Abstract:
A method and apparatus for cooling produce contained in ventilated trays arranged in a five-down configuration on a pallet. The ventilated trays according to the present invention have openings that correspond to fluid passageways in contained clamshells in order to efficiently and effectively channel cooling air into the clamshells and over the contained produce. The present invention creates direct airflow channels to the produce that cause an optimal amount of the forced air to enter and flow over the produce within the produce carrying containers and not around the produce carrying containers as can occur with conventional six-down configurations. As a result, more air enters the produce carrying containers, more passes over the produce and more produce is effectively cooled.

Description:
The present invention relates to a method and apparatus for cooling produce contained in shipping/cooling trays carried on shipping pallets, more specifically, the present invention relates to a method and apparatus for cooling produce contained in shipping/cooling trays that are arranged on a pallet in a five-down configuration. 
     BACKGROUND OF THE INVENTION 
     Many fresh produce products are harvested and packaged in the field. These produce products include, but are not limited to, berries, such as strawberries, grapes, mushrooms, radishes, tomatoes, including cherry tomatoes, broccoli florets, lightweight tree fruit, and other fruits and vegetables. Many of these produce items require substantial post-harvest cooling in order to enable shipping over long distances and to prolong their shelf life. 
     In an attempt to provide some cooling to the packaged produce, the harvested fresh produce is typically packed into small, ventilated plastic containers that are ultimately purchased by the end consumer. These ventilated containers are commonly referred to as “clamshells”. Eight of these small, ventilated containers are placed into larger shipping trays that, in turn, are stacked on pallets for shipping. The conventional shipping trays can each include a bottom wall, a pair of opposed sidewalls, and a pair of opposed endwalls. The endwalls of these shipping trays commonly have a recessed portion along their length that permits the cooling air to pass into the ventilated containers. These conventional shipping trays have a length of twenty inches and a width of sixteen inches. 
     The conventional shipping trays are loaded onto the pallet in a “six-down” configuration. In the six-down configuration, a layer of the shipping trays is formed on the pallet by positioning six of the shipping trays so that their longitudinal axes extend in parallel directions and their recessed endwalls extend in parallel planes (See  FIG. 11 ). These parallel endwall planes extend perpendicular to the directions that the sidewalls extend. The shipping trays are typically arranged on the pallet in multiple stacked layers until a predetermined number of shipping trays, such as forty-eight, is achieved. The most common pallet used in the produce industry is the forty-inch by forty-eight inch wooden pallet, and the vast majority of produce handling, storage and shipping equipment is designed around this sized pallet. 
     After the stacked shipping trays are loaded onto their respective pallet, the loaded pallet is moved to a forced air cooling chamber to cool and/or store the fresh produce. In the air cooling chamber, the pallets are arranged in rows against a wall that includes a vacuum fan. The rows are spaced apart and a canvas sheet is draped over the rows and the opposing end of the chamber to create an airflow channel. When the fan is turned on, it draws ambient cold air from the room through the vent openings in the trays carrying the produce. Typically, the room temperature is maintained at 32 degrees Fahrenheit and the target temperature for the produce is about 36.5 degrees Fahrenheit. 
     During the cooling process, the ambient cooling air arrives within each shipping tray by entering through one of its respective recessed endwalls. The cooling air then enters the individual containers carried by the tray in an attempt to cool the produce stored therein. As the air cools the produce, it picks up heat from the produce. The warmed air is eventually exhausted from the shipping tray through the opposite recessed endwall. After cooling the fresh produce in the shipping containers, the shipping containers are transported to grocery stores and fresh produce markets, where the fresh produce is sold to consumers. 
     The orientation and arrangement of the conventional six-down shipping tray configurations does not permit multi-directional cooling of the stored produce. As a result, the arrangement of pallets is limited. Additionally, the amount of cooling air entering the shipping trays may also be limited, thereby effecting the survival of the produce. 
     SUMMARY OF THE INVENTION 
     An aspect of the present invention relates to an apparatus that permits produce trays to be arranged in a “five-down” configuration on a pallet so that the produce is effectively and efficiently cooled during storage and transportation to the location where the produce will be sold to consumers. Another aspect of the present invention relates to a method of cooling produce by arranging ventilated trays on a pallet in a five-down configuration. 
