Other

N A Williams

William J Bakker

A packaging film which shrinks to form at least part of a package when exposed to heat. The packaging film includes a thin film substrate that contracts or shrinks when heated and which is substantially transparent to radiant energy. The film also includes a susceptor material carried by the film that is sufficiently opaque to radiant energy to absorb and transfer to the substrate enough heat energy to cause the substrate to shrink, when the film is exposed to a source of radiant energy. In one embodiment the packaging film takes the form of lids of beverage containers.

Packaging film for forming packages

A device for heat shrinking thin film onto open-topped containers to form spill-resistant covers is shown. A radiant energy source is intermittently energized in association with timers to direct radiant energy towards the thin film. An energy absorbing body is associated with the thin film to absorb energy and create heat adjacent to the film which in turn causes the thin film to shrink. The energy absorbing body can be the adaptation of the thin film to be opaque to the radiant energy by either being coated with an energy absorbing coating such as printing, or being made partially opaque by means of tinting. The container can also be adapted to absorb energy by including a darkened band adjacent the upper edge of the rim. The device can also interpose an energy absorbing body, such as a darkened aluminum screen adjacent to the film to be heated to cause the thin film to shrink. The device shrinks the thin film around the rim first, then shrinks the film across the top of the container to form a spill-resistant cover. In one embodiment, printed patterns on the film can be used to create perforations.

Growing community of inventors

Don Mills, Canada

N A Williams