US 6,296,886 B1Granted

Method of film crease elimination and patch bag without crease within lay-flat bag side

AssigneeCryovac, Inc.

InventorsLarry W. DePoorter, Donald B. Moore, Jr., Robert A. Odabashian, Joseph M. Ramirez, Carl L. Tucker, Richard M. Worley

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Abstract

A process for removing creases from a film eliminates a problem in the quality of the heat seal for a patch bag having at least a segment of one or more bag side edges (or the bag bottom edge) covered by one or more patches. The film creases are removed by inflating the film tubing which is later converted to a bag, heating regions containing the creases with a heating means to a temperature which, in combination with the pressure within the inflated tubing, causes the creases to relax. The heated crease-containing regions are then cooled and the inflated tubing is deflated and wound up in a new configuration in which at least one patch covers at least one side edge or the bottom edge.

Claims16

Dependent claims

A process for making a patch bag, comprising:

(A) adhering a patch to a first lay-flat side of a film tubing while the tubing is in a first lay-flat configuration, whereby a lay-flat tubing-patch laminate is formed, the lay-flat tubing having a first crease along a first side edge and a second crease along a second side edge;
(B) passing the lay-flat tubing-patch laminate through a first pair of nip rolls with the tubing being inflated by a trapped bubble of gas between the first pair of nip rolls and a second pair of nip rolls, whereby an inflated tubing-patch laminate is formed;
(C) heating a first region of the inflated tubing-patch laminate which contains the first crease, and a second region of the inflated tubing-patch laminate which contains the second crease, the heating being carried out so that each of the creases is removed;
(D) cooling the first and second regions of the inflated tubing-patch laminate;
(E) deflating and flattening the inflated tubing-patch laminate into a second lay-flat configuration by passing the inflated tubing-patch laminate through the second pair of nip rolls which have a nip which is oriented from about 10 to 90 degrees off-parallel relative to a nip of the first pair of nip rolls, so that a reconfigured lay-flat tubing-patch laminate is formed in which the patch covers a segment of a first new side edge of the tubing;
and
(F) sealing and cutting the reconfigured lay-flat tubing-patch laminate in the second lay-flat configuration so that the patch bag is formed from a segment of the tubing having the patch adhered thereto.

4 more elements

Dependencies are inferred from the claim text.

Facts

Application: 08/819,841Filed 17 Mar 1997
Granted: 2 Oct 2001
Term ends: Not estimatedThe source records don’t support an estimate.

Classification8 codes

B65D 33/02
Details of, or accessories for, sacks or bags: local reinforcements or stiffening inserts, e.g. wires, strings, strips or frames
B32B 27/08
As the main or only constituent of a layer, which is next to another layer of the same or of a different material: of synthetic resin
B31B 70/003
Making flexible containers, e.g. envelopes or bags: opening or distending bags
B31B 70/10
Feeding or positioning sheets, blanks or webs: feeding or positioning webs