Fmc Corporation

Emiel Y Lambrecht

Peter J Hatchell

Danford C Anderson

Rene F deBin

William Van Der Gucht

Rene Francois De Bin

Eric DeSmedt

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 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, an apparatus and method are disclosed for tracking the positions of each seal and each perforation and comparing the difference between these positions to a desired difference and thereafter adjusting the rate of rotation of the perforator blade until the difference between the positions of each seal and each perforation is equal to the desired difference to thereby maintain a desired spacing between each seal and each perforation.

Method and apparatus for maintaining proper perforation phasing

In an apparatus for rolling up web material which comprises a disk or turret rotatably mounted on a stationary frame and a plurality of mandrels rotatably mounted to the disk, each mandrel being indexable to each of a take-up position, a waiting position and a removal position through selective rotation of the disk, the improvement which comprises a source of compressed air connected to the frame adjacent the removal position, a separate vacuum tube apparatus connected to the frame adjacent the waiting position and being axially movable toward and away from the waiting mandrel, a vacuum pump connected to the vacuum tube apparatus for creating a vacuum in the vacuum tube apparatus, the mandrels each comprising a longitudinal bore extending from an open end thereof and a plurality of radial nozzles communicating with the longitudinal bore, wherein the vacuum tube apparatus is selectively movable into contact with the open end of the waiting mandrel so that the vacuum is communicated through the nozzles to thereby draw the web material around the waiting mandrel, and wherein the source of compressed air is communicated with the mandrel in the removal position so that compressed air is communicated through the nozzles to thereby assist in removing the completed roll of web material from that mandrel.

Apparatus for rolling up web material

Disclosed is a mechanism, associated with a thermoplastic bag making machine, for preparing a strip of thermoplastic to produce bags having the upper edges of the bag mouth formed in a sinusodial shape such that the peak of such shape is substantially equi-distant relative to the side edges of the bag. While the disclosed bag machine is of the type that advances the web strip incrementally, shaping of the web strip in the sinusodial shape occurs while a portion of the web strip is advanced at substantially constant velocity. A mechanism is provided for maintaining constant tension in the web despite the constant and intermittent feeding of the web.

Thermoplastic bag machine

A method and apparatus for producing thermoplastic bags from an elongate web. Apparatus for feeding the web includes devices for producing mounting holes and perforations along a circular path surrounding the holes. The web is severed and sealed to produce sheets containing a mounting hole encircled by the perforations. A selected number of successive sheets are impaled on a post projecting through the holes. A stack having a selected number of sheets is accumulated on a post fixed to a support supporting a medial zone of the sheets which are combined by a heated punch penetrating the sheets in the area enclosed by the perforations.

Method and apparatus for producing bags

Disclosed is an apparatus for slitting a continuous strip of thermoplastic web by a knife heated to a temperature below the melting or fusing temperature of the web. By heating the knife the cutting force is substantially reduced.

Cutting thermoplastic webs

The disclosed cutting method and apparatus produces a pattern cut in web material by providing a generally conically-shaped rotatable anvil and oppositely disposed knife edge shaped to produce the pattern cut. The axes of symmetry containing the apex of the cone is positioned at an acute angle to the axes about which the cone is rotated. With the web positioned over the knife, the knife is brought into pressure engagement with the anvil thereby piercing the web substantially at a point. Rotation of the anvil effects progressive cutting as the anvil surface traces the cutting edge of the knife.

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Gijzegem-Aalst, Belgium

Emiel Y Lambrecht