US20090126600A1

US20090126600A1 - Insulated cargo container and methods for manufacturing same using vacuum insulated panels and foam insulated liners

Info

Publication number: US20090126600A1
Application number: US11/724,490
Authority: US
Inventors: Ronald J. Zupancich; Joseph A. Seiter
Original assignee: Individual
Current assignee: Martin Marietta Materials Inc
Priority date: 2006-03-15
Filing date: 2007-03-15
Publication date: 2009-05-21

Abstract

An insulated cargo container is composed of an underframe, a floor, a first side wall, a second side wall, a roof, and at least one door being connected together to form an enclosure. At least one insulating liner is mounted to the interior surfaces and exterior surfaces of the enclosure in an amount sufficient to achieve a UA rating of less than about 300 for the cargo container.

Description

FIELD OF USE

The present application relates to insulated cargo containers and, more particularly, to insulated cargo containers and their methods of manufacture.

BACKGROUND OF THE INVENTION

Currently, many shippers utilize insulated or refrigerated large cargo containers (such as boxcars) to transport items that require the maintenance of specified temperatures during transit. Because these containers are required to maintain certain temperatures, the thermal efficiency of these containers is an important feature. Thermal efficiency is characterized by the thermal conductivity of a particular component or its inverse, its resistance to heat transfer commonly referred to as an R value.
In the past, large cargo containers were typically constructed of a combination of wood and metal members. Because members of this type typically possessed a low R-value, insulation, such as foam insulation, was often installed in these cargo containers to increase their thermal efficiency. Even with the use of insulation, however, the thermal efficiency of cargo containers of this type has not been as high as desired by users of these cargo containers. Therefore, there is a need for methods of constructing cargo containers with improved thermal efficiency.
One such existing method has involved placing additional insulating materials on the interior of the container. One drawback of this method is that placing additional insulating materials on the interior of the container reduces the interior dimensions of the cargo container. In turn, reducing the interior dimensions of the cargo container reduces the amount of space available for cargo. In addition, insulating materials located on the interior of a cargo container can also be subject to damage from the placement of cargo in the containers. This also reduces the thermal efficiency of the cargo container.
Therefore, there exists a need for methods of constructing boxcars with improved thermal efficiency without substantially reducing the interior dimensions of the car.

SUMMARY OF THE INVENTION

In accordance with the present invention, an insulated cargo container broadly comprises an underframe having a top surface and a bottom surface; a floor connected to the top surface of the underframe; a first side wall and a second side wall each having an interior surface and an exterior surface and each of the side walls includes a door having an interior surface and an exterior surface; a first end wall and a second end wall each having an interior surface and an exterior surface; a roof having an interior surface and an exterior surface, wherein the underframe, the floor, the first and second side walls, the first and second end walls and the roof being connected to form an enclosure; and one or more insulating liners, each comprising an insulating core disposed between an exterior skin and each of the interior surfaces or each of the exterior surfaces or both the interior surfaces and the exterior surfaces of the enclosure, in an amount sufficient to achieve a UA rating of less than about 300.
In accordance with another aspect of the present invention, a method for insulating a boxcar to achieve a UA rating of less than 300, the boxcar broadly comprising an underframe having a top surface and a bottom surface; a floor connected to the top surface of the underframe; a first side wall and a second side wall each having an interior surface and an exterior surface, and each of the side walls includes a door having an interior surface and an exterior surface; a first end wall and a second end wall each having an interior surface and an exterior surface; a roof having an interior surface and an exterior surface; wherein the underframe, the floor, the first and second side walls, the first and second end walls and the roof being connected to form an enclosure, broadly comprising the steps of attaching one or more insulating liners to the interior surfaces or the exterior surfaces or both the interior surfaces and the exterior surfaces of the enclosure, of the side walls, wherein the one or more insulating liners substantially cover the surfaces of the side walls; attaching one or more insulating liners to the interior surfaces or the exterior surfaces or both the interior surfaces and the exterior surfaces of the enclosure, of the end walls, wherein the one or more insulating liners substantially cover the surfaces of the end walls; attaching one or more insulating liners to the interior surface or the exterior surface or both the interior surface and the exterior surface of the enclosure, of the roof, wherein the one or more insulating liners substantially cover the surfaces of the roof; attaching one or more insulating liners to the floor, wherein the one or more insulating liners substantially cover the floor; installing at least one closure on the boxcar to cover a portion of an exterior surface of the boxcar not covered by the one or more insulating liners; and applying an insulating material to the bottom surface of the underframe.
The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the invention will be apparent from the description and drawings, and from the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a perspective view of a boxcar;

FIG. 1B is a side view of the boxcar of FIG. 1A;

FIG. 2 is a schematic view of a portion of the floor of the boxcar of FIGS. 1A and 1B;

FIG. 3 is a side view of the boxcar of FIGS. 1A and 1B;

FIG. 4 is an enlarged view of a door track of the boxcar of FIGS. 1A and 1B;

FIG. 5 is an enlarged view of a door track and a door track closure of the boxcar of FIGS. 1A and 1B;

FIG. 6. is an enlarged view of a door track and door track stops of the boxcar of FIGS. 1A and 1B;

