The development of modern science does not stand still. Together with it, as already known materials are improved, so new ones appear. The basis, as a rule, without ...

Polyurethane. What is this material, its properties and applications

By Masterweb

The development of modern science does not stand still. Together with it, as already known materials are improved, so new ones appear. As a rule, synthetic polymers, such as polyurethane material, are taken as the basis. What kind of substances they are and what application they have found in all spheres of life and production, we will find out a little later. Physical and technological characteristics make it possible to use them even in the most critical industries: mechanical engineering, the manufacture of insulators and fasteners. Without them, it is simply impossible to imagine the daily life of a person.

For a step forward

Despite constant development, the urgent need for new quality materials remains very high. Modern life requires a huge variety of different substances: plastic and solid, stretchable and durable. They must withstand stress, temperature extremes, aggressive operation.

This need is forcing scientists to experiment with the synthesis of polymeric compounds, with the compatibility of inorganic and organic components in an attempt to obtain more versatile compounds. Polyurethane is such a polymer. It has a whole set of unique properties that have made it one of the most actively used in almost all spheres of life and production.

What is this material: polyurethane?

First, it is worth understanding in more detail the substance itself and why it is called thermoplastic.

This polymer compound combines the hardness of durable plastic with the ductility of natural rubber. It appeared only in the middle of the last century, thanks to the efforts of scientists from the United States who were able to synthesize it. The physical characteristics of this material are directly dependent on the main component.

Basic raw material

There are several types of raw materials from which polyurethane material is produced for the sole. These are simple and complex polyesters, as well as aliphatic isocyanate.

Now that we know what kind of material it is - polyurethane, we need to figure out its possible compositions.

If a polyether (propylene and ethylene oxide, isoprene) has a larger percentage in the basis of a substance, then the final substance becomes more resistant to the hydrolysis process, and also receives increased frost-resistant and wear-resistant characteristics.

Polyester bases (linear products of phthalic acid) give the final substance the following features:

• increase in tensile strength;
• increased wear resistance;
• the ability to restore the original shape.

For wheels, the polyurethane material based on the latter component receives increased UV resistance and ductility, even at sub-zero temperatures.

The main method for obtaining this substance is casting from granulate. The final elastomer can be in two states: viscous liquid and solid. Solids can be both crystalline and amorphous (i.e., have only a short-range order of atomic structure).

Glycols, water, glycerol ether or castor oil are used to lengthen and structure the chains. These reagents set the molecular weight for linear polyurethanes.

The catalyst for the formation of polyurethane can be tertiary amines, compounds of beryllium, iron, vanadium or copper, as well as lead or tin naphthenates.

The main feature of the substance

Finished products made from polyurethane material (insoles, for example) have different final properties, which may vary for each application. The key feature is the ability to set and correct the necessary parameters at the initial stage of obtaining the material. This contributes to the ever-increasing expansion of the scope of its use.

If you do not pay attention to the predominant component that underlies thermoplastic polyurethane, then the resulting material also has a whole set of common properties.

Key Features

Firstly, this substance has stamina and endurance and keeps its shape well. Secondly, its high strength under various deformations, such as stretching or bending, allows it to become indispensable in industries where the plasticity of the material comes to the fore. Thirdly, a good level of noise and vibration absorption makes polyurethane popular, for example, in mechanical engineering.

In addition, the substance can be subjected to coloring, which does not affect the wear resistance parameters, since the paint is applied not only to the top layer, but paints over the entire volume.

The temperature range of application of this elastomer ranges from -60 to +80 degrees Celsius.

Polyurethane, as a shoe sole material, is resistant to fats, microbes, bacteria, temperature extremes, sea water, aging, and mechanical stress. To increase the overall strength of the material, it can be coated with a layer of reinforced fiberglass. Solutions of polyurethane in organic solvents are converted into various types of high-strength adhesives.

And one very nice bonus: this substance can be recycled.

Application industries

The main areas of use for thermoplastic polyurethane are:

• Automotive industry;
• production of consumer goods;
• footwear industry;
• production of sporting goods;
• cable production.

