Fabric (woven – knitted – or nonwoven textile or cloth – etc.) – Scrim – Woven scrim
Reexamination Certificate
2000-02-23
2004-08-10
Cole, Elizabeth M. (Department: 1771)
Fabric (woven, knitted, or nonwoven textile or cloth, etc.)
Scrim
Woven scrim
C442S041000, C442S043000, C442S049000, C442S058000
Reexamination Certificate
active
06774062
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates generally to net-reinforced films and, more particularly, relates to a net-reinforced film having a modified netting strand profile to facilitate seal alignment and increase seal strength when the netting is sealed to an opposing netting strand or film.
BACKGROUND OF THE INVENTION
Film sheeting for use in waste bags, food storage bags, and other packages can be made stronger by the attachment or coextrusion of a netting onto the film layer. To use such films for bags or other packages, it is often necessary to seal one section of film to another in a heat seal process. Such seals are necessary, for example, at the sides and/or the bottoms of food storage bags and waste bags. The addition of netting complicates the sealing process because it can be difficult to line up netting strands with each other or with a heating element to assure a complete and strong seal when net-reinforced films must be sealed to each other. Further, sealing films along a thin netting strand can result in a weak seal.
Common net-reinforced films include a uniform profile for the netting strands over the entire span of the net. Sealing is commonly accomplished by the application of heat by a heating element along the seal point. Though the uniform-strand configuration has become standard in the art, it contains netting strands along seal points having the same thin profile as netting strands in the rest of the net. This thinness at the seal points makes it difficult to achieve complete, strong seals because the manufacturer must perfectly align a thin seal strand, a heating element, and an opposing thin seal strand or film.
SUMMARY OF THE INVENTION
Accordingly, an object of the present invention is to provide a net-reinforced film that allows for stronger seals between pieces of film and, at the same time, allows for greater mechanical tolerances in the sealing process.
These objects are achieved by altering the netting strand profiles at seal points. Creating a wider netting profile at seal points allows for greater mechanical tolerances when aligning strands with each other or with a heating element during the seal process. In addition, altering the netting strand profile to have a wider seal area at the seal points enables a stronger seal to be formed than is formed using the standard, thinner netting strand profile at the seal points. Consequently, there is a need for net-reinforced films that have altered netting strand profiles at seal points.
This and other objects are realized by providing a unique net-reinforced film structure. The net-reinforced film structure includes a film layer and a netting attached to the film layer having a pattern of netting strands. The netting strands are sealed to an opposing film structure along a generally linear seal area. The opposing film structure may be either a similar net-reinforced film or a standard non-reinforced film sheet. The netting strands in the non-sealed areas of the net-reinforced film structure are free from attachment to the opposing film structure. The netting strands along the linear seal area have a wider cross-section than the netting strands at the non-sealed areas, and this wider cross-section facilitates the sealing process.
The above summary of the present invention is not intended to represent each embodiment, or every aspect of the present invention. This is the purpose of the following figures and detailed description.
REFERENCES:
patent: 3193604 (1965-07-01), Mercer
patent: 3214320 (1965-10-01), Lappala et al.
patent: 3349434 (1967-10-01), Hurea
patent: 3490507 (1970-01-01), Grashorn
patent: 3595722 (1971-07-01), Dawbarn
patent: 3616130 (1971-10-01), Rogosch
patent: 3884935 (1975-05-01), Burns, III
patent: 4207983 (1980-06-01), Wolske
patent: 4265853 (1981-05-01), Havens
patent: 4265956 (1981-05-01), Colijn
patent: 4285998 (1981-08-01), Thibodeau
patent: 4315963 (1982-02-01), Havens
patent: 4340558 (1982-07-01), Hendrickson
patent: 4348445 (1982-09-01), Craig
patent: 5490596 (1996-02-01), Katz
patent: 5586732 (1996-12-01), Yamauchi et al.
patent: 0 677159 (1996-06-01), None
patent: 0 742093 (1996-11-01), None
patent: 2 153 216 (1971-09-01), None
patent: 2 703 704 (1993-04-01), None
patent: 2 718 509 (1994-04-01), None
patent: 2 748 417 (1996-05-01), None
patent: 2 128 462 (1984-05-01), None
patent: 2 289 398 (1995-11-01), None
patent: 82037452 (1982-08-01), None
patent: 82037453 (1982-08-01), None
Cole Elizabeth M.
Jenkens & Gilchrist
Pactiv Corporation
Pierce Jeremy R
LandOfFree
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