Abstract:
Example insulated pliable door panels or curtains include various internal vapor barriers. The vapor barriers have a relatively high water vapor transmission rate that inhibits water vapor from permeating through the door panel. With such vapor barriers, outer sheets of the door panel can be made of polyurethane or other tough materials that might have an inadequate water vapor transmission rate. In some examples, the vapor barrier encircles or encloses a thermally insulating pad. In some examples, the door panel includes a sleeve or pocket that holds the vapor barrier in place. Some examples include means for draining water that might condense within the door panel.

Description:
FIELD OF THE DISCLOSURE 
     This patent generally relates to insulated doors and more specifically to doors that comprise a flexible panel such as an insulated curtain. 
     BACKGROUND 
     Cold storage rooms are refrigerated areas in a building that are commonly used for storing perishable foods. Cold storage rooms are typically large enough for forklifts and other material handling equipment to enter. Access to the room is often through a power actuated insulated door that separates the room from the rest of the building. To minimize thermal losses when someone enters or leaves the room, the door preferably opens and closes as quickly as possible. 
     Vertically operating roll-up doors and similar doors with flexible curtains are perhaps some of the fastest operating doors available. When such a door opens, its curtain usually bends upon traveling from its closed position in front of the doorway to its open position on an overhead storage track or take-up roller. 
     Such bending is not a problem if the curtain is relatively thin. However, an insulated curtain may not bend as well due to the required thickness of the insulation. When a take-up roller or curved track bends a thick curtain, relative translation may occur between opposite faces of the curtain. Designing a thick, insulated curtain that can accommodate such translation can be challenging. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a front view showing an example door in a closed position. 
         FIG. 2  is a front view similar to  FIG. 1  but showing the example door partially open. 
         FIG. 3  is a front view similar to  FIGS. 1 and 2  but showing the example door in an open position. 
         FIG. 4  is a cross-sectional view taken along line  4 - 4  of  FIG. 3 . 
         FIG. 5  is a front view of the example door panel of  FIGS. 1-3  with a lower-left section of the panel&#39;s outer sheet cutaway. 
         FIG. 6  is a cross-sectional view taken along line  6 - 6  of  FIG. 5 . 
         FIG. 7  is a cross-sectional view similar to  FIG. 6  but with the insulation omitted to more clearly show one of the example baffles. 
         FIG. 8  is a cross-sectional view taken along line  8 - 8  of  FIG. 5 . 
         FIG. 9  is a cross-sectional view similar to  FIG. 8  but showing the example door panel being assembled. 
         FIG. 10  is a cross-sectional view similar to  FIG. 8  but showing another example assembly and with one pad removed. 
         FIG. 11  is a cross-sectional view similar to  FIG. 10  but showing another example assembly. 
     
    
    
     DETAILED DESCRIPTION 
     Certain examples are shown in the above-identified figures and described in detail below. In describing these examples, like or identical reference numbers are used to identify the same or similar elements. The figures are not necessarily to scale and certain features and certain views of the figures may be shown exaggerated in scale or in schematic for clarity and/or conciseness. Additionally, several examples have been described throughout this specification. Any features from any example may be included with, a replacement for, or otherwise combined with other features from other examples. 
       FIGS. 1-4  illustrate an example of a vertically operating door  10  that includes a flexible, insulated door panel  12 . Door  10  is shown closed in  FIG. 1 , partially open in  FIG. 2 , and fully open in  FIGS. 3 and 4 . In the illustrated example, as door  10  opens and closes relative to a doorway  14 , door panel  12  bends over a mandrel  16 . Mandrel  16 , in some examples, is a fixed bar or a roller extending across the width of doorway  14 . Although door panel  12  is shown having a certain double-bend, stored configuration, other stored configurations, such as coiled, wound on a roll tube, single-bend horizontal, serpentine, vertically planar, etc., are all well within the scope of this disclosure. 
     Although door  10  is useful in unlimited applications, door  10  is particularly suited for providing access to refrigerated cold storage rooms or for separating rooms or areas that are at different temperatures, such as, for example, the interior and exterior of a building at a truck loading dock. In such temperature differential installations, one side of door panel  12  is often colder than the other side, which can subject door panel  12  to an adverse water vapor pressure gradient. While  FIGS. 1-9  disclose general features of example door panel  12 ,  FIGS. 10 and 11  disclose more detailed features specifically intended to address the problems associated with the water vapor pressure gradient. 
