It solves the shortcoming that the PVA material can only be dissolved in boiling water before, and can be dissolved in water at room temperature.

PVA is a water-soluble polymer with a wide range of uses. The molecular chain contains a large number of side groups - hydroxyl groups, so it has good water solubility, non-toxic, non-irritating to the skin, and its performance is between plastic and rubber. Water (below 60°) accelerates dissolution.