Abstract:
A method of making a cabinet for refrigerators and the like. The method includes forming a liner and a wrapper. The method further includes providing a vacuum insulated core that includes a filler material disposed inside a substantially impermeable envelope that is evacuated to form a vacuum inside of the envelope. The vacuum insulated core includes a first wall and a second wall extending transversely relative to the first wall. The core is adhesively secured to the wrapper, and the liner is adhesively secured to the core. The wrapper and the liner are sealed together at the peripheries thereof.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    Known refrigerator cabinets and doors may be constructed utilizing polyurethane insulation that is disposed between an outer wrapper and an inner liner. However, polyurethane foam has somewhat limited insulating properties. Various types of vacuum insulated panels for refrigerator cabinets and doors have been developed in an effort to decrease the wall thickness and/or increase the insulating properties of these structures. However, known insulated cabinet and door structures may suffer from various drawbacks. 
       SUMMARY OF THE INVENTION 
       [0002]    A method of making a cabinet for refrigerators and the like includes forming a liner and a wrapper having a periphery. The method further includes providing a vacuum insulated core that includes a filler material disposed inside a substantially impermeable envelope. The envelope is evacuated to form a vacuum inside of the envelope. The vacuum insulated core is folded to form a 3D core having a first wall and a second wall extending transversely relative to the first wall along a fold line. The 3D core is adhesively secured to the wrapper, and the liner is adhesively secured to the 3D core. The wrapper and the liner are sealed together at the peripheries thereof. 
         [0003]    These and other features, advantages, and objects of the present disclosure will be further understood and appreciated by those skilled in the art by reference to the following specification, claims, and appended drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0004]      FIG. 1  is an isometric view of a refrigerator; 
           [0005]      FIG. 2  is an isometric view of interior components of the refrigerator of  FIG. 1 ; 
           [0006]      FIG. 3  is a fragmentary view of a portion of the refrigerator cabinet of  FIG. 2 ; 
           [0007]      FIG. 4  is a cross sectional view taken along the line IV-IV;  FIG. 2 ; 
           [0008]      FIG. 5  is a cross sectional view of the refrigerator door of  FIG. 1  taken along the line V-V; 
           [0009]      FIG. 6  is a partially schematic isometric view of a vacuum insulated core during fabrication thereof; 
           [0010]      FIG. 7  is an isometric view of the vacuum insulated core of  FIG. 6  after folding; 
           [0011]      FIG. 8  is a partially fragmentary cross sectional view of a portion of a refrigerator; 
           [0012]      FIG. 9  is a partially fragmentary cross sectional view of a portion of a refrigerator; and 
           [0013]      FIG. 10  is a partially fragmentary cross sectional view of a portion of a refrigerator. 
       
    
    
     DETAILED DESCRIPTION 
       [0014]    For purposes of description herein, the terms “upper,” “lower,” “right,” “left,” “rear,” “front,” “vertical,” “horizontal,” and derivatives thereof shall relate to the disclosure as oriented in  FIG. 1 . However, it is to be understood that the disclosure may assume various alternative orientations and step sequences, except where expressly specified to the contrary. It is also to be understood that the specific devices and processes illustrated in the attached drawings, and described in the following specification, are simply exemplary embodiments of the inventive concepts defined in the appended claims. Hence, specific dimensions and other physical characteristics relating to the embodiments disclosed herein are not to be considered as limiting, unless the claims expressly state otherwise. 
         [0015]    With reference to  FIGS. 1 and 2 , a refrigerator  1  includes an insulated cabinet  2  having a fresh food compartment  4  and a frozen food compartment  6 . The fresh food compartment  4  can be accessed through access opening  5  by opening doors  8  and  10 , and the frozen food compartment  6  can be accessed through access opening  7  by sliding door/drawer  12 . The refrigerator  1  may include an ice/water dispenser  14  mounted to door  8 . The ice/water dispenser  14  may be connected to an ice box  16  formed in door  8 . 
         [0016]    As shown in  FIG. 2 , vacuum insulated cabinet  2  includes an external wrapper  18 , and a first liner  20  that is disposed within wrapper  18 . Liner  20  forms fresh food compartment  4 . A second liner  22  is also disposed within external wrapper  18 . The second liner  22  forms frozen food compartment  6 . The first and second liners  20  and  22  may be constructed utilizing substantially similar materials and processes. The external wrapper  18  may comprise sheet metal, and the liners  20  and  22  may comprise polymer materials. However, the wrapper  18  and liners  20  and  22  may be fabricated from a variety of materials as may be required for a particular application. 
         [0017]    With further reference to  FIG. 3 , cabinet  2  includes a vacuum core  24  that is disposed in a space  26  between wrapper  18  and liner  20 . As discussed in more detail below, vacuum core  24  may be adhesively secured to wrapper  18  by a suitable adhesive such as hot melt adhesive or two-sided adhesive tape  28 . A thin layer of adhesive  30  may be disposed in a gap “G” between vacuum core  24  and liner  20 . As also discussed below, adhesive  30  preferably has a low viscosity prior to curing such that liquid adhesive  30  flows into and fills gap G prior to curing. 
