Abstract:
A repulpable moisture resistant poultry box having a composite corrugated structure with a fluted medium formed of a top backing board secured to one side of the fluted medium and a bottom backing board secured to the other side of the fluted medium, the box being impregnated with a hydrogenated triglyceride and coated with an acrylic styrene copolymer. The box has a bottom panel, side panels integral with the bottom panel and end panel assemblies integral with the bottom panel. The end panel assemblies comprise an outer end panel and a plurality of reinforcing end panels positioned adjacent said outer end panel. Each of the panels in the end panel assembly defines a cut out which is aligned with each other cutout panel in the end panel assembly to present a single uniformly configured cutout. The reinforcing end panels define a tab cut adjacent the outer end panel and each bottom corner of the bottom end panel forming a tab to seal the bottom corners of the box.

Description:
RELATED APPLICATIONS 
       [0001]    This is a utility patent application claiming priority and benefit from U.S. Provisional Patent Application No. 62/265,162, filed Dec. 9, 2015. 
     
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
       [0002]    Not applicable. 
       REFERENCE TO SEQUENCE LISTING, A TABLE, OR A COMPUTER PROGRAM LISTING COMPACT DISC APPENDIX 
       [0003]    None. 
       FIELD OF THE INVENTION 
       [0004]    The present invention generally relates to moisture resistant and water proof paper products including linerboard and corrugated board. Particularly, this invention relates to moisture resistant corrugated paper boxes used primarily in the poultry industry that are waterproofed and can be repulped and recycled to be part of the feedstock for corrugated paper products that minimizes environmental concerns. 
       BACKGROUND OF THE INVENTION 
       [0005]    In the manufacture of paper and paperboard and of products made from same, petroleum derived paraffin waxes and synthetic polymers have been used for many years as moisture retardants, water repellents, oil repellents, stiffeners, strengtheners, and release agents. Besides paraffin, the material used most often in such products is polyethylene. However, other widely used polymers in the field include polymerized acrylics, vinyls, styrenes, ethylenes and copolymers or hetero-polymers of these monomers. 
         [0006]    The paper and paperboard to which traditional wax materials are applied is difficult and often impossible to repulp and recycle in standard paper mill processes because the petroleum derived polymers and, particularly, the petroleum waxes are non-biodegradable in mill white waters (circulated process waters) and discharge effluents. Furthermore, the residue of the petroleum waxes that is not removed from pulp fibers during the repulping and recycling processes causes severe problems due to buildup that occurs on the screens and felts used during the process of forming and making the paper or paperboard sheet. In addition, paper and paperboard coated or impregnated with petroleum waxes resist biodegradation and composting when disposed of in landfills and other waste disposal systems. Paper and paperboard coated or impregnated with traditional synthetic polymers and hetero-polymers are also difficult and often impossible to repulp and recycle owing to their resistance to separation from the fiber in the standard repulping processes resulting in significant fiber losses in efforts to repulp and recycle them. These products are also non-biodegradable and therefore resist composting. 
         [0007]    Water repellent packaging currently utilizes petroleum based liquid polymer coatings or polymer film laminates (including polyethylene or similar film laminates such as polyolefin, polyester, polyvinyl alcohol, polyvinyl acetate, polystyrene, polypropylene, and the like) which are recyclable after extensive treatment, All of these laminates require the installation of specialized repulping machinery that separates the pulp fibers from the coated or laminated films and/or is far more expensive in terms of operating costs and/or recycled pulp fiber yields. The action of separating the fiber from the film damages some fibers causing the fibers to be selected out of the recycled pulp and presented for reuse, while the separated film waste carries some of the fibers out of the repulpate when its adherence is not interrupted by the repulping process. Likewise, coatings and impregnating products made from or based on paraffin waxes and/or similar petroleum derivatives can only be repulped for recycling in specially configured repulping equipment that removes and separates the paraffin waxes. In the laminated film repulping process, the more intense physical and chemical requirements of this repulping process coupled with the lost fibers that become trapped in paraffin wax wastes, causes the recyclable repulped fiber levels to fall far below those of standard repulping processes. Moreover, boxes made from such products are not biodegradable and must be separated and deposited in separate landfill areas. 
