Abstract: Due to variations in the thickness of the film used in wrapping packaged product and various other reasons, the wrapping film such as polyethylene, polypropylene, etc., occasionally causes uneven pulling on the film with resultant turning around or twisting of the film on the packaged product, which causes a breakdown in the wrapping operation. Such breakdowns are avoided by placing on each side of the film wrapping apparatus, a film tracking, preferably electrostatic, probe appropriately spaced from the film so as to position an electrostatic charge thereon. If the film tries to creep sideways, one side of the film is exposed much more to the static generating cone on that side and less on the other. The resultant static friction forces built up on one side of the film and less on the opposite side cause the film to creep towards the side with less static friction build up until the static forces on both sides become equal and cure or avoid the twisting procedure.

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.

Abstract: A machine and method for separation of nested articles such as trays. Nested articles of the type that do not separate from one another under the influence of gravity alone are stacked in vertical nesting relation to one another. Plural blade members are movably mounted about the periphery of the tray members. In a first embodiment, the blade members move horizontally and vertically in a novel sequence to dislodge one tray from the lowermost end of the stack during each cycle of the operation. In a second embodiment, the blade members are pivotally mounted.

Abstract: A shrink wrap packaging machine that shrink wraps twice as many packages per unit of time as conventional machines. The machine includes a pair of longitudinally spaced sealing and cutting elements. Both elements are preceded by a sensor. The first sealing and cutting element is activated when the trailing edge of even numbered packages are detected whereas the second sealing and cutting element is activated when the second sensor detects the trailing edge of odd numbered packages. Packages are therefore wrapped in groups of two after leaving the first sealing and cutting station and are individually wrapped after leaving the second sealing and cutting station. The conveyor belt that carries packages through the machine operates at nearly twice the speed of prior art machines but the sealing and cutting elements of the present machines operate at the same rate as prior art machines.