Abstract:
A pallet includes a number of runners which may be sandwiched between upper and lower face sheets of corrugated paperboard. Each runner is comprised of multiple layers of corrugated paperboard with the flutes of the corrugations oriented vertically to provide compression strength to the runners and the associated pallet. Each runner also may include at least one reinforcing insert most preferably of hardboard to provide beam strength to the runner and a band to avoid failure without a prior indication. Moreover, the system and method for manufacturing the runners with reinforcing inserts overcomes problems of delaminating and separation of the adhesively bonded layers of the runner.

Description:
[0001]    This is a continuation-in-part of U.S. patent application Ser. No. 09/629,530 filed Jul. 31, 2000 which in turn was a continuation-in-part of U.S. patent application Ser. No. 09/182,263 filed Oct. 29, 1998 and issued as U.S. Pat. No. 6,095,061 on Aug. 1, 2000. Each of these patents/applications are hereby incorporated by reference in its entirety. 
     
    
     
       BACKGROUND OF THE INVENTION  
         [0002]    This invention relates to a method and associated system for manufacturing a runner for use alone or with a pallet in the storage and/or transport of goods and, more particularly, to such a system and method for manufacturing a recyclable and reinforced runner and pallet design.  
           [0003]    For many years, various types of objects have been used to separate and support loads that are stored and transported generally in a stacked arrangement. The equipment that is primarily used for performing this stacking arrangement is a front end loader, lift truck or fork lift truck which raises the individual loads so that they can be stacked one on top of the other or on a rack. To separate the loads from each other, off the rack or off of the floor, a pallet, riser or runner is positioned beneath the load so as to allow space for the insertion of the forks of the lift truck or the like for moving and positioning the loads for storage or transportation. Generally, the load supporting pallets are mainly made from wood and consist of platforms having parallel runners longitudinally and/or transversely secured to the underside by nails, staples, strapping or other suitable fasteners.  
           [0004]    While such wooden pallets in the past have been found to be satisfactory in many regards for their intended use in transporting and storage of materials and articles from one location to another, there are many disadvantages associated with wooden pallets. Increased environmental awareness has become a significant factor in the packaging, transportation and shipping industries. Wood is difficult to readily recycle and, hence, many wood packaging or pallet components are finally disposed of in land fills. However, available land fill sites are becoming full and, if available, require significant fees for dumping such materials.  
           [0005]    For the international shipment of goods, wooden pallets present additional environmental problems because they tend to serve as hosts for germs and bugs. Wooden pallets are often quarantined or burned upon arrival in the destination country according to governmental regulations or general precautionary practices to avoid the spread of undesirable insects, bugs or germs.  
           [0006]    To avoid some of the objections to the use of wood pallets, alternative pallet designs utilize materials such as corrugated paperboard, scrapped paperboard, plastics, aluminum and other materials. While solving certain problems associated with wood pallets, pallets and runners from non-wood materials often have significant deficiencies. While non-wood pallets may be light weight and inexpensive for some applications, their strength and rigidity under static and dynamic loading is insufficient to permit wide spread general use for all types of goods. Such non-wood pallets often have excessive deflection and lack beam strength which causes their sagging under loads thereby making the handling, stacking and racking of the pallets impractical and even dangerous. Many so called improved pallet designs do not offer the strength necessary to withstand buckling, crushing or compression when placed upon a rack under a load.  
           [0007]    A solution to many of these problems is disclosed in applicant&#39;s own prior U.S. Pat. No. 6,095,061 which discloses a reinforced, rackable and recyclable pallet and runner. The pallet/runner design disclosed in the &#39;061 patent is light weight and provides significant strength and increased load bearing capability and resistance to compression and crushing while still providing the significant advantages of being entirely processable in a paperboard recycling system or the like for convenient, economical and ecological disposal.  
           [0008]    The &#39;061 patent discloses a pallet which includes at least two spaced generally parallel runners and each of the runners is constructed of a number of layers of double wall or double face corrugated paperboard glued together in face-to-face orientation with the flutes of the corrugations being generally aligned in a generally vertical direction. Each of the runners also includes at least one generally vertically oriented reinforcing insert positioned between adjacent layers of the corrugated paperboard.  
