Container preform

A container preform, comprising:

• 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 (TBWT) of the base having a constant minimum thickness that is smaller than or equal to a wall thickness of the body;
• the number of multiple curves used to define the inside and outside surfaces of the base are the same;
• the outside surface of the base, disregarding any gate vestige thereon, is defined by three different outside curves of radii that are tangential and have centers inside the preform, the first two outside curves of radii, starting from the intersection of the base with the body of the preform, have centers that may lie off of the center line of the preform, whereas the third curve of radius has a center that lies on the center line of the preform;
• the interior shape of the base is defined by three different interior curves of radii that are tangential and have centers inside the preform, the first two inside curves of radii, starting from the intersection of the base with the body of the preform, have centers that may lie off of the center line of the preform whereas the third inside curve of radius has a center that lies on the center line of the preform;
• wherein the radii of the inside and outside surfaces are selected to define the thinnest bottom wall thickness along the elongate portion thereof between a central outside curve of radius and a central inside curve of radius that are concentric.