US 2467268 A
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April 12, 1949. a. MERKLE SHIPPING PACKAGE USING DRY ICE Filed Dec. 8, 1943 INVENTOR GUSTAV MERKLE ATTORNEY Patented Apr. 12, 1949 2,467,268 snirrmc PACKAGE USING par ICE Gustav Merkle, Philadelphia,
to Sherman ucts Corporation, Newton Upper Falls, Mass.,
Pa., assignor, by
Paper Proda corporation of Massachusetts Application December 8, 1943, Serial No. 513,422 "1 Claims. (Cl. 62-1) My invention is an improved refrigerated shipping package for the transportation of perishable articles at a temperature substantially below that of the ambient atmosphere but substantially above the temperature of the refrigerant, and the primary object of my invention is the provision of a shipping package in which all of the perishable articles in the package are maintained at a substantially uniform temperature, and such temperature is maintained substantially constant over a considerable period of time.
My invention is particularly designed to provide a shipping package suitable for the shipment of perishabl articles which retain their quality only within a relatively narrow temperature range and are subject to deterioration by freezing temperatures or by temperatures warm enough for bacterial growth.
The sensitivity of sea food, in particular, to deterioration by relatively slight variations in temperature has hitherto precluded the utilization of intense refrigerants, such as solidified carbon dioxide, commonly known as dry ice," in the commercial transportation of such products, although many efforts have been made to provide fish and oyster shipping packages refrigerated by dry ice.
My invention provides a light and strong ship ping package by which fish, oysters, clams and other thermal sensitive products, as well as perishable products of less be economically shipped without danger of deterioration or spoilage and with a minimum consumption of dry ice."
In accordance with my invention, a subliming refrigerant, preferably solidified carbon dioxide, is disposed between two layers of perishable products which are separated from the refrigerant by separators or thermal control pads of low and preferably unequal thermal conductivity, and the cold gas sublimed from the refrigerant is retained adjacent to th perishable products by a carton enclosing the refrigerant, the pads and the perishable products: the carton being so constructed and sealed as to retard the escape of the cold gas, at least until the carton is completely filled therewith. Preferably the refrigerant and the thermal pads on the opposite sides thereof are housed within an enclosure or folder having flaps forming corner joints permitting sion of gas therethrough, whereas the perishable articles are enclosed in-boxes each comprising a telescoping body and lid limiting the ingress of cold gas into the interiors thereof.
The characteristic features and my improvements thermal sensitivity, may
relatively free emisverse sectional will further appear from the following description and the accompanying drawing of an illustrative embodiment of my invention.
In the drawings, Fig. 1 is a perspective view of a shipping package embodying my invention,
with parts broken away to show the interior; Fig.
2 is an exploded perspective view showing the components of my improved shipping package arranged in the order of their assembly as a shipping package, with parts broken away on some of the components; Fig. 3 is a fragmentary diagrammatic plan view of a thermal insulator embodied in thermal control pads utilized in the preferred form of my improved shipping package; Fig. 4 is a fragmentary enlarged diagrammatic sectional view of laminations of a thermal control pad; Fig. 5 is a cross sectional view of the upper thermal control pad utilized in my improved shipping package; and Fig. 6 is a transview of the lower thermal control pad utilized in such package.
In the embodiment of my in the drawings, there is utilized a corrugated fibre board carton I comprising the bottom 2, the side walls 3 and 4, the end walls 5 and 6, and the overlapping flaps I, 8, 9 and III, which are overlaraped and sealed by an adhesive strip H to form a p.
The carton I contains a bottom box l2 comprising telescoping body and lid members 13 and H. The box I! is preferably inserted in" the carton I, as shown in Fig. 1, so that the mouth of the edge slot between the members [3 and II I opens upward, that is, toward the refrigerant chamber, so that cold gas admitted to the refrigerating chamber l5 formed by the box enters at the bottom thereof. The box may, however, be inserted in the opposite position, Fig. 2.
The refrigerating chamber I5 is packed with perishable products for transportation under controlled temperature conditions.
A cardboard folder [6 is formed with a base l1 having hinged thereto sides l8, l9 and ends 2|! and 2|, and top flaps 22, 23, 24 and 25 are hinged to the sides and ends to provide an enclosure for .a plurality of thermal control pads 26 and 21 on opposite sides of the refrigerant 28; the refrigerant consisting of a slab of solidified carbon dioxide.
The lower pad 26 is of less thermal conductivity (viz., provides greater insulation) than the upper pad 21. When the pads and refrigerant are advantages of lit-assembled, the flaps 22, 23, 2t and 25 are folded invention illustrated as shown in chamber, so that v temperature of the room over so as to provide a case containing a refrigerant chamber and forming a spacer between upper and lower refrigerated chambers. Such case permits controlled egress, through its open corner and top joints, of carbon dioxide gas sublimed from the refrigerant 28. v
An upper box 29, comprising telescoping base and lid members 30 and 3|, is placed above the refrigerant chamber formed by the case [6. The box 29 provides a second refrigerated chamber 32 for perishable products. Preferably the mouth of the edge slot between the base 30 and lid 3| opens downward, that is, toward the refrigerant cold gas passing .between the telescoped members into the chamber 32 enters the top thereof.
It will be understood that the admission of cold gas to the portions of the refrigerating chambers remote from the refrigerant tends to compensate for the greater conductance between the refriger ant and the portions of the refrigerated chambers proximate to the refrigerant.