           [0009]    One method for manufacturing such a runner is to laminate layers of corrugated paperboard one on top of another in face-to-face relation with the reinforcing insert or inserts positioned therein. The various layers of paperboard and reinforcing insert may be adhered in a face-to-face relation by an adhesive commonly known in the industry to form the billet. Typically, the billet of sheets or layers of corrugated paperboard and reinforcing insert is then stacked with similar billets one on top of another, typically four to six high, and compressed in an effort to bond the various layers in the respective billets to one another. After compressing the multiple billets in a single batch process, the individual billets are then sawed or cut into the individual runners for ultimate use or incorporation into a pallet.  
           [0010]    However, applicant discovered that during the production of the runners according the &#39;061 pallet and the above described method, frequently the adjacent layers of paperboard separate one from another and/or from the reinforcing insert particularly at the lateral ends of the runners. Increased pressure on the multiple billets, increased adhesive volume and alternative adhesives did not significantly improve the situation or minimize the occurrence of runner separation. Therefore, a need exists for an improved method and associated system for manufacturing paperboard pallet runners that have at least one reinforcing insert that avoids the problem of delaminating or separation of the adjacent layers of glued materials.  
         SUMMARY OF THE INVENTION  
         [0011]    The improved method and associated system for manufacturing a runner adapted to support a load during transit and storage by itself or in combination with a pallet overcomes the above-described disadvantages. Advantageously, the manufacturing method and system for a runner according to this invention economically, efficiently and reliably produces a runner having a number of layers of corrugated paperboard and a reinforcing insert therein, such as that shown in U.S. Pat. No. 6,095,061. Moreover, the improved manufacturing method and system produces a runner that does not delaminate or separate after the billet is constructed.  
           [0012]    Specifically, a presently preferred method of manufacturing a runner according to this invention includes juxtaposing a number of layers of corrugated paperboard together in which each layer of paperboard has generally parallel flutes and a pair of spaced faces. Each of the adjacent layers of paperboard are aligned in face-to-face relation and an adhesive is applied between the confronting faces of the adjacent layers of paperboard. At least one layer of a reinforcing insert is interposed between a pair of adjacent layers of corrugated paperboard. Advantageously, the reinforcing insert is recyclable and is most preferably hardboard or particle board. The reinforcing insert is similarly oriented with respect to the layers of paperboard and in face-to-face relation therewith. Adhesive is applied between the confronting faces of each layer of the reinforcing insert and the adjacent layers of paperboard to form a billet.  
           [0013]    Pressure is then applied to the billet in a direction generally perpendicular to the faces of the layers of paperboard to thereby bond the adhesive to the respective faces and adhere the layers together. Advantageously, the present invention benefits from the discovery that the layers of paperboard commonly have a degree of inherent curvature or warp and are not strictly planar layers. While pressure was applied to a number of billets in a stacked relation previously, having the reinforcing insert in each of the billets inhibits or prevents the pressure applied at the top and bottom of the multiple billet stack from transmitting through the entire stack to achieve optimum face-to-face contact between the warped layers of paperboard and adjacent layers. The slightly warped configuration of the paperboard is inherent in the material. However, typically the reinforcing insert of hardboard, particleboard or the like is not warped. One of the many advantages that the reinforcing insert provides to the runner is significant strength and load bearing capability while resisting compression or crushing of the runner. While these characteristics of the reinforcing insert are beneficial to the ultimate utility of the resulting runner, these characteristics also minimize the effectiveness of the pressure applied to a stack of multiple billets during prior manufacturing practices. The pressure applied to the stack of billets was not transmitted through the various layers to overcome the warp of the corrugated paperboard layers because of the reinforcing inserts. Therefore, proper face-to-face contact between various adjacent layers of the paperboard and reinforcing insert was not obtained in prior manufacturing operations. As such, the adhesive between such layers of paperboard and adjacent layers of paperboard or reinforcing insert did not effectively bond the layers together which ultimately resulted in delamination or separation of the runner at those locations.  
