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:
Apr. 25, 1989
Filed:
Feb. 22, 1988
David K Stock, Green Bay, WI (US);
Amplas, Inc., Green Bay, WI (US);
Abstract
A draw tape bag forming apparatus includes an edge folder for folding the edges of pliable plastic web to form a hem in the edge. A draw tape is fed into the open hem which is then heat sealed along the inner edge of the hem wall to form a tubular hem. The web is of an indefinite length and moves continuously through the machine. The heat sealed hem is an expanded air-filled type hem. An electrostatic generator unit is mounted downstream of the ballooned hem. The generator unit includes a charging bar mounted in spaced relation to reference ground plate to form a gap with the ballooned hem passing therebetween. The hem is aligned with the bar. A 120 volt power supply is connected to the charging bar and establishes a high voltage along the length of the bar. An electrostatic field is created across the gap and induces a charge in the walls of the hem the hem collapses against the ground plate to form a flat hem in the web for subsequent passing of the web through a bag making machine which seals and severs the web on longitudinally spaced lines to form the bags. The power supply may establish a negative voltage relative to the ground plate. The power supply may be directly connected to the bar and plate.