     To operate door  10 , in some examples, a powered drive sprocket  18  ( FIG. 4 ) engages a cogged strip  20  at each lateral edge of door panel  12  to move door panel  12  between a lower guide track  22 , where door panel  12  is blocking doorway  14 , and an upper track  24  where door panel  12  is clear of the doorway  14 . It should be noted, however, that door panel  12  can be applied to various other types of doors that operate with different drive or storage configurations. 
     In some examples, door panel  12  includes a plurality of pliable baffles  26  ( FIGS. 5, 8 and 9 ) that restrict the redistribution of air contained between a first sheet  28  and a second sheet  30  of door panel  12 . Sheets  28  and  30  are joined and generally sealed along their outer perimeter to create one large overall air chamber  32  between sheets  28  and  30 . Baffles  26  divide chamber  32  into a plurality of more manageable smaller chambers  34 . For illustrative clarity, baffles  26  and chambers  32  and  34  are shown in  FIG. 5  to extend slightly less than a full width  40  of door panel  12 , however, baffles  26  and chambers  32  and  34  preferably extend the full width of door panel  12 . As door  10  opens and creates a horizontal crease in sheets  28  and  30  (e.g., where door panel  12  bends over mandrel  16 ), baffles  26  help prevent air trapped within chamber  32  from over inflating the lower end of door panel  12 . Thus, baffles  26  prevent the area between mandrel  16  and a lower leading edge  36  of door panel  12  from bulging excessively as door  10  opens. 
     In some examples, baffles  26  are sufficiently flexible to accommodate some relative translation between sheets  28  and  30  as door panel  12  bends over mandrel  16 . The flexibility of baffles  26  may also enable door panel  12  to restorably break away if something were to accidentally collide with the door  10 . Additionally or alternatively, some examples of baffles  26  are sufficiently flexible to conformingly mate with the lateral edges or vertical seams  33  of sheets  28  and  30  so that there is minimal leakage or air exchange between chambers  34 . Further, in some examples, baffles  26  are sufficiently stiff to maintain a desired spacing between sheets  28  and  30 , particularly in examples where insulation is not used for maintaining such spacing. Further yet, in some examples, baffles  26  have a thermal resistance (i.e., R-value) that is equal to or greater than that of sheets  28  and  30 . 
     Although the actual construction of door panel  12  may vary, the illustrated examples have sheets  28  and  30  being made of any suitable polymeric or natural fabric material that is preferably pliable and can be joined along their outer perimeter by adhesion, tape, melting/fusing/welding, sewing, hook-and-loop fastener, snaps, rivets, zipper, etc. The term, “polymeric,” as used in this patent to describe a material means that the material includes at least some plastic or polymer base, substrate or coating. The term, “pliable” as used in this patent to describe a sheet of material means the sheet is sufficiently flexible to be folded over onto itself and subsequently unfolded without appreciable permanent damage. For toughness, wear resistance, heat seal weldability and flexibility, some examples of sheets  28  and  30  comprises polyurethane sheet material between about 1 and 2 mm thick (thickness  52 ). In some examples, substantially the entire outer perimeter, including seams  33  and the upper and lower edges of door panel  12 , is sealed to prevent appreciable amounts of air from flowing in and out of chamber  32 . Inhibiting moist air from repeatedly entering chamber  32  can prevent mold-promoting water vapor from condensing inside chamber  32  on a panel sheet that is facing, for example, a cold storage room. 
     Baffles  26  can be made of a material similar to or different than that of sheets  28  and  30 . The flexibility of sheets  28  and  30  enables door panel  12  to bend over mandrel  16 , while the flexibility of baffles  26  enables limited relative translation between sheets  28  and  30  as door  10  opens and closes. As door  10  opens or closes and door panel  12  travels and bends across mandrel  16 , this action urges relative vertical translation between sheets  28  and  30 . In some examples, thermally insulating pads  38  (e.g., resiliently compressible foam pads, polyester batting, etc.) are installed within chambers  34 . The term, “thermally insulating,” as used in this patent to describe pads  38  within door panel  12  means that the pads provide the greatest contribution of the door panel&#39;s overall thermal resistance or R-value. 