     The ventilated trays according to the present invention have openings that correspond to the openings and gaps in the contained clamshells to channel cooling air into the clamshells and over the contained produce. The cooling airflow over the produce according to the present invention is such that the cooling rate achieved by using the ventilated tray is substantially equal to that of the trays arranged in the six-down configuration. The present invention creates direct airflow channels that cause an optimal amount of the forced air to enter and flow over the produce within the produce carrying containers and not around the produce carrying containers as can occur with the six-down configuration. As a result, more air enters the produce carrying containers, more passes over the produce and more produce is effectively cooled. 
     An aspect of the present invention relates to a shipping tray for receiving produce carrying containers. The shipping tray comprises a bottom and a plurality of walls extending from the bottom. Each wall extends at an angle to an adjacent one of the walls. Each wall also includes a plurality of ventilation openings sized and configured to cooperate with openings in the produce carrying container so as to allow cooling fluid to pass through the walls and into the containers when the containers are positioned within the shipping tray. 
     Another aspect of the present invention relates to a tray for being arranged in a five down configuration on a pallet. The tray comprises first and second walls extending at angles to each other. The first wall includes a plurality of ventilation openings for aligning with fluid passages in produce carrying containers that are positionable within the tray. The second wall includes a plurality of ventilation openings for aligning with the fluid passages in the produce carrying containers so that fluid can pass through both walls of the tray and the produce carrying containers when said tray is positioned on the pallet. 
     A further aspect of the present invention also includes a method of cooling produce. The method comprises the steps of positioning a plurality of produce carrying trays on a pallet in a five-down configuration and placing the trays into a cooling chamber. Each of the produce carrying trays includes a first wall with ventilation openings that extends at an angle to a second wall that also includes ventilation openings. The method also includes the step of introducing a cooling fluid into a plurality of the produce carrying trays arranged in the five-down configuration through the ventilation openings in their respective first walls and into the remaining produce carrying trays arranged in the five-down configuration through ventilation openings in their respective second walls. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         FIG. 1  illustrates a cooling chamber/room including a plurality of shipping pallets loaded with ventilated shipping trays in five-down configurations according to the present invention; 
         FIG. 2  is an end view of a ventilated produce container that is positioned within the ventilated trays illustrated in  FIG. 1 ; 
         FIG. 3  is a side view of the container of  FIG. 2 ; 
         FIG. 4  is top plan view of the container of  FIG. 2  with a hinged cover open; 
         FIG. 5  is a side view of the container of  FIG. 2  with the hinged cover open; 
         FIG. 6  is a perspective view of a plurality of ventilated shipping trays stacked on a pallet in a five-down configuration without the produce containers; 
         FIG. 7  is a plan view of a blank for an embodiment of the ventilated container according to the present invention; 
         FIG. 8  is a plan view of a blank for another embodiment of the ventilated container according to the present invention; 
         FIG. 9  is a plan view of the cooling fluid flow through the ventilated chambers arranged in a five-down configuration; 
         FIG. 10  is a graph illustrating the cooling rates of five-down and six-down configured trays; and 
         FIG. 11  is a plan view of the cooling fluid flow through conventional ventilated chambers arranged in a six-down configuration. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     As shown in  FIG. 1 , the present invention includes ventilated carrying/shipping trays  10  having a plurality of openings and recesses that cooperate with openings in individual produce carrying containers  100  ( FIG. 2 ) that are positioned within the ventilated trays to provide optimum cooling fluid flow around the contained produce. The openings of the ventilated trays  10  are aligned with openings in the containers  100  so that cooling fluids, such as air, enter the individual packages  100  and flow over the contained produce to effectively and efficiently cool the produce between the time that it is packaged and the time that it is sold to the consumer. As discussed below, the ventilated trays  10  are carried on conventional forty by forty-eight inch shipping pallets  5  in a “five-down” configuration. The shipping pallets  5  can be formed of wood, plastic or other known materials. 
     As shown in  FIGS. 2–5 , each produce carrying container  100  include a plurality of sidewalls  101 , endwalls  102 , a bottom surface  103  and a hinged cover  104  that form an interior, produce carrying region. The cover  104  is secured to one of the sidewalls  101  along its length by a hinge  105  so as to form a unitary, one-piece container. The hinge  105  can be continuous or include spaced openings. The dimensions of the container  100 , such as height, can change depending on the carried produce. For example, in a preferred embodiment that can be used for carrying produce such as strawberries, the container  100  has a height extending from its lowest surface to its uppermost surface of between about 2.25 inches and 3.0 inches, preferably about 2.72 inches. The container  100  also has a length of between about 6.5 and 7.0 inches, preferably about 6.72 inches, and a width of between about 4.50 and 5.0 inches, preferably about 4.86 inches. 
