Detailed knowledge of foam classification

Foam classification:

According to the pore structure: open cell foaming, semi-open cell (independent) foaming, closed cell foaming (independent foaming), microcellular foaming.

According to the material, it can be divided into: silicone foam, PU foam, EPDM sound-absorbing cotton, EPE pearl cotton, PVC foam, PE foam, PPP foam, CCR foam, EVA foam, XPE foam, IXPE foam, Acrylic foam, etc.

Classified by material:

Polyethylene foam: PE foam (chemical cross-linking, electronic cross-linking), EVA foam.

Polyester foam: polyether foam (chemical foaming, physical foaming), polyurethane foam.

Rubber foam: CR foam (neoprene rubber), NR foam (nitrile rubber), SBR foam (styrene-butadiene rubber), EPDM foam (ethylene-propylene-diene rubber).

Classified by foam structure:

Open-cell foam: soft texture, high water absorption rate, high compression rate, suitable for sound-absorbing sealing applications, such as compressed sponge for earphones, air-conditioning sealing strips, etc.

Closed-cell foam: independent foaming, low compression residual rate, low water absorption, good heat insulation and cushioning performance, good dustproof, suitable for sealing dustproof, waterproof and shock absorption of electronic products.

Closed-cell foam is mostly used in the mobile phone industry, and polyethylene and polyurethane are mostly used as materials. At present, the products of the following companies are mostly used in the market:

Rogers (USA) mainly produces PU foam, brand Poron, Bisco

Inoac (Japan) mainly produces PU foam, brand Poron, Nanex

Nitto (Japan) mainly produces PO&PP foam, brand SCF

S&K (Korea) mainly produces PU foam, the brand Nanocell

SK (Korea) mainly produces PU foam, brand Esobra

Sekisui (Japan) mainly produces PE foam, brand Volara, Alveolit

NHK (Japan) mainly produces PU foam, brand Nippalay

Saintgobain (France) mainly produces PU foam, brand Korel

Application scenario:

Shock-absorbing foam: component damage prevention and shock absorption, motor shock absorption

Dust-proof foam: dust-proof between lens and LCD, Camera

Sound insulation and sound absorption: combined with screen mesh for Speaker

Conductive foam: used for filling conductive shielding

Pads, padding: shock absorption, non-slip, padding