17 SEMI-FINISHED PLASTICS, NAMELY BLOCKS, SLABS, CYLINDERS, SLICED FOILS, RINGS, BARS, TUBES, DISKS AND ROLLS, MOLDINGS AS SEALS FOR BEARINGS AND ARTICULATED HEADS, STOP SPRINGS AND AUXILIARY SPRINGS, VIBRATION, END-POSITION AND FRICTION DAMPERS; PIPE AND TUBE SUPPORTS, COUPLING ELEMENTS, ROLLERS, GRINDING WHEELS; SEMI-FINISHED PRODUCTS MADE OF PLASTIC(IN THE FORM OF SHEETS, BARS, BLOCKS, PIPES, CYLINDERS, RUBES, RING BOARDS; INSULANTS MADE OF PLASTIC AGAINST HEAT, COLD, IMPACT AND/OR SOUND IN THE FORM OF BOARDS, BEADS, MOLDINGS, CHIPS, LIQUIDS OR SHREDS; SEALANTS, PACKAGING CORDS, GASKETS