FLIP SIDE BOX WITH MOISTURE BARRIER

Abstract: A package (10, 40) especially suited for shipping and storing unwrapped sheets of paper comprises a box (11) having a lid (12) that may be removed and one side (20, 20') which may be pivoted down when the lid (12) is removed to facilitate access to the contents of the box (11) for ease of unloading of paper from the box (11) and ease of reloading. A preferred construction employs a moisture barrier (38) to maintain the moisture content of the paper in the box (11) within acceptable limits when the package (10, 40) is subjected to adverse environmental conditions. In accordance with another aspect of the invention, the package (10, 40) is recyclable.

Description: Flip Side Box With Moisture Barrier Technical Field: This invention relates to packaging, and especially to a package for paper products. More particularly, the invention relates to a box or carton having an openable side in addition to a removable lid, to facilitate access to the contents of the box for removing or reloading the contents without destroying the integrity of the box. The invention also relates to such a package having moisture barrier means whereby it may be used for shipping and storing unwrapped sheets of paper, including but not limited to reprographic paper, photocopy paper and the like, while maintaining the moisture content of the paper within acceptable limits. Background Art: Many products are shipped in boxes designed to closely fit the contents. Such boxes generally have either a removable lid or foldable flaps to close the top of the box, and the lid is removed or the flaps opened to form an open top through which product is removed from the box. With such packaging it is difficult to remove the contents without damaging the box or inverting it to pour the contents out because of the lack of space to insert the hands of the user between the side walls of the box and the product stored therein. This feature of conventional packaging is particularly bothersome in boxes used for shipping and storing sheets of paper as used, for example, in printers, photocopiers and the like. High speed, high volume copiers, especially, must frequently be filled with paper, and conventional packaging slows the process of removing paper from the box and loading it into the equipment. The performance of paper products used in office equipment is especially sensitive to the physical properties of the paper. This is especially true of paper used in laser printers and photocopiers. The physical properties of paper used in such equipment must be maintained within a relatively narrow range of acceptable limits for proper performance. For use in photocopiers particularly, it is important that the sheets of paper have a proper moisture content and a uniform flat shape without folds, tears or bends. In this regard, the moisture content of photocopy paper should generally be within the range of from about 3.7% to about 5.6%, and preferably about 4.5%, since moisture content outside this range adversely affects the mechano-sorptive property of the paper and may result in non-uniform print quality. The physical properties of photocopy paper are especially important in high speed photocopiers, and/or those which perform two-sided copying or collating and the like. Paper produced and packaged at a 4.5% moisture content is only stable at an ambient humidity of about 30 %RH in a normal temperature range. If the paper is exposed to a significantly different environment, the paper releases or absorbs atmospheric moisture to reestablish a state of equilibrium. However, the change in moisture content induces an appropriate shrinkage or swelling of the sheet. These dimensional changes are usually not uniform or reversible, and result in permanent sheet deformation such as cockled appearance. Cockling and gross changes in the flat size of the sheet can cause missing print or misfeeds and machine jams in high speed photocopiers. In order to protect the paper from environmental damage, it is typically packaged in cardboard boxes containing several reams of paper sheets. These reams are individually wrapped in a material having a low water vapor transfer rate, such as polyethylene coated wrapping paper, which serves as a moisture barrier to prevent excessive absorption or desorption of moisture in hostile environments. The cardboard box protects the paper from physical damage such as bent corners and the like. Traditional packages for paper products such as reprographic paper contain ten individually wrapped reams of paper. These individually wrapped reams of paper must be opened and the wrap discarded. Additionally, the standard ream wrap material comprises polyethylene coated wrapping paper, which is not readily recyclable. Further, ten reams of paper are quite heavy, making it difficult for many people to handle the packages. There is thus need for a box for shipping and storing sheets of paper, such as