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:
Aug. 15, 2000
Filed:
Feb. 10, 1998
Donald J Salzsauler, Georgetown, CA;
Edward R Salzsauler, Barbados, WI (US);
Richard G Salzsauler, Rockwood, CA;
Saltech Inc., Barbados, US;
Abstract
A roll of sheet material, such as plastic film wrap, having an inner layer wound at low tension and an outer layer wound under greater tension provides a coreless roll. Eliminating the need for a core reduces the cost of producing rolls of sheet material, and reduces the weight and outer dimensions of the roll with a consequent reduction in shipping and storage costs. An apparatus and method for producing such a roll, from a pre-wound master roll or as part of a production line for forming the sheet material, involves varying the longitudinal tension applied to sheet material as it is wound onto an expandable mandrel. After the roll has cured, the mandrel is collapsed and disengaged from the roll to provide a coreless roll. The mater roll can be prestretched prior to forming the coreless roll, if desired, and can be prestretched as a step in the formation of the coreless roll.