     For the illustrated examples, baffles  26  are horizontally elongate, which enable the baffles  26  to not only restrict vertical airflow within door panel  12  but also to accommodate relative vertical translation between sheets  28  and  30 . In other examples, door panel  12  is provided with vertically elongate baffles or a combination of vertical and horizontal baffles. 
     To effectively restrict airflow within door panel  12 , horizontally elongate baffles  26  preferably extend along at least most of the full width  40  of door panel  12 . To facilitate manufacturing, however, baffles  26  can be made slightly shorter than the panel&#39;s full width  40  to make it easier to join the lateral vertical edges of sheets  28  and  30  together. Baffles  26  being a little shorter than full width  40  of door panel  12  places the plurality of air chambers  34  in fluid communication with each other. Thus, as door  10  opens and door panel  12  travels across mandrel  16 , some air within door panel  12  will be temporarily redistributed to at least one of the lower chambers (e.g., air chamber  34 ′) of the plurality of chambers  34 , thereby slightly increasing the air pressure within chamber  34 ′ temporarily, but not really detrimentally. 
     Although the general assembly of door panel  12  can be accomplished by various means,  FIG. 9  illustrates one example manufacturing method. One horizontal edge of each baffle  26  is melted or ultrasonically welded to first sheet  28 , thereby creating a plurality of fused joints  42  between sheet  28  and each of baffles  26 . Fusing baffles  26  to at least one of sheets  28  and  30  is schematically depicted by the block at reference number  44  of  FIG. 9 . Alternate methods of attaching baffles  26  in place include, but are not limited to, bonding, taping, sewing, fastening via hook-and-loop fastener, riveting, etc. 
     An outer perimeter of sheet  28  is fused, sewn or otherwise connected to sheet  30  as schematically depicted by the block at reference number  46  of  FIG. 9 . The plurality of baffles  26  are installed between sheets  28  and  30 , as schematically depicted by arrow  48  and insulation pad  38  is installed within chambers  34 , as schematically depicted by arrows  50 . The example method represented by the block at reference number  44  and arrows  48  and  50  may be done generally together in a progressive sequence from one end of door panel  12  to another or in any other suitable order.  FIG. 9 , for example, shows door panel  12  being assembled progressively from the bottom up. 
     Sheets  28  and  30 , when made of polyurethane, have significant resistance to water vapor transmission therethrough. Nonetheless, some water vapor might still permeate the warmer of sheets  28  and  30  and migrate through pads  38  toward the colder sheet  28  or  30 . If sheet  30 , for example, is warmer than sheet  28 , water vapor might permeate door panel  12  through sheet  30  and condense and perhaps freeze on the inner surface of sheet  28 . An accumulation of trapped liquid water or ice within chamber  34  may inhibit normal operating characteristics of the door panel  12 . 
     To address this potential problem, thermally insulating pads  38 , as shown in the example of  FIG. 10 , is substantially encircled and/or surrounded and preferably encased by a sheet  54  (third sheet) that has a lower water vapor transmission rate than that of polyurethane. In some examples, sheet  54  starts as a tube in which pad  38  is inserted. After pad insertion, the axial ends of the sheet&#39;s tubular form are, in some examples, heat sealed to totally encase pad  38  within sheet  54 , somewhat analogous to a bed pillow in a pillow case. Examples of sheet  54  include, but are not limited to, polyester, polyethylene and aluminum foil. In some examples, sheet  54  is between about 0.1 and 0.2 mm thick (thickness  56 ) with an R-value that is less than that of sheets  28  and  30 . Sheet  54  being much thinner than sheets  28  and  30  maximizes the insulating pad&#39;s thickness and thus the pad&#39;s R-value for a given door panel thickness. Having sheet  54  be relatively thin is a viable option because sheet  54  is protected by the tough outer sheets  28  and  30 . While the above example describes the sheet  54  surrounding the pad  38 , in other examples, the sheet or sheets  54  may be positioned adjacent one or more surfaces and/or faces of the pad  38 . For example, the sheet  54  may be positioned adjacent a face of the pad  38  between pad  38  and the sheet  30  (e.g., the sheet to be adjacent a warmer side of the building) while not being adjacent the other faces of the pad  38 . In other examples, the sheets  54  may be positioned adjacent opposing surfaces of the pad  38 , one of which being positioned between the surface  30  and the pad  38  and the other of which being positioned between the surface  28  and the pad  38 . 
