Artificial resins semi-finished products, namely,, plastics in form of bars, blocks, pellets, rods, sheets and tubes for use in manufacturing; plastic substances, semi-processed, namely, plastic in the form of pellets for use in manufacturing; stuffing of rubber or plastic; packing cushioning, stuffing materials of rubber or plastics; reinforcing materials, not of metal, for plastic pipes not for building purposes; stuffing rings of plastic, for connecting pipes to prevent gas or water spill...