Elevated bottom carton

0001The present invention relates to a carton having an elevated bottom. Specifically, the present invention relates to a carton having the edge portions of the bottom elevated to protect the raw paperboard edges from damage and absorption of moisture.

0002Cartons fabricated from a carton blank on a form, fill and seal packaging machine risk absorption of moisture into the raw paperboard edges of the bottom of the carton. This absorption is accelerated if the raw paperboard edges are damaged and the carton is continuously exposed to moisture. The transportation, loading and storage of the carton from the conveyance between the packaging machine/packer unit and the retailer display are all sources for damage and moisture absorption.

0003The raw paper edges are a by-product of the composition of the carton blank. Generally, the carton blank is cut and scored from a sheet of coated fiberboard material. The coated fiberboard material is usually composed of three layers, and may have a barrier layer juxtaposed between fiberboard layers. The exposed surfaces of this sheet are coated with a polymer material such as polyethylene. However, the coating does not extend to the edges which are thus left uncoated, and partially unprotected at least to moisture and sensitive to damage. When the carton is erected and partially formed, these raw paper edges are most prevalent at the bottom of the carton. If moisture is absorbed into the raw paper edges, the water may be absorbed throughout the fibreboard interior layer, which due to its cellulose-like nature, has a strong affinity for liquids. This absorption of moisture may compromise the integrity of the carton thereby rendering it defective.

0004This problem has yet to be directly addressed by the packaging industry. However, inventions directed to resolving the stability of cartons have been disclosed in the prior art. <patcit id="pcit0001" dnum="US5482204A"><text>U.S. Patent Nos. 5,482,204</text></patcit>, and <patcit id="pcit0002" dnum="US5588943A"><text>5,588,943</text></patcit>, respectively for a Carton Bottom Sealer and Carton Bottom Sealing Dies disclose cartons having an embossed inverse pyramidal bottom which is directed to providing greater stability to the filled carton and to reduce bulging of the carton. It should be noted, as shown in <figref idref="f0008">FIGS. 8</figref> and <figref idref="f0009">9</figref> of these Patents, that the end portions of the exposed raw paper edges of the bottom of the carton are not embossed, and therefore are susceptible to moisture absorption.

0005<patcit id="pcit0003" dnum="US5222667A"><text>U.S. Patent No. 5,222,667</text></patcit>, for a Container Made of Paper-Base Laminate, similarly discloses a carton having an inverted V-shaped bottom to provide greater stability to the carton. As shown in <figref idref="f0006">FIG. 6</figref> of the Patent, the raw paper edge of panel 27 is not inverted and is susceptible to moisture absorption since the V-shaped inversion begins at the raw paper edge and since the inversion must be centered to provide stability to the carton.

0006Reference is also directed to <patcit id="pcit0004" dnum="US3586232A"><text>US Patent No. 3,586,232</text></patcit> which discloses a paperboard carton formed from a scored blank. Its bottom closure has overlapped and adhesively secured flaps, and is shaped to provide two opposing ridges with a recessed portion therebetween.

0007The present invention is directed at a carton having a plurality of side panels and a plurality of bottom panels corresponding thereto, the plurality of bottom panels folded and sealed together to form a sealed base, the last folded and sealed bottom panel having an end exposed edge traversing the base of the carton. The base comprises a primary elevated portion inverted into the carton and extending along the length of the end exposed edge and first and second substantially planar portions of the bottom panels respectively on either side of the elevated portion and extending to the ends of the side panels corresponding thereto, each portion being substantially perpendicular to the corresponding side panel.

0008According to a first aspect of the invention the last folded and sealed bottom panel has a side exposed edge substantially perpendicular to the end exposed edge. The side exposed edge is elevated relative to its adjacent substantially planar portion by means of a side elevated portion extending the length of the side exposed edge between the primary elevated portion and the respective side panel.

0009According to a second aspect of the invention the penultimate folded and sealed bottom panel has a side exposed edge substantially perpendicular to the end exposed edge. The side exposed edge is elevated relative to its adjacent substantially planar portion by means of a side elevated portion extending the length of the side exposed edge between the primary elevated portion and the respective side panel.

0010The primary elevated portion in a carton of the invention will normally comprise a planar section. It is also preferred, but not essential, that the substantially planar portions are substantially equal in area. Neither is it essential that the end exposed edge is at the centre of the primary elevated portion.

0011The present invention offers a solution to the problem of absorption of moisture through raw paper edges by providing a carton having the raw paper edges elevated in order to protect the raw paperboard edges and reduce the susceptibility of moisture absorption. This is accomplished without adversely affecting the carton.