In the automobile and mechanical engineering industry, this substance is used for the production of handles, shock-absorbing chassis mounts, mats, springs, visors, various toggle switches and switches, insulators. In some cases, decorative parts of the car interior are made from it.

In the areas of public consumption, soles, insoles and other similar components of shoes, tips for umbrellas and so on are made from it.

Polyurethane in the footwear industry

Polyurethane found its main use in everyday life in the shoe industry. Due to the basic qualities (frost resistance, elasticity, strength, durability and resistance to constant mechanical stress), excellent soles are obtained from it, especially for winter types of shoes. The ergonomics of this polymer is high along with antiseptic properties, which allows it to be used for the manufacture of insoles.

The production of goods for recreation and sports also cannot do without polyurethane. It is used to make wheels for roller skates, sports tires, bushings and gaskets, tips for skis, special sports boots for snowboarding and speed skating, wheels for skateboards, connecting elements and various fasteners.

Brief summary

Now that we know what kind of material it is - polyurethane, it's worth summing up. So, this elastomer is one of the most commonly used compounds. It is distinguished by a number of excellent technological, physical, chemical and structural characteristics, which ensure its use in a variety of industries and industries.

All these characteristics make the material cost-effective for mass production. At the same time, the costs of this process are quite modest both financially and in terms of time costs.

As a lining material, polyurethane is used for winding power cables and decorative elements of car interiors, for roller skates and insoles. The ability to set the necessary characteristics at the manufacturing stage allows you to expand the scope of this polymer and makes them almost limitless.

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Application for a product / service

(briefly PU) is a polymer characterized by elasticity, wear resistance. Polyurethane products are widespread in the industrial market due to a wide range of strength characteristics. These materials have replaced rubber products, as they can be used in aggressive environments, under high dynamic loads and in a wider range of temperatures. The operating temperature range for this material is respectively -60 °C - +110 °C.

In the industrial market, polyurethane is most often presented in the form of solid blanks (sheets, rods). But softer forms are also used - foamed forms of polyurethane, as well as material in liquid form.

Buy sheet polyurethane can be from 5 to 80 mm thick, sheet size - 50 × 50 centimeters mm. Rods - with a diameter of 20 - 200 mm with a length of 400 - 600.

Polyurethane products are a serious competitor to metal, plastic and rubber counterparts.

PU is a modern, popular and safe polymer. It is exploited to produce a variety of consumer, industrial products that make our lives more convenient and at the same time are environmentally friendly.

Properties, characteristics of polyurethane

Polyurethane (PU), characterized by high elasticity, viscosity, belongs to the group of elastomers. These materials are able to elongate under load (stretch) and return to their original state without structural change after the load is removed.

If we consider a pair of "polyurethane - rubber", then the first material is superior to the second in:

• elasticity - relative elongation at break of polyurethane is twice as high;
• strength - strength is twice as high;
• abrasion resistance - the wear resistance of polyurethane is three times greater;
• resistance to ozone - does not collapse when interacting with ozone.

Polyurethane sheets, rods, other products are distinguished by physical and chemical properties that determine the possibility of their use in various industries:

• polyurethane is neutral to a number of acids, solvents, so it is used: in printing houses (rollers for printing devices), the chemical industry, for the storage of chemical reagents;
• high hardness (about 98 units on the Shore scale) allows it to be used instead of metal where there are high mechanical loads. For example: for the manufacture of leading structural elements of tracked machines;
• the elastomer has a high impact strength, resistance to vibrations. These qualities allow it to be used for the production of drive belts, conveyor belts, springs, screens for screens in the mining industry, dampers, and other products;
• resistance to increased pressure makes it possible to use for the production of cuffs, rings, bushings, liners, high-strength seals;
• PU has low thermal conductivity. It retains elasticity at low temperatures down to -50 °C. It also works at temperatures up to 110°C and can even withstand a brief increase in temperature up to 140°C. This makes it possible to use the polymer for the insulation of refrigerated warehouses, the manufacture of polyurethane wheels or wheels gummed (rubberized) with polyurethane;
• Due to the resistance to gasoline and oils, the aforementioned rubberized wheels are more preferable in terms of service life than rubber and rubber ones. Also in terms of service life, polyurethane seals used in the oil industry win;
• polyurethanes are dielectrics, so the polyurethane coating provides not only water, thermal, but also electrical insulation;
• chemical inactivity, resistance to mold, microorganisms makes it preferable to use in the food industry, medicine;
• polyurethane sheets, bushings, rods, and other products are capable of being subjected to repeated deformations without changing their strength properties. Long service life, reliability make such products more in demand, in comparison with rubber counterparts. For various industries, it is possible to manufacture wheels, rolls, rollers, shafts with a polyurethane coating, as well as rubber mill drums or directly grinding surfaces.

