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Polyimide ( PI )

Material Information

Buy Polyimide on-line

We stock and supply the following standard forms:
Film Laminate Metallised Film Rod Sheet Tube
Film Laminate Metallised Film Rod Sheet Tube

Choose a form to search our on-line catalogue  
Common Brand Names:
Kapton, Kinel, Vespel
General Description:  

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

Availability of DuPont™ Kapton® Grades

Unfortunately due to export restrictions and rationalisation of the DuPont™ Kapton® product range, there are potential issues with the supply of some grades and thicknesses.

DuPont™ Kapton® HN 0.008 mm thick: This specific thickness of DuPont™ Kapton® HN is controlled under ECCN 9A515(x) requirements and is not offered outside of the US.

DuPont™ Kapton® XC & CB: These products are controlled under ECCN 9A515(x)requirements and are not offered outside of the US.

DuPont™ Kapton® KJ & MTB: Regrettably these grades are no longer produced by DuPont™ and we only have a limited range available from our stock.

Please contact your local sales office for an up to date statement on the availability of all grades of DuPont™ Kapton®.

DuPont™, Kapton® & Nomex® are registered trademarks of E.I. du Pont de Nemours and Company.


Chemical Resistance

Acids - concentrated Poor
Acids - dilute Fair
Alcohols Poor
Alkalis Poor
Aromatic hydrocarbons Good
Greases and Oils Good
Halogenated Hydrocarbons Good
Halogens Fair
Ketones Good

Electrical Properties

Dielectric constant @1MHz 3.4
Dielectric strength ( kV mm-1 ) 22
Dissipation factor @ 1kHz 0.0018
Surface resistivity ( Ohm/sq ) 1016
Volume resistivity ( Ohmcm ) 1018

Mechanical Properties

Coefficient of friction 0.42
Elongation at break ( % ) 8-70
Hardness - Rockwell E52-99
Izod impact strength ( J m-1 ) 80
Tensile modulus ( GPa ) 2.0-3.0
Tensile strength ( MPa ) 70-150

Physical Properties

Density ( g cm-3 ) 1.42
Flammability V0
Limiting oxygen index ( % ) 53
Radiation resistance Good
Refractive index 1.66
Resistance to Ultra-violet Poor
Water absorption - over 24 hours ( % ) 0.2-2.9

Thermal Properties

Coefficient of thermal expansion ( x10-6 K-1 ) 30-60
Heat-deflection temperature - 1.8MPa ( C ) 360
Lower working temperature ( C ) -270
Specific heat ( J K-1 kg-1 ) 1090
Thermal conductivity @23C ( W m-1 K-1 ) 0.10-0.35
Upper working temperature ( C ) 250-320

Properties for Polyimide Chopped Fibre

Property Value
Extension to break % 30
Limiting Oxygen Index % 38
Shrinkage @180C % <1
Specific Tenacity cN/tex 38

Properties for Polyimide Film

Property Value
Coefficient of thermal expansion x10-6 K-1 20 60
Corona Resistance @ 20kV mm-1 50 Hz hr 200 >100,000
Density g cm-3 1.42 1.42 1.85 1.85 1.54 1.42 1.36
Dielectric Constant @ 1kHz 3.4 4.5 4.2 4.2 3.9 3.4
Dielectric Constant @ 1MHz 3.4
Dielectric Strength @25µm thick kV mm-1 300 80 165 70 @ 0.075mm 290 200
Dissipation Factor @1kHz 0.0018 0.19 0.003 0.0016
Dissipation Factor @1MHz 0.01
Elongation at Break % 70 45 50-60 50-60 45 20-30 150
Initial Tear Strength g µm-1 20
Moisture absorption % 2.8 3 3 1
Permeability to Carbon Dioxide @25C x10-13 cm3. cm cm-2 s-1 Pa-1 0.5
Permeability to Hydrogen @25C x10-13 cm3. cm cm-2 s-1 Pa-1 1
Permeability to Nitrogen @25C x10-13 cm3. cm cm-2 s-1 Pa-1 0.03
Permeability to Oxygen @25C x10-13 cm3. cm cm-2 s-1 Pa-1 0.1
Permeability to Water @25C x10-13 cm3. cm cm-2 s-1 Pa-1 400
Permeability to Water @38C x10-13 cm3. cm cm-2 s-1 Pa-1 500
Shrinkage @400C % 1.2-1.5 1 1 1 0.6
Surface Resistivity Ohm/sq 3.6x1016 50-1x109
Tensile modulus GPa 2.5 2.7 4 4 3.2 3.3-3.6 2.7
Tensile strength MPa 230 135 125 125 150 110-120 135
Thermal Conductivity @23C W m-1 K-1 0.16 0.45 0.45 0.38 0.12
Volume Resistivity Ohmcm 1.5x1017 1013 1014 1014 2.3x1016 2.5x1017

Buy Polyimide on-line

We stock and supply the following standard forms:
Film Laminate Metallised Film Rod Sheet Tube
Film Laminate Metallised Film Rod Sheet Tube

Choose a form to search our on-line catalogue