     In addition or alternatively, in some examples, baffles  26  lean downward toward the warmer sheet, e.g., toward sheet  30 . In the illustrated example, the baffles  26  are at a non-perpendicular angle relative to a longitudinal axis of the panel  12  such that ends of the baffles  22  are longitudinally displaced along the longitudinal axis of the panel  12 . This allows baffles  26  to drain any accumulated liquid water within chamber  34  down through optional condensate drain holes  58  in sheet  30 . Baffle  26  being inclined also allows adjacent pads  38  to overlap at the pads&#39; upper and lower edges, thereby ensuring vertically overlapping insulation at baffles  26 . A baffle  26 ′ is an alternate example configuration of baffle  26 . 
     In addition or alternatively, as shown in  FIG. 11 , a sheet  60  (another example third sheet) having a lower water vapor transmission rate than that of polyurethane is installed between pad  38  and sheet  30  to block water vapor on the exterior side of sheet  30  from penetrating chamber  34 . Examples of sheet  60  include, but are not limited to, polyester, polyethylene and aluminum foil. In some examples, sheet  60  is about 0.5 mm thick (thickness  62 ) with an R-value that is less than that of sheets  28  and  30 . The lower R-value of sheet  60 , in some examples, is due to sheet  60  being thinner than sheets  28  and  30 . 
     To help hold multiple sheets  60  in place, in some examples, a continuous or segmented sheet  64  (fourth sheet) is thermally or otherwise joined to sheet  30  and/or baffles  26  to create a plurality of pockets  66  in which sheets  60  are inserted. To facilitate effective thermal bonding of sheet  64  with sheet  30  and/or baffle  26 , in some examples, baffles  26  and sheets  28 ,  30 , and  64  each comprise polyurethane. 
     An example flexible door panel movable between an open position and a closed position relative to a doorway includes a first pliable sheet made of a first polymeric material. The first sheet has a first water vapor transmission rate. The example flexible door panel also includes a second pliable sheet made of a second polymeric material. The second sheet is generally parallel to the first sheet when the door is in the closed position. The second sheet has a second water vapor transmission rate. The example flexible door panel also includes a thermally insulating pad between the first sheet and the second sheet. The thermally insulating pad is resiliently compressible. The example flexible door panel also includes a third sheet between the first sheet and the thermally insulating pad. The third sheet has a third water vapor transmission rate. The third water vapor transmission rate is lower than the first water vapor transmission rate, and the third water vapor transmission rate is lower than the second water vapor transmission rate. 
     In some examples, the first sheet has a first R-value, the second sheet has a second R-value, and the third sheet has a third R-value. The first R-value is greater than the third R-value, and the second R-value is greater than the third R-value. In some examples, the first sheet has a first thickness, the second sheet has a second thickness, the third sheet has a third thickness. The first thickness is greater than the third thickness, and the second thickness is greater than the third thickness. In some examples, at least one of the first sheet or the second sheet includes polyurethane. In some examples, at least one of the first sheet or the second sheet defines a condensate drain hole. 
     In some examples, the example flexible door panel also includes a plurality of baffles connecting the first sheet to the second sheet to define a plurality of chambers between the first sheet and the second sheet. The plurality of baffles is connected to the first sheet and the second sheet at a plurality of fused joints. In some examples, the example flexible door panel also includes a plurality of thermally insulating pads disposed within the plurality of chambers. The plurality of thermally insulating pads includes the thermally insulating pad. In some examples, the third sheet encircles the thermally insulating pad. In some examples, the example flexible door panel also includes a fourth pliable sheet made of a fourth polymeric material. The fourth sheet has a fourth water vapor transmission rate that is greater than the third water vapor transmission rate of the third sheet. The fourth sheet is joined to at least one of the first sheet or the plurality of baffles to define a pocket between the fourth sheet and the first sheet. The third sheet is disposed within the pocket. The fourth sheet is interposed between the third sheet and the thermally insulating pad. In some examples, the first sheet is to be colder than the second sheet when the door is installed in the doorway of a cold storage room. 
