US 4,682,941 AGranted

Flattening and take-off apparatus for providing a plastic film web from a blown tubular film

AssigneeWindmoller & Holscher

InventorsHartmut Upmeier, Rudolf Peters

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Abstract

Flattening and take-off apparatus for use with a device for providing a blown tubular film. The apparatus includes a flattening device for flattening the tubular film, and a cutting device for cutting one lateral edge of the flattened film. A pair of pinch rollers is provided and is driven to carry the cut and flattened film to an unfolding device, which is defined by a pair of edges that are inclined relative to the direction of movement of the film web, and over which respective ones of the juxtaposed portions of the cut flattened web are adapted to pass to define a single ply web. The pinch rolls include removable spacing rings to prevent the formation of a fold line on the opposite lateral edge from the cut edge of the flattened film. The unfolding device is movable laterally and parallel to the direction of movement of the film.

Claims11

Dependent claims

A flattening and take-off apparatus for a tubular plastic film extruded from a stationary film extrusion head, said apparatus comprising:

(a) flattening means positioned downstream of the film extrusion head for flattening a tubular film;
(b) a pair of rotatable pinch rolls positioned downstream of said flattening means and having their axes in parallel relationship for receiving flattened tubular film therebetween;
(c) cutting means positioned between said pinch rollers and said flattening means for longitudinally cutting said flattened film along one lateral edge thereof to define a pair of juxtaposed film portions connected at an opposite lateral edge of said flattened tubular film;
(d) unfolding means positioned downstream of said pinch rollers for receiving said cut flattened film and for progressively turning each of said juxtaposed film portions in opposite directions about said opposite lateral edge until the juxtaposed film portions are substantially coplanar to provide a substantially flat web, said unfolding means including an edge contact member in contact with said opposite lateral edge of said film, and outwardly diverging elongated edge members about which respective ones of said juxtaposed film portions are adapted to pass;
and
(e) adjusting means for adjusting the position of said unfolding means relative to the axis of said tubular film.

3 more elements

Dependencies are inferred from the claim text.