Stackable carton for perishable commodities

A blank and a stackable carton produced from the blank and particularly suited for packing fresh fruits and vegetables includes a tray with a rectangular floor panel and vertical side walls. The side walls includes side cover flaps extending from fold lines defining the outer edges of the side walls. Pairs of side wall flaps are provided, each flap in each pair extending from a fold line defining an end of the side walls. A generally rectangular stacking panel is fitted into each end of the tray. Each stacking panel may include a pair of recesses at its lower edge which are aligned with openings in the rectangular floor panel of the tray. The trays can be vertically stacked with the openings in the floor of one tray aligned with tabs protruding from the upper surface of the lower tray.

The present invention relates to carton blanks and to stackable cartons 
formed therefrom. The cartons are particularly suitable for holding 
perishable commodities. 
Growers of fruits and vegetables have traditionally used wooden boxes for 
storage and shipment of their products. Wooden boxes can be reaidly packed 
either in the field or at packing sheds and stand up well during short 
term or long term storage. 
Wooden boxes suffer from the disadvantage however they are somewhat 
expensive to make because of the cost of raw materials and of labor in 
making such boxes. Also, wooden boxes must be manufactured in their 
erected form and shipped fully erected to the grower. Since the boxes are 
bulky even when empty, the costs of shipping them to the user in quantity 
are high. 
Paper materials, such as corrugated, are less expensive than wood and can 
be readily formed into erected cartons which can be shipped to a user in a 
collapsed condition to save freight costs. However, corrugated cartons 
have not been widely accepted by growers of fruit and vegetables because 
of concerns that such cartons may be more easily degraded by moisture than 
wooden boxes and because it is thought that cardboard cartons do not stack 
as well as wooden boxes of the same size. 
The present invention is concerned with the problem of providing carton 
blanks and cartons erected therefrom which (a) may suitably be treated; 
i.e., with wax, to inhibit degradation under moisture conditions and (b) 
which may readily be shipped in collapsed state and erected on site for 
loading with perishable commodities and thereafter stacked. 
With the foregoing in mind we provide in accordance with the invention a 
blank which may be erected into a stackable storage and shipping tray 
after a single pass through an adhesive applicator device and for use in 
combination with generally rectangular shaped stacking panels wherein the 
erected tray includes opposed triple-ply adhesively connected end wall 
assemblies, said blank being characterized by a generally rectangular 
floor panel (4), first and second generally rectangular side wall panels 
extending from fold lines defining opposite edges of said floor panel, 
first and second generally rectangular side cover flaps extending from 
fold lines defining the outer edges of said first and second side wall 
panels, respectively, first and second pairs of side wall flaps, each flap 
in each of said pairs extending from a fold line defining an end of one of 
said side wall panels, each of said side wall flaps including at least one 
tab extending upwardly from an upper edge thereof and at least one recess 
at its lower edge in vertical alignment with said tab, first and second 
generally rectangular end wall panels extending from opposite end edges of 
said floor panel, each of said end wall panels having first and second 
recesses at its lower edge, said floor panel end edges having openings 
therein, said end wall panel recesses and said floor panel end edge 
openings being in vertical alignment when said blank is folded to form 
said tray. 
We also provide in accordance with the invention a stackable storage and 
shipping tray which is characterized by comprising a generally rectangular 
floor panel, first and second side wall panels extending generally upright 
from opposite edges of said floor panel, each of said side wall panels 
including side wall flaps extending from opposite ends thereof and a side 
cover flap extending from the free side thereof, each said side cover flap 
including recesses adjacent its side edges, each said side wall flap 
including at least one tab extending upwardly from an upper edge thereof 
and at least one recess at its lower edge in vertical alignment with said 
tab, first and second end wall panels extending generally upright from the 
remaining opposite edges of said rectangular floor panel, each said end 
wall panel having first and second recesses at its lower edge and being 
adhesively connected to the outer surface of the associated side wall 
flaps of said side walls, said first and second recesses being aligned 
with the recess in each of said side wall flaps, and first and second 
generally rectangular stacking panels with the outer surface of each 
stacking panel being adhesively connected to the inner surface of the 
associated side wall flaps of said side wall, said end wall panels, side 
wall flaps and stacking panels forming tripleply adhesively connected end 
wall assemblies wherein each tab on a side wall flap extends through a 
recess in one of said side cover flaps.

