Semi-worked plastic substances; foils of plastics in the nature of semi-finished products; plastics materials in the form of blocks in the nature of semi-finished products for further manufacture; plastic material in the form of rings in the nature of semi-finished products for further manufacture; plastic material in the form of discs in the nature of semi-finished products for further manufacture; plastics materials in the form of tapes in the nature of semi-finished products for further ma...