Abstract:
Egg carton and method for transporting filled egg cartons that enables ready stacking of multiple cartons, one filled carton on top of another, for stable transport with or without the use of exterior containers for holding together the stack as are typically used in the industry,

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates to plastic egg cartons and more particularly to an egg carton having features that enable aligning and stacking multiple cartons for transport. 
       BACKGROUND 
       [0002]    Many factors are taken into consideration in the design of egg cartons. Egg protection, stackability, transportability, aesthetic appearance, print surface area, strength, weight, nestability/denestability, adaptability to accommodate various size eggs, and consistent manufacturing are factors which may be considered to varying degrees in the design of an egg carton. 
         [0003]    Polystyrene egg cartons are formed and trimmed from a single sheet of polystyrene foam material to integrally define a lid and a tray connected by a hinged area. The formed egg cartons are transported, typically by conveyer belt, to a printing machine and imprinted with an egg distributor&#39;s trade style, government mandated nutritional information, and retail information, such as UPC labels. The egg cartons are then nested one within another and packaged in bags or pallets for shipping to egg distributors. The distributor then fills the cartons with eggs at a filling station and transports the filled cartons to another location. The process of transport of filled egg cartons requires that cartons first be stacked in a stable arrangement such that when physically moved on a pallet the multitude of stacked, filled cartons are transportable without risk of falling off the pallet, falling out of the stacked arrangement, and/or otherwise moving or collapsing so as to cause damage to the eggs. 
       SUMMARY OF THE INVENTION 
       [0004]    The present invention provides a plastic egg carton and a method for aligning and stacking filled egg cartons, one filled carton on top of another, for stable transport without requiring the use of additional packaging, such as corrugated cases, wire or plastic baskets, or the like. By keeping the stacked cartons squarely aligned without the need for master containers, the invention reduces overall packaging cost, waste, and protects fragile eggs. The new carton is suited for direct pallet stacking, such as on grocery pallets 40″×48″, optionally with slip sheets between every 4, 5 or 6 layers, enabling the cartons to be stacked 20 to 25 cartons high. 
         [0005]    The new cartons can, if desired, be packaged or otherwise supported in, for example, existing standard master corrugated containers (e.g., full or half case), plastic or wire baskets, carts, wrapped in film or the like. 
         [0006]    In one embodiment, a pair of contoured bosses are provided on the lid top, disposed on opposite ends of a centerline of the carton, either widthwise or lengthwise, to restrict movement of adjacent cell bottoms (of an adjacent carton). The height of the lid bosses can be adjusted, with for example a minimum height of 3/16″ being effective to securely hold a weighted carton stack on top (e.g., 20 to 25 cartons high). The cartons may be made of polystyrene foam, of dimensions and thickness that are standard in the industry. 
         [0007]    In accordance with one embodiment of the invention, an egg carton is provided comprising a stackable egg carton of plastic material having a lid and a tray hingedly connected to the lid, said egg carton having a width and length;
       the tray having a plurality of cells for receiving individual eggs, the cells being arranged successively adjacent each other along the width and along the length of the carton,   each cell having an under-surface forming a bottom of the tray,   the under-surface of the cells forming a series of recesses between adjacent cells; and   a pair of bosses projecting upwardly from an outer top surface of the lid, the pair of bosses being arranged at opposing ends along the length or width of the carton for positioning between two recesses of an adjacent carton stacked on top thereof, wherein the two recesses restrict movement of the bosses for maintaining the cartons in a stacked configuration.       
 
         [0012]    According to one embodiment of the invention, the lid has a trough that extends between the bosses. 
         [0013]    According to one embodiment of the invention, the trough extends up to and terminates at the bosses. 
         [0014]    According to one embodiment of the invention, the trough has a width that is about the same as a width of the bosses. 
         [0015]    According to another embodiment of the invention, the bosses have an upper surface contour that is complementary to a contour of the two recesses to resist lateral and/or longitudinal movement of the cartons relative to each other. 