FIG. 7 is a representation of an exemplary fastener for attaching a vacuum insulated panel to a sidewall of the boxcar;

FIG. 8 is a flowchart illustrating an exemplary process for manufacturing an exemplary insulated boxcar;

FIG. 9 is a representation of a boxcar prepared to receive the exemplary vacuum insulated panels;

FIG. 10 is a representation of the installation of the exemplary vacuum insulated panels in the exterior sidewalls of the boxcar of FIG. 9;

FIG. 11 is a representation of the installation of the exemplary vacuum insulated panels in the exterior endwalls of the boxcar of FIG. 10;

FIG. 12 is a representation of the installation of the exemplary vacuum insulated panels in the exterior roof of the boxcar of FIG. 11;

FIG. 13 is a representation of the installation of the end closures to the boxcar of FIG. 12;

FIG. 14 is a representation of the installation of the roof closures to the boxcar of FIG. 13;

FIG. 15 is a representation of the installation of the bottom closures to the boxcar of FIG. 14;

FIG. 16 is a representation of the installation of the bottom side closures to the boxcar of FIG. 15;

FIG. 17 is a representation of the installation of the appliances to the boxcar of FIG. 16;

FIG. 18 is a representation of an exemplary insulated boxcar described herein manufactured according to the exemplary process of FIG. 8;

FIG. 19 is a photograph of foam insulation applied to the underframe of the exemplary insulated boxcar described herein;

FIG. 20 is a photograph depicting the installation of the vacuum insulated panels within the interior surfaces of the exemplary insulated boxcar;

FIG. 21 is a photograph depicting the interior surfaces of the exemplary insulated boxcar;

FIG. 22 is a cross-sectional view of a vacuum insulated panel;

FIG. 23 is another cross-sectional view of the vacuum insulated panel of FIG. 22;

FIG. 24 is a perspective view of an exterior skin and steel L-beams of the vacuum insulated panel of FIG. 22;

FIG. 25 is a perspective view of an interior skin and composite L-beams of vacuum insulated panel of FIG. 22;

FIG. 26 is a perspective view of the vacuum insulated panel of FIG. 22 during assembly; and

FIG. 27 is a cross-sectional view of an insulating liner.

Like reference numbers and designations in the various drawings indicate like elements.

