Retortable plastic container

A method of forming a retortable plastic container, the method comprising:

• forming a side wall having at least one flexing portion extending from a top horizontal line around a circumference of the side wall to a bottom horizontal line around the circumference of the side wall, the flexing portion having an inwardly directed surface relative to the circumference of the side wall, the inwardly directed surface having:
• a first length measured along the inwardly directed surface, in a central vertical plane from the top horizontal line to the bottom horizontal line, which is greater than a straight line distance between the top and bottom horizontal lines in the same vertical plane, and
• a second length measured along the inwardly directed surface along a perimeter of the flexing portion, in a horizontal plane, which is greater than a circumference of a circle having a radius of an average distance from a central vertical axis of the container to the inwardly directed surface, the circumference of the circle being in the horizontal plane.

A method of reducing differential pressure on a plastic container during retort, the method comprising:

• providing a side wall of the plastic container, the side wall having at least one flexing portion extending from a top horizontal line around a circumference of the side wall to a bottom horizontal line around the circumference of the side wall, the flexing portion having an inwardly directed surface relative to the circumference of the side wall, the inwardly directed surface having:
• a first length measured along the inwardly directed surface, in a central vertical plane from the top horizontal line to the bottom horizontal line, which is greater than a straight line distance between the top and bottom horizontal lines in the same vertical plane, and
• a second length measured along the inwardly directed surface along a perimeter of the flexing portion, in a horizontal plane, which is greater than a circumference of a circle having a radius of an average distance from a central vertical axis of the container to the inwardly directed surface, the circumference of the circle being in the horizontal plane.