초록 ▼

A reclosable bag is formed of a first wall and a second wall of a polymeric sheet material joined to form an enclosure with a mouth defined by the wall edges. The bag has a closure for selectively opening and sealing the mouth. The closure includes a first and a second mutually interlocking profile,

A reclosable bag is formed of a first wall and a second wall of a polymeric sheet material joined to form an enclosure with a mouth defined by the wall edges. The bag has a closure for selectively opening and sealing the mouth. The closure includes a first and a second mutually interlocking profile, each of which extends along and is bonded to the internal surface of its respective first and second wall. The first and second mutually interlocking profiles are extruded from a first polymeric resin material, and have a web portion which is bonded to the wall. Coextruded onto the web portions, or applied to the web portions following the extrusion of the strips, is at least one rib of a second polymeric resin material which includes an ultraviolet-light-excitable tracer material. The second polymeric resin material has a lower melting point than the first polymeric resin material, and is used to bond the profiles to the sheet material of the walls. Before such bonding, the ribs appear as discrete lines under ultraviolet light. After a complete bonding, the ribs disappear and are replaced by a smeared brightening of the region between the profiles and the sheet material of the walls. The appearance of ribs after bonding indicates an unsuccessful bonding operation that could possibly lead to an increase in the occurrence of leaking packages.

대표청구항 ▼

[ What is claimed is:] [1.] A closure for selectively opening and sealing the mouth of a reclosable bag, said closure comprising:a first mutually interlocking profile and second mutually interlocking profile extruded from a polymeric resin material, said first and second mutually interlocking profil

[ What is claimed is:] [1.] A closure for selectively opening and sealing the mouth of a reclosable bag, said closure comprising:a first mutually interlocking profile and second mutually interlocking profile extruded from a polymeric resin material, said first and second mutually interlocking profiles including a web portion, an interlocking member on one side of said web portion, and at least one fusible rib of a polymeric resin material on the other side of said web portion, said at least one fusible rib on at least a portion thereof including an ultraviolet-light-excitable tracer material, so that said ribs may be visible under ultraviolet light and whereby upon bonding said closure to a bag material the region of said bond may be viewed under ultraviolet-light to determine that said ribs have fused to said bag material.