What are polyurethane molds for artificial stone. Polyurethane molds by hand

Natural stone is a valuable material for interior decoration. However, its price is high. Qualitatively simulated artificial stone for a common man in the majority of cases is indistinguishable from natural products. At the same time, it costs less, weighs less and can have a variety of textures. Modern polyurethane molds and innovative color technologies can turn ordinary concrete or gypsum into an exclusive material, in appearance and quality, almost inferior to the natural product.

Material for molds

For the production of quality molds that can accurately convey the texture of natural material, polyurethane rubbers have recently been used. This unique material is characterized by wear resistance, elasticity, corrosion resistance, withstands significant mechanical loads.

Polyurethane molds are produced by cold polymerization. Raw materials for forms are two-component polyurethane compounds. Despite the apparent simplicity of the technological process, it takes a lot of experience to manufacture the matrices, because the quality depends on the shape of the finished product.

The cost of the finished form at times exceeds the cost of raw materials for the manufacture of the matrix. The perfectly made form is capable of copying with an incredible accuracy even the imprint of a human hair on the casting.

Manufacturers of polyurethane

To date, the world produces more than two hundred different polyurethane compounds. For the production of artificial stone, shapes are needed that combine the optimal density, strength, elasticity and casting consistency.

Two-component Ecomould compounds have medium flow (the consistency of liquid honey), suitable for the production of artificial stone with small negative angles. Compounds are relatively inexpensive and suitable for small runs of concrete products with a simple relief.

Polyurethanes from VytaFlex Series are characterized by greater elasticity, good wear resistance, a wide choice in strength characteristics. The use of matrices from such compounds makes the process of molding products easy and fast even without the use of separating compounds.

Polyurethane molds from Duramould and LEPTA-108 CX compounds are suitable for gypsum castings, they also withstand alkaline media of concrete, are adapted for manual mold making without the use of vacuum degassing.

Advantages of polyurethane molds

Polyurethane molds for artificial stone have a number of advantages. Thanks to their elasticity, they make it possible to easily extract finished castings with minimal waste products. Compared with plastic forms, concrete products in elastic forms can be kept half the time.

Due to precise detailing of the face surface of the copied sample, it is possible to achieve the similarity of the finished product with the texture of the bark of trees, the petrified bone, antique fresco and other materials. Forms are durable, even with an intensive production mode, their safety factor is sufficient for 2 - 3 years of operation.

You can expand the range of products, using as raw materials concretes and modified gypsum. The ability of the polyurethane to retain the dye particles on the surface of the molds combines the painting process with casting the matrix with the molding material.

Selecting a form

Polyurethane is a capricious material. To ensure the quality of the mold from such material, you need a lot of experience in the manufacture of matrices, you also need to know the subtleties of the process, observe polymerization regimes, and use proven compounds from leading manufacturers of injection molded polyurethanes.

The choice - to buy a ready-made matrix or to manufacture it yourself - depends on many factors. To make perfect polyurethane molds for stone at home without experience is quite difficult. Since raw materials are not cheap, it is better not to experiment, but to purchase a ready-made matrix. This option is suitable, if there is confidence in the professionalism of producers.

On the other hand, making molds independently, in due course it is possible to acquire the necessary experience and not depend on the available assortment of finished products, but it is easy to expand it by manufacturing new types of finishing materials that competitors will not have.

Manufacture of a matrix with own hands

To make polyurethane molds with your own hands, you need an artificial stone or samples of natural material and a two-component molded polyurethane. To produce the frame, it is necessary to prepare a straight piece of MDF or chipboard according to the size of the mold and the length of the boards for the sidewalls.

On the surface of the plate with sanitary silicone are attached copied samples of stones. The distance between them and from the samples to the side walls should not be less than one centimeter. Further, formwork is assembled from the boards. The joints of the frame are sealed with silicone. Samples and formwork are treated with a release agent.

The polyurethane is prepared as follows: the components are measured in separate containers according to the instructions and mixed without foaming until homogeneous by a low-speed drill with a nozzle. The finished solution is poured on top of the samples above the level of stones by 1 to 3 cm. After settling for 24 hours, the formwork is disassembled, the samples are taken out of the mold and the time necessary for the process is allowed to settle.

Forms of industrial manufacturing

To organize the industrial production of forms tried repeatedly, but the complexity of detailing the surface of the material being copied made little effort. Nevertheless, serial production of molds for artificial stone on machine tools was established.

Such a technological process was mastered by the company Zikam Stone. Polyurethane molds produced by its technology are almost half the cost of similar import matrices. Some characteristics of the molds even surpass the samples from the leading manufacturers working on the cold polymerization technique.

Molds made by machine are characterized by stamping on the back (rough) surface of the matrix. Regular casting molds can be labeled only on the front or side surfaces.

Choosing a Qualitative Matrix

If it is decided to purchase industrial polyurethane molds for the production of artificial stone, special attention should be paid to their rear side. In a qualitative matrix, it should be smooth without the slightest porosity.

The presence of traces from the bubbles of the outgoing air will indicate the air saturation of the entire thickness of the matrix. This form will not last long. To determine the strength, you can try to pinch a piece of material from the matrix - a quality polyurethane will actively resist this. The cut thin strip from the sample of the matrix under tension is torn with effort.

It makes sense to buy a matrix to insist on a trial fill in the presence of the seller fast-hardening composition. The cast specimen should have a clear relief of natural stone without polished smoothness and gloss. Unnecessarily thick bridges and sidewalls (up to 3 - 5 cm) will indicate the substitution of polyurethane with a similar material with similar properties.

Polyurethane molds from "Zikam Stone"

Sidewalk tile for rubble stone, imitation of marble, limestone, sandstone, composition of slate, decorative brick and stone veneer - all this is possible with the technology of "Zekam Stone." Polyurethane molds made by the specialists of this company are ideal for the production of artificial stone based on cement. From gypsum it is possible to make an original stucco molding, a mosaic, moldings and bas-reliefs.

For those who want to try their hand at making artificial stone, Zikam Stone offers materials for home making of polyurethane matrices. Economy class kits are available that contain, in addition to the basic casting molds of polyurethane, detailed process instructions, modifying additives and pigments for gypsum. The "Standard" class equipment, in addition to the listed materials, also has a sample for painting and additional technological equipment. The "Premium" package also includes a professional airbrush and matrix pallets.

High-quality polyurethane molds "Zikam" even in a small private workshop make it possible to establish the production of artificial stone. With the proper quality of products and moderate prices, such a business can compete even with factory production.