Abstract:
The stack-top dunnage can have a sheet having two opposite end sections and a center section therebetween; each end section being successively folded thus forming a thicker ledge portion. The stack-top protector can be placed on top of a stack and the ledges thence receive tie bands that tie the stack to a pallet for shipping.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This specification claims priority of U.S. Provisional application No. 61/108,633 entitled “Stack-top Dunnage” and filed on May 22, 2009 by applicant. 
     
    
     TECHNICAL FIELD 
       [0002]    The specification relates to material handling, and more specifically discloses a dunnage for use on a top of a stack. 
       BACKGROUND OF THE INVENTION 
       [0003]    Stacks of material to be shipped, such as stacks of paper sheets for example, are often placed onto a support such as a pallet for shipping. Such stacks are typically tied onto the pallet using bands made of plastic or metal and which contribute to holding the stack together. It was common to place a sheet of wood on top of the stack prior to wrapping the stack with the bands. This was done for two reasons. 
         [0004]    First, the rigidity of the wood helps prevent damage to the stacked material, and especially to the uppermost sheets thereof, which can be caused by the bands which are used to wrap the stack. With the sheet of wood in place, the bands are kept spaced apart from the uppermost portions of the stack, and the sheet of wood contributes to even out the pressure exerted by the bands onto a greater surface and reduce the occurrences of high pressure points on the stack. 
         [0005]    Second, sometimes the stacks can include a number individual piles of materials. Because the tops of the individual piles are not linked to one another, they can tend to open up, and even fall in opposite directions during shipping. Using a sheet of wood as dunnage on top of two or more such piles, with the bands holding the sheet of wood down onto the piles, serves as a link between the tops of the piles and greatly reduces the possibility that the piles open up during shipping. 
         [0006]    Although the use of wood sheets as stack-top dunnage was satisfactory to a certain degree, it did have some inconveniences, such as relatively high costs, weight, and cumbersomeness between uses. There thus remained room for improvement. 
       SUMMARY OF THE INVENTION 
       [0007]    In accordance with one aspect, there is provided a stack-top dunnage comprising: a first component having a first sheet material with a central section between two opposite end sections, the first sheet material being successively folded at each of the two end sections thus forming corresponding ledges on opposite sides of the center section, the ledges being spaced-apart from one another by a first distance; and a second component having a second sheet material with a central section between two opposite end sections, the second sheet material being successively folded at each of the two end sections thus forming corresponding ledges on opposite sides of the center section, the second component having a width to fit between the ledges of the first component. 
         [0008]    In accordance with another aspect, there is provided a stack-top dunnage comprising: a first sheet having two opposite end sections and a center section therebetween, each end section having a first number of equal-width, longitudinally adjacent and parallel panels folded atop one another and atop an edge of the center section in an accordion manner, the two folded end sections thus forming corresponding ledges of a first thickness on opposite sides of the center section, and being spaced-apart by a first distance; a second sheet having two longitudinally opposite end sections and a center section therebetween, each end section having a second number of equal-width, longitudinally adjacent and parallel panels folded atop one another and atop an edge of the center section in an accordion manner, the two folded end sections thus forming corresponding ledges of a first thickness on opposite sides of the center section; wherein the second sheet is oriented perpendicularly to the first sheet and positionable into the spacing between the ledges of the first sheet, on the center section of the first sheet, in a manner that the center section of the second sheet is surrounded by the ledges of the first and second sheets. 
         [0009]    In accordance with another aspect, there is provided a stack-top dunnage comprising a sheet having two opposite end sections and a center section therebetween; each end section having a number of equal-width adjacent panels folded atop one another in an accordion manner and thus forming a thicker ledge portion, wherein the stack-top dunnage can be placed on top of a stack and the ledges thence receive tie bands that wrap the stack. 
         [0010]    In accordance with another aspect, there is provided a method of palletizing paper sheets comprising: positioning sheets of paper in a stack on a pallet; placing a sheet of cardboard having two opposite end sections each having a number of adjacent panels folded atop one another in an accordion manner and thus forming two corresponding thicker ledge portions, on top of the stack and pallet, and wrapping two bands around the stack, one covering each ledge portion, the two bands tying the stack and sheet of cardboard to the pallet. 
     
