Two-component polyurethane for molds: overview, features and reviews

Two-component polyurethane is a polymer that is made by mixing two ingredients. The first are isocyanate compounds, whereas the second may be compounds of the hydroxyl group. Elements interact, resulting in a polymer with a polyurethane structure.

Varieties of polyurethane

To obtain the polymer it will be necessary to mix the hardener and the substrate in certain proportions. Two-component polyurethane can be a cold and hot polymerization species. The latter version of the material requires exposure to an elevated temperature, whereas the former is polymerized at natural temperature.

Key Features

The described materials used for molds have high strength characteristics, they are resistant to aggressive media and harmful effects, as well as high temperatures. All these features expand the field of use of polyurethane. It is suitable for production:

• Paints;
• Glutinous compositions;
• Sealants;
• Varnishes.

After mixing the components, the composition acquires an excellent fluidity, which makes it possible to manufacture parts from it by casting technology. As an example, one can distinguish bushings for mechanisms. In the article we are talking about a two-component polyurethane casting variety. The material properties are determined by the source components. The composition of the isocyanate hardener and the base is important.

Additional features

The properties of the material can vary depending on the addition of various substances, for example, fillers and colorants. Some polyurethanes replace rubber, because they are highly elastic. You can find polyurethanes, which are able to restore the original shape with mechanical damages, this makes them especially valuable in the industry.

Overview of application areas

Two-component polyurethane has found wide distribution today. Used material for the manufacture of jewelry, various mechanisms and casting gears. The operational properties of the parts produced are quite high. This allows the material to be used even in difficult conditions. As a result, it is possible to obtain viscous, hard and chemically resistant parts. As the last can act:

• Gears;
• Shafts;
• Pulleys;
• Wheels;
• rollers;
• Toothed belts;
• Sealing elements;
• Various protective coatings;
• Couplings;
• Pipelines;
• Details of bearings;
• Bushings.

The parts are ready to serve qualitatively and for a long time, because they are resistant to wear and have high strength. The liquid, flexible two-component polyurethane is the basis for wheels for trucks and forklifts. As a result, it is possible to obtain products that are much stronger than rubber. They are ready to work even if the tread is damaged.

The material forms the basis of support and guide rollers, which are operated together with belt conveyors and conveyors. Elements are ready to last much longer than rubber belts, caterpillars and tracks.

The material is used for shock absorbers and sealing elements, because it is more resistant to wear and durability. That is why rubber parts have recently been replaced with polyurethane ones. Elasticity remains at the same level. Two-component injection molded polyurethane has found application in the production of pipelines, which are characterized by chemical resistance and strength. Elements are obtained as a whole. In addition, with the help of the material it is possible to protect the pipelines not only from the inside, but also from the outside.

Feedback on additional areas of use

According to consumers, two-component polyurethane is used in the production of adhesive compounds and varnish-and-paint products. The mixture after polymerization turns out to be resistant to external negative influences, is firmly held and ready to last for a long time. Liquid polyurethane is particularly often used in the manufacture of molds, which are performed using casting technology. Subsequently, such products are used for casting:

• Concrete;
• Polyester resins;
• Wax;
• Gypsum.

According to consumers, liquid two-component polyurethane is also used in the field of medicine, where the material is the basis for removable dentures. Polyurethane is often used also in the manufacture of jewelry. From it you can even pour floors that are characterized by durability, resistance to wear and high resistance to stress.

According to consumers, in some areas, polyurethane parts exceed steel by a number of parameters. However, the manufacturing process is much simpler, which allows you to get miniature parts and massive castings at the output, the first of which can weigh not more than a gram, while the latter can have a mass of 500 kg or more.

In addition to mold polyurethane

Two-component polyurethane for molds is able to withstand a certain number of castings. If it is a question of ordinary marks, then the casting of a stone can be carried out 1200 times a minimum. If the best materials were used in the production process of the mold, and the requirements for the preparation of the mixture were met, the mold will be ready to withstand up to 4000 castings. This is also true for the case when the form was confirmed by vacuum treatment, and was also used for pouring not very abrasive, aggressive and adhesive materials.

Having become acquainted with the assortment of the international market, you will be able to understand that polyurethane today is represented by several brands, among them:

• Volccoprens;
• Volcollans;
• Adiprene;
• Pomogolds.

If you prefer Russian brands, you should choose SIC-PU 5, SKU-PFL-100. They are made of polyester domestic production, and the quality is no worse than foreign analogues. Moreover, by some parameters they are leading.

Polyurethane grades are distinguished by their chemical composition, the number of urethane groups, the construction of the polymer chain, and the molecular weight of the material. The properties can be regulated by careful selection of the raw materials. As a result, it is possible to obtain branched and cast chains of polymers.

Additives for polyurethane for molds

Two-component polyurethane for molds can be supplemented with different substances, namely:

• Modifiers;
• Fillers;
• Dyes.

They are necessary to improve the quality of the composition. For example, to speed up the reaction, modifiers are used, which are added to small products. As for the pigments, they are able to change the appearance of the element by the method of color correction. In order to reduce the content of plastic, fillers are used, which make it possible to reduce the cost of products.

Fillers can be:

• talc;
• a piece of chalk;
• Technical carbon;
• Chemical, glass, carbon fibers.

However, this list can not be called complete. Polyurethane molds for stone have color shades from light yellow to brown. If you use special additives, you can get almost any color.

Conclusion

Polyurethanes today have found their application in almost all areas of industry. The material is also used in everyday life. As one of the promising directions is a liquid two-component polyurethane. Its use simplified and accelerated the work on casting from concrete and gypsum. With the help of polyurethane it became possible to produce small architectural forms, paving slabs and decorative elements even at home.