Patent Publication Number: US-2018044100-A1

Title: Blank for a produce tray, produce tray and method of erecting a produce tray

Description:
This application claims the benefit of Australian Patent Application No. 2016213769, filed Aug. 10, 2016, which is hereby incorporated by reference. 
     FIELD OF THE INVENTION 
     The present invention relates to a blank for a produce tray, a produce tray and a method of erecting a produce tray. 
     BACKGROUND OF THE INVENTION 
     Produce trays are used for transportation and storage of produce and it is important that they have sufficient strength to support the produce to prevent the tray collapsing or sagging and damaging the produce during transportation or storage, particularly when stacked and as the trays can be used in high humidity environments. Also, it is desirable for produce trays that are convenient to handle and to maintain their integrity when manually handled. 
     It is also important that produce trays allow for ventilation so that the produce in the tray can be cooled when placed in a refrigerated environment, and also to allow heat generated from the ripening process to escape to prevent undesirable acceleration of the ripening process. This is particularly a problem as produce trays of this type are commonly stacked into columns once full. If ventilation of a produce tray can be improved, cooling requirements can be reduced, potentially saving energy and equipment costs. Although it is desirable to provide improved ventilation, it is commonly accepted that providing ventilation reduces the structural integrity of the tray and therefor there the need to provide adequate ventilation must be balanced against the strength requirements of the tray when designing a produce tray. As such, it is desirable to provide a produce tray which is stronger than previous trays yet provides increased ventilation. 
     Numerous advances in the field of produce cooling have been made by the present applicant, such as those disclosed in WO2014/085845 also to the present applicant. The present disclosure has been made in view of these advances. 
     Examples of the invention seek to solve, or at least ameliorate, one or more disadvantages of previous produce trays. 
     SUMMARY OF THE INVENTION 
     According to the present invention, there is provided a blank for an open top produce tray, the blank having a base portion that corresponds to a base of the tray when erected and side and end portions which can be folded to form respective side and end walls of the tray, wherein the side walls are formed of two parts foldable relative to each other so as to lie one inside of the other in the erected tray, wherein one of the parts of the side portions is formed with a flap which is foldable from the blank so as to lie in the erected tray between the two parts with a lowermost edge in contact with the base to form a three layered side wall, and wherein the fold of the flap constitutes an upper edge of the side wall along the length of the flap with the upper edge thus formed and being below the parts of the side wall on sides of the flap. 
     According to a preferred embodiment, the flap is formed by a cut line made in the blank, the cut line defining three sides of the flap and a fold line between opposite sides of the flap. Preferably, once folded, the flap provides a side ventilation opening. 
     The blank can further include ventilation apertures formed on a crease line between the base and end portions. Preferably, two ventilation apertures are formed, the ventilation apertures being spaced apart at approximately one quarter and three quarters of the length of the end portion. The side portions can be formed with extensions that, when folded, are secured to the end portions. The end portion can be formed with an aperture engagable by a user for lifting the tray. The end portion can be recessed at an upper end thereof to form a ventilation opening. 
     According to the present invention, there is also provided a produce tray erected from a blank according to any preceding claim. 
     According to the present invention, there is also provided a produce tray containing bananas, wherein when a series of like trays are stacked, a lowered side edge of the produce tray provides a substantial aperture to allow passage of air into an interior of the stacked trays. 
     According to the present invention, there is also provided a method of erecting a produce tray, including the steps of:
         providing a blank of the above described type;   folding the flap from the blank and folding the two parts of the side portion to form a three layered side wall;   folding end portions of the blank to form end walls; and   securing the end walls to the side walls to form the produce tray.       