     In another preferred embodiment of the container  100  that can be used for carrying produce such as grapes, the container  100  has a height of between about 4.0 inches and 4.50 inches, preferably about 4.22 inches. The container  100  also has a length of between about 6.50 and 7.0 inches, preferably about 6.72 inches, and a width of between about 4.50 and 5.0 inches, preferably about 4.86 inches. 
     The interior, produce carrying region is open to the exterior via multiple fluid passages. These fluid passages include a horizontal ventilation gap  106  formed between the hinged cover  104  and the sidewalls  101 , endwalls  102  of the container  100 . The gap  106  extends around at least three or more sides of the container  100  and has a vertical height of between about 0.05 and 0.30 inch. In a preferred embodiment, the height of the gap  106  is about 0.19 inch. The fluid passages also include ventilation openings  107  formed in the bottom surface  103 . In a preferred embodiment, the container  100  includes twelve ventilated openings  107  positioned proximate support pillars  108 . These support pillars  108  allow forced airflow and vacuum turbulence of the airflow through the bottom surface  103  and upward through the produce carried by the container  100 . In a preferred embodiment, the pillars  108  include small projections or buttons on the bottom surface  103  of the container  100  that support the container above a surface, such as the inner bottom surface of the tray  10  and create a fluid channel  109  along the bottom of the container  100  so that cooling fluid can travel below the bottom surface  103  of the container  100  and enter the container  100  through the openings  107 . The cooling air can experience either or both laminar and turbulent flow within the containers  100 . In one embodiment, the cooling air experiences turbulent flow around the contained produce within the containers  100 . These containers  100  are available from Intec Alliance under the name GENESYS. As discussed below, eight containers  100  are typically placed within each ventilated tray  10 . 
     Certain embodiments of the container  100  may not include a ventilation gap  106 . One such embodiment is discussed above for carrying grapes. In this embodiment, the endwalls  101  and sidewalls  102  will include vertically oriented ventilation slots. These slots operate in a similar manner to the ventilation gap  106 . Specifically, they contribute to the efficient introduction of cooling air into the container  100  and the efficient removal of warmed air from the container  100 . 
     As illustrated in  FIGS. 6 and 7 , each ventilated shipping tray  10  according to the present invention that receives the container  100  includes four sidewalls  20 , a bottom surface  25  that extends between the sidewalls  20  and an open inner space  40 . The ventilated trays  10  can be formed of any known material, such as paperboard, corrugated board, wood or plastic. The ventilated tray  10  can have a square or rectangular shape (horizontal cross section). In a preferred embodiment, such as that depicted in  FIG. 6 , the ventilated tray  10  has a rectangular shape. In such an embodiment, the cooling tray  10  includes first and second endwalls  22  and first and second sidewalls  24 . The terms “endwall” and “sidewall” are not limiting to the position of the cooling trays  10  on the pallet  5 . 
     Referring to the embodiment illustrated in  FIGS. 6 and 7 , the endwalls  22  and the sidewalls  24  each include a plurality of ventilation openings  30  that permit cooling fluids, such as air, to enter the tray  10  and the fluid passages in the containers  100  in order to cool the produce contained in the containers  100  as discussed below. These ventilation openings  30  are sized and arranged on the endwalls  22  and sidewalls  24  so as to align with respective fluid passages  106  and the fluid channel  109  of the carried containers  100 . As a result, optimized cooling airflow will enter the ventilated trays  10  and the carried containers  100 . Therefore, the size and location of the openings  30  will differ on trays  10  used to carry different sized containers  100 . The size and orientation of the openings  30  will mate with the size and openings in the containers  100  so that the cooling laminar fluid flow will not be obstructed as it moves from the tray  10  into the container  100  from any one or more of the sides of the pallet. For example, it may be more preferred to use the ventilated tray  10  illustrated in  FIG. 7  with containers  100  carrying fruits such as strawberries. Similarly, it may be more preferred to use the ventilated tray  110  illustrated in  FIG. 8  to carry fruits or other produce such as grapes that require a taller container  100 . 
