unevenness pattern of a cement product according to the present invention is such that when the unevenness pattern is formed on the surface of the cement molded product immediately after molding by pressing, the mold and the surface of the molded product are separated from each other. The space is made a closed space, and the closed space is made a negative pressure space, and then the surface of the molded product is pressed by the mold.

[0007]

According to the method for pressing the unevenness pattern of the cement product of the present invention, when pressing the unevenness pattern on the surface of the uncured cement molded body, a closed space is provided between the press die and the surface of the molded product prior to pressing by the press, The inside of this closed space is made negative pressure, and then the surface of the molded product is pressed by the mold. Therefore, when pressing, there is very little or almost no trapped air between the molded product and the press die surface,
These obstacles are completely eliminated. Further, since the negative pressure in the closed space is performed before the press die is brought into contact with the surface of the product, neither cement particles nor the like is sucked from the air suction hole, and clogging does not occur.

[0008]

Embodiments of the present invention will be described below. FIG. 1 is a sectional view showing a pre-pressing step of the method of the present invention, and FIG. 2 is a sectional view showing a step at the time of pressing.

[Example 1] Cement 47.5% by weight, silica sand 4
A cement mixture consisting of 7.5% by weight and 5% by weight pulp fiber, 22.5% by weight of methylcellulose and 12.5% by weight of the cement mixture was extruded to obtain a thickness of 2c.
A band-shaped compact G having an m and a width of 30 cm was formed.

As shown in FIG. 1, on the surface of the band-shaped molded body G, a mold surface of 30 cm × 90 cm, a difference of unevenness of 8 mm, a pitch of 6 cm × 9 cm, and a continuous brickwork-like unevenness having a width of 8 mm at a pitch of 6 cm × 9 cm. As shown in FIG. 1, the mold 1 to which the pattern is attached faces the molded product G, and first, the cylinder 1A surrounding the mold 1 is lowered to move the mold 1
A closed space S is formed between the molded product G and the molded product G, and the closed space S is sucked from the suction deaeration hole 3 provided in the mold 1 to 0.5 Torr.
The following negative pressure space was used.

Next, as shown in FIG. 2, the mold 1 is lowered to form an uneven pattern on the surface of the molded product G, and then the deaeration hole 3 is used at the time of releasing the mold.
The reverse injection was performed from 3 and the mold was released. A plate-shaped molded product having a brickwork-like uneven pattern having a deep and sharp uneven pattern with a joint depth of 8 mm could be molded.

The mold 1 is constructed such that the bottom surface of the concave portion 1A for molding a convex brick portion on the surface of the molded body G is constituted by filters 2 and 2 which are finer than the cement particles, and the mold 1 is connected to the outside for communication. The mold body plate 1C having a large number of pores 3 ... 3 fixed to the surface of the molded body G via ridge bars 1B and 1B for forming recess joints was used.

In the embodiment, 1D is a checker plate constituting the mold 1, 1E is the same punching plate,
4 and 4 are bolts for fixing the projecting bar 1B and the filter 2, G1 is a product pallet, and 1F is a lower frame.

[Embodiment 2] Cylinder 1 in Embodiment 1
As shown in FIG. 3, in place of the mold having A, a mold 1 is provided around the mold 1 with a frame 1F having a height corresponding to the thickness of the molded product G. The frame 1F is made of rubber having a thickness of 1 mm. Using the mold with which the seal 1H is in contact, first lower the mold with respect to the molded product, temporarily stop the mold 1 with the frame 1F slightly biting into the surface of the molded product, and set the inside of the mold to a negative pressure of 0.5 TorrL or less. A pressure space was created, and then pressing was performed in the same manner as in Example 1. A plate-shaped molded product having a brickwork-like uneven pattern having a deep and sharp uneven pattern with a joint depth of 8 mm could be molded.

As a comparative example, a press die having no vent holes was provided with the same unevenness pattern as in the embodiment, but the linearity of the joint was poor due to the escape of the material, and the contour of the unevenness was clearly defined by the air pressure trapped in the recess. Only uneven patterns could be formed. Further, in the case of molding with a framed press, the contour of the concavo-convex pattern became less clear than in the comparative example due to the air trapped in the frame.

[0016]

EFFECTS OF THE INVENTION The method for pressurizing the surface of a cement product according to the present invention is such that, when the surface of the product is subjected to the concavo-convex press, a closed space is provided between the mold and the product surface before the mold is lowered and suction degassing is performed. After making the negative pressure space, the press is lowered to add an uneven pattern, so the patterning obstacles caused by air entrapment are removed and it is possible to easily create an uneven pattern with deep engraving and good linearity. It becomes. Also,
In the present invention, the closed space is evacuated in a state where the mold is not in contact with the surface of the molded product, so that there is no clogging due to cement particles in the suction and deaeration holes, and the production management is greatly simplified.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a process before pressing according to the present invention.

FIG. 2 is a cross-sectional view showing a step during pressing according to the present invention.

FIG. 3 is a cross-sectional view showing a process before pressing of another example.

[Explanation of symbols]

 G ... Molded body 1 ... Mold 1A ... Cylinder 1F ... Frame S ... Sealed space 3 ... Suction degassing hole

Claims (1)

[Claims] 1. When the surface of a cement molded product immediately after being molded is provided with a concavo-convex pattern by a press, a closed space is formed between the mold and the surface of the molded product, and a negative pressure space is formed in the closed space. A method for pressing a concavo-convex pattern on a cement product, which comprises pressing the surface of the molded article with.