What's the difference between sponge and foam?

PVA sponge: Polyvinyl alcohol formaldehyde is a condensate of polyvinyl alcohol and formaldehyde, which is a white or yellowish amorphous solid. Its softening point is higher than that of homologous acetals (140-150 C). Its strength, rigidity and hardness are larger, and it has outstanding bonding function. It has good oil resistance, electrical insulation and other aspects. It has excellent water resistance, alkali resistance and acid resistance. Flammable, black smoke. Melt dripping and has a special odor.

Bubble foam: high density, stronger liquid absorption, more tough and elastic foam, good wear resistance, will not scratch the device to be scrubbed, will not chip. Particles and liquids will not fall out or be easily extruded when they enter foam holes. They have excellent locking ability. Foam is a porous elastomer obtained by crosslinking reaction of a specific water-soluble resin. It has strong water absorption ability because of its hydrophilicity in molecular structure.

PVA foam is different from ordinary methylcarbamate sponge in that it has very high hydrophilicity, and capillary phenomenon occurs in the interlaced micro-pore with canine teeth, which plays an effective water absorption and retention function. When water is touched, it is adsorbed at a high speed and stored in the inner part of the sponge. Generally, the water absorption rate is 8-10 times of its own component.