DETAILED DESCRIPTION

The present disclosure describes an existing cargo container, e.g., a boxcar, and method(s) for insulating the cargo container. FIGS. 1A-6 illustrate the cargo container to be modified consistent with the method(s) described herein. The invention as claimed, however, is broader than boxcars and extends to the modification of other large insulated cargo containers, such as, shipping containers used on seagoing container vessels, truck trailers, straight trucks, refrigerated buildings, or the like. In addition, the boxcars described herein may include refrigeration components as known to one of ordinary skill in the art such that the refrigerated boxcars may be insulated using the insulating panels and liners described herein. Such insulating panels and liners may be modified as understood by one of ordinary skill in the art to accommodate refrigerator units, air plenums and other structural and mechanical components as well as design features commonly attributable to refrigerated boxcars.
FIGS. 1A-6 illustrate several representations of views of a boxcar. A boxcar is an enclosed rail car used to transport freight. As shown in FIGS. 1A-1B, a boxcar 100 includes side walls 110, a roof 120, a floor 130, end walls 140, and a door opening 150. Wall panels 110, roof 120, floor 130, and end walls 140 combine to form an enclosure 160. Door opening 150 provides access to enclosure 160 through door 170 and its components, e.g., door tracks 182, 184, door track closures 186, door stops 188, 190 and a center door seal (not shown). Enclosure 160 can be used to store articles at specified temperatures. As shown in FIG. 1B, boxcar 100 may also include doors 170. The thermal efficiency of boxcar 100 depends, in part, on the construction of side walls 110, roof 120, floor 130, end walls 140, and doors 170.
As illustrated in FIGS. 1A-3, a boxcar, such as boxcar 100, typically includes a floor, such as floor 130. A floor 130 will usually comprise a floor panel or panels having a top surface, which forms the interior floor surface of enclosure 160 and a bottom surface, which forms an outer surface of the boxcar 100. In addition, the floor 130 generally includes an underframe disposed underneath the floor panel or panels. The underframe may include one or more various structural members that provide structural support to the floor panel or panels by supporting at least some portion of the load applied thereupon as well as existing insulating members commonly utilized to reduce heat loss from underneath the boxcar 100. Various structural members may include, but are not limited to, I-Beams 200, cross members 210, center sill 220, insulating members 230 and the like (See FIG. 2). The floor panel or panels are removed to allow access to the existing structure below the floor panel, such as the aforementioned structural members. The floor panel or panels may be removed using any number of methods known to one of ordinary skill in the art, including the use of manual labor and/or machinery to lift the floor panels from the structure.
Generally, the aforementioned structural members are usually exposed to ambient conditions. As a result, the connection of these structural members to the floor panel can create a thermal short. A thermal short in an insulated enclosure is a portion of the structure where heat loss can bypass insulation and thereby reduce the thermal efficiency of the enclosure.
It is contemplated in the present disclosure that the floor panels mentioned above comprise insulating material such as insulating panels or insulating liners as will be described herein in greater detail. The insulated floor materials are designed to reduce heat loss from the connection of structural members, such as center sill 220 and I-Beams 200 to a floor panel. The insulated floor materials are located on each structural member (i.e., center sill 220 and I-Beams 200) or, in the alternative, on certain structural members. The insulated floor material is preferably constructed to withstand about 20,000 pounds per square inch (psi) to about 30,000 psi as applied by a forklift, for example. Although the thickness of the insulated floor materials may vary, the thickness of each insulated floor panel is preferably about 1 inch to about 4 inches. A single piece of insulated floor material may embody a size suitable to form the entire floor 130 of the boxcar 100. For example, a single panel or liner extending the entire length and width of the entire cargo container floor may be employed. In the alternative, several pieces of insulated floor materials may be used, which when connected to one another, will generally extend the entire length and width of the cargo container floor.
The insulated floor materials may be attached to the structural members and other structural features located on the floor with a structural adhesive, such as Pliogrip® 7700 commercially available from Ashland Specialty Chemicals of Ashland, Ohio. Other suitable means of attaching the insulated floor materials together may also be utilized in addition to, or in the alternative to, an adhesive such as bolts or other mechanical fasteners. For example, a fastener 240 may be inserted into an aperture 250 of an insulating panel 300 to attach the panel 300 to a sidewall 110 of the boxcar 100 (See FIG. 7). The exemplary fastener 240 may include a washer, nut and bolt as shown. The insulated floor materials may be attached to one another by a combination of one or more of the following: mechanical fasteners, interlocking edges, adhesives, and the like. In the alternative, the insulated floor materials may be disposed within the floor area using any one of several methods known to one of ordinary skill in the art such as a combination of nails and nested metal planks.
In the alternative, the aforementioned insulated floor materials may be disposed upon the existing floor panels of floor 130. More particularly, the aforementioned insulated floor materials may be attached on top of the existing floor 130. For example, a plurality of insulated floor panels or liners may be attached to the existing floor 130 or a single panel or liner extending the entire width and length of the floor may be installed.
The insulated floor material, e.g., panels or liners, may also be implemented as insulated side wall material, insulated end wall material and insulated roof material throughout the interior of the boxcar 100. In each of these implementations, the insulation materials may be attached to the respective interior surfaces of each side wall 110, end wall 140, roof 120 and components mounted within the door opening 150 using any of the methods and/or means for attachment previously described herein. For example, the insulation material may be sized and dimensioned accordingly to affix to door tracks 182, 184, door track closure 186, door stops 188, 190 and optionally a center door seal (See FIG. 3). As is recognized by one of ordinary skill in the art, center door seals are resilient sealing members constructed from an effective thermal insulating material.
