Fabric (woven – knitted – or nonwoven textile or cloth – etc.) – Woven fabric – Including a free metal or alloy constituent
Reexamination Certificate
1999-08-26
2001-06-05
Cole, Elizabeth M. (Department: 1774)
Fabric (woven, knitted, or nonwoven textile or cloth, etc.)
Woven fabric
Including a free metal or alloy constituent
C442S237000, C428S198000, C428S594000, C428S911000
Reexamination Certificate
active
06242371
ABSTRACT:
BACKGROUND OF THE INVENTION
1. FIELD OF THE INVENTION
The present invention relates to material which may be used to wrap rolls or sheets of metal that is both tear and puncture resistant, and particularly to laminated thermoplastic materials.
2. DESCRIPTION OF THE RELATED ART
Various materials have been made with combined layers of material so that the final product exhibits the properties of both layers. No materials exist, however, possessing the unique properties of the present invention, including tear resistance, puncture resistance and corrosion inhibitors.
U.S. Pat. No. 2,742,388 issued Apr. 17, 1956 to A. W. Russell discloses a method of bonding and curing two or more plastic sheets to provide enough rigidity for use as structural members. The cellophane strip longitudinally between the edges to form a pocket in which a shaping tool may be inserted with the application of heat to soften and shape the fibers.
U.S. Pat. No. 3,130,647 issued Apr. 28, 1964 to W. E. Anderson, et al. describes a method of bonding a resilient or fragile layer to a relatively nonresilient layer, such as paper, by heat bonding with the application of pressure. U.S. Pat. No. 3,715,251 issued Feb. 6, 1973 to J. S. Prentice teaches lamination of nonwoven mats of thermoplastic fibers by adhesives or point welding to produce a laminated nonwoven sheet of material.
U.S. Pat. No. 4,668,566 issued May 26, 1987 to Ralph V. Braun discloses a multilayer material comprising a layer of polyethylene bonded to a layer of polypropylene to form a nonwoven fabric. U.S. Pat. No. 4,748,070 issued May 31, 1988 to David C. Beehler teaches a polypropylene web bonded to a polypropylene film to increase the tear strength of the film. U.S. Pat. No. 4,749,423 issued Jun. 7, 1988 to Vaalburg, et al. describes a method of bonding a nonwoven web of thermoplastic fibers.
U.S. Pat. No. 5,272,023 issued Dec. 21, 1993 to Yamamoto, et al. describes a method of making a hot melt adhesive fiber sheet. U.S. Pat. No. 5,342,469 issued Aug. 30, 1994 to Bodford, et al. discloses a method of laminating a spunbond web of polyethylene fiber to a film using adhesive in which the adhesive layer is discontinuous. U.S. Pat. No. 5,424,115 issued Jun. 13, 1995 to Ty J. Stokes teaches a method of point bonding sheets of conjugate fibers such as polyolefin and polyamide fibers.
Canadian Patent No. 639,751 published Apr. 10, 1962 teaches a method of spot welding polyethylene film sheets. French Patent 1,307,386 published Sep. 17, 1962 describes methods of bonding sheets of plastic materials. German Patent 1,490,626 issued Aug. 13, 1963 describes an insulating paper for high tension wires bonded by spot adhesives. Japanese Patent 52-43594 describes bonding paper or cloth to a polypropylene base by adhesives. Japanese Patent 60-68934 describes a waterproof laminate composed of three layers, the second being polyurethane.
U.S. Pat. No. 4,290,912, issued Sep. 22, 1981 to Boerwinkle, et al., describes an article having volatile corrosion inhibiting properties, the article being a polyolefin polymer to which a mixture of an inorganic nitrite salt, a 2,4,6-trisubstituted phenol containing 9 to 24 carbon atoms, and fumed silica is added. The use of volatile corrosion inhibitors in packaging materials and to protect steel from corrosion is discussed in
Corrosion
, Vol. 2 (Sheir, L. L. and Jarman, R. A., eds.), published by Butterworth Heinemann in 1994, pp. 17:6 to 17:9, and in Steelwork Corrosion Control, D. A. Bayliss and K. A. Chandler, published by Elsevier in 1991, pp. 318-320.
