Fmc Corporation

Eric DeSmedt

Ronald L Lotto

Peter J Hatchell

Emiel Y Lambrecht

Danford C Anderson

Julien Antoons

In an apparatus for making plastic bags or the like from a continuous film of material comprising a sealing drum having at least one seal bar for imparting transverse seals to the film at regularly spaced intervals and a perforator having a rotatable perforator blade for imparting transverse perforations to the film at regularly spaced intervals, the film comprising print marks appearing thereon at regularly spaced intervals, an apparatus and method are disclosed for tracking the positions of each print mark and each perforation and comparing the difference between these positions to a desired difference and thereafter adjusting the angular position of the perforator blade until the difference between the positions of each print mark and each perforation is equal to the desired difference to thereby maintain a desired spacing between each print mark and each perforation.

Maintaining perforation phasing

In combination with a web winding machine comprising a spindle for winding up a web of material having a leading edge and an apparatus for transporting the web to the spindle, an air horn proximate the spindle having an arm, a first air tube connected to a forward portion of the arm and a second air tube connected to the arm rearward of the first air tube, wherein the arm comprises an inner surface generally conforming to the spindle and a plurality of apertures extending between each of the first and second air tubes and the inner surface; and wherein the first and second air tubes are connected with a source of air, whereby the air is directed through the apertures to force the leading edge up off of the conveyor belt and against the spindle.

Growing community of inventors

Opwijk, Belgium

Eric DeSmedt