         [0008]    The poultry box industry has previously used wax to coat the boxes (EVA—poly (ethylene vinyl acetate) which takes a significantly long period of time to compost and leaves a chemical residue from those compounds. There appears to be little or no decomposition of higher molecular weight resin and EVA fractions. 
         [0009]    In the prior art, a number of patents have attempted to address the above noted problems but have only moved incrementally forward in solving the customer&#39;s problems. U.S. Pat. No. 6,103,308 issued Aug. 15, 2000 is directed toward a paper and paperboard coating composition using vegetable oil triglyceride as a paper coating while U.S. Pat. No. 6,201,053 issued Mar. 13, 2001 is directed toward various triglycerides mixed with catalysts for use as a waterproofing agent on paper coating. 
         [0010]    U.S. Pat. No. 6,846,573 issued Jan. 25, 2005 discloses the use of hydrogenated triglycerides having a melting point above 50° as a coating material for the surface of paper products to improve wet strength and moisture resistance in addition to being repulpable. 
         [0011]    U.S. Pat. No. 7,413,111 issued Aug. 10, 2008 is directed toward a container for storing and shipping produce which is reinforced with at least one cross beam extending across the bottom wall of the container to form a bridge under loose product placed in the container to support at least a portion of the weight of the product and prevent sagging of the container bottom. The cross beam is positioned and held in place by engaging the ends of the cross beam in recesses formed by crushed areas on an inner surface of opposing side walls, or cut-outs in the side walls, and/or by flaps folded upwardly from the container bottom wall and to which the cross beam is attached. 
         [0012]    U.S. Pat. No. 8,455,068 issued Jun. 4, 2013 discloses the combination of impregnation of the poultry boxes with hydrogenated triglyceride and covering the outer surface of the liners with a dimethyl or ethylene terephthalate (PET) resulting in corrugated poultry boxes which provided moisture resistance and were recyclable and repulpable. The boxes, however, were only able to obtain a 30 minute Cobb value of 20-30. 
         [0013]    U.S. Pat. No. 5,752,648 issued May 19, 1998 is directed toward an eight sided poultry box formed of corrugated paperboard. The lower ends of each of the four corner panels are provided with folds, which extend from the peripheral corner portions of the box bottom toward the exterior surfaces of the corner panels. The folds function as abutments and restrict rotational movement of the corner panels about their longitudinal axes occasioned by compressional forces generated on the box ends during shipment and handling. This box is widely used in the industry but allows corner leakage which causes corner crushing and panel tearing when the boxes are stacked. 
         [0014]    None of the noted references have provided a repulpable, recyclable corrugated box capable of holding iced products and being moisture resistant while maintaining crush and tear strength. All of these corrugated boxes are susceptible to corner leaks which spill out of the box chamber reducing box tear strength and increasing corner crushing. Typically, poultry boxes are stacked seven layers high with seven boxes forming each layer. The prior art boxes allow collection of moisture and have leakage at the corners causing stacked boxes to crush and tear with spillage of the contents at the corners which results in boxes of poultry and other foodstuffs to be rejected by the receiver of the goods and the end purchasers of the goods. The spillage also causes fluids to be discharged over the corrugated container which might present a health hazard or contaminate foodstuffs in other containers. 
         [0015]    The present invention has been developed to solve these problems in the industry. 
       SUMMARY OF THE INVENTION 
       [0016]    The present invention is directed to a backed corrugated paper box product which has the outer paper liner or backer sheet surfaces coated with a copolymer styrene acrylic emulsion with the inner corrugated paper medium and liner sheets being impregnated with a hydrogenated triglyceride such as tallow or palm oil. The coated paper box is constructed with a reinforced end panel assembly, hand cut outs and covered corners ranging from about ⅝ inch to about 1⅜ inches to prevent leakage. 