In addition, it is also contemplated that the insulation materials are also mounted to the exterior surfaces of the side walls 110, end walls 140 and roof 120. The insulation materials may also be mounted to the exterior surfaces of the cargo container using any of the methods and/or means for attachment previously described herein. For example, when mounting the insulation material to the exterior surfaces of the side walls, the insulation materials may be mounted flush to and between the side wall protrusions 180. In the alternative, the insulating materials may be applied over both the protrusions 180 and exterior surface of the side wall. When applying insulating materials to the exterior of boxcar 100, portions of the insulation materials will be cutout to provide space for appliances and fixtures. Appliances are structures located at least partially on the exterior of the boxcar such as ladders, side ladder pans, air conditioners and the like. The insulation materials may be sized to accommodate dimensions and shape of the appliances. As described above, the insulation materials may be mounted to these appliances and fixtures using any of the aforementioned methods and/or means for attachments. The insulation materials applied to appliances, fixtures and other areas of potential exposure to the atmosphere are generally referred to in the industry as “closures”.
The insulating panels 300 may be mounted to the exterior of boxcar 100 according to the exemplary process illustrated in the flowchart of FIG. 8, representations of FIGS. 9-18, and photograph of FIG. 19. As illustrated in FIG. 9, the exterior surfaces of boxcar 100 are exposed and prepared to have at least one exemplary vacuum insulated panel 300 installed upon each exterior surface. The vacuum insulated panels 300 may be installed upon the exterior sidewalls 110 as described herein at step 260 of FIG. 8 and illustrated in FIG. 10. Once completed, vacuum insulated panels may then be installed upon the exterior endwalls 140 as described herein at step 262 of FIG. 8 and illustrated in FIG. 11. As disclosed, the vacuum insulated panels may be sized to accommodate dimensions and shapes of appliances and fixtures attached to the sidewalls 110, endwalls 140, and the like. Vacuum insulated panels 300 may then be installed upon the roof 120 as described herein at step 264 of FIG. 8 and illustrated in FIG. 12. Once all of the vacuum insulated panels 300 are installed, a quantity of foam insulation material sufficient to prevent thermal shorts may be applied to the underframe of boxcar 100 using any one of a number of techniques known to one of ordinary skill in the art at step 266 of FIG. 8 and illustrated in the photograph of FIG. 19.
After insulating the underframe, at least one endwall insulation closure 280 may be installed upon each insulated endwall 140 as described herein at step 268 of FIG. 8 and illustrated in FIG. 13. Following their installation, at least one roof insulation enclosure 282 may be installed upon the insulated roof 120 as described herein at step 270 of FIG. 8 and illustrated in FIG. 14. At least one underframe insulation enclosure 284 may be installed upon the insulated underframe as described herein at step 272 of FIG. 8 and illustrated in FIG. 15. Once completed, at least one underframe side insulation closure 286 may be installed at the point where the insulated underframe and insulated sidewall meet as described herein at step 274 of FIG. 8 and illustrated in FIG. 16. After installation of the various insulation closures is complete, various fixtures and appliances 288 known to one of ordinary skill in the art may be installed along the exterior of boxcar 100. The interior of the exemplary insulated boxcar 500 of FIG. 18 may then be prepared to be insulated. Alternatively, the interior of boxcar 100 may be insulated prior to insulating the exterior surfaces. The photographs of FIGS. 20 and 21 depict the installation of the vacuum insulating panels 300 within the boxcar 100 and the completion of their installation, respectively.
Referring now to FIGS. 22-27, an insulating panel 300 may comprise an interior skin 320. A plurality of first support angles 330 may be mounted upon an interior surface of the boxcar walls 310. A plurality of second support angles 340 may be disposed upon an interior surface of interior skin 320 and preferably mounted thereto. At least a portion of first support angles 330 and at least a portion of second support angles 340 are in contact with each other to form an area 350 and secure the interior skin 320. Preferably, first support angles and second support angles are secured together and their position with respect to one another may be adjusted. A quantity of insulating material 360 may be disposed within areas 350. The interior skins 320 may then be mounted upon the insulating panels 300. Generally, wherever one insulating panel or liner described here meets another to create a seam, some type of cover, rub rail, etc. as known to one of ordinary skill in the art may be mounted upon the seam to eliminate a thermal short. Once the rub rails are in place, a Z-frame (not shown) as known to one of ordinary skill in the art may then be installed flush to the interior skins 320.
Interior skin 320 may comprise any durable, non-porous material such as but not limited to a resin material free of or containing additives and/or reinforcement materials, various types of metals and alloys, e.g., steel, and the like. Preferably, interior skin 320 is constructed from steel such as cold rolled steel as known to one of ordinary skill in the art, commercially available from U.S. Steel® of Pittsburgh, Pa. Generally, cold rolled steel is sheet steel which has been rolled to thickness at low temperature in a continuous cold rolling mill operation. Cold rolled steel generally possesses a lighter weight and manufactured to a few mils in thickness. In another embodiment, interior skin 320 is a fiberglass reinforced plastic such as ArmorTuf® and/or GatorPlate® commercially available from Kemlite® Company, Inc. of Joliet, Ill. The interior skin 320 may possess flat surfaces to enable flush mounting to the interior and exterior surfaces of the floor, roof, side walls, end walls and appliances. In the alternative, the interior skin 320 may possess surface features, such as corrugations. Although these surface features could introduce air between, e.g., the sidewall interior surface and the insulating material, the air pockets may be filled with any one of several blown foam materials known to one of ordinary skill in the art.
