Plates, sheets, film, foil and strip, of noncellular plastics, n.e.s., not reinforced, laminated, supported or similarly combined with other materials, without backing, unworked or merely surfaceworked or merely cut into squares or rectangles (excl. selfadhesive products, those of addition polymerization, condensation and rearrangement polymerization products, floor, wall and ceiling coverings of heading 3918 and sterile surgical or dental adhesion barriers of subheading 3006.10.30)