         [0017]    The present invention is easier to repulp and recycle without detriment to production equipment, processes, or manufactured product quality or performance. 
         [0018]    It is an object of this invention to produce a paper box product which can be compacted, repulped and recycled. 
         [0019]    It is another object of the invention to produce a poultry box which is biodegradable. 
         [0020]    It is still another object of the invention to produce a poultry box which has superior moisture resistance and does not leak at the corners. 
         [0021]    The invention will be better understood and objects other than those set forth above will become apparent when consideration is given to the following detailed description thereof. Such description makes reference to the annexed drawings wherein. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0022]      FIG. 1  is a perspective view of a prior art poultry box with top removed; 
           [0023]      FIG. 2  is a perspective view of the inventive poultry box with top removed; 
           [0024]      FIG. 2A  is a perspective view of a standard top used with the inventive poultry box of  FIG. 2 ; 
           [0025]      FIG. 3  is a perspective view of the poultry box of  FIG. 2  with an end panel assembly opened; 
           [0026]      FIG. 4  is an enlarged partial view of end panel assembly and the bottom corner pinch seal tabs of the poultry box shown in  FIG. 2 ; 
           [0027]      FIG. 5  is a finished blank of the poultry box shown in  FIG. 2 ; 
           [0028]      FIG. 6  is a finished blank of another poultry box based on the poultry box shown in  FIG. 2  with pinch corner tabs located 1⅜ inches and 1¼ inches from the end panel assembly fold line; 
           [0029]      FIG. 7  is a finished blank of yet another poultry box based on the poultry box shown in  FIG. 2  with pinch corner tabs located 1⅛ inches and 1 inch from the end panel assembly fold line; 
           [0030]      FIG. 8  is another embodiment of a finished poultry box blank 43 7/16 inches in length by 33¼ inches in width with glued end panels and without a hinged panel flap. 
           [0031]      FIG. 9  is an embodiment of the finished poultry box blank of  FIG. 8 , 42 1/16 inches in length by 31¾ inches in width with glued end panels and without a hinged panel flap. 
           [0032]      FIG. 10  is an enlarged cross section of the corrugated blank used in the poultry boxes shown in  FIGS. 2-9 ; and 
           [0033]      FIG. 11  is a schematic of the corrugator used in making the poultry box of  FIG. 2 . 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0034]    The preferred embodiment and best mode of the invention are shown in  FIGS. 2 through 7 and 10 . While the invention is described in connection with certain preferred embodiments, it is not intended that the present invention be so limited. On the contrary, it is intended to cover all alternatives, modifications, and equivalent arrangements as may be included within the spirit and scope of the invention as defined by the appended claims. 
       Definitions 
       [0035]    As used herein the following abbreviations and terms are understood to have the meanings as set forth: 
         [0036]    The term “Triglyceride” includes both animal fats and vegetable oils and is derived from one or more of them. Animal fats include beef tallow, pork lard, poultry grease and fish oils. Vegetable oils include palm oil, soybean oil, peanut oil, olive oil, coconut oil and cottonseed oil. 
         [0037]    The term “Paraffin” is a wax-like product derived from petroleum. 
         [0038]    The terms “Paper” and “Paperboard” includes substrates and surfaces of cellulosic material. 
         [0039]    It has been found that hydrogenated triglycerides and preferably lard or tallow triglycerides can be substituted for petroleum based paraffin waxes and wax compounds in the manufacturer of paper products. All of these application systems involve melted triglycerides held at temperatures in the range from around 125° F. to 170° F. which is either squeezed, rolled, cascaded, sprayed, or doctored onto the linerboard, paper, carton stock, or corrugated medium surface to impregnate the same. 
         [0040]    The method and machinery or equipment for repulping and recycling scrap paper in the paper and paperboard or liner board industry is both an established and well known art, and the equipment required is standard and commonly installed at most mills incorporating recycled paper in their manufacturing feed stocks. Thus, those skilled in the paper making art are also knowledgeable in re-pulping and recycling. 