           [0014]    However, with the present invention, pressure is applied to only a single billet or a limited number of assembled layers to thereby achieve increased face-to-face contact and adhesive bonding between the adjacent layers. Applying pressure to only one billet or a limited number of layers allows the assembly process to effectively achieve adequate face-to-face contact to allow adequate bonding of the adhesive. The reinforcing insert does not detrimentally minimize the ability of the pressure applying process to overcome the slight warp in the paperboard layers. Therefore, the warp in the paperboard layers is effectively overcome by the pressure and adequate face-to-face contact is achieved to avoid delamination and separation of the resulting runner. Ultimately, the bonded billet of paperboard and reinforcing insert layers is cut or sawed in a direction generally perpendicular to the layers to separate individual runners from the billet for use directly on the load or as part of a pallet during the storage and shipping and goods.  
           [0015]    The associated system for manufacturing a runner according to a presently preferred embodiment of this invention includes a pair of gluing stations for applying adhesive to at least one face of selected layers of paperboard and reinforcing insert. One of the gluing stations is utilized for applying adhesive to the paperboard and the other gluing station applies adhesive to the reinforcing insert layers. Downstream from the gluing stations is a set-up station is provided to arrange and juxtapose the various layers of paperboard and reinforcing insert in face-to-face relationship to form a billet.  
           [0016]    The system includes at least one or a number of pressing stations down stream from the set-up station for applying pressure to each of the billets individually or to a limited number of layers. Once again, the pressure is applied in a direction generally perpendicular to the layers of paperboard over substantially the entire surface area of the billet. The individual pressing stations are adapted to apply pressure to individual billets at a time to thereby overcome at least some of the warp in the paperboard layers and achieve increased face-to-face contact and adhesive bonding between the adjacent layers. A cutting station which in one embodiment includes a number of parallel circular saw blades spaced one from another is located downstream from the pressing stations. The cutting station cuts the individual billets in a direction generally perpendicular to the layers of paperboard and reinforcing insert to separate the individual runners. The system also includes a mechanism for transferring the various layers of paperboard, reinforcing insert and billets to and between the respective stations in the form of roller conveyors, wheeled carts on rails or the like.  
           [0017]    As a result of the improved manufacturing system and associated method for producing recyclable paperboard runners with reinforcing inserts according to this invention, delamination and separation of the resulting runners is avoided. As a result, the manufacturing operation is significantly more efficient, effective and reliable while minimizing ways to end defective runners as a result of the benefits of overcoming the slight warp inherent in the layers of corrugated paperboard to achieve appropriate face-to-face contact and adhesive bonding in the runner.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0018]    The objectives and features of the invention will become more readily apparent from the following detailed description taken in conjunction with the accompanying drawings in which:  
         [0019]    [0019]FIG. 1 is a perspective view of a presently preferred embodiment of a pallet having a number of spaced runners and supporting a load on a rack with a portion of the load and an upper deck sheet of the pallet being broken away to expose the runners of the pallet;  
         [0020]    [0020]FIG. 2 is a cross-sectional enlarged view of a portion of a pallet including a runner according to one embodiment of this invention;  
         [0021]    [0021]FIG. 3 is a perspective view of a stack of layers of corrugated paperboard showing inherent warp in the layers of paperboard;  
         [0022]    [0022]FIG. 4 is a side elevational view of a stack of billets under pressure according to a prior art manufacturing operation in which selected layers of paperboard are not compressed into face to face contact with the adjacent layers;  
         [0023]    [0023]FIG. 5 is a side elevational view of a billet according to this invention under compression in which the inherent warp of the paperboard layers is overcome to thereby achieve face-to-face contact over substantially the entire surface of the layers;  
         [0024]    [0024]FIG. 6 is a top plan view of a system for manufacturing a runner according to one embodiment of this invention;  
         [0025]    [0025]FIG. 7 is a side elevational schematic view of a gluing station of the system of FIG. 6;  
         [0026]    [0026]FIG. 8 is a top plan view of a billet used to manufacture runners according to one embodiment of this invention; and  
