PEEK or Polyether Ether Ketone is a colorless organic polymer in the polyaryletherketone (PAEK) family. There are a number of grades currently available. Unfilled PEEK is not reinforced with glass or carbon but is one of the strongest unfilled polymers. PEEK 30% glass filled offers the same chemical resistance as unfilled PEEK but offers nearly double the tensile strength. Peek is also offered in a 30% carbon-filled grade. The carbon fibers enhance the strength and stiffness of the material. This grade of PEEK offers optimum wear as well as excellent load carrying capacity. PEEK 30% carbon filled offers 3 1/2 times higher thermal capacity than unfilled PEEK. There is also a bearing grade PEEK, called KetronTM HPV.
As polyether ether ketone is a semi-crystalline organic polymer, it exhibits superior mechanical performance and thermal properties, including creep resistance and low flammability. PEEK has a flammability rating of UL 94 V-0, which means a vertical specimen stops burning within 10 seconds. In the test, particle drips are allowed as long as they are not inflamed. PEEK’s operating temperature goes up to 450 °F and the material has a continuous service temperature of 356°F (180°C.). PEEK has a glass transition temperature of 143°C (289°C) and melts at 343°C (662°F.) PEEK can also withstand large doses of radiation. It has excellent hydrolysis resistance, meaning that it can be exposed to high pressure water and steam without degrading. PEEK is chemically resistant to most common chemicals including acids, salts, solvents, oil and steam. PEEK is so acid resistant it can only be dissolved in concentrated sulfuric acid, which makes it the appropriate material for highly acidic applications. It is heat, flame, and abrasion resistant and does not breakdown when exposed to water. PEEK displays excellent strength and stiffness up to 527°F (275°C.) It is highly wear resistant with a low coefficient of friction. It is susceptible to halogens and aliphatic hydrocarbons at high temperatures. PEEK also exhibits low smoke and toxic-gas emissions. Additionally, it is highly UV resistant therefore it will not degrade in sunlight.
PEEK screws, nuts, spacers, custom parts and other hardware are used in a wide variety of industries, including automobile, marine, nuclear, oil well, power, electronics, aerospace, medical, as well as in semi-conductor wet benches and various military applications. For example, PEEK screws are used to construct wet benches because they are resistant to the hydrofluoric acid used in the photoresist process used to make semiconductors. Also, PEEK is a high purity polymer, so it is also suited to FDA food contact and any other application where high purity is necessary. It is incorporated into the automotive industry to minimize the weight of in-engine components by replacing parts of the engine which are traditionally constructed from metals. The combination of properties and the large temperature operating range of PEEK make it a preferred product in the aerospace industry, especially in conditions where it may be exposed to low temperatures and atmospheric particles. Common applications in this industry include valve seats and pump gears.
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