0012The invention and embodiments thereof will now be described by way of example and with reference to the accompanying drawings. In the drawings: <ul id="ul0001" list-style="none" compact="compact"><li><figref idref="f0001">FIG. 1</figref> is a perspective view of a carton according to the state of the art ;</li><li><figref idref="f0002">FIG. 2</figref> is a plan view of a blank for the carton according to the state of the art of <figref idref="f0001">FIG. 1</figref>;</li><li><figref idref="f0003">FIG. 3</figref> is a bottom perspective view of the carton according to the state of the art of <figref idref="f0001">FIG. 1</figref>;</li><li><figref idref="f0004">FIG. 4</figref> is a bottom perspective view of the bottom of a carton according to a first embodiment of the present invention;</li><li><figref idref="f0005">FIG. 5</figref> is a bottom perspective view of the bottom of another carton according to the first embodiment of the present invention;</li><li><figref idref="f0006">FIG. 6</figref> is a perspective view of a carton according to the state of the art ;</li><li><figref idref="f0007">FIG. 7</figref> is a plan view of a blank for the carton according to the state of the art of <figref idref="f0006">FIG. 6</figref>;</li><li><figref idref="f0008">FIG. 8</figref> is a bottom perspective view of the carton according to a second embodiment of the present invention ; and</li><li><figref idref="f0009">FIG. 9</figref> is a bottom perspective view of the bottom of another carton according to the second embodiment of the present invention.</li></ul>

0013The carton 10 not according to the invention in <figref idref="f0001">FIG. 1</figref> has a plurality of side panels 12a and 12b, a top panel 14, a top fin 16, bottom score lines 18a and 18b defining the bottom from the side panels 12a and 12b, and an elevated portion 20. The side panel 12b is actually folded over and sealed to a sealing panel 22. The folding and sealing of the carton creates a raw paper edge which extends from the top 16 to the bottom of the carton 10 along this intersection of the sealing panel 22 and side panel 12b, top panel 14, top fin 16 and the bottom panel corresponding to side panel 12b.

0014<figref idref="f0002">FIG. 2</figref> illustrates a blank 30 for the carton 10 not according to the invention of <figref idref="f0001">FIG. 1</figref>. The side panels 12a-d are separated from bottom panels 32a-d by bottom horizontal score lines 34 and each of the side panels 12a-d and bottom panels 32a-d are separated from each other by vertical score lines 36. The side panels 12a-d are separated from top panels 14 and 14b-d by top horizontal score lines 38. The top fin panels 16 and 16b-d are separated from top panels 14 and 14b-d by upper horizontal score line 39. The sealing panel 22 is separated from side panel 12a by a vertical score line 36. A top sealing panel 22b and a bottom sealing panel 22c further define sealing panel 22. The raw paper edge 40 extends along top fin 16, top panel 14, side panel 12b and bottom panel 32b.

0015As shown in <figref idref="f0003">FIG. 3</figref>, the bottom of the carton 10 not according to the invention has the elevated portion 20 bounded by substantially planar portions 60 and 62. The planar portions 60 and 62 are substantially perpendicular to side panels 12a, 12b and 12c and 12d, not shown. The planar portions 60 and 62 contact the conveyor belt 54 while elevated portion 20 is elevated above the belt 54 and any moisture thereon. The same applies during distribution whether in a crate or a shelf at a store.

0016The elevated portion 20 is further defined by angled portions 64 and 66 and elevated planar portion 70. The elevated planar portion 70 is further defined as elevated planar portion 70a and elevated planar portion 70b. The elevated planar portion 70a substantially includes a portion of panel 32b while elevated planar portion 70b includes a portion of panel 32d. The exposed raw paper edge 40a traverses the bottom of the carton 10, extending from the end of panel 12 a to the end of panel 12c, not shown. Likewise, the elevated portion 20 traverses the bottom of the carton 10. Preferably, elevated portion 20 is centered on the bottom of the carton 10 with planar portions 60 and 62 being equal in area to each other. However, those skilled in the pertinent art will recognize that planar portions 60 and 62 may be unequal and elevated portion 20 may be uncentered.

0017It is readily apparent that elevated portion 70a, angled portion 64 and planar portion 60 all are part of bottom panel 32b. Also, elevated portion 70b, angled portion 66 and planar portion 62 all are part of bottom panel 32d.

0018<figref idref="f0004">FIG. 4</figref> shows a first embodiment of the present invention. <figref idref="f0004">FIG. 4</figref> is similar to <figref idref="f0003">FIG. 3</figref> except that all exposed raw paper edges 40a and 40b are elevated. The exposed edge 40b is substantially perpendicular to exposed edge 40a. A second elevated portion 20a elevates this exposed edge 40a thereby preventing moisture absorption as with exposed edge 40b. The second elevated portion 20a has an angled portion 70 that engages planar portion 60, side panel 12a, and angled portion 64. Those skilled in the art will recognize that the exposed raw edges may be elevated in a similar fashion.

