Patent attributes
A semi-rigid collapsible container (10) has a side-wall with an upper portion (5), a central portion (6), a lower portion (7) and a base (8). The central protion (6) includes a vacuum panel portion having a control portion (2) and an initiator portion (1). The control portion (2) is inclined more steeply in a vertical direction, i.e. has a more acute angle relative to the longitudinal axis of the container (10), than the initiator portion (1). On low vacuum force being present within the container panel following the cooling of a hot liquid in the container (10), the initiator portion (1) will flex inwardly to cause the control protion (2) to invert and flex further inwardly into the container (10) and the central portion (6) to collapse. In the collapsed state upper and lower portions of the central portion (6) may be in substantial contact so as to contain the top-loading capacity of the container (10). Raised ribs (3) made an aditional 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.