Device and method for applying a static seal
AssigneePolycerf, Inc.
InventorAlain A. Cerf
Life of this patent
Estimating the term…
Abstract
A static seal is applied to overlapping edges of film wrapped about a product. A hollow forming head forms the film into a generally tubular configuration so that longitudinally extending opposite edges of the film overlap. A first electrode is disposed within the tubular cavity defined by the film and bears downwardly upon the overlapped edges of the film as the film travels past the first electrode. A second electrode is positioned downwardly of the overlapped edges and outside the tubular cavity. A stream of electrons flowing across an air gap between the electrodes applies the electro static seal.
Claims21
A device that applies an electrostatic charge to overlapping edges of flexible film of the type used to wrap packages, said film defining a generally tubular cavity means, comprising:
- An electrode means disposed wholly internally of said cavity means;
- and
- mounting means for positioning said electrode means wholly within said cavity means defined by said flexible film so that the amount of overlap is unrestricted.
The device of claim ,3, further comprising conveyor means for transporting packages wrapped in said film past said electrode means.
A device that imparts a static seal to flexible film within which packages are wrapped, comprising:
- a hollow forming head means for forming said film into a generally tubular configuration;
- a generally tubular cavity means being defined by said film when so formed;
- a first longitudinally extending edge region of said film being disposed in overlying relation to a second longitudinally extending edge region of said film when said film is formed into said generally tubular configuration;
- a first electrode means disposed in overlying, abutting relation to said first edge region;
- a second electrode means disposed in underlying, spaced apart relation to said second edge region;
- and
- said first electrode means being disposed in its entirety within said generally tubular cavity means defined by the film;
- whereby a stream of electrons flowing between said first and second electrode means imparts an electrostatic charge of a first polarity to said first edge region and an electrostatic charge of a second polarity to said second edge region so that said first and second edge regions cling tightly to one another to form an electrostatic seal that prevents inadvertent unwrapping of said film from a package.
A method for forming an electrostatic seal between overlapping edges of a flexible film means, comprising the steps of:
- shaping a flexible film means into a generally tubular form so that opposite edges of said film means are disposed in overlapping relation to one another;
- positioning all of the structure of a first electrode means wholly within a tubular cavity means defined by said film means;
- mounting said first electrode means so that it bears against the overlapped edges of said film means;
- positioning a second electrode means externally of said tubular cavity means;
- and
- establishing a potential difference between said first and second electrode means so that electrons flow across an air gap that separates said first and second electrode means.
Dependencies are inferred from the claim text.