         [0027]    [0027]FIG. 9 is a top plan view of an alternative embodiment of a system for manufacturing the runner according to this invention. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0028]    Referring to FIG. 1, a presently preferred embodiment of a pallet manufactured according to this invention is shown. The pallet  10  includes a plurality, three of which are shown in FIG. 1, of generally parallel runners  12 . It will be readily understood that the pallet  10  supports a load  14  and may include two, four (FIG. 1A) or another number of runners  12  within the scope of this invention. The runners  12  are sandwiched between an upper deck sheet  16  adhered, preferably by adhesive or the like, to an upper surface of each of the runners  12  and a lower deck sheet  18 , likewise adhered by adhesive or the like, to a lower surface of the runners  12 . The lower deck  18  sheet contributes to the structural integrity of the pallet  10  when rolling down the rollers of a conveyor (not shown), without crushing or collapsing the pallet  10  under the load  14 . The lower deck sheet  18  as such aids in the alignment of the runners  12  for proper vertical orientation while used on the conveyor. However, in certain applications, it would be understood that the lower deck sheet  18  and/or the upper deck sheet  16  may be eliminated. The pallet  10  supports the load  14  during transportation of the load  14  or storage thereof, for example, on the spaced beams  24  of a rack  26  such as that shown in FIG. 1. Typically, the beams  24  are spaced about  36  inches apart and in some applications are  42  inches apart and extend generally parallel to one another and perpendicular to the runners  12  in the pallet  10 .  
         [0029]    The runners  12  are spaced and generally parallel to one another so that tines  28  of a lift truck (not shown) or the like may be inserted between the runners  12  below the upper deck sheet  16  and above the lower deck sheet  18  for lifting, maneuvering and/or transporting the pallet  10  and load  14 . Each of the runners  12  further includes a pair of spaced notches  30  which are generally aligned with the notches  30  in the other runners  12  of the pallet  10  and extend the width of the respective runner  12 . The notches  30 , according to one presently preferred form of the invention, are open to the bottom face of the runner  12  and provide for entry of the tines  28  of the lift truck into the runner  12  for lifting the pallet  10  and the load  14  for maneuvering and/or transporting the pallet  10  and load  14  combination. Alternatively, the runners  12  may include portals (not shown) formed as through holes generally perpendicular to the runner  12 . As a result, the spaced runners  12  and notches  30  or portals thereof provide for four-way entry to the pallet  10  by the tines  28  of the lift truck or the like as is common in the popular Grocery Manufacturers Association (GMA) type pallets.  
         [0030]    In a presently preferred form, each runner  12  is approximately 48 inches in length, 3.5 inches in width and 3.5 inches in height. Preferably, the upper and lower deck sheets  16 , 18  (if provided) each measure approximately 40 inches by 48 inches and upstanding sidewalls of a tray configuration (not shown) of the upper deck sheet  16  are approximately 4 inches in height. The flutes of the upper and lower deck sheets  16 , 18  are preferably oriented perpendicularly to the runners  12 .  
         [0031]    Referring to FIG. 2, a cross-sectional view of one embodiment of the pallet  10  and one of the runners  12  thereof is shown. Specifically, the runner  12  is preferably constructed of a plurality of layers of paperboard  36 , each of which are corrugated and built up and adhered in face to face relation by an adhesive such as polyvinyl alcohol (PVA) or another suitable adhesive commonly known in the industry. Each layer of corrugated paperboard  36  of the runner  12  of FIG. 2 preferably is  125 # paperboard with type A or type C flutes  38 , although any flute configuration or paperboard can be employed with this invention. The flutes  38  in the runners  12  extend generally vertically in single wall or double face corrugated paperboard  38 . Preferably, the runner  12  of FIG. 2 includes four plies of double wall corrugated paperboard  36  on either side of a center reinforcing insert  40  which is most preferably a layer of one-quarter inch thick hardboard. Advantageously, the reinforcing insert  40  is sandwiched interiorly of the runner  12  and is oriented generally vertically or perpendicular to the deck sheets  16 ,  18  to provide beam strength to the runner  12 . Additionally, locating the reinforcing insert  40  on the interior of the runner  12  allows the corrugated paperboard  36  layers to assist in maintaining the reinforcing insert  40  vertical when the pallet  10  or runner  12  is loaded. The corrugated paperboard  36  and vertically aligned flutes  38  advantageously provide compression strength to the runner  12  and associated pallet  10  as well as the alignment of the runner  12 ; however, the corrugated paperboard offers little or no beam strength which is provided by the reinforcing insert  40 .  
