VICTREX®PEEK™ polymer belongs to the family of polyaryletherketones (PAEK). It is a linear, aromatic, semi-crystalline polymer recognised as one of the most advanced thermoplastics in the world. This material includes the unique combination of properties such as exceptional chemical resistance, excellent tribological properties, electrical characteristics and heat resistance. It is an alternative to conventional materials and substitute for metals. It is a versatile material used in the design and manufacture of products with very demanding parameters. It gives great freedom of design, thus allowing a significant reduction in manufacturing costs.
The group of VICTREX®PEEK™ products includes variations in the form of granules and powders for injection and extrusion. VICTREX®PEEK™ coatings and films are sold under the name VICOTE® and APTIV™. VICTREX®PEEK™ polymer replaces metal in poppet valves in compressors.
Manufacturers of control and safety valves used in hydraulic and pneumatic compressors are constantly looking for new ways to improve the quality of their products. Performance of valves determines the efficiency of the compressor more than any other element. In order to reduce fluid leaks and noise, to extend the working life of valves and also to reduce their production costs, the manufacturers of these elements often ask for help to specialists in the field of plastic injection moulding. Those in such cases often propose to replace the metal poppet valves with valves made of VICTREX®PEEK™. By replacing metal with plastic we retain the strength characteristic of metal, but also improve corrosion resistance, reduce component weight and achieve greater freedom of designing parts.
One of the main benefits of the use of VICTREX®PEEK™ is that the valves can operate at high and low pressure. This advantage increases the possibility of the use of such valves and compressors in a variety of applications. One of the common causes of valve failures are leaks caused by repeated pressure spikes. VICTREX®PEEK™ has exceptional resistance to shock loads, which is why these elements in certain applications, can withstand up to 20 million cycles. Machine-finishing of the surface of poppet valves is difficult and expensive, and the working sealing surface is non-uniform, precisely because of difficulty machining of the surface. In many applications, poppet valves made of VICTREX®PEEK™ more easily adapt to the valve face which, compared to parts made of metal, provides higher tightness. Repair of traditional pumps and valves is costly and time-consuming. Replacing metal with elements made of VICTREX®PEEK™ is a great way to reduce production downtime and to definitely reduce the cost of such operations.
Industrial bearings made of VICTREX®PEEK™ polymer
One of the largest bearing manufacturers Daido Metal Co. Ltd. has developed and launched large bearings which form part of hydrogenerators. Due to the high requirements of the devices, such as mechanical strength and excellent sliding properties, it was decided to use VICTREX®PEEK™. So far, due to high loads and high speed during operation, bearings operating in hydrogenerators (and similar devices) used to be made of copper, tin and tin alloys. Knowing the imperfections of white metals in terms of heat resistance and mechanical strength, Daido applied VICTREX®PEEK™ mainly due to its exceptional mechanical strength, thermal resistance and low friction coefficient. The use of the new material has improved the load strength by 50% and reduced the friction coefficient by 30-40%. This, in turn, has allowed to reduce the bearing surface by approx. 60% and to increase operating temperature to 250°C (compared to 125°C in the case of white metals). Laboratory tests carried out at Daido also showed that the total period of operation of such a bearing can be twice as long as in the case of metal.
While the use of bearings made of white metal alloy required the use of oil filters and oil used for start-up of large appliances, it is no longer necessary with the use of VICTREX®PEEK™ and its excellent sliding properties. Additionally, due to excellent chemical resistance of the PEEK polymer, there is no need for isolation of the bearings.
These examples show unique properties of VICTREX®PEEK™. With its specific, excellent combination of properties, this polymer found its place in other demanding applications and other industries. An example would be the use for the manufacture of gears used in the automotive and other industries where it surpasses the properties of metals.
In the aerospace industry, composites and parts moulded of VICTREX®PEEK™ replace aluminium and reduce the weight of many components. This material is specified and approved for use by major aerospace companies Boeing and Airbus, mainly due to their mechanical strength, natural self-extinguishing properties and very low or no emission of fumes in case of fire.
The very polymer is characterised by exceptional resistance to hydrolysis and chemical resistance.
With these features VICTREX®PEEK™ can replace stainless steel, and even titanium in medical instruments which require resistance to multiple sterilisation cycles.
In general, in all fields of industry there is a trend towards the use of systems of lower weight and greater mechanical strength. These characteristics that allow for the reduction of production costs and maintenance. VICTREX®PEEK™ is a highly advanced polymer that enables engineers to find new technical solutions that meet the growing demands of the market.