As above noted, paperboard that has been wax-saturated is very expensive 
and there is a great deal of wood particle board available which is less 
costly than is saturated paperboard. We have found it advantageous with 
our blank to use a particle board stacking or end panel to strengthen the 
erected blank. Also, we modify the side wall flaps as hereinafter more 
fully described to accommodate the stacking panels. 
More particularly and referring to FIG. 1, the carton blank has a 
rectangular floor panel 10 and upright side wall panels 12 and 14. The 
remaining two sides of the blank are formed by end wall panels 16 and 18. 
Side cover flaps 20 and 22 extend from fold lines 24 and 26 defining, when 
the blank is erected, the upper edge of the side wall panels 12 and 14, 
respectively. Each of the end wall panels 16 and 18 carries an end cover 
flap 32 and 34, respectively. 
The carton is ventilated by a series of openings, such as opening 36, along 
the upper edge of each side wall panel and by spaced vertical slots, such 
as slot 40, in the body of each side wall panel. 
The rectangular floor panel 10 has a first pair of openings 42a and 42b 
adjacent a fold line 44 defining one end of the panel 10. Similarly 
rectangular openings 46a and 46b are formed through panel 10 at the 
opposite end edge 48. Elongated openings 50a and 50b exist in end cover 
flap 32 at a fold line 52. A similar pair of elongated openings 54a and 
54b exist in the opposite end cover flap 34. In the erected carton, each 
of those elongated openings is vertically aligned with a corresponding one 
of the openings in the floor panel 10. 
Smaller elongated openings 56a and 56b are formed along fold line 52 while 
similar openings 58a and 58b are formed along the fold line 60 dividing 
end cover flap 34 from end wall panel 18. The carton material is slit at 
the inner end of each of the small elongated openings. For example, a 
short slit 62 extends parallel to the fold line 52 from elongated opening 
56a. In the erected carton, the openings 56a, 56b, 58a and 58b are used in 
conjunction with locking tabs (to be described) in order to hold the side 
cover flaps 20 and 22 or cover panel means in their closed positions 
parallel to the floor panel 10. 
Side wall flaps 64 and 66 extend from the upper and lower edges, 
respectively, of the side wall panel 12. Substantially identical side wall 
flaps 68 and 70 extend from the upper and lower edges, respectively, of 
the opposite side wall panel 14. 
End wall panels 16 and 18 and side wall flaps 64, 66, 68 and 70 are covered 
with several strips 71 of a suitable adhesive, which can be applied in a 
single pass through a conventional adhesive applicator device. Such a 
device may be located at the blank manufacturing facility but is 
preferably located at or near the growers' locations to allow the cartons 
to be shipped and stored flat until they are to be used. 
Each of the side cover flaps 20 and 22 includes a pair of locking tabs. 
More specifically, side cover flap 20 includes generally tapered locking 
tabs 72 and 74 at its opposite ends. The tapered base or straight side of 
each locking tab is parallel to the adjacent edge of the side cover flap. 
Referring specifically to locking tab 72, a material bridge 76 connects 
the tapered body 78 of the tab to the side cover flap. The side cover flap 
20 includes generally rectangular notches 82 and 84 at its upper and lower 
edges, respectively. 
The side cover flap 22 is a mirror image of side cover flap 20 including 
first and second locking tabs 86 and 88 and generally rectangular notches 
92 and 94 at the upper and lower edges, respectively. The carton described 
thus far is used in combination with generally rectangular particle board 
stacking or end panels 96, a preferred embodiment of one such panel being 
shown in FIG. 2. 
