Trademark Notice
Kalrez® is a registered trademark of DuPont de Nemours, Inc.; Chemraz® is a registered trademark of Greene Tweed & Co.; Simriz® is a registered trademark of Freudenberg Sealing Technologies; PTFE refers to polytetrafluoroethylene, while Teflon® is a registered trademark of The Chemours Company FC, LLC. All trademarks remain the property of their respective owners. The following article is based on publicly available datasheets and technical resources.
Introduction: Why Compare Kalrez® 4079, Chemraz® 615/555, and Simrizm® 498?
When engineers search for terms like “Kalrez 4079 datasheet,” “Chemraz 615 data sheet,” “Chemraz 555 temperature,” “Simriz 498 temperature range,” or even “FFKM chemical compatibility chart,” they are usually addressing one core challenge: how to ensure reliable sealing in environments that combine extreme heat, aggressive chemicals, and demanding cycle conditions.
In this arena, Kalrez® 4079, Chemraz® 615/555, and Simriz® 498 stand out as flagship high-temperature FFKM grades. Each is designed to withstand operating conditions far beyond the reach of conventional elastomers, and each comes with its own balance of strengths and limitations.
1. Product Positioning and Technical Background
Kalrez® 4079 (DuPont)
- Designed primarily for semiconductor etching, deposition, and cleaning processes
- Continuous service temperature: up to 316 °C (600 °F)
- Typical properties: Hardness 75 Shore A, tensile strength 16.9 MPa, elongation 150%, compression set ≈25% after 70 hr @ 204 °C
- Limitations: Not recommended for use in amine environments; hot water and steam resistance should be evaluated case-by-case
Chemraz® 615 (Greene Tweed)
- Broad chemical resistance with low compression set at high temperatures
- Temperature range: −18 °C to 324 °C (0–615 °F)
- Often promoted as a strong alternative for long-term, high-temperature sealing
Chemraz® 555 (Greene Tweed)
- Developed specifically for chemical processing industry
- Service temperature: up to 316 °C (600 °F)
- Balances high temoerature and chemical resistance in chemical processing industry
Simriz® 498 (Freudenberg)
- Marketed as the high-temperature flagship compound within the Simriz family
- Temperature capability: 320–325 °C (617 °F)
- Recognized in European markets for its stability in aggressive acids and bases
2. Core Property Comparison
| Material | Service Temperature Range | Key Characteristics | Typical Applications |
|---|---|---|---|
| Kalrez 4079 | −20 ~ 316 °C | Broad chemical resistance; exception with amines | Semiconductor, chemical processing (mainly) |
| Chemraz 615 | −18 ~ 324 °C | Excellent compression set resistance at high T | Chemical and process industries |
| Chemraz 555 | −15 ~ 316 °C | Chemical processing industry; optimized for pump sealing | Chemical and process industries |
| Simriz 498 | −5 ~ 325 °C | High-temperature flagship, excellent chemical stability | Semiconductor, pharmaceutical |
Note: values are based on published datasheets; direct comparisons should account for test methods and conditions.
3. Chemical Compatibility Highlights
- Kalrez 4079: Performs reliably in concentrated sulfuric, nitric, HF, and NMP, but not suitable for amines.
- Chemraz 615/555: Strong across acids and solvents, especially valued for low compression set at elevated temperatures.
- Simriz 498: Widely adopted in Europe for handling acids, bases, and oxidizers in high-temperature settings.
Because datasheet test conditions vary—volume swell, compression recovery, or immersion duration—it’s essential to confirm compatibility with actual process media.
4. Frequently Asked Questions (FAQ)
Q1: What are the main differences between Kalrez 4079 and Chemraz 615/555?
If you compare the Kalrez 4079 datasheet with a Chemraz 615 data sheet, the differences become clear. Kalrez 4079 is rated to 316 °C with broad chemical coverage but excludes amines. Chemraz 615 extends to 324 °C and is often praised for maintaining low compression set under prolonged heat. Chemraz 555, at 316 °C, is tailored for chemical processes where high temperature is critical.
Q2: What is the maximum temperature capability of Simriz 498?
Many searches for “Simriz 498 temperature range” highlight its datasheet rating of 320–325 °C, making it one of the highest-temperature Simriz formulations and a direct competitor to Kalrez and Chemraz in semiconductor and pharmaceutical equipment.
Q3: How does FFKM differ from PTFE?
When engineers consult an FFKM chemical compatibility chart, the distinction becomes obvious: PTFE offers near-universal chemical inertness but lacks elasticity, restricting it to static seals. FFKM compounds like Kalrez, Chemraz, and Simriz provide both chemical resistance and elastic recovery, making them far better suited for dynamic sealing and thermal cycling.
Q4: Why is Kalrez 4079 not recommended for amine environments?
According to DuPont data, exposure to amines can cause significant swelling or degradation in 4079, leading to premature seal failure. This limitation is clearly noted in the manufacturer’s guidance.
Q5: Which of these materials offers the longest lifetime at high temperature?
The answer depends on process conditions. Kalrez 4079 and Chemraz 615 are both rated near 600 °F (316–324 °C); Chemraz 615 is often selected where long-term compression set resistance is critical, while Simriz 498 offers a slightly higher ceiling but may require validation for specific media.
5. Key Takeaways for Material Selection
- Temperature vs. thermal cycling
- Kalrez 4079: 316 °C
- Chemraz 615: 324 °C
- Chemraz 555: 316 °C
- Simriz 498: 320–325 °C
- Chemical compatibility
- Kalrez 4079 is robust against acids and oxidizers but unsuitable for amines.
- Chemraz 615/655 emphasize balanced resistance and compression set control.
- Simriz 498 offers broad stability in both acids and bases.
- Compression set behavior
- Critical for long-term seal life. Chemraz 615 is frequently highlighted as superior in this area.
- Application preferences
- Semiconductor: Kalrez 4079, Chemraz 615
- Chemical processing: Kalrez 4079, Chemraz 555
- European markets: Simriz 498
Conclusion
For high-temperature sealing applications, the choice often narrows to Kalrez® 4079, Chemraz® 615/555, or Simriz® 498. All three can operate above 300 °C, but the nuances—chemical resistance, compression set, or application-specific optimization—determine the best fit.
If your search queries look like below, visit our Resource page or Contact us for support.
- Kalrez 4079 datasheet
- Chemraz 615 data sheet
- Chemraz 555 temperature
- Simriz 498 temperature range
- FFKM chemical compatibility chart
