A blow molding method and machine and more particularly a method and machine for extruding a multi-layer parison for blow molding, wherein at least two layers of molding plastics, each plastic compensating the poor or undesirable physical and chemical properties of the other plastic and/or each having a different color are forced to flow through different passages having an annular cross sectional configuration, and are joined at the junction of a short passage to be extruded into a multi-layer parison.
