Extruded zipper strips for bags

Abstract From the Canadian patent

A bag has a reclosable zipper between wall panels and extending between side edges at the top end of the bag the zipper comprising a continuous length of extruded profile plastic strip folded upon itself for zipper closing interengagement of its profile parts, the profile strip portions being spot welded together at the fold in the strip which may be at one of the side edges of the bag such as a, fold in the material which provides the walls of the bag. The strip may be notched out to facilitate folding. Bydifferential mass or differential spacing, or tilted, biasing of profile parts of the zipper strip and provision, of a laterial flange of substantial width on the strip not only is …