A method for manufacturing a resin container includes: a first injection-molding step of injection-molding a bottomed cylindrical resin intermediate molded body; a second injection-molding step of injection-molding a resin material on an outer side of the intermediate molded body to manufacture a multilayered preform having a resin layer laminated on an outer peripheral side of the intermediate molded body; and a blow-molding step of blow-molding the preform to manufacture a resin container having a thick portion.

When a hollow molded body using a preform to be molded with a thin bottom portion is produced while taking advantage of the roughening of the outer surface of an injection core mold, transferred roughening marks are prevented from appearing on the bottom portion of hollow molded bodies, so that the hollow molded body with an aesthetic bottom portion is obtained. An injection core mold (12) has an outer surface of its tip portion corresponding to a preform bottom portion (10) and a lower end portion (14a) of a preform body portion (14). The outer surface corresponding to the preform bottom portion (10) and the lower end portion (14a) of the preform body portion (14) is a mirror-finished surface (20), and the outer surface of the injection core mold for forming the preform other than the mirror-finished surface is a roughened surface (15).

Described herein, amongst other things, is a container preform that is blow moldable into a container. The container preform includes a tubular body having a neck finish and a base at an open end and a closed end thereof respectively. The base is defined between inside and outside curved surfaces at least one of which is composed of multiple tangential curves, wherein an elongate portion is defined between adjacent inside and outside concentric curves that define a thinnest bottom wall thickness of the base having a constant minimum thickness that is smaller than or equal to a wall thickness of the body.

A generally hollow preform for making a stretch blow-molded container may include a threaded finish portion; a neck portion depending from the finish portion; a transition portion depending from the neck portion; a main portion depending from the transition portion; and a closed, generally rounded tip portion depending from the main portion. The preform may include stretch ratios with respect to the container including an axial stretch ratio of about 3.0 to 3.5, a hoop stretch ratio of about 5.0 to 5.5, and a total stretch ratio of about 15 to 19.25. In some embodiments, high stretch ratios may be achieved with less material, yielding substantial cost savings.

A mold for blow molding a container from a preform, the container including a wall portion and a base including a high standing ring and a central outwardly-inclined invertible diaphragm, the mold including sidewalls forming a counter print of the wall portion of the container (1) and a mold base (36) having an upper surface (37) defining a counter print of the container base, wherein the upper surface (37) includes: an annular peripheral face (43) corresponding to an annular support flange of the container base; a frusto-conical outer face (44) corresponding to an inner portion (11) of the high standing ring, the outer face (44) protruding upwardly with a draft angle (A2) from an inner edge of the peripheral annular face (43) up to a sharp apex (45), and a frusto-conical downwardly inclined inner face (46) corresponding to the invertible diaphragm.

A preform configured to form a container by stretch blow molding. The preform includes a finish portion and a tip portion. The finish portion is at a first end of the preform and is a container finish of the container. The tip portion is at a second end of the preform opposite to the first end. The tip portion is configured to form a container base and a container heel of the container. An outer surface of the tip portion includes a flat surface, a first radius on a first side of the flat surface, a second radius between the first radius and the flat surface, a third radius extending from the flat surface on a second side of the flat surface, and a fourth radius extending from the third radius towards the second end of the preform through which a longitudinal axis of the preform extends.

The present application includes an injection molding step and a stretch blow molding step. The stretch blow molding step is configured to include: a first step in which preliminary blow air is introduced into a preform to stretch the preform in a state in which a stretching rod does not contact the bottom of the preform; a second step which is executed after the first step, and in which the preliminary blow air is introduced into the preform and the stretching rod is moved at a set speed and pressed against the bottom of the preform to stretch the preform; and a third step which is executed after the second step, and in which final blow air is introduced into the preform to stretch the preform.

A preform for a stretch-blow-molded plastic container includes an elongated, tube-like preform body. An outer wall and an inner wall delimit a bottom thickness (b). An outer wall and an inner wall delimit a wall thickness (w). An inner surface and an outer surface (E1) curved in three-dimensionally convex manners are spaced apart such that a distance from their respective apex (S, S′) to the preform body continuously increases. Extensions of the outer wall of the preform bottom along the outer three-dimensionally curved surface (E1), and of the inner wall of the preform bottom along the inner three-dimensionally curved surface (E2) are configured to be interrupted by set-backs area outside of their respective apex (S, S′) thereof.

A preform created through additive manufacturing and a process for blow molding an additive manufactured preform. The preform has one or more self-supporting overhangs.

A method for producing a blow molded plastic bottle starting from a preform comprises providing a preform with a specific wall thickness distribution and a blow mold are provided, the cavity of the mold having at least one channel at the locations of the plastic bottle that are to be strengthened. Subsequently, the preform is heated in such a way that the portion of the preform that correlates with the channel of the cavity is thinned to a lesser extent during the stretching and/or blow, and an accumulation of plastics material is brought about in the channel during the main blow molding operation. A plastic container produced by this process has strengthening elements formed as at least one outwardly protruding bead of material and have a wall thickness that is at least 30%, greater than the wall thickness of a portion of the wall adjacent to the bead of material.