the fabrication of an injection - molded plastic part using a blow - mold resin includes a first step of modifying an injection - molding machine by enlarging resin passages in order for that machine to accept a more viscous resin . the next step in the fabrication process is to provide a mass of blow - molded resin heated to a viscosity suitable for the modified injection - molding machine . a third step is to introduce the mass of blow - molded resin into the modified injection - molding machine . the fourth step is operating the modified injection - molding machine in a manner consistent with the normal operation for injection - molding of the desired plastic part . a part of the present invention is the specific method of modifying component parts of the injection - molding machine so that those component parts are compatible with a more viscous plastic resin .