         [0016]    According to one embodiment of the invention, the pair of bosses is disposed at about the centerline of the length or of the width of the carton. 
         [0017]    According to one embodiment of the invention, the bosses are arranged along or adjacent the opposing lengthwise or widthwise edges of the carton. 
         [0018]    According to one embodiment of the invention, the bosses are disposed beyond the lengthwise or widthwise edges of the lid and are supported by angled portions of a lid sidewall. 
         [0019]    According to one embodiment of the invention, the bosses are arranged along or adjacent the lengthwise edges of the carton. 
         [0020]    According to one embodiment of the invention, the plastic comprises a thermoplastic which is foamed or unfoamed, and comprises one or more of polystyrene, polyester, polyolefin, and poly(lactic acid), including homopolymers, copolymers, mixtures and blends thereof, and including virgin and reclaimed materials. 
         [0021]    According to one embodiment of the invention, the plastic comprises polystyrene foam. 
         [0022]    According to one embodiment of the invention, a stack is provided comprising a plurality of stacked egg cartons. 
         [0023]    According to one embodiment of the invention, where the stack comprises at least four layers of the cartons stacked one above the other. 
         [0024]    According to one embodiment of the invention, the stack rests on a pallet. 
         [0025]    According to one embodiment of the invention, the stack includes a stacking sheet between every 4, 5 or 6 layers of cartons. 
         [0026]    According to one embodiment of the invention, the stack is disposed on a pallet for transport without exterior support to the stack. 
         [0027]    According to one embodiment of the invention, the stack is disposed on a pallet for transport with only an outer film wrap supporting the stack. 
         [0028]    In accordance with another embodiment of the invention, a plastic egg carton is provided for packaging a plurality of eggs, said egg carton having a width and a length, the carton comprising:
       a lid and a tray hingedly connected to the lid;   the tray having a plurality of cells for receiving individual ones of the eggs, the cells being arranged successively adjacent each other along the width and along the length of the carton,   the lid having a top surface and being pivotable around the hinged connection into a closed position enclosing the cells,   each cell having an under-surface forming a bottom of the tray, the under-surface of the cells forming a series of recesses between adjacent cells,   the top surface of the lid having a pair of bosses projecting upwardly from the top surface of the lid, the pair of bosses being arranged at opposing ends along the length or width of the carton;   the bosses having an upper surface contour that is complementary to a selected contour of at least two recesses on the bottom, the at least two complementary recesses being arranged on the bottom for simultaneous receipt of a pair of bosses on the lid of a carton when the lid is in a closed position;   wherein when the pair of bosses are received within the at least two complementary recesses on the bottom of another one of the cartons, the complementary contours of the bosses and recesses resist lateral and/or longitudinal movement of the cartons relative to each other.       
 
         [0036]    According to one embodiment of the invention, the tray comprises a 2×6, 3×6, 4×6, 5×6 or 6×6 matrix of cells. 
         [0037]    According to one embodiment of the invention, the plastic comprises a thermoplastic which is foamed or unfoamed, and comprises one or more of polystyrene, polyester, polyolefin and poly(lactic acid), including homopolymers, copolymers, mixtures and blends thereof, and including virgin and reclaimed materials. 
         [0038]    According to one embodiment of the invention, the plastic comprises polystyrene foam. 
         [0039]    According to one embodiment of the invention, the lid comprises a generally planar sheet having a trough formed in the sheet that extends between the bosses. 
         [0040]    According to one embodiment of the invention, the trough extends up to and terminates at the bosses. 
