Pail closure application method and pail closure combination

摘要

A method of securing a two piece plastic nozzle and overlying screw cap closure assembly to a plastic pail cover wherein the nozzle has a cylindrical body portion which is inserted into a cover opening to form a friction fit therewith. The overlying screw cap is then rigidly supported as a sonic welding horn is brought into axial engagement with the protruding nozzle body portion. Energization of the sonic welding horn causes the nozzle body portion to soften and deform radially outwardly into a circumferentially enlarged rivet connection. Continued axial displacement of the sonic welding horn creates a plastic bond about the periphery of the rivet connection so as to close off any leakage path therearound. At the same time any radial dispersion of plastic material resulting from the bonding process is locally contained about the rivet connection periphery.