Patent ID: 6409946
Filing Date: 2002-06-25
Classification: B29C,B29K

Abstract:
Single-stage method for the production of preforms of thermoplastic resin comprising the steps of:filling a plurality of multiple-cavity molds with molten resin for forming said preforms, holding and cooling down said molten resin inside said molds, removing the molded preforms from said molds, subjecting said preforms to a subsequent temperature conditioning stage, transferring said preforms to appropriate blow-molding tools and clamping them therein for their final stretch-blow molding operation, wherein each one of said multiple-cavity molds comprises a plurality of cavities defined in several (n) distinct clusters belonging to the same mold, said cavities being cooled down by means of a forced circulation of cooling medium through appropriate cooling conduits provided in the body of each such mold, wherein the cavities belonging to a same cluster are cooled in a distinct and differentiated manner with respect to the cavities belonging to the other clusters of cavities provided in the same mold.