photocopy paper or the like, which not only protects the paper against physical damage from the environment, but which also enables the sheets of paper to be easily and quickly unloaded from the box. The box should prevent excessive absorption or desorption of moisture in the paper, even when it is stored in an environment having either very high or very low humidity, and should be lightweight and easy to handle, and preferably recyclable. Disclosure of the Invention: The present invention comprises a box constructed for shipping and storing items in a way to permit easy access to the items for unloading them from the box. The box of the invention is particularly suited for shipping and storing paper products, especially sheets of paper for use in printers, photocopiers and the like. Even more specifically, the box is particularly adapted to ship and store unwrapped sheets of paper, although it may equally as well be used for shipping and storing individually wrapped reams of paper. The box includes at least one side wall which may be pivoted downwardly to open the box and expose the contents for easy removal. A lid is telescopically engaged over the open top of the box to close the top of the box and normally hold the pivoted side wall In closed position. When the lid is removed, that side panel may be pivoted downwardly. The openable side panel enables the user to easily and quickly grasp and unload the items stored in the box, without the necessity of forcing the hands or fingers between the box side walls and the contents, or turning the box over and dumping out the contents, as is necessary with conventional packaging. This feature is particularly useful when the box is used to ship and store sheets of paper. Moreover, the use of a moisture barrier in the construction of the box permits the paper to be placed in the box in loose sheets, without the necessity of wrapping individual reams in a protective cover, as done in conventional packaging. With the invention, the user may grasp and unload as many sheets as desired, without the need to open individual reams. This is especially helpful when high speed, high volume copiers are being restocked with copy paper. Studies have shown that it takes approximately 31 % less time to load paper into the desired equipment using the box of the invention as compared with traditional packaging. In a preferred form of the invention, the box is provided with a moisture barrier to maintain the proper moisture content of the paper stacked inside. The moisture barrier preferably comprises a coating of material that is recyclable, and which provides an effective gas or vapor barrier. For example, a suitable coating could comprise an emulsified material that forms a close-grained crystal structure which is hydrophobic upon curing. A repulpable coating with water vapor barrier properties may also be formed from available dispersions such as acrylates and the like. Further, the moisture barrier may comprise a layer of polyethylene extruded onto or otherwise applied to paper. A specific construction comprises a lamination of low density polyethylene (LDPE) and Kraft paper applied as the inner or outer lining of the box. Although polyethylene forms an effective moisture barrier, it is not recyclable. A variety of coating materials and structures were tried by applicant, including water repellant coatings applied to the outer liner before box converting, but this failed to provide a barrier to water vapor. Such coatings therefore appear to be more suitable where liquids are encountered, and have little effectiveness in preventing transfer of water vapor. Additionally, a test sample was constructed using linerboard coated with a resin emulsion, but this provided no moisture barrier. A box coated with LDPE in accordance with the invention provides essentially the same protection to the unwrapped sheets of paper stacked in the box as individually wrapped reams, with sheets at the top of the stack and sheet edges not having a significantly different moisture content than the sheets at the center of the stack. Sheets of paper stacked loose in untreated or unprotected boxes, on the other hand, showed high spatial moisture differences (as much as 50% after 24 hours) between the center of the stack, the top of the stack and along the edges. The box of the invention may be opened to gain access to the paper stacked inside, and reclosed without destroying the integrity of the box structure, including the moisture barrier. It may therefore be reused for refilling, shipping, filing and storage. The box of the invention is also preferably dimensioned to hold five reams (2500 sheets) of paper, as opposed to the more traditional ten reams, and is therefore much lighter and easier to handle, weighing only about 25 pounds as opposed to about 50 pounds for traditional packages. It could, of course, be dimensioned to hold a greater or lesser amount of paper (or other material) without