0019A similar first embodiment of the present invention is illustrated in <figref idref="f0005">FIG. 5</figref>. As shown in <figref idref="f0005">FIG. 5</figref>, the exposed edge 40b is substantially perpendicular to exposed edge 40a. A side elevated portion 20a elevates this exposed edge 40a thereby preventing moisture absorption as with exposed edge 40b The side elevated portion 20a has an angled portion 72 which engages planar portion 60, side panel 12a, and angled portion 64. Those skilled in the art will recognize that the exposed raw edges may be elevated in a similar fashion.

0020Approximately in the center of the elevated portion 20 is a secondary elevated portion 100. The secondary elevated portion 100 prevents loss of elevation in the center of the bottom of the carton 10 during transportation from a packaging machine to the retailer/wholesaler to the consumer. As is apparent, the center of the bottom of the carton 10 is most susceptible to deelevation from the weight of the product. The weight of the product in the carton 10 is focused on the center of the bottom of the carton 10, and thus it is necessary to provide greater elevation in this area. This greater elevation is provided by the secondary elevated portion 100 which compensates for gravitational forces exerted by the product on the center of the bottom of the carton 10.

0021As shown in <figref idref="f0005">FIG. 5</figref>, the secondary elevated portion 100 is triangular in shape with its apex 101 near the exact center of the bottom of the carton 10. The secondary elevated portion 100 is substantially contained within elevated planar portions 70a and 70b. However, there is a transition to angled portion 66. Alternatively, the triangular shaped embodiment of the secondary elevated portion 100 may be rotated any degree from 1-360 degrees, about apex 101. Thus, the secondary elevated portion 100 may lie entirely within elevated planar portion 70a.

0022The secondary elevated portion 100 is also partially defined by secondary angled portions 102, 104, 106 and 108. The secondary angled portions 102 and 104 form a transition from the secondary elevated portion 100 to elevated planar portion 70a whereas the secondary angled portions 106 and 108 form a transition from the secondary elevated portion 100 to elevated planar portion 70b.

0023The bottom of the carton 10 is usually formed on a mandrel of a form, fill and seal packaging machine, not shown. The carton blanks 30 are fed from a magazine, not shown, to a bottom forming station of the machine, not shown. During the transfer from magazine to bottom forming station, the carton blank is erected. On the bottom forming station, the bottom panels are pretreated if necessary, and then heat-sealed together to form the bottom. This is accomplished by pressing against the bottom panels as they lie on the mandrel. In order to achieve the elevated bottom of the present invention, one may have a special press and mandrel that allows for the elevated bottom of the present invention.

0024A carton 210 not according to the invention is shown in <figref idref="f0006">FIG. 6</figref>. The carton 210 has a plurality of side panels 212a and 212b, a top panel 214, a top fin 216, bottom score iines 218a and 218b defining the bottom from the side panels 212a and 212b, and an elevated portion 220. A sealing panel 222, partially shown in <figref idref="f0006">FIG. 6</figref>, is connected to the side panel 212a and is folded over and sealed to the side panel 212b, not shown. The folding and sealing of the carton creates a raw paperboard edge which extends from the top 216 to the bottom of the carton 210 along this intersection of the sealing panel 222 and side panel 212b, top panel 214, top fin 216 and the bottom panel corresponding to side panel 212d.

0025<figref idref="f0007">FIG. 7</figref> illustrates a blank 230 for the carton 210 not according to the invention of <figref idref="f0006">FIG. 6</figref>. The side panels 212a-d are separated from bottom panels 232a-d by Bottom horizontal score lines 234 and each of the side panels 212a-d and bottom panels 232a-d are separated from each other by vertical score lines 236. The side panels 212a-d are separated from top panels 214a-d by top horizontal score lines 238. The top fin panels 216a-d are separated from top panels 214a-d by upper horizontal score line 239. The sealing panel 222 is separated from side panel 212a by a vertical score line 236. A top sealing panel 222b and a bottom sealing panel 222c further define sealing panel 222. The raw paperboard edge 240 extends along the entire perimeter of the carton blank 230. However, the most important portions of the raw paperboard edge 240 are portions 240a and 240b which lie on the bottom of the carton. All other portions of the raw paperboard edge 240 are either covered by a coated panel, or are elevated above the surface when the blank 230 is formed into a carton 210. Thus, moisture absorption by these portions of the raw paperboard edge 240 is highly unlikely.