Referring now to FIGS. 24-26, the plurality of first support angles 330 and second support angles 340 are mounted to the boxcar walls 310. First support angles 330 may be constructed out of any durable material such as various metals and alloys, e.g., steel, using any number of methods known to one of ordinary skill in the art to fashion a first flange 332 and a second flange 334 to form an angle. Second support angles 340 may also be constructed out of any durable material such as various composites using any number of methods known to one of ordinary skill in the art to fashion a first flange 342 and a second flange 344 to form an angle.
First support angle 330 may be an L-beam comprising steel or a suitable alloy and second support angle 340 may also be an L-beam comprising a composite material. In other embodiments, first support angle 330 may be an I-beam, a T-beam or even a Z-beam, for example, a Z-beam offset with a bracket mounted to the boxcar wall 310. In the alternative, at least one mechanical and/or chemical means for mounting may be employed rather than the first and second support angles. The chemical means may include, but are not limited to, any adhesive capable of bonding the aforementioned insulated panels and liners to the boxcar walls 310. The mechanical means may include, but are not limited to, fasteners, brackets, bolts, rivets, screws, nails, blind hucks, combinations comprising at least one of the foregoing, and the like.
With regard to the first and second support angles 330, 340, each steel L-beam includes a plurality of apertures 336 designed to align with a plurality of adjustment slots 346 of each composite L-beam. In the alternative, the steel L-beam may include the plurality of adjustment slots while the composite L-beam may include the plurality of apertures. The steel L-beams and composite L-beams are connected together by aligning each aperture 336 with each adjustment slot 346 and inserting there through a means for attachment such as, but not limited to, a screw, bolt, pin, dowel, combinations comprising at least one of the foregoing, and the like. In addition, all of the insulated panels include edges cut to engage the edge of an adjacent insulated panel to prevent thermal shorts. For example, the edges may include a cut joint having a 45° angle, a step joint, flat joint, mitre joint, tongue and groove joint, lap joint, F-joint, a parallelogram angled cut, a trapezoidal angled cut, and the like. As a result, all of the interior insulating panels and exterior insulating panels are joined together, respectively, and also move together. The ability to adjust the position of the composite L-beam to the steel L-beam permits the insulating panels to move and adjust to the movement of the boxcar as is understood by one of ordinary skill in the art. In addition to imparting some flexibility to the insulating panels, the resulting U-shaped support can transfer loads more effectively as opposed to common static support structures.
For purposes of illustration, and not to be taken in a limiting sense, the angles of first and second support angles 330, 340 are right angles. However, each angle formed may be less than or greater than 90° in accordance with the construction of the insulating panel 300. The angle formed by the first support angle 330 is preferably complimentary to the angle formed by the second support angle 340, and vice versa, such that first flanges 332, 342 mate with each other to form a surface that makes contact, preferably flush, with the insulating material. The first and second support angles 330, 340 combine to form a retaining clip for the insulating material 360. With respect to the construction of the insulating panel, the insulating material will be formed accordingly in order to engage the surface formed by first flanges 332, 342 of first and second support angles 330, 340. For example, preformed, cut foam material may be inserted in a vertical direction, that is, from the top to the bottom, between the L-beams until reaching the floor 130. The aforementioned Z-frame (not shown) as known to one of ordinary skill in the art may then be installed flush to the interior skins 320.
The insulating material employed may comprise any type of closed cell or closed pore foam material. The foam material may be injected or infused under an atmosphere, or may be preformed and cut to meet the dimensions of the areas 350 and angles formed by the steel and composite L-beams. The foam material may include, but is not limited to, froth foam, pour foam, boardstock foam, bunstock foam, vacuum foam panels and the like. Preferred vacuum foam panels are Instill® commercially available from Dow Chemical® of Midland, Mich.; Threshold® commercially available from Thermal Visions of Granville, Ohio. Preferred froth foam is commercially available from FSI of Lewisville, Tex.; and also Polycell® which is commercially available from Imperial Chemical Industries, PLC of London, United Kingdom. The foam material may also include, but is not limited to, cellular elastomeric foam, cellular glass foam, cellular polystyrene, cellular polyurethane, cellulosic fiber, aldehyde condensed phenols, polyethylene, polyisocyanurate, polyolefin, polyvinyl chloride, polyvinyl fluoride, polyvinyl, vinyl and combinations comprising at least one of the foregoing foam materials. All of the exemplary foam materials mentioned herein are all closed cell or closed pore foam materials.
Referring now to FIG. 27, another embodiment of a foam insulating liner made in accordance with the present invention is depicted. A foam insulating liner 400 may comprise a liner frame having a first side 410, a second side 420 and an edge 430 disposed about at least two sides of an insulating core 440. The edges 430 may be cut to engage the edge of an adjacent insulated liner 400 to prevent thermal shorts. For example, the edges 430 may include a cut joint having a 45° angle, a step joint, flat joint, mitre cut, and the like. As described earlier, all of the interior insulating liners and exterior insulating liners are joined together, respectively, and also move together. Insulating core 440 may comprise an injected foam insulating core comprised of a foam material. Insulating core 440 is formed by injecting a quantity of foam material between first 410 and second side 420 of the liner frame as will be described in greater detail below.
The foam material may comprise any injectable foam material known to one of ordinary skill in the art. For example, the foam material may include but is not limited to cellular elastomeric foam, cellular glass foam, cellular polystyrene, cellular polyurethane, cellulosic fiber, aldehyde condensed phenols, polyethylene, polyisocyanurate, polyolefin, polyvinyl chloride, polyvinyl fluoride, polyvinyl, vinyl and combinations comprising at least one of the foregoing foam materials. In addition, the foam material may also comprise a froth foam.
