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:
Mar. 26, 1991
Filed:
Feb. 27, 1990
Bora Tekkanat, Milwaukee, WI (US);
Alan A Kovacich, Milwaukee, WI (US);
Bryan L McKinney, Shorewood, WI (US);
William H Tiedemann, Cedarburg, WI (US);
Hoover Universal, Inc., Ann Arbor, MI (US);
Abstract
A method and apparatus for determining the environmental stress crack resistance of plastic articles, such as polyethylene terephthalate containers, are provided. In accordance with the method of the invention, the internal chamber of a hollow plastic article is pressurized, the exterior of the base is then exposed to an environmental stress cracking agent, and it is then determined if crazing and/or changes in the base clearance of the plastic article have occurred. Subsequent increases in pressure and subsequent exposures and determinations yield information on the environmental stress cracking characteristics of the container.