SEMI-RIGID COLLAPSIBLE CONTAINER

A semi-rigid collapsible container has a side-wall with an upper portion, a central portion, a lower portion and a base. The central portion includes a vacuum panel portion having a control portion and an initiator portion. The control portion is inclined more steeply in a vertical direction, i.e. has a more acute angle relative to the longitudinal axis of the container, than the initiator portion. On low vacuum force being present within the container panel following the cooling of a hot liquid in the container the initiator portion will flex inwardly to cause the control portion to invert and flex further inwardly into the container and the central portion to collapse. Raised ribs made an additional support for the container in its collapsed state. In another embodiment the telescoping of the container back to its original position occurs when the vacuum force is released following removal of the container cap.