PROCESS AND APPARATUS FOR PRODUCING BLOW MOLDED THERMOPLASTIC ARTICLES HAVING IMPROVED WELD STRENGHT

摘要

Articles are blow molded by introducing an inert gas into an extruded parison having its laver end pinched shut by a previous molding operation. A blow mold is then closed about the parison pinching its upper end shut and cutting it, and the closed ended parison so formed is blown using a gas containing an oxidizing agent. Preferably the inert gas is nitrogen and the oxidizing agent is present in a quantity 0.1% to 10% by volume. Fluorination, where used, improves the barrier properties to hydrocarbon solvents.