The present invention teaches a film having a pattern of protruding
structures. When used in the vacuum packaging bag material context, the
result is a vacuum packaging bag that a consumer can effectively evacuate
and hermetically seal. The protruding structures tend to form channels
that enable gas to evacuate from within a vacuum packaging bag. In
certain embodiments, the protruding structures are formed only on an
inner side of the vacuum packaging film, typically through a hot casting
or heat-extrusion process. As a result, far less bag material is required
than in the prior art patterned film formed through cold embossing
processes. The present invention also contemplates a variety of
applications for the films, including preformed bags and bag rolls, as
well as a variety of apparatus for manufacturing the films and appliances
for utilizing the bags and bag rolls.