Summarize. Polyurethane parts are little subject to the aging process, resistant to environmental influences, moisture, chemical elements, abrasive wear, and corrosion. By their properties, they are not inferior to metal, plastic and surpass rubber products.

Sheet polyurethane is a rectangular plate made of an elastic elastic polymer. The quality of polyurethane sheets is regulated by TU 84-404-78.

Methods for the manufacture of polyurethane sheets - pressing, extrusion (extrusion), casting. The surface of polyurethane sheet, depending on operational requirements, can have both anti-friction and anti-slip properties. Properties are determined by the chemical composition, structural features.

Most often, sheets are produced with a width of 0.1 to 0.2 m, a length of 1 to 1.5 m, a thickness of 20 to 300 mm. This size range can be changed at the request of the customer.

Most common molded polyurethane SKU-PLF, SKU-7L.

Consider the physico-chemical characteristics of cast polyurethane SKU-7L:

• tensile strength - 30 MPa;
• conditional stress when the sample is stretched up to 100% - about 2 MPa;
• operating temperature range - from -50 °C to 100 °C;
• hardness on the Shore scale - 75-85 units;
• polyurethane density - 1180 kg / m³;
• relative elongation - 450%.

The unique properties of PU sheet products (sheets, plates, plates), due to their durability, practicality, make them widely demanded in many industrial areas. So, for example, the following products are produced from sheet PU:

• construction industry - non-slip floor coverings; parts of facades resistant to vibration;
• design of machines, mechanisms - parts in contact with oils, tires, bushings;
• heavy industry - shock absorber parts, lining;
• light industry, for example shoe - soles for shoes.

Polyurethane rods

This is a cylindrical billet made of wear-resistant elastic polymer. The quality of polyurethane rods is comparable to TU 2226-001-37455706-2011.

The production methods of PU rods are similar to those of PU sheets: casting, extrusion, pressing.

Two main overall dimensions of the rods: diameter from 20 to 300 millimeters, length, which is determined by the indirect method according to TU 84-404-78. The main condition is that a workpiece of a certain diameter should not weigh more than 150 kilograms.

Unique properties polyurethane rods, due to the ability to synthesize polymers with different properties (for example, with different coefficients of friction), make them widely demanded in many industrial areas. So, for example, the following products are made from polyurethane rods:

• construction industry - facade elements, fasteners resistant to vibration loads;
• production of machines, mechanisms - parts in contact with oils, shafts, bushings, bearings;
• medicine - implants, prostheses;
• light industry, as an example - footwear, textile.

Foamed PU (foam rubber)

It is a porous, gas-filled 85-90% inert gas synthetic product. Depending on the method of production, composition - it differs in the degree of elasticity. It can be either soft (foam rubber) or hard, which is almost not subject to deformation.

Widely demanded in industry, construction two-component foam polyurethane- PPU, which is formed by mixing two components. The reaction proceeds very quickly - within 5-10 seconds, the foam foams, then hardens. The result is a light mass with low thermal conductivity, which does not rot, does not support independent combustion, is not exposed to moisture, alkalis, organic solvents, weak acids. Foamed polyurethane foam is very much in demand as a heater, sound insulation. Perfectly fills the pores, thus preventing the formation of cold bridges. It is used in a wide temperature range from -60°C to +140°C, practically does not change its properties over time.

Advantages, disadvantages

Used in industry along with other materials such as metal, rubber, plastic. One of the main advantages of PU is the ability to obtain a product with the required adjustable friction coefficient. It should also be noted strength, hardness, comparative lightness, the ability to elongate up to 650%. In addition, PU is a dielectric that is resistant to weathering and chemicals.