departing from the invention. A preferred construction of the box for use with automated loading or filling equipment includes relatively short or narrow flaps on the openable panel, and wider flaps on the fixed panel. The shorter flaps on the openable panel prevent sheets of paper from being pulled from the box when the openable panel is pivoted downwardly to open the box. The flaps on the two panels abut one another when the openable panel is closed, improving the strength and stability of the box. That portion of the flaps on the openable panel which first enter between the box end panels and the paper remaining in the box after it has been opened are rounded to facilitate reentry of the flaps back into the box between the end walls and the paper when the openable panel is being closed. In another form of the invention the end flaps on the pivoted panel are the same width as the flaps on the fixed panel, and the flaps meet or abut one another at approximately the midpoint of the end walls of the box. A specific package constructed in accordance with the invention has overall inside dimensions of about 8 1 /. X 1 1 X 9 7 /β inches and holds approximately 2500 sheets of 8 Vz X 1 1 paper. The box is constructed of corrugated cardboard having an inner liner of 38# Kraft paper, a medium of 26# fluting, and inner liner comprising a laminate of two 1 7# sheets of Kraft paper with a moisture barrier layer between them. The moisture barrier may comprise a sheet of LDPE, or other material suitable for the intended purpose, and may be sprayed, rolled, printed or otherwise applied onto one of the sheets of Kraft paper or applied as a separate sheet adhesively secured between the sheets of Kraft paper. The moisture barrier may have any suitable thickness, ranging from about h mil thick for less severe ambient conditions upwardly to any desired or necessary thickness. A .001 inch thick sheet of LDPE, for example, performs satisfactorily even in hostile environments. A plastic strap is placed around the box or carton to secure the lid in place during shipment and storage. The strap is removed to enable the lid to be opened to gain access to the paper inside the carton, and thereafter the lid may be easily replaced and removed during use. Brief Description of the Drawings: The foregoing as well as other objects and advantages of the invention will become apparent from the following detailed description when considered in conjunction with the accompanying drawings, wherein like reference characters designate like parts throughout the several views, and wherein: Fig. 1 is a top perspective view of a preferred package constructed in accordance with the invention; Fig. 2 is a top perspective view of the package of figure 1 with the lid removed; Fig. 3 is a top perspective view of the package of figure 2 with the movable side panel pivoted to a partially open position; Fig. 4 is a top perspective view of the package of figure 3 with the movable panel fully opened and depicting the removal of several sheets from the stack inside the box; Fig. 5 is a plan view of the blank from which the lid is formed; Fig. 6 is a plan view of the blank from which the box is formed; Fig. 7 is a fragmentary, enlarged perspective view showing the different layers comprising the walls of the box of the invention; and Fig. 8 is a somewhat schematic, top perspective view of a second form of box of the invention, with the lid removed and portions broken away for purpose of clarity, showing essentially equal sized end flaps on the side panels of the box, and illustrating how these flaps extend inwardly toward one another to meet at approximately the midpoint of the ends of the box, and showing in dot-and-dash lines how one of the side panels is pivoted downwardly to open the side of the box. Best Mode of Carrying Out the Invention: Referring more particularly to the drawings, a preferred package in accordance with the invention is indicated generally at 10 in figures 1-7. In this form of the invention the package comprises a rectangularly shaped box 1 1 with a bottom 13, opposite side walls 14 and an open top 15. A lid 12 is telescopically received over the open top and has a depending skirt 16 which extends down¬ wardly a short distance in encircling relationship over the side walls of the box. A strap S of plastic or other suitable material is placed around the box and over the lid to secure the lid in place during storage and shipment. This strap is removed when it is desired to gain access to the contents of the box, and the lid may thereafter be easily removed and replaced. As seen best in figures 4 and 6, the side walls include two end panels 17 and 18 and two side panels 19 and 20, each integrally joined to a respective edge of the bottom wall 13 along fold lines 21. A first side panel 19 has end flaps 22 and 23 joined to the ends of the panel along fold lines 24 and 25, and a seond side panel 20 has end flaps 27 and 28 joined to