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Kalrez® Semiconductor Compounds Kalrez O-ring FFKM Comparison


DuPont™ Kalrez® Spectrum™ 6375

A carbon black-filled product for general use in O-rings, seals, diaphragms and other parts specifically for the chemical process industry. This product has excellent broad chemical resistance, good mechanical properties, and outstanding hot-air aging properties. Kalrez® Spectrum™ 6375 is well suited for use in mixed process streams because of its excellent resistance to acids, bases, and amines. It is also recommended for use in hot water, steam, pure ethylene oxide and propylene oxide.


DuPont™ Kalrez® Spectrum™ 7075

Enhanced physical properties including very low compression set and improved seal force retention. It is a carbon black-filled product utilizing proprietary cure chemistry. Its mechanical properties are designed for improved sealing performance in both high temperature environments and temperature cycling situations. Kalrez® Spectrum™ 7075 O-rings have a glossy finish. This product was specifically developed for the chemical and hydrocarbon industries to provide improved chemical and thermal resistance better than the industry standard set by Kalrez® 4079.


DuPont™ Kalrez® 4079

A low compression set product for general-purpose use in O-rings, diaphragms, seals, and other parts used in the process and aircraft industries. It is a carbon black-filled product with excellent chemical resistance, good mechanical properties, and outstanding hot air aging properties. It exhibits low swell in organic and inorganic acids and has good response to temperature cycling effects. This product is not recommended for use in hot water/steam applications or in contact with certain hot aliphatic amines, ethylene oxide, or propylene oxide.


DuPont™ Kalrez® Spectrum™ 6380

A non-black product specifically developed for chemical processes involving hot, aggressive amines. It has also been successfully used in applications involving highly oxidizing chemicals. In addition, it has excellent overall chemical resistance. This cream colored product is easily identifiable when selecting an O-ring material for harsh chemical plant services.


DuPont™ Kalrez® Spectrum™ 7090

A product for uses requiring higher hardness/higher modulus than more typical applications. Kalrez® Spectrum™ 7090 perfluoroelastomer parts are well suited for both static and dynamic applications as well as specific sealing applications requiring extrusion resistance at high temperatures. These specialty black parts have excellent thermal and mechanical properties, including excellent compression set and seal force retention, resistance to temperature cycling effects, and rapid gas decompression (RGD). Short excursions to higher temperatures may also be possible.


DuPont™ Kalrez® 0090

A black product with broad chemical resistance combined with high modulus and high hardness. Kalrez® 0090 parts have outstanding resistance to extrusion and rapid gas decompression (RGD). This product has been independently tested and certified by the Materials Engineering Research Laboratory (MERL – UK) to meet NORSOK-M-710 Rev 2 requirements.


DuPont™ Kalrez® Spectrum™ 0040

A black product specifically designed for low temperature environments where significant chemical resistance is required. Kalrez® Spectrum™ 0040 parts maintain elasticity and seal force at temperatures unattainable by other perfluoroelastomers.


DuPont™ Kalrez® 1050LF

A carbon black-filled product for O-rings, seals, and other parts used in chemical process industries. It has good hot water/steam, and excellent amine resistance. Kalrez® 1050LF is not recommended for use in organic acids, or inorganic acids at high temperatures.

Miscellaneous Kalrez® Properties

Many miscellaneous properties are of interest for specific applications. Some of these are unaffected by compound choice, while others vary with hardness or extensibility. As an example, coefficient of friction typically increases as hardness decreases. In general, miscellaneous physical properties are similar to those of Viton® fluoroelastomer.

Note: Other specialty or custom compounds may be available or developed to applications that require different properties than the above compounds offer: 8375, 8385, 8101, 4001......

Kalrez Compound Comparison

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Typical Phisical Properties*

Kalrez® Compound Kalrez® 6375 Kalrez® 7075 Kalrez® 4079 Kalrez® 6380 Kalrez® 7090 Kalrez® 0090 Kalrez® 0040 Kalrez® 1050LF

Maximum Application Temp,
°C (°F)

275 (527) 327 (620) 316 (600) 225 (437) 325 (617) 250 (482) 220 (428) 288 (550)

Durometer Hardness,
Shore A, points ±5
( ASTM D2240 )

75 75 75 80 90 95 70 82

100% Modulus, MPa / psi
( ASTM D412, 500 mm/mm (20in/mm) )

7.24 / 1050 7.58 / 1100 7.24 / 1050 6.89 / 1000 15.51 / 2250 14.20 / 2060 6.61 / 960 12.40 / 1080

Tensile Strength at Break, MPa / psi
( ASTM D412, 500 mm/mm (20in/mm) )

15.16 / 2200 17.91 / 2600 16.88 / 2450 15.86 / 2300 22.75 / 3300 19.51 / 2830 13.72 / 1990 18.60 / 2700

Elongation at Break, %
( ASTM D412, 500 mm/mm (20in/mm) )

160 160 150 160 75 80 180 125

Compression Set,
% at 70 hrs at 204ºC (400ºF)
(ASTM D395B, pellets)

25 12 25 38 12 40 38 35

TR-10, ºC / ºF
(ASTM 1329)

-3 (26.6) -4 (24.8) -2 (28.4) -5 (23.0) -5 (23.0) -7 (-19.4) -17 (1.4) -4 (24.8)

The information set forth herein is furnished free of charge and is based on technical data that DuPont Dow Elastomers believes to be reliable.  It is intended for use by persons having technical skill, at their own discretion and risk.  The handling precaution information contained herein is given with the understanding that those using it will satisfy themselves that their particular conditions of use present no health or safety hazards.  Because conditions of product use and disposal are outside our control, we make no warranties, express or implied, and assume no liability in connection with any use of this information.  As with any material, evaluation of any compound under end-use conditions prior to specification is essential.  Nothing herein is to be taken as a license to operate under or a recommendation to infringe on any patents.

*Not to be used for specifications

Kalrez® Semiconductor Compounds Kalrez O-ring FFKM Comparison

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