CN108274589B - Method for making decorative concrete products - Google Patents

Abstract

The invention discloses a method for manufacturing a decorative concrete product, which solves the problems of complex process and poor pattern forming fineness of the existing concrete surface pattern modification method. The technical scheme comprises the following steps of preparing concrete decorative paper: coating a film on one surface of the paper, and partially coating a film on the other surface according to a design pattern to obtain concrete decorative paper; the paper is absorbent paper, and the membrane is a hydrophobic membrane; paving the concrete decorative paper at the bottom of the mould, and enabling one surface of the film with the pattern to face upwards; pouring concrete in the mould; maintaining, hardening and then removing the mold; finally uncovering the concrete decorative paper; and washing the surface of the concrete product with the torn concrete decorative paper by using water to obtain a pattern on the surface of the concrete product. The invention has simple process, low production cost, easy operation and high pattern forming precision.

Description

Method for making decorative concrete products

technical field

The invention relates to the technical field of concrete decoration, in particular to a manufacturing method of a decorative concrete product.

Background technique

In the nearly two hundred years since the advent of concrete, in most cases, it has been developed with its advantages of high strength, low cost and durability. It seems that the concrete itself has no decorative effect. It needs to be covered up with materials such as tiles and plaster to make the building complete. If the concrete itself is decorative, it can save the cost of building surface construction and decoration, and it has an original and natural beauty.

Based on this situation, some people began to use fair-faced concrete. Fair-faced concrete is a kind of concrete in which concrete is directly exposed as a decorative surface after molding. It doesn't need any exterior decoration, the concrete itself is the decoration. This can be said to be a big leap. However, fair-faced concrete has relatively high requirements for construction, especially maintenance. For example, in the same project, the cement must be fired in the same furnace to keep the color of the cement consistent. Sand and stone fields must be protected separately to ensure stable quality. The curing process of fair-faced concrete is also strict, otherwise it is easy to cause color difference on the surface of the concrete. Therefore, in general, my country's existing construction background is difficult to promote fair-faced concrete on a large scale. Others are starting to use other decorative concretes. But the current cement decorative panel, the change of its shape and style, mainly depends on the shape change of the concrete mold. There are steel molds, wooden molds, plastic molds, etc., and there are many patterns. The characteristic of this method is that in order to obtain concrete of different patterns, it is necessary to have molds of different patterns. Obviously, such a process has high cost, difficult mass production, long cycle and large waste. This is also the reason why it has not been promoted in the country.

Based on this situation, it is reported that the use of transfer printing technology to do concrete veneer. Its transfer technology is realized by printing the retarder on the PVA base film. Including the examples listed in this document, the retarder is usually a water agent, and after such a liquid retarder is printed on the base film by screen printing, the liquid retarder will change during the concrete pouring and vibrating process. The pattern formed by the agent on the concrete, the retarder is extremely easy to diffuse, migrate and change shape, resulting in insufficient local retarder, unable to achieve the retarding effect, unable to obtain the pattern, or the retarder migrates or changes shape, It directly leads to the deformation of the final pattern, which affects the fineness of the pattern.

SUMMARY OF THE INVENTION

The purpose of the present invention is to solve the above-mentioned technical problems, and to provide a method for making decorative concrete products with extremely simple process, easy operation and high pattern forming precision.

The technical solution includes the following steps:

a. Preparation of concrete decorative paper: one side of the paper is fully covered with film, and the other side is partially covered with a film according to the design pattern to obtain concrete decorative paper; the paper is absorbent paper, and the film is a hydrophobic film;

b. Lay the concrete decorative paper: lay the concrete decorative paper on the bottom of the mold, so that the side of the film with the pattern is facing up;

c, pouring concrete: pouring concrete in the mold;

d. Curing and demoulding: After curing and hardening, demolding is done to obtain concrete products;

e. Uncover the concrete decorative paper: tear off the concrete decorative paper from the surface of the concrete product;

f. Rinse with water: Rinse the surface of the concrete product with the concrete decorative paper torn off with water, so that part of the aggregate is exposed, and a pattern is obtained on the surface of the concrete product.

The Cobb value of the paper is 15 to 400 g/m ² .

The Cobb value of the paper is optimally 30-300 g/m ² .

The thickness of the paper is 0.02-0.5 mm.

The thickness of the film is 0.005 mm to 0.030 mm.

In view of the problems existing in the background technology, the inventor creatively changed the way of thinking, and skillfully used the combination of paper and film to solve the above-mentioned technical problems. The side of the film with the pattern is facing up. After the concrete is poured, the concrete is partially in contact with the film and partially in direct contact with the paper. Since the paper is absorbent, it will absorb the water in the cement layer in contact with the paper. The cement-water-cement ratio of the water layer in the area is reduced and cannot be coagulated; while the concrete cement layer in other areas in contact with the membrane can be coagulated normally. After demoulding, rinse with water, and the cement layer in the uncondensed part is washed down, exposing the aggregate, other Areas with no exposed aggregates create visual contrast to form patterns. In the method of the present invention, the conventional thinking of using retarder and coating and printing technology is completely abandoned, and the ingenious water absorption principle of paper not only greatly reduces the operation difficulty and production cost, but also solves the problem of coating liquid retarder. Diffusion, migration, changing shape, etc.