Various methods of forming nonwoven fabrics generally, are discussed in Kirk-Othmer,
Encyclopedia of Chemical Technology, Vol.
10, pp. 546-47. A further description of forming nonwoven, spunbonded plastic fabrics is disclosed in Kirk-Othmer,
Encyclopedia of Chemical Technology
, Vol. 17, pp. 303-309 and 336-338, and their use as packaging for steel and aluminum coils is particularly disclosed at p. 366.
None of the above inventions and patents, taken either singularly or in combination, is seen to describe the instant invention as claimed. None of the above inventions and patents describe a material combining tear and puncture resistance with corrosion inhibition suitable for wrapping rolls or sheets of metals such as steel and aluminum. Thus a tear/puncture resistant semi-laminate material solving the aforementioned problems is desired.
SUMMARY OF THE INVENTION
In steel mills it is useful to wrap or separate rolls or sheets of steel for protection during storage or transport. Currently the material used is composed of a layer of woven polyethylene bonded to a 1 mil extrusion of film and a reinforcing ply of kraft paper. When tears or punctures develop, the kraft paper tends to absorb water, and consequently the steel can become corroded.
Further, the material currently used is prepared by extruding the film over the layer of woven polyethylene and heat bonding the layers by processing the combined layers through the nip of rollers under pressure to produce a material uniformly bonded throughout its length and width. By uniformly bonding the two layers of material together, the material loses some of its elasticity.
As described in the original application, the material of the present represents an improvement in the materials currently available in the steel packaging industry, comprising a layer of woven high density polyethylene, bonded at points or in strips around its edges or at discrete, discontinuous intervals across its width to a layer of low density polyethylene film to form sheets 60″ to 120″ wide. The layer of polyethylene film is impregnated with a volatile corrosion inhibitor. Alternatively, the layers may be made from polypropylene.
The layer of woven, high density polyethylene or woven polypropylene was selected for its strength and tear resistance, which are particularly suitable for wrapping large rolls or coils of steel, aluminum, and other metals. However, it has been determined that other forms of polyethylene and polypropylene also provide sufficient strength and tear resistance to be useful for the packaging of rolls of steel or aluminum coils.
It has also been realized that the primary site subject to tearing in the packaging of large rolls of steel, aluminum, and other metals is located over the circumference of the coil, the core of the coil not being exposed to damage from tearing. Therefore, a considerable economy of costs may be achieved by making the two layers of material in different sizes, as by making the tear resistant layer just large enough to fit over the circumference of the coil, the second layer being large enough to cover the entire coil, including both the entire width of the coil between the opposing edges and the core of the coil. Alternatively, the film, or water impermeable layer may be made smaller than the tear resistant layer.
Finally, it will be understood that the description of the semi-laminate material as being formed in sheets 60″ to 120″ wide is by way of illustration and not by way of limitation. The sheets may be formed in any desired width, including widths over 120″.
Accordingly, it is a principal object of the invention to provide a tear and puncture resistant material for wrapping metals for storage or transport having improved moisture protection by layering sheets so that a tear or puncture in one layer does not necessarily extend to another layer.
It is another object of the invention to provide a tear and puncture resistant material for wrapping metals for storage or transport having greater elasticity than materials currently used in the industry by providing a material produced using a method of lamination in which the properties of one layer are not affected by the properties of another layer or by the process of lamination itself.
It is a further object of the invention to provide a material which is tear and puncture resistant and which also inhibits corrosion by using a material having a layer impregnated with a corrosion inhibitor.
It is an object of the invention to p
Cole Elizabeth M.
Litman Richard C.
LandOfFree
Tear/puncture resistant semi-laminate material does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Tear/puncture resistant semi-laminate material, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Tear/puncture resistant semi-laminate material will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2471516