    
     
       DESCRIPTION OF THE FIGURES 
         [0011]      FIG. 1  is a perspective view showing an example of a stack-top dunnage in use on a palletized stack; 
           [0012]      FIG. 2  is an exploded perspective view of the stack-top dunnage of  FIG. 1 ; 
           [0013]      FIG. 3  is a top plan view of the component shown in  FIG. 2 , in an unfolded state; and 
           [0014]      FIG. 4  is a top plan view of an alternate embodiment of the stack-top dunnage in an unfolded state. 
       
    
    
     DETAILED DESCRIPTION 
       [0015]      FIG. 1  shows an example of a stack-top dunnage  10  in use. The stack-top dunnage  10  is positioned on top of a stack  12 , the stack being positioned on a support  14 . In this example, the support  14  is a pallet  14   a,  and the stack  12  includes four piles of paper  16 , the four piles of paper  16  being adjacent to one another. The stack-top dunnage  10  is positioned on top of the stack  12 , and entirely covers the four piles of paper  16 , thereby bridging gaps  18  therebetween on the top of the stack  12 . In this embodiment, two sets of parallel attachment bands  20 ,  22  are used to hold the stack-top dunnage  10  and the stack  12  on the pallet  14   a.  The attachments bands  20 ,  22  are applied onto thicker edge portions, referred to herein as ledges  24 ,  26 ,  28 ,  30  of the stack-top dunnage  10 . 
         [0016]    Turning to  FIG. 2 , it will be understood that, in this embodiment, the stack-top dunnage  10  is made of two components, including an second component  32 , which is nestably received onto a first component  34 . The first component  34  is made from a first sheet  36 . The second component  32  is made with a second sheet  42 . The second sheet  42  has a center section  44 , and two edge sections  38 ,  40 , each edge section  38 ,  40  being on a respective opposite side of the center section  44 . One edge section  40  is shown folded to form a ledge  26  during use, whereas the other edge section  38  is shown partially unfolded, to show the detail of the folds. The partially unfolded edge section  38  can be seen to have a plurality of same width, parallel, and adjacent panels  48  which are folded atop one another and over a portion of the central section  44 , thus foldable into a ledge  24  ( FIG. 1 ) having a greater thickness  50  than the thickness  52  of the center portion  44 . 
         [0017]    The details of the folds are also understandable from  FIG. 3  where the blank of the second component  32  is shown in an unfolded state. 
         [0018]    Back in  FIG. 2 , the first component  34 , or first component, is made with a first sheet  36  of cardboard material and has a similar construction to that of the second component  32  and therefore does not need to be described in fuller detail. The use of thicker ledges  28 ,  30 ,  26  allows to offer a greater resistance along the sides of the stack, where the attachment bands are applied, for a given length of material having a thickness and weight substantially lesser than a panel of wood. 
         [0019]    To achieve the configuration shown in  FIG. 1 , the second component  32 , is inserted into the spacing  54  between the ledges  28 ,  30  of the first component  34 . The second component  32  and the first component  34  are oriented perpendicularly to one another. In this example, both the first component  34  and the second component  32  are made from rectangular blanks, the spacing  54  between the ledges  28 ,  30  of the first component  34  is designed to match the width  56  of the second component  32 , and the length of the second component  32  is designed to match the width of the first component  34 . These latter features are practical, though it will be understood that they are optional and that for instance, alternate embodiments can have different blank shapes, have a second component width smaller than the spacing, or have a second component length different than the width of the first component. Another particularity of the depicted embodiment is that the first component and second component are made of sheet material having the same thickness, and in order to provide ledges  24 ,  26 ,  28 ,  30  all having the same height when in the configuration shown in  FIG. 1 , there is one less panel  48  in the folded edge sections  38 ,  40  of the second component  32  than the amount of adjacent panels folded into the ledges  28 ,  30  of the first component  34 , to account for the thickness of the central portion  58  of the first component  34  which is present underneath the second component  32  during use. The use of four same height ledges  24 ,  26 ,  28 ,  30  is optional, but preferred due to its practicality. 