     The method can further include the step of applying an adhesive to the blank prior to folding the side or end portions. The adhesive can be applied to the side portions only. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Preferred embodiments of the invention will be further described, by way of non-limiting example only, with reference to the accompanying drawings in which: 
         FIG. 1  is a plan view of a blank of one embodiment of the invention; 
         FIG. 2  is a perspective view of a produce tray erected from the blank; 
         FIG. 3  is a perspective view of the blank showing cut and fold lines; 
         FIG. 4  is a plan view of the blank showing locations which adhesives are applied to the blank; and 
         FIG. 5  is a chart showing a comparison between the cooling rate of produce in a standard produce tray and produce in a produce tray of an embodiment of the invention. 
     
    
    
     DETAILED DESCRIPTION 
     With reference to  FIG. 1 , there is shown a blank  10  according to a preferred embodiment of the present invention. The blank  10  is erectable to form an open top produce tray  12 , as illustrated in  FIG. 2 . 
     The blank  10  has a base portion  14   a  that corresponds to a base  14   b  of the tray  12  when erected. The blank  10  also has side portions  16   a  and end portions  18   a  which can be folded to form respective side walls  16   b  and end walls  18   b  of the tray  12 . Each of the side walls  16   b  are formed of two parts  20 ,  22  which are foldable relative to each other so as to lie one inside of the other in the erected tray  12 . In this regard, parts  20  and  22  are foldable along crease line  21  extending between them. 
     One of parts  20 ,  22  is formed with a flap  24  which is foldable from the blank  10  so as to lie in the erected tray  12  between the two parts  20 ,  22  with a lowermost edge  26  in contact with the base  14   b  to form a three layered side wall. By the lowermost edge  26  contacting the base  14   b  of the tray  12 , the side walls  16   b  of the tray  12  may be strengthened to prevent sagging of the tray  12  when loaded, which can be a particular problem in high humidity environments. 
     As can be seen in  FIG. 2 , the fold  28  of the flap  24  constitutes an upper edge of the side wall  16   b  along the length of the flap  24  with the upper edge thus formed and being below the parts  30  of the side wall  16   b  on sides of the flap  24 . 
     The flap  24  is formed by a cut line  32  made in the blank  10 . The cut line  32  defines three sides of the flap  24  with a fold line  28  extending between portions of the cut line  32  that form opposite sides of the flap  24 . Although flap  24  is formed by having fold line  28  on part  22 , it will be appreciated that an alternative configuration may also be possible in which fold line  28  is formed on part  20 . 
     Once folded, the flap  24  provides a side ventilation opening that assists with cooling of produce in the tray  12  and allows heat to escape. By providing flap  24  to strengthen side wall  16   b , good strength properties can be obtained while improving ventilation of the tray  12 , thereby potentially reducing the cooling energy required to cool the produce. 
     The tray also includes ventilation apertures  34  formed on a crease line  36  between the base portion  14   a  and the end portions  18   a . By providing apertures on the crease line, they open into the base  14   b  and end walls  18   b  to allow both horizontal and vertical ventilation. In the illustrated embodiment, two ventilation apertures  34  are formed, with the ventilation apertures  34  being spaced apart at approximately one quarter and three quarters of the length of the end wall  18   b . It will be appreciated that the size and location of the apertures may be varied to achieve the desired cooling performance. 
     The end portion  18  is formed with an aperture  38  engagable by a user for lifting the formed tray  12 . Although shown as being generally triangular, aperture  38  may also be generally rectangular. The end portion  18   a  is also recessed at an upper end thereof to form a further ventilation opening. In this regard, recess  40  is formed in an outermost portion of the end portion  18   a  so as to form an end wall  18   b  which is recessed at an upper portion thereof. Aperture  38  and recess  40  both contribute to providing ventilation of air through the tray  12 . 
     So as to provide structural integrity to the tray  12 , the side portions are formed with extensions  42  that, when folded, are secured to the end walls  18   b  to maintain the tray  12  in an erected state. The extensions  42  may be secured to the end walls  18   b  in a number of methods, such a interlocking tabs for example, however, in a preferred form an adhesive is applied to the blank  10  so as to maintain the tray  12  in its erected state. 
     In use, the tray  12  is erected by providing a blank  10  of the above described type. Flap  24  is folded from the blank  10  and the two parts  20 ,  22  are folded to form a three layered side wall. End portions of the blank  10  are folded to form end walls  18   b  and the end walls  18   b  are secured to the side walls  16   b  to form the produce tray  12 . To facilitate assembly,  FIG. 3  illustrates cut lines  48  and fold lines  50  of the blank  10 . 
     In a preferred form, the method includes the step of applying an adhesive to the blank  10  prior to folding the side portions  16   a  or end portions  18   a . Preferably, the adhesive is applied to the side portions only  16   a  and  FIG. 4  illustrates the locations at which glue is applied. Indicated in straight lines  44  are the locations at which glue is to be applied to an upper surface of the blank  10  and indicated in broken lines  46  are the locations at which glue is to be applied to a lower surface of the blank  10 . The straight lines  44  and broken lines  46  are merely illustrated on the same surface for convenience. 
     It will be appreciated that the method steps may be performed in an alternative order, for example the end walls  18   b  may be formed prior to the side walls  16   a.    
     In use, the tray  12  will be filled with produce, preferably at a packing plant. In one example, the tray  12  is used to pack bananas though it may be used for many other fruits. The lowered side edge  28  of the tray  12  not only provides a substantial aperture to allow passage of air into an interior of the stacked trays, but when packing provides a lowered surface to reduce interference with the hands and wrists of a user, potentially making the tray  12  safer, more convenient and easier to use. 
       FIG. 5  and Table  1  illustrates the cooling effectiveness of the tray  12  as obtained in an experiment conducted by the Applicant. 
     
