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US 4,120,716 AGranted
Method of applying printed labels to flexible envelopes using corona discharge treatment
AssigneeW. R. Grace & Co.
InventorRobert Andre Bonet
Life of this patent
Estimating the term…
Abstract
Plastics bags are formed by welding a continuous tube or a pair of continuous films or a continuous folded film, and the finished bags are marked by attachment of pre-printed panels of plastics material using adhesion by corona-discharge irradiation of both the bag material and the printed panel material.
Claims6
A method of applying printed labels to flexible envelopes comprising
- (a) providing a first flattened tubular thermoplastic film material and sealing it transversely at periodic intervals and then severing the sealed tubing at periodic intervals so as to construct a flexible envelope having a sealed bottom and open top,
- (b) forming printed labels by printing a series of repetitive indicia on a second sheet of thermoplastic film the width of each of said indicia being less than the width of one side of said flattened tubing,
- (c) subjecting a face of the printed labels and at least a portion of the first film material having the same dimensions as said labels to a corona discharge treatment, and
- (d) bringing the treated face of the printed labels into contact with the treated part of the said first film material to bond the printed labels to the said first film material either before, during or after formation of the flexible envelope, and wherein
- the step of bringing into contact is carried out without generalized application of heat.
2 more elements
Dependencies are inferred from the claim text.