0026<figref idref="f0008">FIG. 8</figref> shows the bottom of a carton of the kind shown in <figref idref="f0006">FIGs. 6</figref> and <figref idref="f0007">7</figref>. The bottom of the carton 210 has the elevated portion 220 bounded by substantially planar portions 260 and 262. The planar portions 260 and 262 are substantially perpendicular to side panels 212a, 212b and 212c and 212d, not shown. The planar portions 260 and 262 contact a surface such as a conveyor belt on a packaging machine while the elevated portion 220 is elevated above the surface and any moisture thereon. The same applies during distribution of the carton whether in a crate or on a shelf at a store.

0027The elevated portion 220 is further defined by angled portions 264 and 266 and elevated planar portion 270. The elevated planar portion 270 is further defined as elevated planar portion 270a and elevated planar portion 270b. The elevated planar portion 270a substantially includes a portion of panel 232b while elevated planar portion 270b includes a portion of panel 232d. The exposed raw paperboard edge 240b traverses the bottom of the carton 210, extending from the end of panel 212a to the end of panel 212c, not shown. Likewise, the elevated portion 220 traverses the bottom of the carton 210. Preferably, the elevated portion 220 is centered on the bottom of the carton 210 with planar portions 260 and 262 being equal in area to each other. However, those skilled in the pertinent art will recognize that planar portions 260 and 262 may be unequal and elevated portion 220 may be uncentered.

0028It is readily apparent that elevated portion 270a. angled portion 264 and planar portion 260 all are part of bottom panel 232b. Also, elevated portion 270b, angled portion 266 and planar portion 262 all are part of bottom panel 232d.

0029The exposed edge 240a is substantially perpendicular to exposed edge 240b. A side elevated/angled portion 220a elevates this exposed edge 240a thereby preventing moisture absorption as with exposed edge 240b. The side elevated/angled portion 220a has an angled portion 272 which engages planar portion 260, side panel 212a, and angled portion 264. Those skilled in the art will recognize that the exposed raw edges may be elevated in a similar fashion.

0030A similar second embodiment of the bottom of a carton of the present invention is shown in <figref idref="f0009">FIG. 9</figref>. The carton 210 of <figref idref="f0009">FIG. 9</figref> is similar to the carton 210 of <figref idref="f0008">FIG. 8</figref> except that approximately in the center of the elevated portion 220 are secondary elevated portions 300 and 301. The secondary elevated portions 300 and 301 prevent loss of elevation in the center of the bottom of the carton 210 during transportation from a packaging machine to the retailer/wholesaler to the consumer. As is apparent, the center of the bottom of the carton 210 is most susceptible to deelevation from the weight of the product. The weight of the product in the carton 210 is focused on the center of the bottom of the carton 210, and thus it is necessary to provide greater elevation in this area. This greater elevation is provided by the secondary elevated portions 300 and 301 which compensate for gravitational forces exerted by the product on the center of the bottom of the carton 210.

0031In an exemplary embodiment, the secondary elevated portions 300 and 301 are triangular in shape with apices 302a-b facing the center of the bottom of the carton 210. The secondary elevated potions 300 and 301 are substantially contained within elevated planar portions 270a and 270b. However, there is a transition for each secondary elevated portions 300 and 301 to angled portions 266 and 264, respectively. Alternatively, the triangular shaped embodiment of the secondary elevated portions 300 and 301 may be rotated any degree from 1-360 degrees, about apices 302a-b. Thus the secondary elevated portions 300 and 301 may lie entirely within elevated planar portion 270b and 270a, respectively.

0032In this embodiment, the secondary elevated portions 300 and 301 are partially defined by secondary angled portions 304a-d. The secondary angled portions 304a-d form a transition from the secondary elevated portions 300 and 301 to the elevated planar portions 270b and 270a.

0033In an alternative embodiment not shown, the carton 210 of <figref idref="f0009">FIG. 9</figref> may only have one secondary elevated portion 300 or 301 which may be disposed on either of planar portion 270a or 270b.

0034The bottom of the carton 210 is usually formed on a mandrel of a form, fill and seal packaging machine, not shown. The carton blanks 230 are fed from a magazine, not shown, to a bottom forming station of the machine, not shown. During the transfer from magazine to bottom forming station, the carton blank is erected. On the bottom forming station, the bottom panels are pretreated if necessary, and then heat sealed together to form the bottom. This is accomplished by pressing against the bottom panels as they lie on the mandrel. In order to achieve the elevated bottom of the present invention, one may have a special sealing plate and mandrel which allows for the elevated bottom of the present invention.