Heat tunnel for film shrinking
AssigneeDouglas Machine Inc.
InventorsIrvan Leo Pazdernik, Bruce Malcolm Peterson, Paul Howard Wagner, Bradley Jon VanderTuin, Richard Jerome Schoeneck
Life of this patent
Estimating the term…
Abstract
A heat tunnel for applying heated air to articles enclosed in shrink-wrap film includes at least one air supply unit; a conveyor; and a heat shroud spaced from the conveyor. The air supply unit includes a source of heated air, a fan, a heated air plenum, air ducts, and a return air plenum. Multiple air supply units can be provided along the conveyor to create a heat tunnel of desired length.
Claims10
Method for shrink wrapping comprising:
- providing a group of articles wrapped with a tube of film having a lap seam extending under the group of articles between first and second open ends and beyond the group of articles;
- moving the tube wrapped group of articles in a movement direction perpendicular to the lap seam, over a top surface of a heated air plenum and through a film shrinking area extending along the movement direction;
- and
- providing heated air in the heated air plenum beneath the tube wrapped group of articles, with providing heated air comprising flowing air through apertures in the top surface of the heated air plenum below the tube wrapped group of articles and into the film shrinking area to shrink the tube of film onto the group of articles to form a package, with providing the heated air further comprising flowing air from beneath the tube wrapped group of articles and from the heated air plenum into a first duct having an opening, with the opening extending continuously along the movement direction and spaced above the top surface and the lap seam while the tube of film is being shrunk to form the package.
Apparatus for applying heat to at least a first group of articles wrapped with a tube of film comprising, in combination:
- a heated air plenum having a top surface, an upstream end and a downstream end, with heated air being introduced into the heated air plenum flowing in a movement direction between the upstream and downstream ends, with the group of articles wrapped with a tube of film moving in the movement direction along the top surface, with the heated air passing from the heated air plenum past the top surface into a film shrinking area extending in the movement direction;
- and
- a first duct extending from the heated air plenum above the top surface and having an opening, with the opening extending continuously along the movement direction between the upstream end and the downstream end in the film shrinking area and parallel from and spaced above the top surface.
Dependencies are inferred from the claim text.