Polyurethane or metal?

Let's compare the pair "metal - polyurethane" to determine the positive properties of the latter. PU parts are more elastic, less heavy, resistant to abrasives. Does not conduct electricity, has soundproof properties. Polyurethane parts are more durable, cheaper than similar parts made of metal. The use of PU in production requires less investment during operation and repair, which leads to a reduction in the cost of the final product.

Polyurethane or rubber?

A pair of "rubber - polyurethane" reveals the following advantages of PU: resistance to high loads, pollution, oil; the ability to quickly restore shape after deformation; high elasticity.

PU or plastic?

And considering the pair "plastic - polyurethane", one can note the following advantages of PU: resistance to mechanical, impact, elasticity (even at low temperatures); resistance to abrasive compounds. It is also possible to form a thicker layer from polyurethane, if necessary, than from plastic.

The main disadvantage of polyurethane sheets, rods, and other products is the complexity of processing and waste disposal.

The material is unstable to the effects of such chemical reagents as nitric, phosphoric, methane acids. In addition, at high temperatures, PU can be destroyed by long-term interaction with alkalis. Polyurethane parts can change their physical and chemical parameters when operating in a temperature range different from the operating one.

A number of products that are made from PU have significant drawbacks. For example, shoes with polyurethane soles are considered "poorly breathable". And stucco molding, cornices made of foamed polyurethane can be easily damaged during operation due to the porous structure.

Polyurethane manufacturing

PU is produced by casting, pressing, extrusion, pouring on special equipment. The polyol and isocyanate included in the composition are products that are synthesized from petroleum.

The following types of elastomer are used in the industrial market:

• liquid, foamed (polystyrene, foam rubber);
• solid (sheet, rod, plate);
• sprayable (polyurea).

For the manufacture of solid PU, the most commonly used technology is injection molding or pouring a liquid molten mixture into open dies without pressure. Less commonly, to obtain solid PU, the extrusion (extrusion) technological process is used.

Price, dimensions, weight

The total cost of polyurethane sheets is determined by their thickness, dimensions, brand, manufacturer, total order volume, and other factors (for example, delivery). The wholesale price is always lower than the retail price. Wholesale cost of 10 mm polyurethane sheet (0.5 × 0.5 m) - from 1878 rubles. (import production) to 2160 (domestic). Plates with a thickness of 40, 50 mm are more expensive - 8600 and 10760 rubles / sheet, respectively, the dimensions are standard, 0.5 × 0.5 m. For a polyurethane sheet with a thickness of 80 mm in standard sizes, you will have to pay 14,800 rubles, the weight of the plate will be about 24.5 kg ).

Weight of polyurethane sheet measuring 0.5 * 0.5 meters (thickness, mm - weight, kg):

• 5 - 1,65;
• 10 - 3,12;
• 15 - 4,74;
• 20 - 5,9;
• 25 - 7,95;
• 30 - 9,2;
• 40 - 12,5;
• 50 - 15,5;
• 60 - 19,6;
• 80 - 24,5.

The wholesale price of polyurethane rods starts from 94 rubles / piece (length 0.5 m, diameter 20 mm, weight - 240 gr., imported). The cost of 1 kg of polyurethane rods (domestic) - from 690 rubles. A polyurethane rod with a diameter of 35 mm will cost 335 rubles. per piece, 50 mm - 665 rubles, 60 - 975, 80 mm - 1400 rubles, 100 - 2700, 150 mm - 6090, 200 mm - from 10810 rubles.

The price of foamed polyurethane starts from 400 rubles per kilogram.

Story

Experiments to obtain a universal product capable of competing with plastic, rubber, metal were carried out independently in the USA, Germany in the period from the 30s to the 40s of the last century. The American chemist W. H. Carothers invented artificial rubber and nylon, and the famous German chemist-technologist O. G. Bayer is considered the inventor of polyurethane. OG Bayer and his team synthesized flexible, hard elastomers-polyurethanes for the first time.

The industrial production of the material was started in Germany in 1944, in America more than ten years later - in 1957.

In the USSR, work on the problem of polyurethane synthesis began only in the 60s.

During the work, both domestic and imported products have undergone many changes aimed at improving quality, developing materials with unique characteristics.