         [0041]    Poultry boxes are unique paper products that need to withstand water and poultry fluid. The present inventive poultry box is made of double backer corrugated board having a corrugated medium of 30 to 40 lb./1000 sq. ft. (MSF) paperboard of an “A”, “B”, “C”, “E” and “F” flute size (weight depends upon various external factors). The preferred flute size used in the invention is a “C” flute having 39+/−3 flutes per lineal foot with a flute thickness of 5/32 inch. A flat liner or backer board of Kraft paper (various grades) is glued to one side of the fluted medium with a starch based adhesive and a second flat liner or backer board of Kraft paper is adhered to the other side of the fluted medium with a starch based adhesive to form a backed corrugated board as seen in  FIG. 10 . The Kraft paperboard liner may be bleached white, coated white (white coat), mottled white or colored. As is well known in the art, the medium paper is humidified by means of high pressure steam which softens the paper fibers to facilitate the formation of the flute and consequent gluing. After formation of the board, this humidity is removed by drying in the dry-end. In the present invention, the newly formed corrugated liner board is heated from the bottom by hot plates and the adhesive holding components of the structure is cured. 
         [0042]    The present repulpable inventive degradable poultry box  10 , a cross section of which is seen in  FIG. 10 , is constructed with an inner Kraft paper liner or backer  12  impregnated with a hydrogenated triglyceride, preferably tallow at 2.5 lbs/MSF, a corrugated paper medium  14  impregnated with a hydrogenated triglyceride, preferably tallow when animal fats are used at 3.5 lbs/MSF and an outer Kraft paper liner or backer  16  which is also impregnated with tallow at 2.5 lbs/MSF. Other animal fats which can be used include pork lard, poultry grease and fish oils. Hydrogenated triglycerides which can be used in the invention are animal fats and vegetable oils. Vegetable oils include soybean oil, peanut oil, olive oil, palm oil, coconut oil and cottonseed oil with the preferred oil being palm oil. Hydrogenated triglycerides used in the impregnation are commercially available from C.J. Robinson Co. and Chemol Corporation. 
         [0043]    After impregnation of the paper liners, both liners or backers  12  and  16  are coated on their outside surfaces with a coating  18  of a styrene acrylic co-polymer water based solution ranging from about 75% to about 95% by weight mixed or blended with hydrogenated triglyceride preferably in the nature of tallow ranging from about 5% to about 25% by weight to form an emulsified coating. A most preferred embodiment of the coating  18  is about 80% by weight styrene acrylic co-polymer solution and about 20% by weight hydrogenated triglyceride which is preferably in the form of tallow or palm oil. The coating emulsion is heated and mixed at the general time of application and heated to a temperature from about 160° F. to about 180° F., preferably at about 170° F. 
         [0044]    The coating  18  is a water based high solid fluid solution (% by weight of the styrene acrylic co-polymer ranging from about 50% to about 55%) most preferably about 52% and has a pH ranging from about 8-9 with fully cured Tg of +7, a specific gravity of ranging from about 1.04 to about 1.6 and viscosity (cps) of about 400, a vapor density the same as water with 30 minute Cobb values of 10 or better. The coating is fast drying, recyclable, repulpable and is printable and glueable. 
