Full definition
Closed-cell expanded EPDM rubber combining the inherent weather, ozone, UV, and moisture resistance of EPDM with the insulating, cushioning, and compressible sealing properties of foam structure. Density: typically 80-250 kg/m³. Cell structure: closed cells provide waterproof, dustproof seal. Temperature range: -40 to +120°C (higher than neoprene foam). Per ASTM D1056 classification 2C2 or 2C3 (closed-cell, soft to medium). Key properties: excellent long-term outdoor durability without degradation (no bloom, no cracking), good compression set resistance, and inherent resistance to steam and hot water. Thicknesses: 1.5-50 mm. Available as rolls, sheets, self-adhesive tapes, and die-cut parts. Applications: automotive door, hood, and trunk weatherstrips (the dominant material for OEM weatherseals), architectural window and curtain wall gaskets, HVAC duct sealing tape, outdoor electrical enclosure gaskets, solar panel edge seals, and general-purpose weather sealing. Limitations: incompatible with mineral oils (same as solid EPDM). Manufacturing: continuous extrusion + chemical blowing agent (OBSH, ADC) or autoclave expansion. Brands: Volara (Sekisui), LAIRD, Rogers PORON.