         [0018]    With further reference to  FIG. 4 , liner  20  may include chamfered or radiused corners  32  forming vertically extending inner corner spaces  34  between the liner  20  and vacuum core  24 . Vertically extending outer corner spaces  36  may be formed adjacent vertical spaces  34  adjacent edges  38  of vacuum core panels  24 . The vertically extending spaces  34  and  36  may be filled with polyurethane foam  40  that is substantially similar to polyurethane foam used in prior refrigerator cabinets that are not vacuum insulated. As discussed in more detail below in connection with  FIGS. 6 and 7 , the vacuum core  24  may optionally comprise a 3D structure that is formed from a generally flat blank by folding or other suitable process. If core  24  comprises a folded structure without edges  38 , vertical spaces  36  are not formed. If vacuum core  24  comprises a folded structure, the vertical spaces  34  may be smaller, or they may be eliminated as required for a particular application. Front edge  41  of cabinet  2  may comprise a separate insulated sealing member that interconnects wrapper  18  and liner  20 . Alternatively, the edge  41  may comprise overlapping flanges or the like that interconnect wrapper  18  and liner  20 . 
         [0019]    With further reference to  FIG. 5 , door  8  may include a front portion or panel  52 . The front panel  52  may comprise a vacuum insulated structure, or it may comprise a conventional refrigerator door structure having an outer door panel or wrapper  46 , door liner  48 , and polyurethane foam  50  disposed between the wrapper  46  and liner  48 . Door  8  includes an ice box  16  having a vacuum core  24 A that is disposed between first (outer) and second (inner) ice box components  42  and  44 . The vacuum core  24 A is adhesively secured to first component  42  by a relatively thin layer of adhesive  30 , and vacuum core  24 A is secured to second component  44  by two-sided adhesive tape  28 , hot melt adhesive, or other thin adhesive. The ice box  16  and door front panel  52  may be fabricated separately, and the ice box  16  may be secured to inner surface  58  of front panel  52  utilizing interlocks (not shown) and/or adhesive. 
         [0020]    With further reference to  FIGS. 6 and 7 , the vacuum core  24  may be formed from a blank  60  of core material that may be cut to remove corner portions  62 A- 62 D. The core material  60  may then be folded along fold lines  64 A- 64 D whereby flaps  66 A- 66 D are folded upwardly relative to central portion  68  of core material blank  60  to form a 3D box-like structure  60 B as shown in  FIG. 7 . The core material blank  60  may comprise porous core material such as fiberglass or other suitable material. After the 3D structure  60 B is formed, the 3D structure  60 B is then placed within an envelope  70  that is made from a non-porous barrier film. The non-porous film may comprise one or more layers of polymer, metal foil, or other such materials known in the art. Envelope  70  is substantially impervious to gasses such as nitrogen, oxygen, water vapor, carbon dioxide and other gasses. The envelope  70  is then sealed and evacuated to form a vacuum. Alternatively, the core material blank  60  may be cut to remove corner portions  62 A- 62 D and placed within an envelope  70  prior to folding. The edges of the envelope  70  are heat sealed and envelope  70  is then evacuated to form a Vacuum Insulated Panel (VIP). The VIP is then folded into the 5-sided box shape shown in  FIG. 7 . The sides and/or corners of the box may be taped in place to maintain the box shape. 
         [0021]    As shown in  FIG. 7 , the vacuum core  24  may be generally box-shaped as required to fit between wrapper  18  and liner  20 , or between components  42  and  44  of ice box  16 , or between wrapper  46  and liner  48  of door  8 . The vacuum insulated core  24  may have a variety of shapes and configurations as may be required to fit spaces formed between inner and outer components in a particular application. Also, additional pieces of core material  72  may be utilized to provide additional thickness in one or more areas of core  24 . With reference to  FIG. 10 , the core  24  may also be made by adding additional pieces of core material or alternatively by forming the core material into a 3D shape that substantially matches the internal shape of the door (less allowance for the adhesive  30 ). 
         [0022]    With reference to  FIG. 8 , door  8  may include a 3D vacuum core  24 A that is disposed between a wrapper  18 A and liner  20 A. The vacuum core  24 A includes a generally planar central portion  68 A and sidewalls  74 . The sidewalls  74  have increased thickness that may be formed utilizing additional pieces of core material  72  ( FIG. 7 ). During assembly, two-sided adhesive tape  28  or hot-melt adhesive is utilized to adhesively secure the vacuum core  24 A to external wrapper  18 . Adhesive  30  is then utilized to secure liner  20 A to vacuum core  24 A. Wrapper  18  may include a flange  76  that overlaps a flange  78  of liner  20 A. The flanges  76  and  78  may be attached/sealed utilizing adhesives and/or mechanical fasteners (not shown) or other suitable arrangement. Flanges  76  and  78  may also be held in place by adhesive  30  such that additional adhesives and/or mechanical fasteners are not required to separately interconnect flanges  76  and  78 . The liner  20 A may include an inwardly-projecting portion  80  having an internal space  82  that may be filled with adhesive  30 . 