Further, the water absorption Cobb value of the paper is preferably 15-400 g/m ² , more preferably 30-300 g/m ² , too high will cause the paper to absorb too much water, and the concrete pattern will be too deep to affect the appearance and fineness, and too low. It will cause the paper to absorb too little water, making it difficult for the pattern part to contrast with the non-pattern part, affecting the fineness of the pattern, and even failing to form a pattern. The thickness of the paper is preferably 0.02 mm to 0.5 mm. Too high a thickness will result in too strong water absorption of the paper, which will ultimately affect the fineness of the concrete pattern. Too low a thickness will result in too weak water absorption of the paper, which will ultimately make the concrete unable to form a pattern. The film is a hydrophobic film, such as BOPP (biaxially oriented polypropylene film) or BOPP/PE (polyethylene) or BOPP/CPP (cast polypropylene);

Beneficial effects:

The method of the invention is extremely simple and ingenious in design. The water absorption property of the paper is used to absorb the water of the poured concrete cement layer, so that the cement layer cannot be coagulated, so that the pattern can be easily formed by washing with water after the concrete product is released from the film. The production cycle is short, the production cost is low, and the pattern with clear and accurate lines and uniform etching depth can be formed on the concrete, which has a broad market prospect.

Detailed ways

Process example:

a. Preparation of concrete decorative paper: one side of the paper is fully covered with film, and the other side is partially covered with a film according to the design pattern to obtain concrete decorative paper; the paper is absorbent paper, and the film is a hydrophobic film;

b. Lay the concrete decorative paper: lay the concrete decorative paper on the bottom of the mold, so that the side of the film with the pattern is facing up;

c, pouring concrete: pouring concrete in the mold;

d. Curing and demoulding: After curing and hardening, demolding is done to obtain concrete products;

e. Uncover the concrete decorative paper: tear off the concrete decorative paper from the surface of the concrete product;

f. Rinse with water: Rinse the surface of the concrete product with the concrete decorative paper torn off with water, so that part of the aggregate is exposed, and a pattern is obtained on the surface of the concrete product.

In the above process steps, ordinary Portland cement with a strength grade of not less than 42.5 is used for the concrete.

To quantify the final pattern effect, the rate of change of the final concrete surface pattern from the original pattern is tested. The specific method is to fill the pattern area with dry flour particles, and remove the flour in the non-pattern area, so that the pattern area is white, and the non-pattern area is concrete gray. At this time, take pictures of the concrete, process the graphics with computer software, and compare with the original images to obtain the graphics change rate.

The process steps of embodiment 1-9 are the same as above, wherein water absorption, paper thickness and film thickness and product forming pattern effect evaluation are shown in Table 1:

Table 1 Characteristics of concrete decorative paper and pattern effect of decorative concrete

Comparative example:

The coated surface of the single-sided coated coated paper is printed with liquid retarder according to the pattern, and the coated surface is facing up. The rest are the same as the above steps to prepare decorative concrete. After many experiments, it is finally obtained that the deformation of the concrete pattern cannot be distinguished and diffuse The situation is serious and the depth is inconsistent. The average pattern change rate measured by the same test method is 89%, and the index does not meet the design requirements.

Evaluation of results: After the above procedures, the concrete pattern obtained in this example is clear and fine, without diffusion, the depth is relatively consistent, and the indicators meet the design requirements. However, the liquid retarder in the comparative example cannot form a film, which not only increases the difficulty of the construction process, but also makes it difficult to avoid the occurrence of problems such as diffusion, migration, change of pattern area, and uneven depth. Comprehensively comparing the pattern change rates of Examples 1 to 9 and the Comparative Example, the pattern change rate of the Example is 80% lower than that of the Comparative Example, that is, the degree of fineness is greatly improved.

Claims (3)

1. a preparation method of decorative concrete product, is characterized in that, may further comprise the steps: a. Preparation of concrete decorative paper: one side of the paper is fully covered with film, and the other side is partially covered with a film according to the design pattern to obtain concrete decorative paper; the paper is absorbent paper, and the film is a hydrophobic film; b. Lay the concrete decorative paper: lay the concrete decorative paper on the bottom of the mold, so that the side of the film with the pattern is facing up; c, pouring concrete: pouring concrete in the mold; d. Curing and demoulding: After curing and hardening, demolding is done to obtain concrete products; e. Uncover the concrete decorative paper: tear off the concrete decorative paper from the surface of the concrete product; f. Rinse with water: Rinse the surface of the concrete product with the concrete decorative paper torn off with water, so that part of the aggregate is exposed, and a pattern is obtained on the surface of the concrete product. 2 . The manufacturing method of a decorative concrete product according to claim 1 , wherein the thickness of the paper is 0.02 mm to 0.5 mm. 3 . 3 . The method for manufacturing a decorative concrete product according to claim 1 , wherein the film has a thickness of 0.005 mm to 0.030 mm. 4 .