The invention relates to a container preform made of plastics material having a body exhibiting symmetry of revolution about a central axis and a bottom closing the body from one of its ends. The bottom having an annular bead forming a standing plane of the preform, and the bottom has an external skin oriented toward the outside of the preform and an internal skin oriented toward the inside of the preform. At least one of the internal skin and the external skin has, radially from the central axis as far as the annular bead, a profile having a break in curvature.

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 invention concerns a preform for a container made of plastic material, comprising a cylindrical body that extends along an axis of revolution of the preform and a bottom that closes the cylindrical body. The bottom has an outer profile with a central portion and a curved portion joining the central portion to the cylindrical body. The central portion has, in longitudinal cross-section, a first concave section. The curved portion has successively, in longitudinal cross-section, from the first concave section towards the cylindrical body, a first convex or frustoconical section, a second concave section and a second convex or frustoconical section.

An injection molded thermoplastic preform for blow moulding to form a container, the preform base of a central part having a first, downwardly and radially inwardly tapering portion therebetween which increases in thickness from a radially outer end of the first tapering portion adjacent to the hollow transition portion to a radially inner end of the first tapering portion adjacent to the gate part and the middle part opposite the gate part can allow the injected resin to be urged back through the gate at the end of the injection moulding cycle at a lower fluid pressure in the vicinity of the gate which is associated with high resin temperatures. The technical effect achieved by the first tapering portion is that crystallinity in the gate area is minimized or eliminated, which avoids or minimizes partial blocking of the gate which would otherwise restrict the injected resin from being urged back through the gate at the end of the injection moulding cycle.

The invention concerns a preform for a container made of plastic material, comprising a cylindrical body that extends along an axis of revolution of the preform and a bottom that closes the cylindrical body. The bottom has an outer profile with a central portion and a curved portion joining the central portion to the cylindrical body. The central portion has, in longitudinal cross-section, a first concave section. The curved portion has successively, in longitudinal cross-section, from the first concave section towards the cylindrical body, a first convex or frustoconical section, a second concave section and a second convex or frustoconical section.

According to the present invention there is provided a preform suitable for subsequent blow molding, and a mold stock for producing the preform. The preform comprises a base having an elliptical inner face with a first flat circular bottom portion, and an elliptical outer face with a second flat circular bottom portion. The first and second flat circular bottom portions each have a center on a vertical center axis of the preform and a radius of equal size. The mold stack comprises a core insert comprising a first cavity defining portion with a gate defining portion, and a gate insert comprising a second cavity defining portion. The gate defining portion has a first elliptical curvature with a first flat circular bottom portion, and the second cavity defining portion has a second elliptical curvature with a second flat circular bottom portion. The first and second flat circular bottom portions each have a center on a vertical axis of the mold stack and a radius of equal size.

According to the present invention there is provided a preform suitable for subsequent blow molding, and a mold stock for producing the preform. The preform comprises a base having an elliptical inner face with a first flat circular bottom portion, and an elliptical outer face with a second flat circular bottom portion. The first and second flat circular bottom portions each have a center on a vertical center axis of the preform and a radius of equal size.