Insulating core 440 may be contained within a pre-fabricated liner frame comprising a resin material. Both first side 410 and second side 420 may comprise a resin material, one or more reinforcing materials and one or more additives.
The resin material may include but is not limited to urethanes, polystyrenes, polyesters, epoxies and combinations thereof. The reinforcing materials may include but are not limited to ceramic fibers, fibrous glass, glass cloth, glass fabric, glass fiber, calcium silicate, diatomaceous earth, expanded vermiculite, cellulose fibers, woven fabric, non-woven fabric, compacted powder, compacted fiber, mineral fiber, mineral wool, perlite, refractory materials, wood fibers, poly-paraphenylene terephthalamide fibers, and combinations thereof. The additives may include but are not limited to abrasion resistant materials, sweat resistant materials, chemical resistant materials, blackbody materials, fire resistant materials, fire retardant materials, intumescent materials, water vapor retardant materials, mold resistant materials, mildew resistant materials, solvent resistant materials, caustic resistant materials, freeze-thaw resistant materials, water resistant materials and combinations thereof.
Optionally, the liner frame may also include a coating applied to its exterior surface which may blend with the appearance of the frame or be absorbed into the frame. Moreover, the coating may either be aesthetic in nature or serve a practical, utilitarian purpose. For example, the coating may include but is not limited to anti-abrasive, appearance coverings, blackbody coatings, breather coatings, mastic coatings, moisture barrier coatings, weather barrier coatings and the like, and combinations comprising at least one of the foregoing coatings.
During the manufacture of the pre-fabricated liner frame, the resin material includes one or more catalysts and/or curing agents to promote the cure of the resin material as is understood by one of ordinary skill in the art in order to form the liner frame. In the alternative, another material such as a film cover material as described earlier may be employed such that either both first side 410 and second side 420, or either first side 410 or second side 420, comprise film cover material rather than resin material. The film cover materials may include but is not limited to polyvinyl, polyvinyl ethylene, polyvinyl chloride, Teflon® (polytetrafluoroethylene) and combinations comprising at least one of the foregoing film cover materials.
Generally, the pre-fabricated liner frame may take about 40 minutes to 60 minutes to form depending upon the resin material employed and amount of catalysts and/or curing agents present in the mixture. The liner frame may be manufactured using any number of methods known to one of ordinary skill in the art such as but not limited to molding, machining, extrusion, pultrusion and the like, and combinations comprising any one of the foregoing methods. For example, first side 410 may comprise a film cover material while second side 420 may comprise a molded resin material. During any one of these methods, a surface feature 450 may be imparted, for example, one or more corrugations or a corrugated pattern, while manufacturing the pre-fabricated liner frame. In the alternative, the pre-fabricated liner frame may be flat and not include any exterior surface features. Throughout the fabrication process of foam insulating liner 400, the ambient temperature of the facility housing the equipment, including the production line itself, may be maintained in a range of about 60° F. to 110° F., and preferably at least 60° F.
A method for manufacturing foam insulating liner 400 described herein may include first forming an insulating liner frame comprising first side 410, second side 420. The first side 410 of the insulating liner frame may be disposed within a mold, or a first half of a mold. Prior to either halves of the insulating liner frame into the mold, a quantity of non-adhering material sufficient to prevent the resin material, and other ingredients, from sticking to the mold's interior surface may be applied to the mold. Once the first half is positioned within the mold, the second side 420 of the insulating liner frame may be disposed within the second half of the mold. The two halves of the mold may then be sealed together and a quantity of foam material, as previously described herein, may be disposed into the void between first side 410 and second side 420 of the insulating liner frame. Preferably, the foam material fills the entirety of the void to form insulating core 440. The foam material may be disposed using any number of methods described herein, and known to one of ordinary skill in the art, and is preferably injected between first side 410 and second side 420.
Generally, the injection process is performed using dispensing equipment such as the machines and guns commercially available from Graco Gusmer® of Minneapolis, Minn. After injection, the foam material develops a pressure of about 1 to 10 pounds per square inch [absolute], and preferably 3 to 7 pounds per square inch [absolute] within the insulating liner frame. Depending upon the foam materials utilized and properties of the insulating liner frame, a certain amount of time may be required prior in order for the foam material to set and harden to form insulating core 440. Generally, foam insulating core 440 may take about 40 minutes to 60 minutes to form dependent upon the foam material employed. Once insulating core 440 is set, resultant foam insulating liner may be removed from the mold.
As mentioned earlier, foam insulated liner 400 may be sized and shaped accordingly to meet customer specifications and its intended application. For example, foam insulating liner 400 may comprise a single piece sized and shaped according to customer specifications. In the alternative, foam insulating liner 400 may be cut into pieces such the pieces may be assembled by the customer for his/her intended application. The foam insulated liner pieces may be assembled using any one or a combination of mechanical fasteners including but not limited to dowels, brackets, staples, screws, bolts, nails, rivets, adhesives, sealants, combinations comprising at least one of the foregoing, and the like, as well as bonding agents known to one of ordinary skill in the art.
The insulated cargo container described herein may be assembled using various methods known to one of ordinary skill in the art. In contrast to prior refrigerated boxcars, the present insulated boxcar preferably employs insulated floor materials, that is, either insulated vacuum panels or insulated foam liners described herein, combined with GatorPlate® or ArmorTuf® materials as a substitute to floor panels. As described above, manual and/or machinery may be utilized to install a single piece, or several pieces, of insulation material designed to substantially cover the entire floor and structural members. Afterwards, the GatorPlate® or ArmorTuf® material, for example, may be installed on top of the insulation materials to ensure the floor can withstand about 20,000 psi to about 30,000 psi. The insulation material may then be installed along the interior surfaces of the side walls, end walls and roof.