       
         
           
               
             
               
                 TABLE 1 
               
             
            
               
                   
               
               
                 Cooling rate comparison 
               
            
           
           
               
               
               
            
               
                   
                 Typical Commercially 
                 15 kg 1 Piece Banana 
               
               
                   
                 Available 15 kg 1 Piece 
                 tray of preferred 
               
               
                 Duration (hrs) 
                 Banana tray 
                 embodiment 
               
               
                   
               
            
           
           
               
               
               
            
               
                 0 
                 20.32 
                 20.30 
               
               
                 0.25 
                 19.50 
                 18.97 
               
               
                 0.5 
                 18.02 
                 16.85 
               
               
                 0.75 
                 16.53 
                 14.83 
               
               
                 1 
                 15.17 
                 13.06 
               
               
                 1.25 
                 13.94 
                 11.54 
               
               
                 1.5 
                 12.82 
                 10.23 
               
               
                 1.75 
                 11.80 
                 9.10 
               
               
                 2 
                 10.88 
                 8.12 
               
               
                 2.25 
                 10.05 
                 7.28 
               
               
                 2.5 
                 9.30 
                 6.55 
               
               
                 2.75 
                 8.61 
                 5.93 
               
               
                 3 
                 7.99 
                 5.39 
               
               
                 3.25 
                 7.43 
                 4.92 
               
               
                 3.5 
                 6.92 
                 4.52 
               
               
                 3.75 
                 6.46 
                 4.17 
               
               
                 4 
                 6.04 
                 3.87 
               
               
                 4.25 
                 5.66 
                 3.62 
               
               
                 4.5 
                 5.32 
                 3.39 
               
               
                 4.75 
                 5.01 
                 3.20 
               
               
                 5 
                 4.73 
                 3.04 
               
               
                 5.25 
                 4.47 
                 2.89 
               
               
                 5.5 
                 4.24 
                 2.77 
               
               
                 5.75 
                 4.03 
                 2.66 
               
               
                 6 
                 3.84 
                 2.57 
               
               
                 6.25 
                 3.67 
                 2.49 
               
               
                 6.5 
                 3.51 
                 2.43 
               
               
                 6.75 
                 3.37 
                 2.37 
               
               
                 7 
                 3.24 
                 2.32 
               
               
                 7.25 
                 3.12 
                 2.27 
               
               
                 7.5 
                 3.02 
                 2.24 
               
               
                 7.75 
                 2.92 
                 2.20 
               
               
                 8 
                 2.84 
                 2.18 
               
               
                 8.25 
                 2.76 
                 2.15 
               
               
                 8.5 
                 2.69 
                 2.13 
               
               
                 8.75 
                 2.62 
                 2.11 
               
               
                 9 
                 2.56 
                 2.10 
               
               
                 9.25 
                 2.51 
                 2.08 
               
               
                 9.5 
                 2.46 
                 2.07 
               
               
                 9.75 
