Abstract: A technique for internally cooling a blow molded article with a coolant comprising a mixture of subzero temperature dry air and water. A pressure swing dessicant bed type dryer and chiller are used to supply the dry air having a dew point of the order of -60.degree. F and a temperature ranging from -30.degree. to -50.degree. F for introduction into the blow molded article.

Abstract: A novel procedure for circulating blowing air through an injection blow molded article during the blow cooling cycle of an injection molding process is described. The technique involves the use of a new core rod assembly which permits internal circulation of cool air during the blow cooling cycle of the process. The described assembly may also be used for reconditioning itself by the use of heated air, so avoiding the phenomenon of core rod freeze-up.