     In some examples, a flexible door panel movable between an open position and a closed position relative to a doorway includes a first pliable sheet made of a first polymeric material and a second pliable sheet made of a second polymeric material. The second sheet is generally parallel to the first sheet when the door is in the closed position. The flexible door panel also includes a plurality of baffles connecting the first sheet to the second sheet to define a plurality of chambers between the first sheet and the second sheet. The plurality of baffles is connected to the first sheet and the second sheet. The flexible door panel also includes a plurality of thermally insulating pads disposed within the plurality of chambers. A thermally insulating pad of the plurality of thermally insulating pads is between the first sheet and the second sheet. The thermally insulating pad is resiliently compressible. The flexible door panel also includes a third sheet encircling the thermally insulating pad. 
     In some examples, the first sheet has a first R-value, the second sheet has a second R-value, the third sheet has a third R-value. The first R-value is greater than the third R-value, and the second R-value is greater than the third R-value. In some examples, the first sheet has a first thickness, the second sheet has a second thickness, the third sheet has a third thickness. The first thickness is greater than the third thickness, and the second thickness is greater than the third thickness. In some examples, at least one of the first sheet or the second sheet includes polyurethane. In some examples, at least one of the first sheet or the second sheet defines a condensate drain hole. In some examples, the third sheet has a third water vapor transmission rate. The third water vapor transmission rate is lower than the first water vapor transmission rate, and the third water vapor transmission rate is lower than the second water vapor transmission rate. 
     An example flexible door panel movable between an open position and a closed position relative to a doorway includes a first pliable sheet made of a first polymeric material. The first sheet has a first water vapor transmission rate. The flexible door panel also includes a second pliable sheet made of a second polymeric material. The second sheet is generally parallel to the first sheet when the door is in the closed position. The second sheet has a second water vapor transmission rate. The flexible door panel also includes a plurality of baffles connecting the first sheet to the second sheet to define a plurality of chambers between the first sheet and the second sheet. The plurality of baffles is connected to the first sheet and the second sheet. The flexible door panel also includes a plurality of thermally insulating pads disposed within the plurality of chambers. A thermally insulating pad of the plurality of thermally insulating pads is between the first sheet and the second sheet. The thermally insulating pad is resiliently compressible. The flexible door panel also includes a third sheet between the first sheet and the thermally insulating pad. The third sheet has a third water vapor transmission rate. The flexible door panel also includes a fourth pliable sheet made of a fourth polymeric material. The fourth sheet is joined to at least one of the first sheet or at least one of the plurality of baffles to define a pocket between the fourth sheet and the first sheet. The third sheet is disposed within the pocket. The fourth sheet is interposed between the third sheet and the thermally insulating pad. The third water vapor transmission rate is lower than the first water vapor transmission rate, and the third water vapor transmission rate is lower than the second water vapor transmission rate. 
     In some examples, the first sheet has a first R-value, the second sheet has a second R-value, the third sheet has a third R-value, the first R-value is greater than the third R-value, and the second R-value is greater than the third R-value. In some examples, the first sheet has a first thickness, the second sheet has a second thickness, the third sheet has a third thickness. The first thickness is greater than the third thickness, and the second thickness is greater than the third thickness. In some examples, at least one of the first sheet or the second sheet includes polyurethane. In some examples, at least one of the first sheet or the second sheet defines a condensate drain hole. In some examples, the first sheet is to be colder than the second sheet when the door is installed in the doorway of a cold storage room. 
     An example door includes a first sheet coupled to a second sheet to define a chamber therebetween. The door also includes a thermally insulating pad within the chamber and a third sheet adjacent the thermally insulating pad to substantially prevent water vapor from permeating the thermally insulating pad. The third sheet is positioned between the thermally insulating pad and at least one of first sheet or the second sheet. In some examples, the third sheet substantially surrounds the thermally insulating pad. The door may also include a baffle and a drain hole. The baffle is coupled to the first and second sheets at a non-perpendicular angle relative to a longitudinal axis of the door when the door is in a closed position. The drain hole is defined by one of the first sheet or the second sheet adjacent the baffle to enable liquid to flow within the chamber along at least one of the baffle, the first sheet, or the second sheet through the drain hole. 
     Although certain example methods, apparatus and articles of manufacture have been described herein, the scope of the coverage of this patent is not limited thereto. On the contrary, this patent covers all methods, apparatus and articles of manufacture fairly falling within the scope of the appended claims either literally or under the doctrine of equivalents.