Refrigeration – Refrigerant or coolant – storer or handler – Envelope type
Reexamination Certificate
1998-05-15
2001-08-07
Doerrler, William (Department: 3744)
Refrigeration
Refrigerant or coolant, storer or handler
Envelope type
C062S457100
Reexamination Certificate
active
06269654
ABSTRACT:
REFERENCE TO RELATED APPLICATIONS
Reference is hereby made to the co-pending patent application entitled “Hydration and Freezing Plant for Flexible Refrigerant Media” filed Jul. 11, 1997 as Ser. No. 08/893,405 by two of the same co-inventors as those of the present application, namely, Messrs. Murray and Gaude, the disclosure of which application is incorporated herein by reference, and also to the patent application entitled “Modular Hydration and Freezing Plant for Flexible Refrigerant Media” filed May 8, 1998 as Ser. No. 09/075,429, now U.S. Pat. No. 5,966,962 issued Oct. 19, 1999 also filed by Messrs. Murray and Gaude, the disclosure of which application also is incorporated herein by reference. Reference is also had to U.S. Pat. No. 5,628,845 issued May 13, 1997 entitled “Process for Forming Hydratable, Flexible Refrigement Media” by Murray and Browne, the former being one of the co-inventors hereof, the disclosure of which application likewise is incorporated herein by reference.
TECHNICAL FIELD
The present invention relates to devices used to produce or maintain desired temperature levels different from the ambient for an extended period of time, and more particularly to hydratable packets made of a superabsorbent material packaged between a backing sheet and a porous sheet sealingly affixed together, with the superabsorbent material being contained in spaced, packets or cells presented in sheet form. Such packet sheets are hydrated, in which process the superabsorbent material absorbs a substantial amount of water, with the packet then being typically frozen or heated (e.g. in a microwave unit) to a relative temperature extreme from the ambient. The frozen or heated packet is then typically placed in a container holding goods to be either kept cooled or hot for a significant period of time.
The invention has particular applicability in the transportation and recreational fields, as well as elsewhere.
BACKGROUND ART
It is well known in the transportation industries to attempt to achieve some degree of desired temperature control, using, for example, gel packs, “dry ice” (frozen carbon dioxide) and the like. However, these products have very limited capabilities in the period of time they can affect the desired temperature and/or pose significant safety hazards.
The present invention solves or at least substantially diminishes these prior art problems with sheets of packet materials which include porous cells containing a superabsorbent polymer. These packet sheets are initially submerged in water, hydrating them, and the hydrated sheets are then frozen (for cooling effects) or heated (for heating effects) and placed in juxtaposition to the goods to be cooled/heated. As the sheet(s) begin, for example, to warm up or thaw, the absorbed water goes directly from the frozen state into a gaseous state, avoiding wetness problems. The cells are formed in packets, producing longitudinally and laterally extended separation lines, which allow the completed packet sheets to be folded about either or both axes and thus contoured around the goods being cooled (or heated).
The background of the present invention goes back to the beginning of the breakthrough technology initially suggested in PCT/US92/06486 (published as WO 93/02861 on Feb. 18, 1993) and invented by George Barrett (now deceased), a predecessor to the work that led up to the present invention. In this PCT application there was disclosed an experimental device formed from composite sheets, namely two, layers of laminated textile material, one of which was semi-permeable to moisture, fused or otherwise sealed together, containing between them discrete quantities of a superabsorbent material in cells arrayed in a regular pattern, which superabsorbent readily absorbed water and could then be frozen to provide a substitute for ice and dry ice. The composite sheets were sealed or bonded together using rollers and applying heat and pressure. The fabric used allowed forming such bonds by thermoplastic fusing and the specification, in an off-hand manner, included the statement “or may involve a suitable adhesive” (page 5, line 1) without any further reference or explanation but instead speaks solely of forming the bond between the sheets using only the sheet materials themselves and heat and pressure to form the bond. As noted on page 7, line 10+, “The fabrics are selected to allow formation of a secure bond there-between using heat and pressure produced in the subject machine.” and at page 9, line 16 “The bond is formed under the influence of the heat and pressure thus applied to the bonding area [the area surrounding the cells].” There thus appears to be a teaching away from the use of an adhesive, and there is absolutely no suggestion of putting an adhesive in the areas where the cells are formed, as in the present invention.
The disclosure of this publication is likewise incorporated herein by reference, except for its teaching away from there being an adhesive layer added to one of the layers of sheet material.
In or about 1994 there was a commercialization of such packet sheets using a superabsorbent, single cross-linked polymer (herein after referred to as the “1994 technology” or “1994 product”), described more fully below.
In subsequent U.S. Pat. No. 5,628,845 entitled “Process for Forming Hydratable, Flexible Refrigerant Media” issued May 13, 1997 (filed Sep. 28, 1995) by Murray (a co-inventor hereof) et al, the disclosure of which is incorporated herein by reference, describes the materials to be used in connection with the process to make the flexible refrigerant media as follows:
“a length of impermeable thermally formable media such as a plastic film, for example a 1.22 mil one side sealable biaxially oriented polypropylene film or a 1.75 mil coextruded multiply film including layers of high density polyethylene, a tie layer and a sealant layer. The foregoing examples are not intended to be limiting in as much as the apparatus and process may be used with a number of medias which lend themselves to thermal and pressure bonding.” (Col. 2, lines 40-48.);
“a length of a semi-permeable media such as a non-woven fabric. As used herein and as generally understood non-woven fabrics are made directly from fiber rather than yam (sic) by bonding or interlocking of fibers or both, accomplished by mechanical, chemical, or solvent means and combinations thereof. The non-woven fabric and the plastic film are both preferentially a standard width, such as sixty inches” (Col. 2, lines 49-56.); and
a “quantity of superabsorbent polymer media appropriately selected from the known superabsorbents such as crosslinked acrylics; starch-graft polymers; cross-linked glycote and cellulose esters; and generally refers to water swellable polymers capable of at least a ten fold absorption of aqueous fluids forming a gel which holds fluids by a physicochemical reaction that is resistant to fluid loss under pressure. In the preferred embodiment, the polymer is powder-like or particulate in nature . . . ” (Col. 3, lines 24-34.)
The present invention is directed to a vastly improved and innovative porous, laminated, superabsorbent, hydratable, temperature control pack system, which is able to maintain, for example, its cooling temperature characteristics more than eight (8) times longer than the 1994 technology's hydratable temperature control packet, a factor of more than eight-to-one (>8:1), indicating a difference in kind rather than merely of degree. Additionally, the preferred embodiment of the invention is much stronger and more reliable than the predecessor product.
For further background informational purposes, not prior art purposes, it is noted that, in the above-referenced patent application Ser. No. 08/893,405, the materials disclosed for the plastic film layer is “plastic Polypropylene,” for the porous web material “a non-woven fabric such as 2 oz. Polypropylene” and for the absorbent particulate matter “a super absorbent polymer such as sodium polyacrylate, crosslinked.”
A listing of prior patents and other pu
Don Gaude Lyman E.
Gabel Kimberly Lynn
Murray Joseph C.
Doerrler William
Pugh C. Emmett
Pugh / Associates
Thermal Products, Inc.
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