Heat- and pressure-resistant polyester bottle and process for producing the same

Abstract

A process for producing a heat- and pressure-resistant polyester bottle, comprising a primary blow-molding step of obtaining a primary molded article by biaxially stretch-blow-molding a preform of a polyester resin, a heat-treating step of obtaining a secondary molded article that is heat-shrunk by heat-treating the primary molded article, and a secondary blow-molding step of obtaining a finally molded article by biaxially stretch-blow-molding the secondary molded article, wherein the primary blow-molding step biaxially stretches the neck portion of the primary molded article to a size nearly the same as the neck portion of the finally molded article, and the heat-treating step does not cause the neck portion of the secondary molded article to be heat-shrunk. The heat- and pressure-resistant polyester bottle has a slender neck portion of the shape of a so-called crane neck and is suited for containing beer without eradicating the impression of the traditional glass-bottled beer, wherein the length of the neck portion is in a range of 10 to 40% of the height of the bottle, the crystallinity of the neck portion is in a range of 20 to 35%, and the crystallinity of the body portion is in a range of 35 to 50%.