opposite ends of the panel along fold lines 29 and 30. The end flaps 27 and 28 on panel 20 are considerably shorter or narrower than the end flaps 22 and 23 on the opposite side panel 19. The end flaps on the two side panels are dimensioned so that they abut one another when they are folded inwardly toward one another and the respective side panels are folded upwardly into operative position. The two end panels 17 and 18 are then folded upwardly about their respective fold lines 21 into overlying relationship with the end flaps on the side panels, and adhesively secured to the end flaps 22 and 23 on the side panel 19. However, the end flaps 27 and 28 on side panel 20 are left unsecured so that panel 20 may be folded downwardly about its fold line 21 as shown in figures 3 and 4. Thus, after the lid 12 is removed the panel 20 may be pivoted downwardly about the hinge defined at its juncture with the bottom wall 13, thereby opening the box and exposing the contents for easy access and removal. To facilitate reentry of the end flaps 27 and 28 back into position between the respective end panels 17 and 18 and the contents of the box after the box has been opened, the corners of the flaps which first enter the box are rounded at 30. A notch 31 or other indicator may be provided on one of the panels of the box for detection by a signalling means to obtain predetermined operation of automated equipment used in constructing the package of the invention. Referring to figure 7, one construction of the box includes an outer liner 32 adhesively secured to one surface of a medium 33 of corrugated material, and an inner liner 34 adhesively secured to the opposite surface of the corrugated medium. The inner liner, in accordance with one form of the invention, comprises a laminate 35 formed of two sheets of material 36 and 37 with a moisture barrier layer 38 sandwiched therebetween. in a specific construction, the outer liner 32 comprises a sheet of 38# Kraft paper, the corrugated medium 33 comprises 26# fluting, and the inner liner laminate 35 comprises two sheets 36 and 37 of 17# Kraft paper with a sheet 38 of low density polyethylene (LDPE) sandwiched between them. The foregoing structure provides a package that is much easier to use than conventional packaging, and when used to ship and store paper sheets performs essentially as well as conventional packaging which uses individually wrapped reams of paper. A modification of the invention is indicated at 40 in figure 8, and is identical to that form of the invention previously described except that the end flaps 41 , 42, 43 and 44 on the opposite side panels 19' and 20' are all the same size, whereby they extend to the midpoint of the end panels when the box is fully assembled and closed as shown in full lines in this figure. The openable side panel 20' may be pivoted downwardly to open the box when the lid is removed, as indicated in dot- and-dash lines in this figure. While particular embodiments of the invention have been illustrated and described in detail herein, it should be understood that various changes and modifications may be made to the invention without departing from the spirit and intent of the invention as defined by the scope of the appended claims. What is claimed is:

Claims: C L A I M S 1 . A package for shipping and storing products, comprising: a box having a bottom wall, a plurality of upstanding side walls each joined along a bottom edge to a respective edge of the bottom wall, an open top, ahd a removable lid telescopically engaged over the open top; one of said side walls being unsecured to adjoining side walls and being pivotable about its bottom edge downwardly and away from the box to an open position when the lid is removed to permit easy access to the contents of the box; and said one side wail having inturned flaps on opposite side edges thereof which extend into the box in contiguous, parallel, overlapping relationship with adjacent side walls when said one side wall is in closed position. 2. A package as claimed in claim 1 , wherein: said box is designed for shipping and storing sheets of paper; and said side walls, bottom wall and lid are imperforate and define a moisture barrier to protect the sheets of paper from ambient conditions when said one side wall and lid are in closed position. 3. A package as claimed in claim 1 , wherein: said side wails are integrally joined to the bottom wall, and all except said one side wall are secured and sealed to one another at adjacent side edges. 4. A package as claimed in claim 3, wherein: said box is rectangular in shape, and said side walls comprise a pair of opposed side panels at opposite sides of the box and a pair of opposed end panels at opposite ends of the box, one of said side panels comprising the pivotable side wall; and each of the side panels has a pair of inturned flaps along its opposite side edges which extend into the box in contiguous, parallel, overlapping relationship with the adjacent end panels when the box is closed, said end panels extending over essentially the entire extent of the ends of the box. 5. A package as claimed in claim 4, wherein: said inturned flaps on the opposed side panels extend into edge-to-edge abutting relationship with one another when the box is closed. 