Application

Polyurethane sheets, rods, bushings, and other products, due to their versatility, are used in various industries. Here is some of them:

• construction (thermo-, waterproofing panels, sheets, stucco, cornices);
• chemical industry (adhesives, sealants, varnishes, paints);
• paper, printing industry (rolls, rollers, surface coatings);
• production of machines, mechanisms (assemblies and parts of machines, seals, surface coatings);
• oil and gas (seals, oil-resistant valves);
• mining industry (sieves for screens, coatings and grinding parts of mills);
• radio electronics (insulating materials);
• light industry (thread bobbins, twisting rollers, adhesives, substrates);
• medicine (catheters, implants, prostheses);
• food industry (conveyor belts).

So, polyurethane rods, sheets, and other products in many respects surpass rubbers, ordinary plastics, rubbers, even metal in many respects in their technical characteristics, due to which the consumption of these products increases significantly every year. New application possibilities open up.

Polyurethane is one of the most popular multifunctional polymers and structural materials.

Polyurethane, application in clothing, is it reliable?

1. Polyurethane fibers are a stretchy synthetic fabric. Due to its composition, it can cause allergies. Included in many fabrics, it is widely used for the manufacture of tracksuits, swimwear, underwear, medical corsets, and more. Trade names for polyurethane are lycra, spandex, elastane, dorlastan. Abbreviation - PU.

   No textile product is made from 100% polyurethane yarn, it is always combined with other types of fibers. Features of polyurethane - high elasticity and low shrinkage during washing

   The most well-known brands of polyurethane fibers are Elastan, Spandex and Lycra.

   Positive qualities: lycra: high elasticity, durability special softness, light resistance (does not turn yellow)
   ______________________ elastane: high elasticity, resistance to organic solvents, acids, alkalis and dyes

   Negative qualities: lycra: does not tolerate high temperatures, does not absorb moisture well
   _____________________ elastane: not light resistant (turns yellow in the light), poorly absorbs moisture

2. High-tech clothing made of polyurethane is rightfully considered a new word in the development of the workwear industry. This waterproof material is highly resistant to a large number of aggressive chemicals, is not affected by mold and fungi. Such clothing retains elasticity and strength in a wide temperature range (if necessary, it can be used at temperatures from -65C to +85C). Most varnishes and paints do not stick to the polyurethane surface, which makes it possible to keep clothes clean longer. In our catalog you can find aprons, aprons, pants and jackets made of this material, as well as shoe covers and hats.

   The undoubted advantages of polyurethane overalls include affordable cost compared to clothing made from other materials, and if you remember about durability and high wear resistance, the profitability of such an acquisition becomes obvious. At the workplace, most of us spend a lot of time, so overalls should be distinguished not only by high functionality and convenience, but also by aesthetics. Polyurethane opens up great opportunities for work suit designers. This elastic and non-flowing material is suitable for creating men's and women's clothing. Bright colors of trousers, jackets and aprons make work safer.

   Scope of polyurethane clothing

   The supply of polyurethane overalls is an important activity of Ultravet LLC. Already today you will find in our catalog clothes of different sizes for men and women that meet all the requirements for goods in this category. The polyurethane clothes brought to your attention are widely used in various sectors of the national economy, including food production, oil, chemical and oil refining enterprises, cleaning and medical organizations, as well as companies involved in sanitation, landscaping, waste sorting and processing.

Polyurethane is called the material of the future. Its properties are so diverse that they practically have no boundaries. It works equally well in the environment familiar to us and under borderline and extreme conditions.

Properties of polyurethane

It is based on two types of raw materials - a polyol and an isocyanate. This synthetic polymeric material belongs to the group of polyester polyols and its properties and specifications depend on the molecular structure. Polyurethane is also an elastomer, a material that returns to its original state after stretching.

Numerous additives give it special properties, which, reacting, increase elasticity, give softness or hardness, and resistance to temperature extremes.

So polyurethane has several different states, it is produced in the form of a viscous liquid, soft rubber, hard plastic, it can have a high or low degree of elasticity.