         [0041]    In accordance with another embodiment of the invention, a method of stacking plastic egg cartons one on top of the other is provided, each egg carton having a length and a width and comprising a lid and a tray hingedly connected to the lid; the tray having a plurality of cells for receiving individual eggs, the cells being arranged successively adjacent each other along the width and along the length of the carton, each cell having an under-surface forming a bottom of the tray, the under-surface of the cells forming a series of recesses between adjacent cells on the bottom of the tray, a pair of bosses having a selected upper surface contour above a top surface of the lid such that the bosses project upwardly from the top surface of the lid, the pair of bosses being arranged at opposing positions disposed along the length or width of the carton, the method comprising:
       stacking one carton on top of another carton such that the two complementary recesses on the bottom of the one carton each receive one of the pair of bosses on the top surface of the lid of the other carton.       
 
         [0043]    In accordance with one embodiment of the invention, the pair of bosses and the two complementary recesses are disposed at about the centerline of the width or length of the carton. 
         [0044]    In accordance with one embodiment of the invention, the pair of bosses have a size and configuration such that when the pair of bosses are received within the recesses on the bottom of another one of the cartons, lateral and/or longitudinal movement of the cartons relative to each other is restricted. 
         [0045]    In accordance with one embodiment of the invention, the bosses are disposed at about the centerline of the length or width of the carton. 
         [0046]    In accordance with one embodiment of the invention, the bosses are arranged along or adjacent the lengthwise or widthwise edges of the carton. 
         [0047]    In accordance with one embodiment of the invention, the method includes transporting the stacked cartons. 
         [0048]    In accordance with one embodiment of the invention, the method includes transporting the stacked cartons on a pallet. 
         [0049]    In accordance with one embodiment of the invention, the method includes transporting the stacked cartons on a pallet without providing exterior support to the stack. 
         [0050]    In accordance with one embodiment of the invention, the method includes transporting the stacked cartons on a pallet with only an outer film wrap supporting the stacked cartons. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0051]    The drawings depict various embodiments of the invention wherein: 
           [0052]      FIG. 1  is a top left perspective view of a 4×6 matrix egg carton according to one embodiment of the invention showing the lid closed over on top of the bottom tray portion that receives the eggs; 
           [0053]      FIG. 2  is top plan view of the  FIG. 1  carton; 
           [0054]      FIG. 3  is a front view of the  FIG. 1  carton; 
           [0055]      FIG. 4  is a back view of the  FIG. 1  carton; 
           [0056]      FIG. 5  is a side view of the  FIG. 1  carton; 
           [0057]      FIG. 6  is bottom plan view of the  FIG. 1  carton; 
           [0058]      FIG. 7  is a front view of three  FIG. 1  cartons stacked one on top of each other; 
           [0059]      FIG. 8  is a sectional view taken along lines  8 - 8  of  FIG. 7 ; 
           [0060]      FIG. 9  is a sectional view taken along lines  9 - 9  of  FIG. 8 ; 
           [0061]      FIG. 10  is a side view of a pallet of stacked  FIG. 1  cartons showing a crane depositing another group of stacked  FIG. 1  cartons on top of the stack already on the pallet; 
           [0062]      FIG. 11  is a side view of a stack of cartons wrapped in film on a pallet; 
           [0063]      FIG. 12  is a perspective view of an alternative embodiment of an egg carton wherein the outer edges of the bosses reside beyond the edge of the lid top wall; and 
           [0064]      FIG. 13  is a sectional view showing a boss of the carton of  FIG. 12  engaging a cell of an adjacent carton. 
       
    
    
     DETAILED DESCRIPTION 
       [0065]      FIG. 1  shows in perspective view an egg carton  10  according to one embodiment of the invention. The carton  10 , having general overall dimensions of length L, width W and height H, is comprised of a lid  20  connected via a hinge  12  to a base tray  30 , the tray comprising a plurality of egg receiving cells  40  arranged in a matrix. The carton  10  is typically integrally molded from a sheet of polystyrene foam which is formed into an end product having the components described herein via conventional molding processes, e.g., pressing a foam sheet between male and female dies to form shaped lid and base portions and then removing (trimming) any remaining portions of the sheet to form an integral carton. The formation and structure of components such as the hinge  12 , base locking nubs  14 , associated lid flap and locking apertures  16 , cells  40  and the like are shown and described in the prior art such as in U.S. Pat. No. 6,012,583 and U.S. Pat. No. 5,494,164 the disclosures of which are incorporated herein by reference as if fully set forth herein. 