6. A package as claimed in claim 5, wherein: the inturned flaps on said pivotable panel are relatively narrow so that they may be moved into and out of the box without unduly disturbing the contents of the box. 7. A package as claimed in claim 5, wherein: the inturned flaps on said opposite side panels are equal in width so that they meet in edge-to-edge abutting relationship at approximately the midpoint of the opposite end panels. 8. A package as claimed in claim 1 , wherein: the box and lid are made of corrugated cardboard having an outer liner, an inner liner and a fluted medium. 9. A package as claimed in claim 2, wherein: the moisture barrier comprises a layer of material with a low water vapor transfer rate to protect the sheets of paper therein from ambient moisture conditions and thereby maintain the moisture content of the sheets of paper within a predetermined range. 1 0. A package as claimed in claim 9, wherein: the moisture barrier material comprises a sheet of polyethylene. 1 1 . A package as claimed in claim 10, wherein: the sheet of polyethylene comprises low density polyethylene. 12. A package as claimed in claim 9, wherein: the box and lid are made of corrugated cardboard having an outer liner, an inner liner and a fluted medium; and the layer of moisture barrier material is on the inner liner. 13. A package as claimed in claim 12, wherein: the inner liner is a laminate comprising two sheets of Kraft paper with a polyethylene sheet sandwiched therebetween. 14. A package as claimed in claim 13, wherein: said side walls are integrally joined to the bottom wall, and all except said one side wall are secured and sealed to one another at adjacent side edges. 15. A package as claimed in claim 14, wherein: said box is rectangular in shape, and said side walls comprise a pair of opposed side panels at opposite sides of the box and a pair of opposed end panels at opposite ends of the box, one of said side panels comprising the pivotable side wall; and each of the side panels has a pair of inturned flaps along its opposite side edges which extend into the box in contiguous, parallel, overlapping relationship « with the adjacent end panels when the box is closed, said end panels extending over essentially the entire extent of the ends of the box. 16. A package as claimed in claim 15, wherein: said inturned flaps on the opposed side panels extend into edge-to-edge abutting relationship with one another when the box is closed. 17. A package as claimed in claim 16, wherein: the inturned flaps on said pivotable panel are relatively narrow so that they may be moved into and out of the box without unduly disturbing the contents of the box. 18. A package as claimed . in claim 17, wherein: the inturned flaps on said opposite side panels are equal in width so that they meet in edge-to-edge abutting relationship at approximately the midpoint of the opposite end panels. 19. A package as claimed in claim 4, wherein: one of said panels has indicia thereon which can be detected by signalling means on automated packaging equipment used in making the package. 20. A package for shipping and storing sheets of paper for use in equipment which requires that the moisture content of the paper be within predetermined limits for proper performance of the equipment, comprising: a box having a bottom wall, upstanding side walls, an open top and a lid closing the open top; and said bottom, side walls and lid having moisture barrier means to maintain the moisture content of sheets of paper contained therein within predetermined limits when the box is exposed to ambient conditions having either very high or very low humidity, thereby eliminating the necessity of wrapping individual reams of paper in moisture barrier material. 21 . A package as claimed in claim 20, wherein: the box is made of a paper material and the moisture barrier means comprises a layer of material having a low water vapor transfer rate applied to the bottom, side walls and lid. 22. A package as claimed in claim 21 , wherein: the box is made of corrugated cardboard having an inner liner, a fluted medium and an outer liner; and the moisture barrier layer is formed on the inner liner. 23. A package as claimed in claim 22, wherein: the inner liner comprises a laminate of two sheets of Kraft paper with a sheet of polyethylene sandwiched therebetween, the sheet of polyethylene forming the moisture barrier layer.

Inventors: CANNON BILLY P, PLOMGREN JOHN FREDERICK, CANNON, BILLY, P., PLOMGREN, JOHN, FREDERICK
Applicants: UNION CAMP CORP, UNION CAMP CORPORATION
Application year: 1995
Main classification: B65D85
IPC codes: B65D5, B65D65