As will be seen in FIG. 1, each of side wall flaps 64, 66, 68, and 70 has 
formed therein a trapezoidal shaped tab 98a, 98b, 98c, and 98d, 
respectively, and recesses 104a, 104b, 104c and 104d respectively. When 
the carton is erected, side wall flaps 64, 66, 68 and 70 are bent upwardly 
relative to the side wall panels 12 and 14 and side wall panels 12 and 14 
are then pivoted about the fold lines defining their boundaries with floor 
panel 10 to bring the side walls 12 and 14 into a generally upright 
position. End wall panels 16 and 18 are folded upright bringing their 
adhesive-coated areas into contact with uncoated surfaces of the side wall 
flaps 64 and 68 at one end and flaps 66 and 70 at the other end. The four 
side walls of the tray are secured in their upright positions by the 
adhering surfaces of the end wall panels and side wall flaps. In such 
erected condition, the outer face of the side wall flaps 64 and 68 is 
adhesively secured to the inner face of end wall panel 16 while the outer 
face of side wall flaps 66 and 70 is adhesively secured to the inner face 
of end wall panel 18. In such position, recesses 104a, 104b, 104c and 104d 
are located above and superimposed over recesses 42a, 46a, 42b and 46b, 
respectively in rectangular floor panel 10. They are also superimposed 
over and are congruent with trapezoidal shaped recesses 200a, 200b, 200c 
and 200d, respectively, formed in the base of end wall panels 16 and 18. 
Thus, when the erected carton is stacked on top of a second carton, the 
trapezoidal tabs 98a, 98b, 98c, and 98d of the bottom or second carton 
extend upwardly through recesses 42a, 46a, 42b, and 46b of the top carton 
to recesses 104a and 200a, 104b and 200b, 104c and 200c, and 104d and 
200d, respectively to secure the cartons together. 
It will be understood that to further strengthen the end walls of said 
carton, the particle board end panel 96 shown in FIG. 2, may be utilized 
by adhesively attaching it to the inside of side wall flap pair 64 and 68 
and pair 66 and 70. Since the trapezoidal stacking tabs are integrally 
formed with the carton blank as shown in FIG. 1, they need not be provided 
in the top 102 of end panel 96. Further, if desired, trapezoidal recesses 
104 and 106 may be added to particle board end panel 96 at the bottom 108 
as shown in dashed lines in FIG. 2 if desired to facilitate stacking 
although it is not necessary because such recesses 104a, 104b, 104c and 
104d are already formed in side wall flaps 64, 66, 68 and 70 and end wall 
flaps 16 and 18. Because wax impregnated paper board is so expensive, 
particle board may be used to form the particle board end panel 96 and 
thus not only preserve the strength of the carton end walls but also 
provide for a carton that is more economically constructed. 
If desired, ventilating slots 40 may be added to side wall flaps 64, 66, 68 
and 70, end wall panels 16 and 18, and particle board end panel 96 such 
that corresponding slots are in superimposed relationship when the carton 
is erected. 
When erected to the point described, the carton is ready to be packed with 
fruits, vegetables or other perishable commodities. After packing has been 
completed, the end cover flaps 32 and 34 are bent inwardly until generally 
parallel to the floor panel 10. 
The locking tabs 72, 74, 86 and 88 are bent to right angles relative to the 
surfaces of side cover flaps 20 and 22. The side cover flaps 20 and 22 are 
then folded about the fold lines 24 and 26 to bring the 
downwardly-extending locking tabs 72, 74, 86 and 88 toward the small 
corresponding elongated openings 56a, 56b, 58a and 58b at the upper edges 
of the carton end walls 16 and 18. The locking tabs can be maneuvered 
through the small elongated openings to lock the side cover flaps in a 
closed position parallel to the floor panel 10. 
The tapered locking tab 88 is bent at right angles to the major surface of 
side cover flap 22. The tapered tab 88 can be inserted into the small 
elongated opening 58b in end cover flap 34. A slit 114 at the inner edge 
of rectangular opening 58b may be provided to allow the flap material to 
deform sufficiently to pass tapered locking tab 88. 
Cartons of the type described may be stacked as previously described. 
The blank and carton described in the foregoing material is particularly 
suitable for use in field packing operations since a field worker can pack 
and close the carton without the use of machinery. The closed cartons can 
be stacked on the truck or wagon used to haul them from the fields. 
