Kortec, the United States, introduced a new sandwich hot runner system that allows polypropylene rough products to have barrier properties and blow molding. The system is based on an improved 5-layer nozzle and dual hot runner system, namely for polypropylene and ethylene-vinyl alcohol (EVOH) copolymer materials. First, polypropylene with a volume content of about 30% was injected, and then EVOH was added to the PP to control the barrier layer through the nozzle configuration. At the end, a needle valve is used to close the inner PP layer.