     The endwalls  22  of the ventilated tray  10  each include an array of openings  30 . The array includes two horizontal rows of openings  30  and two vertical columns  30 . In a preferred embodiment, as shown in  FIG. 7 , the openings  30  have the general shape of an elongated oval. In this preferred embodiment, the openings  30  and endwalls  22  have the below discussed dimensions. Each opening  30  has a length A of between approximately 2.5 and 3.0 inches, preferably about 2.75 inches. Each opening  30  has a height of between about 0.25 inch and 0.75 inch, preferably about 0.5 inch. The opening  30  in each row are spaced from each other by a horizontal distance C of between about 4.75 and 5.25 inches, preferably about 5.0625 inches. The openings  30  in each column are vertically spaced from each other by a distance D of between about 1.0 and 1.50 inches, preferably about 1.25 inches. The uppermost openings  30  are spaced from an upper edge of the endwall  22  by a distance of between about 0.4 inch and 0.8 inch, preferably about 0.625 inch. The total height of each endwall  22 , from the bottom surface  25  to the upper edge  29  of the endwall  22  is between about 2.5 and 3.0 inches, preferably about 2.875 inches. The total length of each endwall  22  is between about 15.4 and 15.9 inches, preferably about 15.5625 inches. The endwalls  22 , like the sidewalls  24 , can have any known thickness. 
     The sidewalls  24  each include a plurality of ventilation openings  36  that are arranged in an array having two horizontal rows and four vertical columns. The two outermost vertical columns include an upper large opening  36  having a length G of between about 2.5 and 3.0 inches, preferably about 2.75 inches, and a lower, smaller opening  38  having a length of between about 1.0 inch and 1.5 inches, preferably about 1.375 inches. A distance H of between about 1.0 and 1.5 inches, preferably about 1.25 inches vertically separates these openings  36 ,  38 . The middle two columns include openings  36  that have a length I of between about 2.5 inches and 3.0 inches, preferably about 2.75 inches and that are spaced by the distance H. A distance J of between about 2.75 inches and 3.25 inches, preferably about 3.0 inches, horizontally separates the openings  36  of the inner two columns from the openings  36  of the outer two columns. A distance K of about 1.5 inches and 2.0 inches, preferably about 1.75 inches, horizontally separates the openings of the two middle columns. The openings  36 ,  38  have a height of between about 0.25 inch and 0.75 inch, preferably about 0.5 inch, and are separated from the upper edge  29  of the sidewall  24  by a distance of between about 0.4 inch and 0.8 inch, preferably about 0.625 inch. The length L of each sidewall  24  is between about 22.0 and 24.0 inches, preferably about 23.0 inches, whereas the distance M between the two endwalls  22  is between about 23.0 inches and 24.0 inches, preferably about 23.375 inches when the ventilated tray is assembled. The sidewalls  24  each have two layers, the first, outer layer has a vertical height of between about 2.5 inches and 3.25 inches, preferably about 2.875 inches. The second, inner layer, which is folded over the outer layer, has a height of between about 2.5 and 3.0 inches, preferably about 2.75 inches. Each sidewall  24  also includes protruding members  37  that extend through respective openings  39  in the bottom  25  of a tray  10  that is stacked on top of it. These protruding members  37  and openings  39  stabilized the stacks of trays  10 . In one embodiment, the blank, before folding, has a length of about 29.125 inches and a width of about 29.5625 inches. 
     As mentioned above,  FIG. 8  illustrates another embodiment of the ventilated tray for use with taller containers  100  than those used with the embodiment shown in  FIGS. 6 and 7 . This embodiment of the ventilated tray  110  includes sidewalls  20  having a plurality of ventilation openings for permitting cooling fluids, such as air, to enter the interior space  40  of the ventilated tray  110  and the carried containers  100  in order to cool the produce housed in the containers  100 . The ventilated tray  110  is essentially the same as ventilated tray  10  except for the below discussed differences. 
     The endwalls  22  of the ventilated tray  110  include a first, handle section  132  and a second, ventilation section  134  in which the ventilation openings  130  are formed. The handle sections  132  have a height of between about 7.5 and 8.0 inches, preferably about 7.65625 inches. The ventilation sections of the endwalls  22  have a height of between about 4.25 and 4.75 inches, preferably about 4.5 inches and each include a pair of the openings  130 . The openings  130  have the general shape of an elongated, vertically oriented oval. Each opening  130  has a height N of between about 2.0 and 2.5 inches, preferably about 2.25 inches and a width 0 of between about 0.25 inch and 0.75 inch, preferably about 0.5 inch. The center of each opening  130  is horizontally spaced from the center of an adjacent opening by a distance P of between about 7.5 and 8.0 inches, preferably about 7.8125 inches. 