FIG. 3 is a plan view of a blank which may be erected into an alternate 
embodiment of a stackable storage and shipping tray for use in combination 
with stacking panels shown in FIG. 4, which stacking panels 166 have 
flanges 168 integrally formed with and extending from opposite ends 
thereof by means of score lines wherein the erected tray includes opposed 
triple-ply adhesively connected end wall assemblies and opposed double-ply 
adhesively connected side wall assemblies. In FIG. 2, the blank has a 
generally rectangular floor panel 170, first and second generally 
rectangular side wall panels 172 and 174 extending from respective fold 
lines 176 and 178 which define opposite side edges of said floor panel 
170, first and second side wall flaps 180 and 182 integrally formed with 
and extending from opposite ends 184 and 186 of said side wall panels 172 
and 174 and first and second generally rectangular end wall panels 188 and 
190 extending from opposite end edges 192 and 194, respectively of said 
floor panel 170. 
FIG. 5 is a perspective view of a carton partially erected from the blank 
of the alternate embodiment illustrated in FIGS. 3 and 4. As can be seen 
in FIG. 5, when the carton is completely erected, triple-ply opposing end 
wall panels are formed each from an adhesively connected stacking panel 
166, and at the right side of the carton, first and second side wall flaps 
182, and generally rectangular end wall panel 190 and at the left side of 
the carton, side wall flaps 180 and end wall panel 188. Further, a double 
ply adhesively connected side wall assembly is formed from stacking panel 
flanges 168 and the respective side wall panels 172 or 174. If the 
respective stacking panel flanges 168 are extended on each side as shown 
by dashed lines 196 and 198, the entire side wall assembly assumes a 
double ply thickness. Without such full extensions of the stacking panel 
flanges 168, a double side wall thickness is provided for only the length 
of the stacking panel flange 168. 
FIG. 6 is a plan view of a carton blank which may be used to form another 
embodiment of a carton having a double thickness on all four side walls. 
As can be seen in FIG. 6, the blank comprises a generally rectangular 
floor panel 200, first and second generally rectangular side wall panels 
202 and 204 extending from respective fold lines 206 and 208 which define 
opposite side edges of said floor panel 200, first and second generally 
rectangular end wall panels 210 and 212 extending from opposite end edges 
214 and 216 respectively, and first and second end wall flaps 218 and 220 
integrally formed with and extending from opposite ends 222 and 224 
respectively of said end wall panels 210 and 212. First and second 
generally rectangular end cover flaps 226 and 228 are integrally formed 
with and extend from fold lines 230 and 232 respectively defining the 
outer edges of said first and second end wall panels 210 and 212. Also, 
first and second generally rectangular side cover flaps 234 and 236 are 
integrally formed with and extend from fold lines 238 and 240 respectively 
defining the outer edges of said first and second side wall panels 202 and 
204 respectively. 
When utilized with the stacking panel 240 shown in FIG. 7, a generally 
rectangular carton may be formed as shown in the perspective view of the 
partially erected blank in FIG. 8. 
As can be seen in FIG. 8, double-ply side walls are formed by the adhesive 
connection of end wall flaps 218 and side wall panel 202 and end wall 
flaps 220 and side wall panel 204. Further, double-ply end wall assemblies 
are formed by the adhesive connection of stacking panels 240 and end wall 
panel 212 and stacking panel 240 and end wall panel 210. If end wall flaps 
218 and 220 are sufficiently long, they will cover the entire side wall 
panels 202 and 204 to form the double-ply thickness side wall assembly. If 
the end wall flap 218 and 220 are shorter than one half the length of the 
rectangular floor panel 200, then only a portion of the side wall assembly 
is of double-ply thickness. The end cover flaps 226 and 228 may be folded 
inwardly and side cover flaps 234 and 236 folded inwardly over the end 
wall flaps 226 and 228 to seal the carton. 
While there has been described what is believed to be a preferred 
embodiment of the invention, variations and modifications therein will 
occur to those skilled in the art once they become acquainted with the 
basic concepts of the invention. Therefore, it is intended that the 
appended claims shall be construed to include all such variations and 
modifications as fall within the true spirit and scope of the invention.