         [0023]    The vacuum core  24 A may be configured to fit closely against wrapper  18 A, such that very thin two-sided adhesive tape  28 , hot melt adhesive, or other suitable adhesive may be utilized to secure the vacuum core  24 A to the wrapper  18 A. Due to variations in the dimensions of the wrapper  18 A, liner  20 A, and vacuum core  24 A, a gap “G” is necessary between liner  20 A and vacuum core  24 A to account for the dimensional variations. In a preferred embodiment, the gap G is nominally about 5 mm to accommodate variations in the thickness of core  24 A of about +/−2 mm, and variations in the dimensions of wrapper  18 A and/or liner  20 A. 
         [0024]    The adhesive  30  may comprise a two-part polyurethane adhesive having low viscosity prior to curing. As discussed above, the vacuum core  24 A may be adhesively secured to external wrapper  18 A utilizing two-sided adhesive tape or other thin layer of adhesive. The adhesive  30  can then be poured over vacuum core  24 A in an “open pour” process. Liner  20 A can then be positioned over the vacuum core  24 A, and upper and lower tool components or fixtures  84  and  86  may be utilized to hold the wrapper  18 A and liner  20 A in position relative to one another while adhesive  30  cures. As wrapper  18 A and liner  20 A are pressed together, uncured liquid adhesive flows within and fills gap G. Peripheral flanges  76  and  78  of wrapper  18 A and liner  20 A may also be adhesively or mechanically interconnected utilizing suitable known processes. Alternatively, adhesive  30  may be used to bond flanges  76  and  78  together. After the adhesive  30  cures, the assembled door  8  may be removed from the tools  84  and  86 . 
         [0025]    Alternatively, rather than an open pour process, after vacuum core  24 A is adhesively secured to wrapper  18 A, the liner  20 A may be positioned over the vacuum core  24 A and wrapper  18 A prior to introduction of adhesive  30 . The adhesive  30  may then be injected into the gap “G” between vacuum core  24 A and liner  20 A, and tools or fixtures  84  and  86  may be utilized to retain the wrapper  18 A and liner  20 A in position relative to one another during curing of adhesive  30 . After the adhesive  30  cures, the assembled door  8  may be removed from the tools  84  and  86 . 
         [0026]    The adhesive  30  preferably comprises a relatively low viscosity adhesive that is capable of flowing into the gap “G” ( FIGS. 3 and 8 ) between the liner and the vacuum core panel prior to curing. The adhesive may comprise a two-part polyurethane. The adhesive  30  is preferably significantly lower viscosity than conventional polyurethane foam, and has superior adhesive properties. An example of a suitable adhesive  30  is a Balindur™ polyurethane foam/adhesive available from BASF of Ludwigschafen, Germany. Also, although a two sided adhesive tape  28  ( FIG. 3 ) or hot melt adhesive or other very thin adhesive is preferably used to adhesively bond the wrapper  18  to the core  24 , a thin layer of adhesive  30  may also be utilized to bond wrapper  18  to the vacuum core  24 . 
         [0027]    With reference to  FIG. 9 , door/drawer  12  may include an external wrapper  18 B, liner  20 B, and vacuum core  24 B. The drawer  12  may be fabricated in substantially the same manner as the door  8  as described above in connection with  FIG. 8 , except that drawer  12  includes an internal space  88  formed by an outer portion  90  of wrapper  18 B. The internal space  88  may be filled with polyurethane foam  92 . The polyurethane foam  92  may comprise polyurethane foam of the type utilized to insulate conventional (i.e. non vacuum-insulated) refrigerator cabinets and the like. The wrapper  18 B may be secured to core  24 B by two-sided adhesive tape  28 , hot melt adhesive, or other suitable thin adhesive. The liner  20 B is secured to the vacuum core  24 B by adhesive  30  utilizing one of the processes discussed above in connection with  FIG. 8 . 
         [0028]    With further reference to  FIG. 10 , a drawer or door  94  includes a wrapper  18 C, liner  20 C, and a vacuum core  24 C disposed therebetween. The external wrapper  18 C is secured to the vacuum core  24 C by two sided adhesive tape  28  or other suitable adhesive, and the liner  20 C is secured to the vacuum core  24 C by thin adhesive  30 . The drawer or door  24  may be fabricated utilizing an open pour process, or a closed process as discussed in more detail above in connection with  FIG. 8 . The vacuum core  24 C may have additional thickness in various regions  96  as may be required to fill the space defined between wrapper  18 C and liner  20 C. 
         [0029]    It is to be understood that variations and modifications can be made on the aforementioned structure without departing from the concepts of the present disclosure, and further it is to be understood that such concepts are intended to be covered by the following claims unless these claims by their language expressly state otherwise.