     The sidewalls  24  of the ventilated tray  110  each include a plurality of ventilation openings  136  spaced along its length. The openings  136  have a vertical length S of between about 2.0 and 2.5 inches, preferably about 2.25 inches and a horizontal width of between about 0.25 and 0.75 inch, preferably about 0.5 inch. The center three openings  136  are spaced from each other by a distance T of about four inches. The outer openings  136  are spaced from adjacent center openings  136  by a distance U of between about 3.5 and 4.0 inches, preferably about 3.8125 inches. The sidewalls  24  are between about 4.1 and 4.6 inches tall, preferably about 4.375 inches tall. The interior of the tray  110  is between about 23.25 and 25.5 inches long V, preferably about 23.375 inch long, and between about 15.25 and 15.75 inches wide W, preferably about 15.5625 inches wide. In one embodiment, the blank from which the tray  110  is formed is about 35.5 inches wide and about 47.8 inches long. Each sidewall  24  also includes protruding members  137  that extend through respective openings  139  in the bottom  25  of the tray  110  that is stacked on top of it. These protruding members  137  and openings  139  stabilized the stacks of layered ventilation trays  110  on the pallet  5 . 
     The discussions set forth below are applicable to all of the above-discussed embodiments of the shipping trays. However, for clarity of the explanation, the discussion will be limited to one embodiment—shipping tray  10 . In a preferred embodiment, each ventilated tray  10  can carry up to eight of the one-pound produce carrying plastic containers  100 , illustrated in  FIGS. 2–5 . The containers  100  are typically arranged in two rows of four within the ventilated trays  10  as shown in  FIG. 9 . 
     Five of the ventilated shipping trays  10  are then placed on an upper surface of the pallet  5  in a five down configuration as shown in  FIG. 9  to form a single layer on the pallet  5 . Additional layers of the ventilated trays  10  in a five down configuration are positioned on top of the layer(s) already arranged on the pallet  5  to form a stack of the ventilated trays. When the stack includes a predetermined number of layers on the pallet  5 , such as eight, the stacked pallet  5  is ready for shipping. 
     As shown in  FIG. 9 , the phrase “five-down configuration” relates to a specific arrangement of ventilated trays  10  on the pallet  5 . A five-down configuration includes the formation of a single layer of ventilated trays  10  on the pallet  5  using only five ventilated trays  10 . In this configuration, two of the ventilated trays  11  form a row in their length direction and the remaining three ventilated trays  12  form a row in their width direction. As illustrated, the longitudinal axes  15  of the three ventilated trays  12  are parallel to each other and parallel to two sides of the pallet. The remaining two ventilated trays  11  are positioned on the pallet  5  so that their longitudinal axes  16  are aligned and parallel to each other, and perpendicular to the longitudinal axes  15  of the other three ventilated trays  12 . Multiple five-down configured layers of ventilated trays  10  are stacked on top of the pallet  5  in preparation for transporting the produce to the end consumer. The number of five-down configured layers stacked on top of each other may vary on each pallet  5 . However, in conventional stacking, the pallet  5  would include eight layers of ventilated trays  10  arranged in a five-down configuration. 
     After the ventilated trays  10  have been placed on their respective pallets  5 , the pallets  5  are transferred to the cooling chamber  200  shown in  FIG. 1  and stored in multiple rows. When positioned within the cooling chamber  200 , the cooling fluid, such as air or water, is introduced into the ventilated containers  10  through the endwalls  22  of the two ventilated trays  11  and the sidewalls  24  of the remaining ventilated trays  12  (See  FIG. 9 ). Alternatively, the pallet  5  can be arranged so that the cooling fluid enters through the endwalls of the three parallel positioned ventilated trays  12  and then through the sidewalls of the remaining two ventilated trays  11 . As discussed above, the ventilated trays  10  provide a specific venting pattern that cooperates with the openings in the containers  100  to create a system that cools as rapidly as the conventional six-down configurations. The cooling rates between the five-down configuration (X) and the six-down configuration (Z) are illustrated in the graph in  FIG. 10 . 
     Numerous characteristics, advantages and embodiments of the invention have been described in detail in the foregoing description with reference to the accompanying drawings. However, the disclosure is illustrative only and the invention is not limited to the illustrated embodiments. Various changes and modifications may be effected therein by one skilled in the art without departing from the scope or spirit of the invention.