What are the special features of the material of sponge sandpaper compared with other types of sandpaper?

Material composition
Sponge sandpaper isn't made with paper or cloth as the abrasive carrier. Instead, it's composed of sponge (or TPU) and abrasive. The sponge is the base, and grinding sand is planted on it. This special structure gives sponge sandpaper unique advantages when grinding. But other types of sandpaper, like dry sandpaper and water-resistant sandpaper, mainly have paper or cloth as the base, with abrasive coated or stuck on top.

Special Properties
Advantages in curved surface grinding: Sponge sandpaper is especially good for curved surface grinding. Because its soft sponge base can fit the curved surface well, the grinding is more even and efficient. Other types of sandpaper might not be as flexible and fitting as sponge sandpaper when grinding curved surfaces.
Good at absorbing water and resisting water: Sponge sandpaper can absorb water and keep grinding with water for a long time. This makes it have a big advantage in wet grinding jobs. Water-resistant sandpaper can also work when there's water, but its base material is usually paper or cloth. Compared with the sponge base of sponge sandpaper, its ability to absorb water and resist water might be a bit worse.
Reusability: Sponge sandpaper can be cleaned and used again. This lowers the cost of use to some extent. Other types of sandpaper, especially the ones with a paper base, often need to be changed after one use.

Application fields
Because of these special things about the material of sponge sandpaper, it's widely used in furniture production, car repair, mechanical manufacturing, plastic and glass, decorative handicrafts and other areas. Especially in situations where curved surface grinding, wet grinding or high-quality grinding of the surface is needed, sponge sandpaper does really well.