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:
Jan. 20, 1998
Filed:
Apr. 19, 1996
Applicant:
Inventor:
Wayne Ken Shih, Kingsport, TN (US);
Assignee:
Eastman Chemical Company, Kingsport, TN (US);
Attorneys:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
B29C / ;
U.S. Cl.
CPC ...
264 401 ; 264 403 ; 264 406 ; 264553 ; 425140 ;
Abstract
A thermoforming process window of a rectangular sheet of a thermoplastic material is determined by calculating its Sag Number during heating. The Sag Number is a function of the sheets length, width and apex depth at the center of sag. Upon the Sag Number being between 10 and 40, preferably 15 and 35, and more preferably 19 and 28, the sheet is ready for forming into an end product.