Full definition
A low-density cellular (expanded) elastomer with either open-cell or closed-cell structure, providing high compressibility, cushioning, thermal/acoustic insulation, and sealing properties not achievable with solid rubber. Per ASTM D1056, designated by a suffix code: 2A (closed-cell, firm), 2B (closed-cell, medium), 2C (closed-cell, soft), 2D (open-cell). Closed-cell: sealed gas bubbles provide waterproofing, buoyancy, and thermal insulation; densities 80-500 kg/m³; compresses 25-75% with low force. Open-cell: interconnected pores allow air and moisture passage; softer, more compressible; for cushioning, filtration, and acoustic absorption. Materials: neoprene (best all-around — weather, oil, flame), EPDM (best weathering and steam), silicone (widest temperature range, FDA), SBR/NR (economical), and PVC/nitrile (oil-resistant, economical). Thicknesses: 1.5-50 mm. Available as sheet, strip, tape (adhesive-backed), and die-cut gaskets. Applications: door and window seals, HVAC gaskets, pipe insulation, vibration isolation pads, packaging cushions, and wetsuits. Per ASTM D1056 and ASTM C534 for pipe insulation.