         [0066]    As shown in  FIGS. 1-2  the lid  20  has a generally flat (planar) upper surface  21  and a peripheral sidewall  23  extending downwardly to a peripheral lower edge  25  that mates with a peripheral upper edge  27  of the base tray. The lid  20  top wall is molded to include a recessed trough  50  disposed at and along a centerline C 1  transverse to length L of the carton  10 . A pair of bosses  70  are provided, one at each end of the trough  50 , the bosses having a preselected contour, e.g., size, shape, height P, geometry and/or configuration. The bosses are formed in the lid  20  as protrusions that extend axially A above the planar surface  21  of the lid  20  by a distance P (see  FIG. 5 ) which is preferably a minimum of about 3/16 inches. 
         [0067]    The elongated trough  50  is disposed along the width W of the carton between the bosses  70 , and in the embodiment shown, the ends of the trough  50  terminate in the bosses  70  which, as shown, are disposed with their outermost edges  76  adjacent the lengthwise edges  22  of the lid  20 . The trough  50  is formed within the body of the lid  20  as a generally elongated rectangular depression within the body of the planar surface  21  having elongated continuous walls  51  that extend axially A downwardly and below the planar surface  21  by a distance T, (see  FIG. 1 ), in the opposite axial direction from the upward axial distance of projection P of bosses  70  (see  FIG. 5 ). The walls  51  of the trough  50  preferably extend axially downwardly toward the tray  30  a sufficient distance T to enable the walls  51  to reinforce the lid and/or to laterally engage and act as a barrier or wall to protect eggs that are deposited within those cells  136 ,  138  that are immediately adjacent the lengthwise centerline C 1  (or widthwise centerline C 2  if the trough is aligned along the length) of the tray. Thus by extending a sufficient distance T from the top  21  downwardly toward the tray  30 , the walls  51  can reinforce the lid (increase the mechanical strength of the carton), and in particular reinforce the bosses (to facilitate stacking without undue movement of the cartons with respect to one another) and/or engage and prevent eggs in the two rows of cells immediately adjacent the centerline (C 1 ) from moving laterally within the tray  30 . As shown, the bosses  70  are disposed at and along about the centerline C 1  of the length of the carton  10 . Alternatively, the bosses  70  and the trough  50  could be formed and disposed at and along about the centerline C 2  of the width W of the carton  10 , the location of such bosses  70   a  being shown in schematic in  FIG. 2 . In such an embodiment, the trough  50  can be formed in and extend between bosses  70   a  along the centerline C 2  of the width W. 
