Evoflex® - Flexible Polyurethane Systems

Ravago Petrokimya, which designs durable and high-performance polyurethane systems across a wide range to meet customers' specific needs and stated prerequisites, aims to bring benefits to all aspects of life. With the introduction of polyurethane systems into social life and their continuous development up to the present day, quality of life has also improved. As Ravago Petrokimya, we continue to strengthen globally with our innovative and entrepreneurial culture, producing raw materials for hundreds of thousands of products in 40 different sectors for a better living standard. Polyurethanes are increasingly used in all areas of human life, particularly in applications such as bedding, furniture and automotive. Ravago Petrokimya has been a strong partner to original equipment manufacturers (OEMs) for many years, and with the desire to maintain this strong partnership in the long term, formulates high-performance products with quality certifications suitable for low-emission requirements for manufacturing companies in the furniture, automotive and bedding industries. Furthermore, with the development of fire safety standards, flame-retardant additives have been applied to polyurethane to achieve formulations with various fire-resistance levels.

Evoflex Molded Flexible Polyurethane Systems

• Molded foam systems (furniture, automotive, medical), • Vacuum molded foam systems (furniture, automotive), • Integral skin systems (furniture, automotive, medical), • Molded viscoelastic systems (bedding, medical), • Air filter polyurethane systems (automotive).

Molded Foam Systems

These are open-cell polyurethanes with limited elasticity and shape recovery properties. In applications using the molding method, the liquid polyol system and isocyanate are mixed in a specific ratio with the aid of machinery and injected into the mold. This mixing process causes the two liquids to react. This reaction is an exothermic reaction, and as a result, polyurethane, CO2 and heat are released. The foam formed from the reaction takes the shape of the mold and has a flexible structure. If the prepared polyol systems are not used with the recommended isocyanates, technical problems occur or the foam quality does not meet the desired properties. Additionally, the quality of the foam, the machines performing the mixing operation, and the design of the injected molds greatly affect the result. High-pressure machinery and heated aluminum molds are recommended for foam production. Today, particularly with the development of fire safety standards, the application of these standards in homes, offices and factory production facilities has made it necessary to activate costly fire suppression systems. In addition, as Ravago Petrokimya, with flame-retardant foam formulations that we have developed, we now offer the opportunity to minimize fire risk.

Vacuum Molded Foam Systems

Polyurethane products appear in everyday life in different shapes and properties. One of the application techniques is vacuum molding systems. These systems are ready for direct use after production. After molding, polyurethane foams are covered with textile products such as artificial leather, leather, fabric, etc., but this operation can also be easily applied directly in the mold. If the textile product placed inside the mold is fabric, it is placed directly; if it is artificial leather, it is placed in the mold at 70-80°C, heated to conform properly to the mold shape, vacuum-sealed, and the mold form is obtained. The chemical poured into the mold becomes ready for direct use.

Molded Viscoelastic Systems

Viscoelastic foams, also referred to as "smart foam" that shapes according to body weight, are highly sensitive to heat; they show strong variation characteristics with temperature changes. The characteristic property of viscoelastic foam is its extreme effectiveness in reducing point surface pressure and enabling weight distribution equally to every point on the surface. The foam slowly returns to its original state after the application of such pressure. This property of viscoelastic systems makes them preferred in the bedding, furniture industry and medical sector.

Integral Skin Systems

Polyurethane foams can be rigid, flexible, semi-rigid or semi-flexible in structure depending on the properties of the polyol system and isocyanate used. Foams with flexible and open-cell interior structure and rigid, partially flexible outer shell are called Integral foams, or briefly Integral PU (polyurethane). Integral polyurethanes are sometimes also referred to as semi-rigid polyurethane. The most important properties of semi-rigid foams are impact absorption, damping and sound absorption. For this reason, they are mainly used for vibration prevention and noise-sound insulation purposes.

Integral Polyurethanes

Integral polyurethanes are used in final part production. The part coming out of the mold goes either to a shelf or to waste. Therefore, the raw material, mold and machinery trio must be in complete harmony. Undoubtedly, the mold release agents or mold paints used must also be selected with equal care. Integral polyurethanes are extensively used in the automotive sector, medical and office furniture sectors. While HCFC-141b was used as a blowing agent in formulations used in the integral sector, due to the Montreal Protocol and national regulations, the use of HCFC-141b as a blowing agent in polyurethane (PU) foams was discontinued in Turkey as of 1 January 2013. Although there are many alternative chemicals, only a limited number of chemicals can provide the technical properties required by the polyurethane industry. Ravago Petrokimya uses approved gases in line with international standards with reduced ozone depletion potential.

Air Filter Polyurethane Systems

Filter elements made of high-grade cellulose fibers are used in air filters. The most important purpose of an air filter is to provide adequate protection for the engine against wear in any dusty environment. Today, filters are used in every environment that provides air circulation, particularly in space technology, nuclear power plants, defense and military facilities, the medical sector, industry and manufacturing, automotive, household appliances and equipment. Air filters occupy an important place. Air filters absorb the smallest micron dust particles while showing minimal resistance to air flow. Small and light heavy-duty air filters are particularly used in engines working in very dusty environments, especially in work machines. Thanks to these filters, vehicles with powerful engines are not affected by dusty environments, so the air going to the system maintains high combustion efficiency and does not create problems in the vehicle's operating conditions. As Ravago Petrokimya, we particularly supply polyurethane systems with high elasticity, strong tensile and tear resistance that serve as gaskets in air filters, providing sealing and adhesion properties to filter elements. Polyurethane foams designed in the desired hardness and color with low emission, used in panel and radial lines, are safely used by major OEM companies. Hakan Evran / Flexible Systems Product Manager - Ravago Petrokimya Sales and Marketing Inc.