PEEK (polyetheretherketone) was developed by ICI (British Chemical Industry Corporation) in 1978, and later developed by DuPont, BASF, Mitsui Chemicals, VICTREX and Eltep (USA). As a high-performance polymer material, PEEK has the characteristics of low creep variable, high elastic modulus, wear resistance, corrosion resistance, chemical corrosion resistance, non-toxic, flame retardant, and can maintain good performance even under high temperature and pressure. It can be used in high temperature and pressure valves, nuclear valves, pump compressor valve plates, piston rings, valve cores, and seals under harsh working conditions with high humidity. Why are PEEK valves so popular? This depends on PEEK's excellent properties.
High temperature resistance: PEEK resin has a high melting point (334℃) and glass transition temperature (143℃). Its continuous use temperature can reach 260℃, and the load heat transition temperature of 30% GF or CF reinforced grades can reach 316℃.
Mechanical properties: PEEK resin has good toughness and rigidity, and has excellent fatigue resistance comparable to alloy materials under alternating stress.
Flame retardancy: The combustibility of materials is defined in the standard UL94, which is the ability to keep burning after being ignited at a high energy point of a mixture of oxygen and nitrogen. First, ignite a certain shape of vertical sample, and then measure the time required for the material to automatically extinguish. The PEEK test result is v-0, which is the best flame retardancy level.
Stability: PEEK resin has excellent dimensional stability, which is important for some applications. Environmental conditions such as temperature and humidity have a small impact on the size of PEEK parts, which can meet the requirements of high dimensional accuracy.
PEEK plastic material has small shrinkage during injection molding, which is beneficial to control the dimensional tolerance range of PEEK injection molded parts and make the dimensional accuracy of PEEK parts far higher than that of general plastics; the thermal expansion coefficient is small. The size of PEEK parts hardly changes with the temperature (which may be due to changes in environmental temperature or frictional heating during operation).
Good dimensional stability: The dimensional stability of plastics refers to the dimensional stability of engineering plastics during use or storage. This dimensional change is mainly due to the increase in activation energy caused by the degree of curling of polymer molecules in the chain segment.
Excellent hydrolysis resistance: PEEK has low water absorption at high temperature and humidity. Common plastics such as nylon do not show significant changes in size after absorbing water.
PEEK has developed rapidly in just twenty years and has been widely used in industries such as petroleum and natural gas, aerospace, automotive manufacturing, electronics, medical and food processing. In the petroleum and natural gas industry, the excellent performance of PEEK resin makes it very suitable for use as the main sealing component.