         [0068]    As shown the tray portion  30  of the carton  10  comprises a series of egg receiving cells  40  each formed to receive and accommodate a single egg. Each of the cells  40  is formed with a side wall  139  (see  FIG. 8 ) having an inner receiving surface  140  contoured to receive the ovoid shape of an egg. The side wall  139  extends upwardly to define an open top and, where there is an adjoining cell joins with the sidewall  139  of the adjoining cell  106 , with the two side walls  139  cooperatively defining a cell junction  142  (see  FIG. 8 ). The cell junction  142  has generally at least one rounded shoulder which blends into a raised upper edge. The upper edge is flexible to respond to pressure applied by packaged eggs and provides protection therefor. Preferably, the carton comprises an even number of cells (for example 2, 4, 6, 8, 10, 12, etc.) serially interconnected either widthwise or lengthwise such that the bosses  70  or  70   a  can be positioned at about the center line or point between two adjacent cells while simultaneously being disposed at about the centerline C 1  or C 2  of either the length L or width W of the carton  10  along which an even number of cells are serially interconnected in a straight sequence. In the embodiment shown in  FIGS. 1-10 , the carton  10  comprises 6 rows of 4 cells extending along the width W, or 4 rows of 6 cells extending along the length L of the carton  10 . Typical other cell matrix formats are 2×4, 3×6, 3×4, 4×4, 4×6, 5×6 and 6×6. By way of example only, the polystyrene foam 4×6 matrix carton shown in  FIGS. 1-10  is designed to hold 24 extra large eggs, and is about 8 inches in width, about 11⅝ inches in length, and about 2¾ inches in height; each boss is about 1 inch long and about ½ inch wide and about 3/16 inches deep; the trough is about 5¾ inches long and about ¾ inches wide (at the top end) and about 1⅛ inches deep; the base tray is about 1½ inches deep; the lid is about 1½ inches deep; and each cell (at the top edge) is about 1⅞ inches in length and 1⅞ in width. This is given by way of example only and is not meant to be limiting. 
         [0069]    As shown in  FIG. 6 , the carton  10  has corner cells  135 , exterior cells  138  and interior cells  136 , the exact positioning of which results in recesses  175 ,  176 ,  178  formed between the exterior surfaces of the cells  135 ,  136 ,  138  on the bottom face  90  of the carton  10  having configurations peculiar to the precise position of the various cells  135 ,  136 ,  138 . Generally, the contour of the bottom outside cell surfaces  155 ,  156 ,  158  (of cells  135 ,  138 ,  136  respectively) are similar to each other such that the recesses  175 ,  176 ,  178  formed between adjacent cell outside surfaces  155 ,  156 ,  158  are similar in contour. 
         [0070]    The contour of the upper or outside surfaces of the bosses  70 ,  70   a  (e.g., the size, shape, height, width, depth and/or configuration of the bosses  70  or  70   a ) are selected and formed to be complementary to the contour of at least two of the recesses  175 ,  176 ,  178  such that each of the bosses  70  or  70   a  can be readily inserted into a recess. Preferably, the contour of the bosses  70 ,  70   a  are formed to be complementary to the contour of those recesses that are formed between the outside surfaces of two adjacent outside cells  138 , and more particularly the recesses  178  that are formed between the adjacent sidewall surfaces  158   a  of two adjacent exterior cells  138  that are also disposed immediately adjacent or straddle the centerline C 1  of the length L (or C 2  of the width W) of the carton  10  along an outer lengthwise edge  13  (or widthwise edge  17 ) of the tray  10 .  FIG. 2  shows this arrangement, where the arcuate sidewall contours  70   c  of the bosses are aligned to engage the outer circular contours of the two adjacent exterior cell sidewalls  138  to resist longitudinal and lateral movement therebetween. In this embodiment, the four corners  71 ,  72 ,  73 ,  74  (see  FIG. 2 ) of the boss  70  provide four potential points of engagement with the adjacent cells  158  (defining the recess  178 ) to effectively limit/resist both longitudinal and lateral movement between the stacked cartons. 
         [0071]    This is further illustrated in  FIGS. 7-9  where the two bosses  70  (or  70   a ) are formed and disposed in predetermined positions on the top surface  21  of the lid  20  that match and are complementary in position to the positions on the bottom  90  of the carton  10  of at least two recesses, such as recesses  178   a   1  and  178   a   2 . By such complementary positioning of at least two recesses  178   a   1  and  178   a   2 , the two bosses  70  (or  70   a ) can be readily inserted into these two recesses such that one carton  10   u  can be stacked on top of another  10   l  carton (as shown in  FIG. 7 ) rendering the two cartons aligned and resistant to lateral LAT and/or longitudinal LONG movement relative to each other by virtue of the two separate bosses  178   a   1 ,  178   a   2  being engaged or engageable against the bottom outside surfaces  158   a   1 ,  158   a   2  of the adjacent cells  138   a   1 ,  138   a   2  that form the recesses when the two stacked cartons  10   u,    10   l  are moved laterally LAT and/or longitudinally LONG relative to each other. 
