Which Foam Material Is Best for Shock Absorption & Sealing?
Foam gaskets and cushioning pads look similar on the drawing, but choosing between PU, PE, EPDM, silicone or PORON® changes compression set, water ingress and product lifetime. Below is the decision framework our DFM engineers use when a customer sends a sealed enclosure or drop-test requirement.
1. Silicone foam
Best for wide temperature ranges (−60 °C to +200 °C continuous), UV and weather resistance, and food/medical contact. Higher cost, but the only realistic option for outdoor LED seals or appliance oven gaskets. Closed-cell grades provide excellent water sealing.
2. EPDM foam
The default for outdoor IP-rated enclosures. Good ozone and UV resistance, low water absorption, and a compression set (ASTM D1056) that holds over many years. Slightly less rebound than silicone at extreme temperatures, but typically 30–40% cheaper.
3. PU (polyurethane) foam, including PORON® grades
Excellent rebound and cushioning for drop and shock applications — used in phone battery packs, keypads and display bezel seals. Closed-cell PU resists dust; open-cell grades are acoustic. Temperature limited to roughly −40 °C to +90 °C.
4. PE (polyethylene) foam
Lowest cost, good chemical resistance, and widely used for gasketing in consumer electronics and packaging cushioning. Higher compression set than PU or EPDM — acceptable for static seals but not for dynamic re-assembly.
Quick decision table
- Outdoor / IP67 seal: EPDM or silicone closed-cell
- Drop test / impact cushion: PU (PORON)
- High temperature: silicone
- Cost-sensitive static gasket: PE
Send us your enclosure drawing for a foam recommendation →