General Description : Normally infusible, coloured (often amber) high performance polymers with predominantly aromatic molecules of high thermal stability. Semi-fabricated shapes are usually supplied by the polymer manufacturer and made by powder sintering or working with more tractable pre-cursors and completing polymerisation in final form, though some melt-processable grades of resin are manufactured. They have excellent high temperature properties and radiation resistance, inherently low flammability and smoke emission, low creep and high wear resistance and are very expensive. They have moderately high water absorption and are prone tohydrolysis and attack by alkalis and concentrated acids.

A widely used form is DuPont™ Kapton® film, made in thicknesses from 0.008 to 0.125mm and which is a transparent amber colour. Thicker polyimide items are usually opaque. A range of DuPont™ Kapton® film variants are also available. In each of these, a large measure of DuPont™ Kapton® basic properties are combined with an extra attribute eg increased electrical or thermal conductivity,improved corona resistance, opacity and thermoplasticity.

Films are used for capacitators, insulation, printed circuit boards and in aerospace; other applications include engine components, bearings and mechanical parts exposed to radiation.

Explanation of DuPont™ Kapton® grade descriptions

HN Regular DuPont™ Kapton® - Transparent Amber CB Opaque black version of HN MT Aluminium oxide filled, increased thermal conductivity, opaque yellow MTB Opaque black version of MT
CR Improved corona resistance - translucent yellow XC Electrically (semi-)conductive - opaque black FPC Superior dimensional stability and adhesion compared to HN HPP-ST Similar to FPC a two-sided treated film with superior dimensional stability and superior adhesion compared to HN 200RS100 Two layer film with an electrically conductive layer on one side KJ Thermoplastic - transparent yellow PST A tough film that exhibits an excellent balance of physical, chemical and electrical properties over a wide temperature range, particularly at unusually high temperatures CRC Enhanced corona resistant version of CR FN Heat sealable version of HN with one or both sides coated with DuPont FEP GS Specifically designed and manufactured to expand the processing window and improve yields during artificial graphite sheet production FCR Used in magnet wire insulation that will withstand corona discharge FWN Multi-layer polyimide & fluoropolymer dispersion-coated film MT+ Enhanced version of MT with approaching double its thermal conductivity PRN411 Multi-layer heat-fusible composite film that enables higher operational temperature functionality and improved abrasion resistance