                 2.42 
                 2.06 
               
               
                 10 
                 2.38 
                 2.05 
               
               
                 10.25 
                 2.35 
                 2.05 
               
               
                 10.5 
                 2.31 
                 2.04 
               
               
                 10.75 
                 2.28 
                 2.03 
               
               
                 11 
                 2.26 
                 2.03 
               
               
                 11.25 
                 2.23 
                 2.03 
               
               
                 11.5 
                 2.21 
                 2.02 
               
               
                 11.75 
                 2.19 
                 2.02 
               
               
                 12 
                 2.17 
                 2.02 
               
               
                 12.25 
                 2.16 
                 2.01 
               
               
                 12.5 
                 2.14 
                 2.01 
               
               
                 12.75 
                 2.13 
                 2.01 
               
               
                 13 
                 2.12 
                 2.01 
               
               
                 13.25 
                 2.11 
                 2.01 
               
               
                 13.5 
                 2.10 
                 2.01 
               
               
                 13.75 
                 2.09 
                 2.01 
               
               
                 14 
                 2.08 
                 2.01 
               
               
                 14.25 
                 2.07 
                 2.00 
               
               
                 14.5 
                 2.06 
                 2.00 
               
               
                 14.75 
                 2.06 
                 2.00 
               
               
                 15 
                 2.05 
                 2.00 
               
               
                 15.25 
                 2.05 
                 2.00 
               
               
                 15.5 
                 2.04 
                 2.00 
               
               
                 15.75 
                 2.04 
                 2.00 
               
               
                 16 
                 2.04 
                 2.00 
               
               
                 16.25 
                 2.03 
                 2.00 
               
               
                   
               
            
           
         
       
     
     In this experiment, both a typical commercially available 15 kg 1 piece banana tray and a 15 kg banana tray constructed in accordance with the described embodiment were subjected to forced air cooling while monitoring the temperature of objects within the tray. The tray constructed in accordance with the described embodiment had a ventilation area of 19.3% on the long side panel and 11.6% on the short end panel. 
     The temperature of the items within the trays was monitored during the cooling assessment and data collected to compare the cooling rates of the trays.  FIG. 5  is a graphical representation of the data collected to compare the cooling rates of the trays. It can be seen that the tray  12  cooled at a faster rate than the conventional tray, which is believed to be due to improved ventilation of the tray  10  which allows improved ventilation though a stack of like trays  12 . 
     The embodiments have been described by way of example only and modifications are possible within the scope of the invention disclosed. 
     REFERENCE NUMERAL LIST 
     
         
           10  Blank 
           12  Produce tray 
           14   a  Base portion of blank 
           14   b  Base of tray 
           16   a  Side portions of blank 
           16   b  Side wall of tray 
           18   a  End portions of blank 
           18   b  End wall of tray 
           20  First or outer part of side portion  16   a    
           21  Crease line between first and second parts  20 ,  22   
           22  Second or inner part of side portion  16   a    
           24  Flap 
           26  Lowermost edge 
           28  Fold 
           30  Side parts of side wall  16   b    
           32  Cut line of flap  24   
           34  Ventilation apertures 
           36  Crease line for end wall  18   b    
           38  Handle aperture 
           40  Recess 
           42  Extension 
           44  Glue locations on upper surface 
           46  Glue locations on lower surface 
           48  Blank cut lines 
           50  Blank fold lines