Sponge lining material, often referred to as foam or cushioning lining, is a versatile and essential component used across countless industries for padding, protection, and insulation. Typically made from polyurethane (PU), polyethylene (PE), or other polymer foams, it is characterized by its lightweight, flexible, and compressible cellular structure. This material is the unseen yet critical layer that adds comfort, safety, and functionality to everyday products.