         [0072]    In alternative embodiments, one or more additional bosses (in addition to the pair show in  FIG. 1 ) may be provided to lie within other recesses, between either exterior or interior cell walls. Alternatively, the pair of bosses may be provided not on a centerline. Preferably at least two bosses are provided adjacent or along opposing side edges of the carton, either the lengthwise or widthwise edges. In one embodiment, a first pair of bosses is provided adjacent or along the lengthwise edges and a second pair of bosses is provided adjacent or along the widthwise edges. 
         [0073]    As shown in  FIGS. 8-9 , the outside surface contour of the bosses  70  (or  70   a ) is smooth and is preferably formed with sloped outer surfaces  70   c  and/or smooth curvilinear or curved outer edges  70   d  that are configured so as to readily slide against the bottom outside surfaces  158 ,  158   a  of the cells if and when the boss surfaces  70   c,    70   d  may come into contact with the outside surfaces  158 ,  158   a  of the cells  178 , particularly when the bottom  90  of one carton  10   u  is mechanically positioned above and lowered onto the top side of another carton  10   l.  During such stacking and lowering process the user/operator (and/or machine) performing the stacking will attempt to mechanically align the bosses  70  (or  70   a ) with the recesses  178   a   1 ,  178   a   2  for insertion of the bosses  70  (or  70   a ) within a pair of complementarily positioned recesses,  178   a   1 ,  178   a   2 . Such mechanical alignment by the user cannot be perfect and the sloped, curved and curvilinear surfaces  70   c,    70   d,    158 ,  158   a  serve to facilitate insertion of the bosses into the complementary recesses and thus result in better longitudinal and lateral alignment of two cartons  10   u,    10   l  during the stacking process. 
         [0074]    The side wall  139  in each of the cells extends downwardly to a base wall  144 . In one embodiment, the base wall  144  is formed with a flat interior bottom surface  150  and a flat annular exterior bottom surface  152 , the annular surface  152  having a central raised button portion  154  defined therein (see  FIG. 9 ). The raised button portion  154  may be formed by densifying the polystyrene material of the base wall  144 . The cells  135 ,  136 ,  138  are collectively formed such that the exterior bottom surfaces  152  of all of the cells  135 ,  136 ,  138  of one carton  10   u  are substantially co-planar to form a substantially stable planar bottom surface PB (see  FIG. 7 ), that can readily engage and mate with the flat planar top surface  21  of another carton  10   l  when the one carton  10   l  is mechanically stacked or deposited on top of another carton  10   u.  By force of gravity G (see  FIG. 9 ), the bottom surfaces  152  bear against top surface  21  to provide a degree of stability against lateral LAT and longitudinal LONG movement due to friction between surface  21  and surfaces  152 . 
         [0075]    To provide further stability against lateral LAT and/or longitudinal LONG movement, the bosses  70  (or  70   a ) most preferably are formed with an outside upper surface contour that are complementary (conform) to the contour of the complementary recesses  178   a   1 ,  178   a   2  into which the bosses are intended to be inserted. Such complementary contouring of the bosses to the intended complementary recesses enables the bosses to project into and reside within the depth of the complementary recesses when the bottom surfaces  152  of the bases  144  of the cells  135 ,  136 ,  137  engage the top surface  21 . If and when a carton  10   u  moves laterally LAT or longitudinally LONG relative to carton  10   l,  the outside surfaces  70   c,    70   d  of the bosses will contact, engage and interfere with the bottom outside surfaces  158 ,  158   a  of the cells  178  thus preventing the upper stacked carton  10   u  from moving or otherwise becoming not aligned on top of the lower disposed carton  10   l.  As shown in  FIGS. 7-9 , surfaces  70   c  are formed to be complementary in contour to the surfaces  158   a,  surfaces  70   c  having a partial egg-shape similar to the partial egg-shape of surfaces  158   a.    
