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:
Oct. 11, 1988
Filed:
Apr. 08, 1987
James D Cross, Waterloo, Ontario, CA;
Other;
Abstract
Spark perforation of synthetic plastic film is carried out by applying electrodes to opposite ends of a portion of the film submerged in a water bath that is at a temperature above the onset temperature of glass transition of the film,and applying short fast rise time electrical pulses of an amplitude sufficient to ensure dielectric breakdown of the film. The size of the perforations formed can be controlled by altering the temperature of the water bath. By using short fast pulses, energy consumption, film decomposition and electrode erosion are minimized, and the high dielectric strength of water can be exploited to control perforation while its conductivity can be exploited to remove residual electric charges from the film. Capacitors formed by lengths of coaxial cable are used by a pulse generator for generating pulses having rise times less than one microsecond.