Regardless of the form in which the material is presented, it does not change in the future due to the influence of thermal or mechanical influences, if necessary, the product can, for example, stretch, but after that it always returns to its original shape. Polyurethane is also resistant to contact with chemical liquids, oils, UV rays, bacteria and fungi. It is successfully used in the Far North and in hot countries, in the creation of hydraulic devices and in the space industry, in construction and engineering.

Specifications

The technical characteristics of polyurethane make it an indispensable structural material in many industries where products must have high resistance, wear resistance, and resistance to aggressive environmental influences.

• The density of the polymer depends on its type, the indicators can be in the range of 30-300 kg/m3.
• Shore hardness (A, D) is in the range of 50-98 units, which allows it to be used under high mechanical loads.
• It has an extensive temperature range of operation, from -60 to +80 °C, short-term use at +120-140 °C is possible without loss of technical characteristics.
• The polymer has high elasticity with high hardness of the material, its strength indicators reach up to 50 MPa. It can stretch up to 650% without damage.
• Does not conduct electricity.
• It has a low weight, which gives an alternative to using products with less weight.
• Ozone resistance is also a definite plus, it does not collapse under the influence of ozone, such as rubber.
• High resistance to acids, oils, solvents.
• When producing a polymer, you can program the required coefficient of friction, and get a material with a very low or high coefficient.

The main competitors of polyurethane are rubber, plastic and metal. But they all lose to him in many technical characteristics.

Compared to rubber, it has higher wear resistance and elasticity, is not susceptible to oils, gets dirty less, ages more slowly, takes shape faster after deformation, and better tolerates mechanical stress.

When compared to metal, polyurethane is obviously more elastic, lighter in weight, non-conductive and less susceptible to abrasives. Also, polyurethane is much cheaper to manufacture and maintain, mechanisms equipped with parts from this material create less noise. All this affects the quality and cost of the final product.

In comparison with plastic, polyurethane shows better results at high and low temperatures, it is more elastic, does not crack under shock and other mechanical impact.

The disadvantages include:

1. Air tightness, which is important when creating shoes and clothes;
2. Shrinkage of foamed decorative details and difficulty in applying a clear pattern;
3. Excessive hardness and brittleness during prolonged cold exposure;
4. Low resistance to twisting.

Therefore, it is extremely important to choose the right type of polymer for operation in certain conditions. The absolute disadvantage of the material can be called the complexity of recycling products from it.

Areas of use

Polymeric material has a very wide and diverse scope. It is used in various forms, as a rule, it is: sheet material, liquid or in the form of polyurethane foam.

Lining elements, press parts, coatings for rollers, wheels, shafts, seal rings, cuffs, plugs, etc. are produced from sheet metal. Porous seals, fillers, foam rubber are made of polyurethane foam. Liquid or in the form of a spray is used to coat concrete structures, wagons, car bodies and cabs, hatches, and roofs. It is also included in the composition of sealants, adhesives, varnishes, paints, means for thermal and waterproofing, and is also used in the production of moldings - molds for casting products.

Today, the functioning of many industries is no longer possible without the participation of polyurethane, its use has contributed to the development of new technologies and lower production costs.

In heavy industry, this material is needed for the production of shock-absorbing elements.

In construction, polyurethane is indispensable in the creation of anti-slip coatings, vibration-resistant surfaces, durable facade structures. In mining and quarrying, it replaces rubber and even steel.

The polymer is widely used in the automotive industry. Tires, unstable elements of mechanisms, silent blocks, shafts, bearings and much more are produced from it.

In the furniture industry, it is needed in the production of mattresses, fasteners, gaskets and seals, molded chairs and armchairs, garden furniture, and decorative elements.

Polyurethane is in demand in the textile and footwear industries, soles, waterproof and protective covers, zippers and rivets, carpets and insoles are made from it. They even make clothes from it, for example, polyurethane 100 is an excellent imitation of natural leather, just as soft, eco-friendly, light, only more durable.

In medicine, condoms, prostheses, implants, elements and coatings for crutches, beds, wheelchairs are made from it. Rare medical equipment does without parts from this material.

Polyurethane has also found wide application in the production of sports equipment, running track coatings and stadium coatings.