         [0076]    As shown in  FIG. 10 , in one embodiment a method and system is provided for stacking cartons  10  on the top planar surface  210  of a readily transportable pallet  200  (typically via forklift or crane  300 ) without the necessity of enclosing the stacked cartons  10 ,  10   l,    10   u  within a container such as a box or cage or the like. As shown, the cartons  10  are stacked vertically in series in direct top  21  to bottom PB contact with each other, one on top of each other in collective depths of preferably 3-6 cartons. Slip sheets  250  are preferably disposed between stacks of 3-6 cartons in vertical depth. The slip sheets  250  typically comprise a flexible sheet of paper, plastic or cloth that can be deposited on top of and extend across the top surfaces  21  of a horizontal layer of multiple side-by-side horizontally arranged cartons  400 , typically anywhere from about 2 to about 10 cartons horizontally across. As described above, the coplanar bottom surfaces  152  of the cartons  10  form a planar bottom surface PB which collectively among multiple cartons stacked at the same vertical level form a planar bottom PB 2  such that when multiple cartons  10  are deposited side-by-side  400  on a slip sheet  250 , the friction between PB 2  and the slip sheet  250  provides an additional stability against lateral LAT and longitudinal LONG movement relative to the cartons on which they are stacked. 
         [0077]    In another embodiment, shown in  FIG. 11 , a stack  410  of cartons  10  is disposed on a pallet  412  and the stacked cartons are wrapped in plastic film  414  (around the perimeter of the stack). The film provides the only outer packaging supporting the stack of egg cartons on the pallet. 
         [0078]    The stackable egg cartons of the present invention can, if desired, also be packaged in existing standard master corrugated containers, such as one-half and full cases, plastic and wire baskets, and carts. For example: (a) a corrugated paper container (case), where a full case typically holds 30-dozen 2×6 egg cartons, and a half case holds 15-dozen 2×6 egg cartons; (b) plastic and metal grid baskets where each basket (a half case) typically holds 15-dozen 2×6 egg cartons; (c) milk crates, where each crate typically holds between 12-dozen jumbo 2×6 egg cartons (for jumbo size eggs) and 15-dozen regular egg cartons, (for medium, large and/or extra large eggs); and (d) racks designed to be wheeled or slid into grocery store display cases, where each rack typically holds between 240 to 360 2×6 egg cartons. 
         [0079]    In another alternative embodiment shown in  FIGS. 12-13 , an egg carton  10 ′ is the same as the egg carton  10  of  FIG. 1 , the only difference being the pair of bosses  70 ′ are moved outwardly along the centerline C 1  of the lid  20 ′. Here the outer edges  76 ′ of the bosses  70 ′ reside beyond the lengthwise (or alternating widthwise) edges  22 ′ of the carton. As shown in  FIGS. 12-13 , the bosses  70 ′ are supported by an outwardly angled portion  24 ′, extending away from the upper lid surface  21 ′, of the lid sidewall  23 ′. This angled support portion  24 ′ extends further toward the periphery of the adjacent egg carton cell bottoms  158 ′ to provide enhanced support and stability. Here the more vertically disposed angled portion  24 ′ is disposed at a angle X of 172° with respect to the sidewall  23 ′. 
         [0080]    In various embodiments, the plastic egg carton is made of a thermoplastic which is foamed or unfoamed, and comprises one or more of polystyrene, polyester (e.g., polyethylene terephithlate (PET), polyolefin (e.g., polyethylene (PE), polypropylene (PP)), and poly(lactic acid) (PLA), including homopolymers, copolymers, mixtures and blends thereof, and including virgin and reclaimed materials. 
         [0081]    It is to be understood that the foregoing description is intended to illustrate and not limit the scope of the invention.