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Meldin® Grades Comparison | Chemical Compatibility

Use the Meldin® grades comparison chart to determine which material will work best for your application. Click on the linked grade name at the top of each column to read more about a specific material and let us know if you have any questions.

The chemical compatibility chart (in tab 2) outlines general chemical resistance for Meldin® 7000 series grades.

Meldin® Grades Material Name 7001 7021 7022 7211 7003
Color Gold Black Black Black Black
Characteristics Key highlights Thermal stability, high strength, dielectric insulator, minimal outgassing in vacuum, ductile, cryo to 600°F continuous. Very low friction and best wear properties for seals and bearings, thrust washers, piston rings. Excellent strength at high temps. Best temperature stability and lowest thermal expansion rate of all Meldin® grades. Excellent high temperature structural option for metals. Excellent bearing grade up to 300°F, k factor drops above that and 7021 is better wearing option above 300°F. Very low friction. Best for service in vacuum and in extreme dry conditions. Commonly used as seals, seats, bearings, in space applications.
Composition & Manufacturing Methods Base Resin Polyimide (PI)
Fillers Unfilled Base Resin 15% Graphite 40% Graphite 15% Graphite, 10% PTFE 15% Molybdenum Disulfide
Shape Availability Rod, sheet, finished parts
Up to 37" rod, 12 x 12 sheets
Tubes, Discs, Blocks
MFG Method DF x x x x x
MFG Method HCM x x x x x
MFG Method Isostatic Molding x x x x x
Mechanical Tensile Strength (psi) 12500 9500 8000 7500 9200
Elongation (%) 8.0 4.7 3.0 4.0 5.5
Flexural Strength (psi) 15800 15800 13000 11800 13000
Flexural Modulus (psi x 105) 4.6 5.3 7.7 5.0 4.6
Compressive Modulus (psi x 105) 3.8 4.5 4.8 3.5 3.6
Thermal Max Use Temp 600°F* 600°F* 600°F* 600°F* 600°F*
Tg (Glass Transition Temp.) Has no Tg** Has no Tg** Has no Tg** Has no Tg** Has no Tg**
Thermal Conductivity (BTU in/hr ft2 °F) 2.4 5.0 - 5.2 -
CTE – 73 to 500°F (in/in/°F) 2.7 2.2 1.4 2.4 -
Electrical Dielectric Strength (V/mil) 580 280 - - -
Surface Resistivity (Ohm-Sq) 1015 - 1016 108 - 109 - - -
Other Specific Gravity 1.43 1.51 1.65 1.53 1.61
Hardness (Rockwell E) 40-55 25-40 5-20 1-15 -
Water absorption 24hr / 48hr (%) 0.23 / 0.64 0.50 / 0.10 - - -

* Intermittent exposure to 900ºF

** Meldin® 7000 has no softening point. TGA tests show it burns off less than 5% by weight up to temperatures of 1112ºF.

The list above is only a partial list of available Meldin® materials.

PV data may be exceeded based on specific application requirements. Ask to speak to a TriStar Application Engineer.


Meldin® 7001

Meldin® 7021

Meldin® 7022

Meldin® 7211

Acetic Acid (10%) C C C C
M-Cresol B* B* B* B*
o-Dichlorobenzene A A A A
Diethyl Ether A A A A
Ethanol A A A A
Hydraulic Fluid, Polyphosphate Ester A A A A
Hydrochloric Acid (37% @RT) B B B B
Hydrochloric Acid (5%, 100C) C C C C
JP-4 Jet Fuel A A A A
Jet Engine Oils (MIL L78086, T2) A A A A
Mineral Oil A A A A
Nitric Acid (70%) B-C B-C B-C B-C
Nitrobenzene B* B* B* B*
Nitrogen Tetroxide B B B B
Perchloroethylene A A A A
Silicone Fluid A A A A
Sodium Hydroxide (5%) C C C C
Tricresyl Phosphate B B B B
Toluene A A A A