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US 4,285,750 AGranted
Method for producing a plastic sleeve
AssigneeOwens-Illinois, Inc.
InventorEdward A. DeMartino
Life of this patent
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Abstract
A sleeve forming apparatus wherein a rectangular sheet of thermoplastic material is formed into a tubular shape having overlapped end portions that are sealed together so as to minimize the lap thickness of the seam. Also disclosed is a method of forming a tubular shape wherein the seam area is worked to minimize its thickness while preserving its liquid-tight characteristics.
Claims4
In the method of making a tubular sleeve of thermoplastic sheet material including the steps of;
- (a) feeding a strip of sheet stock to a winding apparatus which includes a rotatable turret,
- (b) severing said strip into individual rectangular blanks each having a leading edge and a trailing edge,
- (c) forming each of said blanks into a cylindrically shaped sleeve by wrapping it around a mandrel,
- (d) overlapping the trailing edge of said blank so that it is exterior of the leading edge of said blank,
- (e) applying a softening medium to the edges of said blank, the improvement in the method of making a sleeve comprising the additional steps of;
- (f) moving said mandrel and its exteriorly positioned blank past an arcuate sealing plate, and
- (g) ironing the overlapped edges of said blank by the relative movement and contact between said sealing plate and said blank whereby the overlapped softened edges fuse together to form a smooth seam.
4 more elements
Dependencies are inferred from the claim text.