         [0045]    The term “tallow” as used herein is meant to also cover palm oil and other hydrogenated triglycerides. The present poultry box  10  is constructed using standard corrugated box making machinery as is well known in the art. As shown in  FIG. 11 , a roll  30  of the medium paper is positioned upstream of the corrugator. The paper is wetted and passed through a standard corrugating machine  35  and formed into a corrugated medium  32  having the desired flute size, preferably a “C” size. The corrugated medium  32  is transported downstream through a hydrogenated triglyceride bath, preferably, a tallow or palm oil bath  36  and associated rollers with the corrugated medium being impregnated with tallow at 2.5 to 3.5 lbs/MSF. The impregnated corrugated medium  37  is carried by belts to an assembly station  60  where the coated liner backers  45  and  55  formed of Kraft paper  40  and  50  as further described below are secured to the corrugated medium  37  to form a composite board or sheet  61 . Two liner rolls of roll stock of Kraft paper  40  and  50  are removed from their respective rolls and the respective liner sheets  41  and  51  are transported by rollers (not shown) through separate hydrogenated triglyceride baths (preferably tallow baths)  42  and  52 . Associated rollers apply tallow to the liner backer sheets  41  and  51  at 2.5 lbs/MSF impregnating the same. The now impregnated liner backer sheets  43  and  53  are then transported by rollers and coated at coating stations  44  and  54  on a single sheet surface side with the emulsion coating  18  heated to about 170° F. The emulsion coating which is preferably a styrene acrylic copolymer or a blend of the styrene acrylic copolymer and hydrogenated triglyceride can be placed on the backer sheet surface by rods, rollers, doctor blades or spraying as is well known in the art. The emulsion coating is translucent to milky white and is water based. The coated liner sheets  45  and  55  are then glued at a gluing station in the assembly station  60  to the corrugated medium  37  with a suitable adhesive as is well known in the art to form a coated corrugated composite board with an emulsified coating  18  on its top and bottom outside surfaces. The coated corrugated composite board  61  is then passed over a heat curing bed  65  to cure and set the adhesive or glue. The heat curing bed  65  is a series of hot plates and pressure rollers which applies light pressure and heat to cure the adhesive which is standard in the corrugated box making art and the glue cures very rapidly. The composite board is run through a chill plate assembly  70  which drops the corrugated temperature to 70° F. allowing the blanks to be cut and stacked without sticking. The cured composite corrugated board sheet  61  is then cut into individual blank sections in a cutting and stacking station  80  with known means stacking the individual flat sheets of composite corrugated board. If desired, air impact dryers can be used to dry the flat sheets. The individual composite corrugated blanks are stacked and dried for a day. The blanks are later placed in a standard box cutting station  90  which cuts and scores the composite poultry box blank  100  in a finished blank form as shown in  FIGS. 5-9 . 
         [0046]    The box blank  100  as shown in  FIGS. 5-7  is cut and scored in the box cutting station to form a bottom panel  102  with opposing integral end panels  104  and  106  being joined thereto at the fold lines  103  and  105 . Each of the end panels  104  and  106  has a hand cutout  107  and a closing flap  108  mounted to each end panel  104  and  106  by a spaced plurality of hinges  110 . Side wall panels  112  and  114  are positioned on opposite sides of bottom panel  102  and are integral thereto being joined along their respective fold lines  113  and  115  allowing the side panels  112  and  114  to be folded upward and positioned transverse to the plane of bottom panel  102 . Each end surface of the side panels  112  and  114  is integral with the end of reinforcing panels  122 ,  128  and  124 ,  126  respectively and is joined to the reinforcing panels by fold lines  117  and  119 . End reinforcing panels  122 ,  124  and  126 ,  128  are positioned on opposite sides of end panels  104  and  106 , respectively. End reinforcing panels  122 ,  124  are separated from the outer end panel  104  by parallel cuts  123 ,  125  and end reinforcing panels  126  and  128  are positioned on opposite sides of outer end panel  106  and are separated from end panel  106  by parallel cuts  127  and  129 . This allows the respective reinforcing panels to be separated from the outer end panels  104  and  106  and folded over each other with the outer end panel then being folded upward adjacent the respective reinforcing panels to form a 3 layer composite end panel assembly  150  so that cut outs  130  of the reinforcing end panels are aligned with cut outs  107  of the outer end panels. Cut lines  123 ,  125 ,  127  and  129  are cut down the sides of end panels  104  and  106  but do not engage or intersect the fold lines  103  and  105 . The cut lines are ended about ⅝ inch to about ¾ inch from the fold lines  103  and  105  as shown in  FIG. 5 . In  FIG. 6 , the cut lines are ended about 1¼ inch to about 1⅜ inch from the fold lines  103  and  105  and in  FIG. 7 , the cut lines are ended about 1 inch to about 1⅛ inch from the fold lines  103 ,  117 ,  119  and  105 ,  117 ,  119 . Cut lines  123 ,  125 ,  127  and  129  of the reinforcing end panels end with a transverse cut  141  extending from the end of each cut line inward into the body of the respective reinforcing end panels. The transverse cut  141  is substantially parallel to the fold lines  103  and  105  with each transverse cut having a distal rounded cut section  142  extending from the transverse cut  141  into the body of the reinforcing end panel. When the reinforcing end panels and outer end panel are folded inward they form an end panel assembly  150  perpendicular to the bottom panel  102 . A corner pinch tab  144  is formed by a transverse cut  141  and distal cut  142  which intersects the transverse cut. The tab  144  is integral with the outer end panel and adjacent reinforcing end panel to form a pinched corner seal as best seen in the partial exploded blank end view of  FIG. 4 . 
