The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 18, 1978
Filed:
Mar. 31, 1972
Richard C Adams, West Barrington, RI (US);
G. T. Schjeldahl Company, Northfield, MN (US);
Abstract
Thermoplastic web treating apparatus, particularly adapted for the fabrication of flexible bags and comprising, in combination, a web treating station along with means for intermittently advancing webs through the station. The treating station includes thermal welding or sealing apparatus with a welding bar and sealing pad combination for forming spaced seals in the web, and a cutting blade for cutting or shearing the web. The apparatus is designed to provide tension during cutting operations, and to eliminate tension prior to and during sealing operations to permit 'relaxation' of the film prior to formation of the seal, as well as to break away any bond which may form between the thermoplastic web and the sealing pad from the sealing operation. This break-away of the bond is accomplished through an initial short duration reversal of the web draw rolls prior to each web advance.