What is the difference between sponge and EVA foam?

Features of EVA foam:

Water resistance: airtight cell structure, no water absorption, moisture resistance, and good water resistance.

Corrosion resistance: resistant to chemical corrosion such as sea water, grease, acid, alkali, antibacterial, non-toxic, odorless, and pollution-free.

Processability: No joints, and easy to process such as hot pressing, cutting, gluing, and bonding.

Anti-vibration: high resilience and anti-tension, high toughness, good shock-proof and cushioning performance.

Thermal insulation: excellent thermal insulation, cold-preservation and low-temperature performance, and can withstand severe cold and exposure.

Sound insulation: airtight cell, good sound insulation effect.

The difference between sponge and EVA foam:

PVA sponge: Polyvinyl formal is a condensation product of polyvinyl alcohol and formaldehyde, which is a white or slightly yellow amorphous solid. Its softening point is higher than that of the same series of acetals (140～150℃), its strength, rigidity and hardness are larger, and it has good bonding performance; it has good oil resistance, electrical insulation, etc.; it has good water resistance , Alkali and acid resistance. It is flammable and emits black smoke. It melts and drips and has a special smell.

Foam: high density, stronger liquid absorption, tougher and more elastic foam, good abrasion resistance, will not scratch the wiped device, will not drop chips. After the particles and liquid enter the foam hole, they will not fall out or be easily squeezed out, and have a good locking ability.

Foam is a porous elastomer obtained by cross-linking of a specific water-soluble resin. It has a strong water absorption capacity due to its hydrophilicity in the molecular structure. PVA foam is different from general urethane sponge. It has extremely high hydrophilicity. It produces capillary phenomenon with the crisscross micropores, and exerts excellent water absorption and water retention performance.