         [0047]    The pinched corner tab  144  ranges from ⅝ inch to about 1⅜ inch in length depending upon the length of transverse cut  141  from the bottom panel and the corner seal depth desired when the box is assembled. See  FIGS. 3-9 . It should be noted that fold lines  117  and  119  are offset from the end panel fold lines  103  and  105  from 1/16 inch to 3/16 inch as shown in the  FIG. 6  so that the bottom panel  102  is slightly offset from the side panels  112  and  114  to form the raised pinch corner tabs  144 . The pinch corner tabs  144  thus forms a seal for each corner of the box extending upward a predetermined distance preventing drainage of fluid at the corners which has leaked into the box chamber. 
         [0048]    The box  10  when folded has the reinforcement panels folded inward parallel to each other with the end panels  104  and  106  being positioned on the outside of the box forming the exterior panel of the end panel assembly. As shown in  FIG. 2 , when the box  10  is assembled, the hinges  110  of the end panels  104  and  106  fold over the adjacent reinforcing end panels separated top cut outs  210  with the end panel flaps  108  extending downward into the box chamber  300  to hold reinforcing panels  122  and  124  in an aligned parallel position with end panel  104  and reinforcing panels  126  and  128  in an aligned parallel position with end panel  106 . All four reinforcing panels  122 ,  124 ,  126  and  128  are provided with a hand cut outs  130  which align with the hand cut outs  107  of end panels  104  and  106  when the box is assembled. As shown in  FIGS. 2 and 3 , neither of the side free end edges of the reinforcing panels engages the opposite side panel or a plane taken across the surface of the opposite side panel. The box is provided with a standard folded lid or cover  11  which is well known in the art and is shown in  FIG. 2A .  FIGS. 5-7  show different dimensioned boxes.  FIG. 5  is a box blank 42 1/16 inches in length and 31¾ inches in width forming a box 18 1/16 inches by 12¾ inches with a 11⅝ inch depth.  FIG. 6  is a box blank 43 1/16 inches in length and 33¼ inches in width forming a box 18 1/16 inches by 12¾ inches with a 10¼ inch depth.  FIG. 7  is a box blank 43 1/16 inches in length and 33¼ inches in width forming a box 18 1/16 inches by 12¾ inches with a 9 9/16 inch depth. 
         [0049]    A second embodiment of the invention is shown in  FIGS. 8 and 9  and is constructed and assembled identical to the preferred embodiment discussed above differing only in that there are no hinges  110  or closing flaps  108  on the outer end panels  104  and  106  and the reinforcing end panels do not have separated top cut outs  210  and have a rounded inward end corners  222 ,  224 ,  226  and  228  which are seated against bottom panel  102 . 
         [0050]    The principles, preferred embodiments and modes of operation of the present invention have been described in the foregoing specification. However, the invention should not be construed as limited to the particular embodiments which have been described above. Instead, the embodiments described here should be regarded as illustrative rather than restrictive. Variations and changes may be made by others without departing from the scope of the present invention as defined by the following claims: