M-Cor Inc. White Paper
Comparative Overview of High-Performance Elastomers for Encapsulated and Extruded Seals
FKM (Bisphenol-Cured) | FFKM | Peroxide-Cured Silicone | Platinum-Cured Silicone | Translucent Silicone
Overview
Since 1987, M-Cor Incorporated has engineered and manufactured advanced sealing solutions for critical industries, including semiconductor, pharmaceutical, aerospace, and bioprocessing.
Our materials are selected not only for thermal and chemical stability but also for compatibility with stringent regulatory and purity requirements.
This white paper compares five primary elastomer systems used in M-Cor’s encapsulated and extruded seal products. Each material is evaluated based on curing system, thermal range, chemical resistance, and application suitability to help engineers and procurement teams select the best compound for their operating environment.
1. Material Comparison Table
| Material | Cure System | Hardness (Shore A) | Continuous Temp (°C) | Short Excursions (°C) | Low-Temp Limit (°C) | Chemical Resistance | Steam/Hot Water | Purity / Regulatory | Typical Appearance | M-Cor Notes |
|---|---|---|---|---|---|---|---|---|---|---|
| FKM (Bisphenol-Cured) | Bisphenol (ionic) | 60–90 | −26 to 204 | up to ~220 | −26 | Excellent vs oils, fuels, and solvents; limited base/amine resistance | Fair – good | FDA / USP Class VI grades | Black | M-Cor extrudes FKM cord and tubing in-house for custom-dimension seals |
| FFKM (Perfluoroelastomer) | Peroxide / proprietary | 75–90 | up to 300–327 | ~320+ | ≈ −15 | Near-universal; resists acids, bases, solvents, and plasma | Excellent | Semiconductor / high-purity / FDA grades | Black / White | Highest temperature and chemical range; used in M-Cor’s critical-process O-rings |
| Silicone (VMQ, Peroxide-Cured) | Organic peroxide | 40–80 | −60 to 200 | up to 250 | −60 | Good vs water and polar media; poor vs fuels and oils | Good | FDA / USP options | Red / Translucent | Cost-effective, wide low-temperature elasticity |
| Silicone (VMQ, Platinum-Cured) | Addition (platinum) | 40–80 | −62 to 232 | up to 250+ | −62 | Similar to peroxide-cured; improved physicals, lower shrink, and minimal residues | Excellent | USP Class VI / FDA | Translucent | Best choice where cleanliness, low extractables, and bioprocess compliance are critical |
| Translucent Silicone (Peroxide-Cured) | Organic peroxide | ~60–70 | −40 to 200 | up to 250 | −40 to −60 | Comparable to peroxide VMQ; translucency allows visual inspection | Good | FDA 21 CFR 177.2600 | Natural translucent | Ideal for applications requiring flow or contamination visibility |
2. Material Insights
FKM (Bisphenol-Cured)
A durable fluoroelastomer ideal for hydrocarbon environments, offering high compression-set resistance and long-term sealing integrity. M-Cor’s in-house extrusion enables precision FKM profiles for encapsulated seals and tubing.
FFKM
The highest performing elastomer for temperature and chemical resistance. FFKM is chosen for semiconductor, plasma, and chemical process environments where contamination or degradation cannot be tolerated. M-Cor manufactures and supplies FFKM O-rings for critical sealing applications requiring near-zero compromise.
Peroxide-Cured Silicone
Peroxide curing yields cost-effective silicone with strong flexibility at extreme low temperatures and high-temperature resilience. It is suitable for general industrial and sanitary applications but has higher extractables compared to platinum-cured silicone.
Platinum-Cured Silicone
Preferred for biotechnology, pharmaceutical, and medical environments where cleanliness and purity are paramount. Platinum curing eliminates peroxide residues, reducing outgassing and ensuring superior biocompatibility. M-Cor’s platinum-cured silicone is available in translucent and rust-red colors, with USP Class VI certification.
Translucent Peroxide-Cured Silicone
Designed for visual process control. The natural translucence allows operators to detect contamination, moisture, or flow irregularities. It’s often selected for pharmaceutical and laboratory environments where monitoring and repeated sterilization cycles are routine.
3. Applications Across Industries
| Industry | Preferred Materials | Primary Considerations |
|---|---|---|
| Semiconductor / Plasma | FFKM | Temperature stability, chemical resistance, and purity |
| Pharmaceutical / Bioprocess | Platinum-Cured Silicone / FFKM | USP Class VI, low extractables, sterilization resistance |
| Aerospace / Energy | FKM / FFKM | Thermal endurance and resistance to fuels and lubricants |
| Food and Beverage | Platinum or Peroxide-Cured Silicone | FDA compliance and sterilization cycle performance |
| Industrial / General Service | FKM / Silicone (Peroxide) | Cost balance and environmental resilience |
4. M-Cor Commitment
M-Cor’s sealing components are digitally measured, traceable, and certified for every order. Each part is backed by M-Cor’s proprietary ENCAP-O-SEAL® technology and Smart Seal™ digital traceability system.
We combine U.S.-based extrusion, encapsulation, and inspection technologies to deliver seals that meet or exceed the expectations of our customers in every critical industry.
Conclusion
Selecting the right elastomer depends on the interplay of temperature, chemistry, purity, and mechanical stress. This comparison demonstrates that no single material meets all conditions—but with M-Cor’s expertise, engineers can achieve the optimal balance of performance, compliance, and value.
For complete technical data or to request a material validation sample, contact engineering@m-cor.com or visit www.m-cor.com.
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