         [0020]    In an alternate embodiment, a single one of the components, such as the first component  34  for example, can be used alone, rather than in the combination disclosed above. In such an alternate embodiment, two attachments bands can still be used along the two opposite ledges  28 ,  30 , instead of four attachment bands such as disclosed above, which can also be satisfactory in some applications. 
         [0021]    The sheet material used in making the first and/or second components will typically be a cellulose pulp sheet material. It can be a cardboard for instance, or a sheet material having at least a layer of cellulose pulp felt. The cardboard can have one layer or more of paperboard and fluted sheet. The paperboard have between 1 and 12 plies, and can be a chipboard, a solidboard, and a box board for instance. The cellulose pulp sheet material can have more than one layer in which case liners can be used. 
         [0022]    Turning now to  FIG. 3 , to achieve a satisfactory folding capability of the sheet material, and more particularly the end sections  38 ,  40  thereof (particularly when using heavy paperboard such as chipboard), slits can be defined into the blank, opposite the folds. This is shown schematically in  FIG. 3 , where slits  60  cut into the exposed side of the cardboard blank are shown in full lines, and slits  60  cut into the opposite side of the cardboard blank are depicted in dotted lines. Folding sequentially along the adjacent slits allows to form the ledges  24 ,  26 . The slits are made on a predetermined side of the blank and the folds are practiced in a manner that the slits  60  open up and face outwardly from the folds. 
         [0023]    The ledges  24 ,  26 ,  28 ,  30  can be held into the folded configuration simply by the application of the attachment bands  20 ,  22  if desired. Alternately, the adjacent panels  48  folded into the ledge  24  can be fixed to one another either by using an adhesive or with fasteners, for example. Optionally, a cohesive adhesive can be used to hold the accordion folded ledge into the folded configuration. A cohesive adhesive is a type of adhesive which is usually not adherent, but which is activated when applied to another surface which is also covered by it. In this application, for example, a cohesive adhesive could be applied entirely to both surfaces of the cardboard blank, could cover only the end portions of the cardboard blank, or can be applied in bands at specific areas of the end portions, on both sides thereof, in a manner that when folded, each one of the adjacent panels has a cohesive covered surface which comes into contact with a cohesive covered surface of an adjacent panel. 
         [0024]    Embodiments such as described above can conveniently be partially or completely produced online. For instance, it is possible in the process of making the sheet material to optionally add rollers which apply cohesive adhesive at selected areas, and to optionally add blades which define slit lines at selected places, for instance. The components can thereafter be trimmed to width and the edge portions be folded into place by an operator, for instance. 
         [0025]    Turning now to  FIG. 4 , still another embodiment of a stack-top dunnage  110  is shown. In this embodiment, a single cardboard blank having a cross shape is used, and fold lines therein are designed in a manner that each one of four edge sections can be folded in an accordion manner to form a corresponding ledge, to finally arrive in a four ledge configuration similar to the embodiment shown in  FIG. 1 . 
         [0026]    For illustrated purposes, sheets of cellulose pulp based material having a thickness between 60 and 160 pts (1.5 to 4 mm) have been found suitable for the applications described above, preferably between 60 and 120 pts (1.5 to 3 mm). The optional slits to ease the folding of the adjacent panels into the ledges can be cut into a depth having between 60 and 80% of the thickness of the sheet for example. The slits can particularly be useful if using heavy paperboard such as chipboard for instance, or a felt, in which cases liners can also be used. Paperboards having of 2 to 12 ply, for example, preferably 2 to 5, can be used. The number of adjacent panels in the folded against one another into the ledges can be of 2 to 20, or preferably 3 to 10 or 4 to 10, for example, and will depend on the thickness of the material used. Many various embodiments can be realized as well. 
         [0027]    The scope is indicated by the appended claims.