Ethylene Propylene Rubber
Ethylene Propylene Rubber (EPR or EPDM) is a versatile synthetic rubber renowned for its excellent resistance to heat, ozone, weathering, and chemicals. Widely used in automotive, construction, and industrial applications, Ethylene Propylene Rubber offers superior durability and flexibility across extreme temperatures (-50°C to +150°C).
Key Specifications of Ethylene Propylene Rubber
- Temperature Range: -50°C to +150°C
- Tensile Strength: 17-25 MPa
- Elongation at Break: 300-600%
- Hardness (Shore A): 40-90
- Specific Gravity: 0.86-1.30
- Dielectric Strength: 20-30 kV/mm
| Grade | Mooney Viscosity | Ethylene Content | Primary Applications |
|---|---|---|---|
| EPDM 4045 | 45 ± 5 | 52% | Automotive seals, HVAC Systems |
| EPDM 5525 | 25 ± 5 | 65% | Wire & Cable, Industrial Hoses |
| EPDM 8010 | 10 ± 5 | 70% | Extrusion Products, Weather Strips |
Why Choose Ethylene Propylene Rubber?
Ethylene Propylene Rubber stands out in the synthetic rubber market due to its unique molecular structure that combines ethylene and propylene with a diene monomer. This composition delivers:
- Exceptional weather and ozone resistance (10x better than natural rubber)
- Superior electrical insulation properties
- Excellent chemical resistance to polar fluids and acids
- Low compression set for long-term sealing performance
- UV radiation stability for outdoor applications
Ethylene Propylene Rubber FAQ
Q: What is the maximum continuous operating temperature for Ethylene Propylene Rubber?
A: Standard Ethylene Propylene Rubber compounds can withstand continuous operation at 125°C, while specially formulated grades may endure up to 150°C. For intermittent exposure, certain formulations can tolerate temperatures as high as 175°C for short durations without significant degradation.
Q: How does Ethylene Propylene Rubber perform in low-temperature environments?
A: Ethylene Propylene Rubber maintains excellent flexibility down to -50°C due to its amorphous polymer structure. The glass transition temperature typically ranges between -55°C to -65°C, making it one of the best-performing elastomers for cold weather applications. Low-temperature grades with proper plasticizers can extend this range even further.
Q: Can Ethylene Propylene Rubber be used for food-contact applications?
A: Certain FDA-compliant grades of Ethylene Propylene Rubber are approved for food contact under FDA 21 CFR 177.2600. These specialized formulations use food-grade additives and meet stringent migration limits. Always verify the specific compound's compliance with current food safety regulations before use in food processing equipment or packaging.
Processing Methods for Ethylene Propylene Rubber
Ethylene Propylene Rubber can be processed using standard rubber manufacturing techniques:
- Compression Molding: Pressure 50-200 kg/cm², Temperature 160-180°C
- Injection Molding: Barrel temperature 60-80°C, Mold temperature 170-190°C
- Extrusion: Screw L/D ratio 12:1 to 15:1 recommended
- Calendering: Roll temperatures 80-120°C for proper sheet formation
Industrial Applications of Ethylene Propylene Rubber
| Industry | Typical Components | Key Properties Utilized |
|---|---|---|
| Automotive | Weatherstrips, Radiator Hoses, Seals | Heat resistance, Weather ability |
| Construction | Roofing Membranes, Window Seals | UV stability, Water resistance |
| Electrical | Cable Insulation, Bushings | Dielectric strength, Tracking resistance |
| Industrial | Gaskets, Conveyor Belts, Tank Linings | Chemical resistance, Durability |