1. Appearance: The finer the appearance of ordinary sponge, the smaller the pores, and the better the quality of sponge.
2, feel: high-quality sponge should be able to rebound quickly, fluffy sponge is the best, on the contrary, sponge with very stiff feel is inferior.
3, smell: normal sponges have a little smell, but not too bad, so if it is a sponge that can't stand the smell, it must be inferior raw materials.
4. Tensile properties: A good sponge must have at least 80% tensile elongation, and if it can't reach it, it is a low-grade sponge.
5, tear strength: high-quality sponge is not easy to tear, just a little finger to break is to cut corners in the production process.