Patent ID: 7833467

Claim:
A polyester container obtained by stretch-forming a preform of a thermoplastic polyester resin formed by injection forming wherein: the polyester container includes a bottom wall and a body wall connected to the bottom wall; the bottom wall consists of a central portion and a surrounding portion adjacent to and surrounding the central portion; the central portion of the bottom wall of the container is formed relatively thicker than a bottom wall portion surrounding the central portion, the central portion corresponding to a gate area of an injection gate used in the injection forming of the preform; the central portion of the bottom wall is substantially amorphous and has a crystallinity less than or equal to 5%; and the bottom wall portion surrounding the central portion is oriented and crystallized, the bottom wall includes a portion at a distance of 10 mm from the center of the central portion of the bottom wall having a crystallinity greater than or equal to 15%, and the bottom wall includes a portion at a distance of 6 mm from the center of the central portion of the bottom wall having a crystallinity less than or equal to 5%.