The vacuum insulated panels and the insulated foam liners may be prefabricated or may require assembly by the customer. If prefabricated, each panel or liner may be installed using any one or more of the methods and/or means for attachment described herein. If assembly of the vacuum insulated panels is required on-site, the vacuum insulated panel may be assembled and then attached to the interior and exterior walls and roof of the boxcar or may be constructed along with the walls and roof.
For example, the exterior skin with or without the steel L-beam already affixed may first be attached to the interior surface, or exterior surface, of a side wall. The steel L-beam, if not already in place, may then be attached to the exterior skin. A piece of pre-fabricated foam insulation, such as boardstock foam or bunstock foam, may then be fitted between the steel L-beams and flush to the exterior skin. The composite L-beams are then affixed to the steel L-beams within the adjustable slots of the composite L-beams. The composite L-beams and steel L-beams are affixed to form the angle which the pre-fabricated foam insulation engages. The interior skin is then mounted to the composite L-beam. A material such as GatorPlate®, ArmorTuf® or the like may be disposed on the exterior surface of the interior skin. The GatorPlate®, ArmorTuf® or the like is utilized to protect the exterior surface of the interior skin from cargo moving within the enclosure of the boxcar. In addition, a rub rail 390 (See FIG. 8) comprising a durable, wear-resistant material may be installed where the edge of the vacuum insulated panel meets the edge of the floor. This process may be altered accordingly to suit the customer's requirements such as when installing the vacuum insulated panels on appliances and door components.
In addition to vacuum insulated panels, the insulated foam liners may also be pre-fabricated or be assembled on-site by the customer. For example, the exterior liner material may first be attached to the interior surface, or exterior surface, of a side wall. A piece of pre-fabricated foam insulation, such as boardstock foam or bunstock foam, may then be affixed flush to the interior surface of the exterior liner material. The interior liner material is then mounted to the pre-fabricated foam insulation. As previously described with respect to installing the vacuum insulated panels, GatorPlate®, ArmorTuf® or the like may be disposed on the exterior surface of the interior liner material to protect the exterior surface from cargo moving within the enclosure of the boxcar. In addition, a rub rail comprising a durable, wear-resistant material may be installed where the edge of the insulated foam liner meets the edge of the floor. Again, this process may be altered accordingly to suit the customer's requirements such as when installing the insulated foam liner on appliances and door components.
The cargo container described herein, the various insulating materials and methods for insulating the cargo container all possess numerous advantages over prior art insulated cargo containers and refrigerated boxcars. The various embodiments and methods of manufacture of the foam insulating liners and vacuum insulated panels described herein provide numerous advantages over the prior art.
First, due to the construction of the panels and liners, the panels and liners may easily be mounted flush to a surface and next to each other to ensure their seamless integration. The pieces are double bonded at the point of contact to ensure a seamless integration which will lessen the formation of and potential for thermal short circuits to occur. Second, the materials employed to construct the panels and liners are solid pieces of steel, foam and films which are all seamless. In order for a thermal short to occur, the heat must travel through the entire piece of panel or liner thus also reducing the likelihood that a thermal short can occur. Third, the foam material employed may be a bunstock foam which permits on-site assembly of both the panels and liners. Bunstock foams do not require an environmental permit so a customer may order either panel or liner materials along with the bunstock foam insulation material and assemble the panels or liners on-site. Fourth, both the panels and liners may be assembled quickly and efficiently by a single person due to their simple design and construction. Fifth, the panels and liners are more cost effective than prior art insulation due to employing fewer materials, requiring less labor for their assembly and/or installation and their reduced weight.
With respect to the liners, refrigerated boxcars employed thirty (30) individual liners in order to insulate the boxcar's exterior alone. The present liners may be fabricated such that only ten (10) liners are required to effectively insulate both the boxcar's interior and exterior surfaces, including the door(s). This represents a significant reduction in costs, labor and weight.
Moreover, the foam insulating liners described herein generally weight approximately forty percent (40%) to sixty percent (60%) less than present commercially available foam insulated liners. The foam insulated liners described herein generally weigh about 15 ounces per square foot (0.9375 pounds per square foot) to 48 ounces per square foot (3 pounds per square foot), preferably about 20 ounces per square foot (1.25 pounds per square foot) to 44 ounces per square foot (2.75 pounds per square foot), and most preferably about 23 ounces per square foot (1 pound 7 ounces per square foot). These cost savings translate to a lower unit price of approximately thirty-three percent (33%) to fifty percent (50%) when compared to present commercially available foam insulating liners.
Lastly, insulated cargo containers and refrigerated boxcars utilizing the vacuum insulated panels and foam insulated liners described herein meet the UA requirements set forth by the American Association of Railroads.
It is to be understood that the invention is not limited to the illustrations described and shown herein, which are deemed to be merely illustrative of the best modes of carrying out the invention, and which are susceptible to modification of form, size, arrangement of parts, and details of operation. The invention rather is intended to encompass all such modifications which are within its spirit and scope as defined by the claims.