Production

Polyurethane is a derivative of polyol and isocyanate, products of the petrochemical industry. To achieve certain technical properties, various additives are added to them, that is, in the production of polyurethane as a raw material, it is necessary to take into account its further scope. Today it represents the world's most sought-after polymer in all major industry segments. Both foreign and domestic materials are presented on the market of synthetic polymers.

In the production of products, such technological methods as casting, extrusion, pressing, pouring are used.

Casting products

The most common method for the production of polyurethane products is injection molding. It is used to manufacture products such as bushings, cuffs, rings, bearings, self-lubricating parts, suspension parts, sealing elements for hydraulic and pneumatic mechanisms. A big advantage of the production of polymer products by pouring is the low cost of molds, which makes the finished product attractive in price.

In the creation of products from this polymer by casting, three technologies are used: rotational casting, free molding and injection molding.

Rotational casting is used to coat large areas and cylindrical parts with polyurethane. The polymer is applied with special equipment on a rotating shaft, the whole procedure is controlled by a computer. Rotational casting is carried out without heating, is a low-waste production and allows you to fully adapt to the needs of the client.

Free casting is used to create complex shapes, in some cases the finished product can weigh half a ton. Thanks to computer control, casting into a mold takes place under precise control of the dosing of the polymer, its temperature and the pressure under which it enters. This allows us to produce high quality products.

Silicone molds are used for free casting, and this method is used to create limited edition products. The advantage of casting is a small time investment and a low cost of the finished product.

Injection molding allows you to speed up production, it is necessary for creating large batches. This method is suitable not only for polyurethane, but also for other polymers.

Features and interesting facts

For the first time, polyurethane was obtained in the 40s in Europe. In the course of long laboratory studies, the famous chemist, scientist and technologist Bayer Otto Georg Wilhelm obtained a previously unknown material with stunning technical properties.

In the same year, the first plant was established and the new polymer was put on the market. But it found wide application only 20 years later, when it began to be widely used in various industries. The American companies Union Carbide and Mobay Chemical Corporation were the first to start producing polyurethane and products from it.

Polyurethane

Polyurethane unique properties of a synthetic polymer, produced from petroleum products. Different ratios of components (the content of catalysts, blowing agents and stabilizers) regulate properties, the range is the widest: from liquids, viscous compounds to elastic rubbers and the strongest plastics. Containing polyurethane fabric It is made with use of threads - elastomers. With special strength, high tensile strength, elasticity, and excellent dielectric characteristics, highly tensile polyurethane fibers are most in demand in the textile industry.

The use of this kind of thread in interior textiles seems absurd only at first glance. In fact, with the help of an inconspicuous highly stretchable elastomer thread, a spectacular one can be sewn (a drawstring is sewn from the inside along the intended contour, an elastic thread or braid threaded into it forms a drapery pattern after tightening). The same technique can be used in decorating a successful design can be seen in the gallery of ready-made kits. Austrian curtains, with spectacular draperies of wide scallops, are made according to the same type; instead of elastic braid, a system of cords is used from the inside of the model. Furniture covers or are sewn using more dense and dimensionally stable fittings designed for high-density massive fabrics.

Polyurethane

The range of polyurethane threads is numerous, determined by the purpose. Some types are produced intertwined with a thread of a different composition (,), some are used as auxiliary ones. Textiles developed on the basis of elastic fibers (knitwear and fabrics with different properties) are indispensable in the production of immobilizing bandages, tight-fitting sportswear, and swimwear. Elastomeric polyurethane fibers ("spandex", "", "neolan", "vayrin", "elastane") are known to admirers of tight-fitting clothing. Polyurethane elastomers are resistant to microorganisms and mold, do not change their properties in wet conditions.

The use in various fields of industry as a structural material intended for work under conditions of intense mechanical loads (steel bending or cold rolling shafts) is due to the strength, vibration resistance and hardness of cast polyurethanes of the NITs PU - 5 type. The most durable elastic ones are used in the production of drive belts, tires , conveyor belts, various seals. An example containing polyurethane fabric maybe high-tech artificial leather (used for accessories for curtains, sewing covers, furniture upholstery). Effective adhesives, varnishes, polyurethane foam, heat-insulating fillers contain polyurethane of a different chemical structure.