17 Polypropylene resins in pellet form for use in further manufacture of rigid structures, such as pipes, reservoirs, ducts, crates, storage boxes and fittings; polyethylene resins in pellet form for use in further manufacture of rigid structures, such as pipes, reservoirs, ducts, crates, storage boxes and fittings; Polypropylene resins for use in further manufacture of rigid structures, such as pipes, reservoirs, ducts, crates, storage boxes and fittings; polyethylene resins for use in further manufacture of rigid structures, such as pipes, reservoirs, ducts, crates, storage boxes and fittings