Claims

1. An insulated cargo container, comprising:

an underframe having a top surface and a bottom surface;

a floor connected to said top surface of said underframe;

a first side wall and a second side wall each having an interior surface and an exterior surface and each of said side walls includes a door having an interior surface and an exterior surface;

a first end wall and a second end wall each having an interior surface and an exterior surface;

a roof having an interior surface and an exterior surface, wherein said underframe, said floor, said first and second side walls, said first and second end walls and said roof being connected to form an enclosure; and

one or more insulating liners, each comprising an insulating core disposed between an exterior skin and each of said interior surfaces or each of said exterior surfaces or both said interior surfaces and said exterior surfaces of said enclosure, in an amount sufficient to achieve a UA rating of less than about 300.

2. The insulated cargo container of claim 1, wherein said insulating core comprises a foam material selected from the group consisting of cellular elastomeric foam, cellular glass foam, cellular polystyrene, cellular polyurethane, cellulosic fiber, aldehyde condensed phenols, polyethylene, polyisocyanurate, polyolefin, polyvinyl chloride, polyvinyl fluoride, polyvinyl, vinyl and combinations thereof.

3. The insulated cargo container of claim 1, wherein said insulating core comprises a foam material selected from the group consisting of froth, pour, boardstock and bunstock.

4. The insulated cargo container of claim 1, wherein said exterior skin comprises cold rolled steel.

5. The insulated cargo container of claim 1, wherein said exterior skin comprises a resin material, optionally one or more reinforcing materials, and optionally one or more additives.

6. The insulated cargo container of claim 5, wherein said resin material is a thermoset polymer or a thermoplastic polymer.

7. The insulated cargo container of claim 5, wherein said resin material is selected from the group consisting of polyvinyl, polyethylene, polyvinyl chloride.

8. The insulated cargo container of claim 5, wherein said resin material is selected from the group consisting of urethanes, polystyrenes, polyesters, epoxies and combinations thereof.

9. The insulated cargo container of claim 5, wherein said reinforcing materials are selected from the group consisting of ceramic fibers, fibrous glass, glass cloth, glass fabric, glass fiber, calcium silicate, diatomaceous earth, expanded vermiculite, cellulose fibers, woven fabric, non-woven fabric, compacted powder, compacted fiber, mineral fiber, mineral wool, perlite, refractory materials, wood fibers, polyparaphenylene terephthalamide fibers and combinations thereof.

10. The insulated cargo container of claim 5, wherein said one or more additives are selected from the group consisting of abrasion resistant materials, sweat resistant materials, chemical resistant materials, blackbody materials, fire resistant materials, fire retardant materials, intumescent materials, water vapor retardant materials, mold resistant materials, mildew resistant materials, solvent resistant materials, caustic resistant materials, freeze-thaw resistant materials, water resistant materials and combinations thereof.

11. The insulated cargo container of claim 1, wherein said insulation liner is disposed flush to said interior surfaces and said exterior surfaces of said enclosure.

12. The insulated cargo container of claim 1, further comprising a mechanical fastener designed to fasten said insulation material to each of said interior surfaces and said exterior surfaces of said enclosure.

13. The insulated cargo container of claim 1, further comprising a rub rail disposed on said exterior skin where an edge of each of said insulating liners makes contact with an edge of each of said interior surfaces and an edge of each of said exterior surfaces of said enclosure.

14. A method for insulating a boxcar to achieve a UA rating of less than 300, the boxcar comprising an underframe having a top surface and a bottom surface; a floor connected to said top surface of said underframe; a first side wall and a second side wall each having an interior surface and an exterior surface, and each of said side walls includes a door having an interior surface and an exterior surface; a first end wall and a second end wall each having an interior surface and an exterior surface; a roof having an interior surface and an exterior surface; wherein said underframe, said floor, said first and second side walls, said first and second end walls and said roof being connected to form an enclosure, comprising the steps of:

attaching one or more insulating liners to the interior surfaces or the exterior surfaces or both the interior surfaces and the exterior surfaces of the enclosure, of the side walls, wherein said one or more insulating liners substantially cover the surfaces of the side walls;

attaching one or more insulating liners to the interior surfaces or the exterior surfaces or both the interior surfaces and the exterior surfaces of the enclosure, of the end walls, wherein said one or more insulating liners substantially cover the surfaces of the end walls;

attaching one or more insulating liners to the interior surface or the exterior surface or both the interior surface and the exterior surface of the enclosure, of the roof, wherein said one or more insulating liners substantially cover the surfaces of the roof;

attaching one or more insulating liners to the floor, wherein said one or more insulating liners substantially cover the floor;

installing at least one closure on the boxcar to cover a portion of an exterior surface of the boxcar not covered by said one or more insulating liners; and

applying an insulating material to the bottom surface of the underframe.

15. The method of claim 14, wherein attaching each of said insulating liners comprises the steps of:

affixing an insulating core flush to each surface and to each other;

disposing an exterior skin flush to said insulating core; and

disposing optionally a rub rail at a juncture where an edge of each exterior skin and an edge of each interior surface or an edge of each exterior surface or all of said edges of the interior surfaces and the exterior surfaces of the enclosure, make contact.

16. The method of claim 15, wherein affixing comprises mechanically fastening or chemically bonding said insulating liners flush to each of the surfaces of the enclosure.

17. The method of claim 15, wherein disposing said exterior skin comprises mechanically fastening or chemically bonding said exterior skin flush to said insulating liners and double bonding each of said exterior skins together where each make contact.

18. The method of claim 15, wherein disposing optionally said rub rail comprises mechanically fastening said rub rail.

19. The method of claim 14, wherein attaching each of said insulating liners comprises the steps of:

affixing said insulating liner flush to each surface and to each other;

mechanically fastening said insulating liner to each surface; and

disposing optionally a rub rail at a juncture where an edge of each insulating liner and an edge of each interior surface or an edge of each exterior surface or all of said edges of the interior surfaces and the exterior surfaces of the enclosure, make contact.

20. The method of claim 14, wherein attaching each of said insulating liners comprises the steps of:

affixing said insulating liner flush to each surface and to each other;

chemically bonding said insulating liner to each surface; and