The pads 26 and 21 preferably consist of laminated and folded sheets of kraft paper, or other suitable fibrous sheet material 33, which is coated with a flexible binder 34 of low thermal conductivity, such as a moisture-resistant, odorless, thermoplastic mixture of petroleum asphalt and oil, in which, if desired, there may be mixed a small amount of wax and/or inert filler.
The binder is applied hot to the base 33. While the binder is still fluent and viscid, it is coveredwith concave-convex, membranaceous particles of low inherent thermal conductivity, such as buckwheat hulls or similar chafl. The edges or small areas of the chaff become embedded in the binder, but the latter is sufficiently viscid to float the chaff and prevent the immersion thereof and its dispersion through the body of the binder. A sufficient quantity of chaff is scattered on the it and form, when the binder has solidified, a porous or honeycombed layer containing numerous small pockets or cells providing dead air spaces. The porous, honeycombed layer of haphazardly arranged, cupular particles prevents or minimizes the formation of convection air currents and acts as a thermal control or insulator. The binder not only positions the membranaceous particles, but prevents precipitation or transmission of moisture and retards the transmission of heat.
Sheets so formed are folded into pads, which may be housed in sealed envelopes 35 and 36, as illustrated in Figs. and 6.
With a package so constructed and assembled I am enabled to maintain perishable products in the refrigerated chambers l5 and 32 at a substantially uniform temperature throughout and at a substantially constant temperature for a considerable period of time.
For instance, twenty-three and a half pounds of solidified carbon dioxide, housed between pads 26 and 21 of unequal thermal conductivity, in a folder I6, as above described, was found sufficient to refrigerate 40 lbsof fresh cod fillets placed in refrigerated boxes I 2 and 29 on opposite sides of the refrigerant 28; the assembly being housed in a sealed shipping carton I. The containing the package was maintained at approximately 70 F. continuously. At the start, the temperatures in various parts of the food compartments or refrigerated chambers were between 37 and 4 F. at the end of twenty-four hours the temperatures in the various parts of the food compartments were between 30 and 38 F.; at the end of forty-eight hours the temperatures in the various parts of the food compartments were between 29 and 36 /2 F.; and at the end of sixty-seven hours the temperatures in the various parts of the food compartments were between 30 and 37 /2 F. Four pounds of Dry Ice remained at the end of the test and the appearance and odor of the fillets were unchanged.
Successful packaging tests for periods up to ninety hours duration have been made when the outside temperature varied from 65 to 75 F., and, under outside temperatures of 75 to 90 F., fresh fish fillets packaged in accordance with my invention were held at satisfactory temperatures for upwards of forty-eight hours with from 28 to 40 lbs. of Dry Ice.
Having described my invention, I claim:
1. A shipping package comprising a carton containing a refrigerant chamber and a pair of refrigerated chambersarranged one above and one below the refrigerant chamber, said chambers each having a length and breadth in excess of its height and each chamber superimposed upon another being removable to afford access to the underlying chamber, and separators of low and unequal thermal conductivity between the refrigerant chamber and the refrigerated chambers for controlling thermal transfer between the refrigerant chamber and the respective refrigerated chambers, and said package including a sealed closure.
2. Ashipping package comprising a carton containing a refrigerant chamber and a pair of refrigerated chambers arranged one above and one below said refrigerant chamber, said refrigerated chambers being separated from said refrigerant chamber by thermal control pads of unequal thermal conductivity, the lower heat conducting 40 pad being located below said refrigerant chamher.
3. A shipping package comprising a carton containing a plurality of superposed refrigerated chambers and a refrigerant chamber between said refrigerated chambers, said refrigerated chambers being separated from the refrigerant pads of laminated sheet material, and the thermal control pad separating the refrigerating chamber from one of said refrigerated chambers located beneath said refrigerant chamber containing a greater number of. laminations than the number of 1aminations contained in the thermal control pad separating the refrigerant chamber from other of the refrigerated chambers.
4. A shipping package comprising a hollow receptacle containing refrigerant and refrigerated chambersseparated from one another, a separator between such chambers comprising a layer of moisture-resistant asphalt and a porous, rough anchored in said asphalt and bodies projecting therefrom, each of said-refrigerated chambers being subject to refrigeration from one face only thereof from said refrigerant chamber.
5. A shipping package comprising an external carton, a plurality of cartons adapted for receivof thermal control pads adapted to receive a subliming refrigerant between them, an enclosure surrounding said pads and forming therewith a refrigerant chamber, a carton on each side of said refrigerant chamber and forming'reirigerated chambers, and a carton enclosing said cartons first named and means for sealing said package.
7. A shipping package comprising acorrugatedboard carton, a plurality of boxes within said carton and each comprising telescoped body and cover members, said boxes being spaced from one another, a plurality of thermal control pads between said boxes and adapted to receive between them a subliming refrigerant, and a folder housing said control pads and having flaps forming joints for controlling the flow of subliming refrigerant to said boxes.
REFERENCES CITED The following references are of record in the fiie of this patent:
5 UNITED STATES PATENTS Number Name Date 688,127 Sayre Dec. 3, 1901 1,713,682 Walter May 21, 1929 In 1,727,878 Griswod Sept. 10, 1929 1,825,068 Jones Sept. 29, 1931 1,943,038 McIlvain Jan. 26, 1932 1,883,938 Killef'fer Oct. 25, 1932 2,149,412 Bangs Mar. 7, 1939 15 2,216,365 Fernandez Oct. 1, 1940 FOREIGN PATENTS Number Country Date 788,169 France Oct. 5, 1935 20 159,500 Switzerland Jan. 15, 1933 10,357 Australia Nov. 29, 1932