         [0032]    According to the embodiment shown in FIG. 2, the lower deck sheet  18  is single wall  200 #B corrugated paperboard. The upper deck sheet  16  is preferably double wall corrugated paperboard with type A or C flutes. The flutes of the deck sheets  16 ,  18  are oriented generally perpendicular to the longitudinal axis of the runners  12 . In certain applications, a layer of hardboard or similar material may be used in place of or in addition to the corrugated paperboard of the upper and/or lower deck sheets  16 ,  18 .  
         [0033]    The reinforcing insert  40  is most preferably hardboard and provides beam strength and resistance to compression for the runner  12 , but offers little or no alignment stability. Preferably, the reinforcing insert  40  is recyclable, provides added strength and is a piece of chipboard, fiberboard, linerboard, Kraft or paperboard. More preferably, the reinforcing insert  40  is a piece of particleboard and, most preferably, a piece of hardboard which provides increased load bearing capability to the runner  12  and associated pallet  10 , increased resistance to compression and is entirely recyclable. However, hardboard is too costly and heavy to be economically and practically used as the only component of the runner/pallet design; therefore, it is advantageously used in combination with paperboard in this invention.  
         [0034]    An alternative embodiment (not shown) of the runner  12  includes two or more reinforcing inserts  40 , most preferably of hardboard, positioned proximate the exterior faces of the runner  12  with two layers of corrugated paperboard  36  on the exterior most sides of the hardboard and six layers of corrugated paperboard interposed between the reinforcing inserts  40 ,  40 .  
         [0035]    The runner  12  according to this invention may be used in combination with other runners  12  and applied directly to the bottom of the load  14 . An adhesive is deposited onto the upper surface of the runner  12  which is preferably non-drying, non-permanent so that the runner  12  may be selectively applied and removed from the lower surface of the load  14  as required. Preferably, the adhesive is deposited onto the open flutes  38  of the paperboard  36  and cool air is blown upwardly from the runner  12  through the flutes  38  to cool the adhesive. Preferably, such an adhesive is Instant-Loc No. 346650 which can be commercially obtained from National Starch and Chemical Company in Cincinnati, Ohio. Preferably, a release agent such as Michem Release Coat No. 40 commercially available from Michelman, Inc. in Cincinnati, Ohio may also be applied.  
         [0036]    Referring to FIG. 3, a stack  34  of corrugated paperboard  36  which may be utilized in the manufacture of the runner  12  according to this invention is shown. FIG. 3 demonstrates the fact that corrugated paperboard  36  of the type used in the runner  12  is not strictly planar but inherently includes a degree of curvature or slight warp across the surface area of the faces of the layers of paperboard. Preferably, during the manufacturing operations of the runner  12 , the adjacent layers of paperboard  36  are similarly oriented so that the curvature or warp is oriented similarly with respect to the curvature or warp of the adjacent layers. Nevertheless, the adjacent layers of the corrugated paperboard  36  and reinforcing insert  40  in the runner  12  are not in face-to-face intimate contact.  
         [0037]    A top plan view of a top layer  36 ,  40  in a billet  32  is shown in FIG. 8. The layers  36 ,  40  may include appropriately positioned and configured ovals  30   a  as shown in FIG. 8. The layers  36 ,  40  of a billet  32  commonly are about 48 inches by 326 inches so that a number of runners  12  may be cut or separated from the assembled layers of paperboard and reinforcing insert. Cut lines  58  are shown in FIG. 8 to separate inward runners  12  from the billet  32 .  
         [0038]    Referring to FIG. 6, one embodiment of a system  42  for manufacturing the runner  12  according to this invention is shown. The system  42  includes a pair of gluing stations  44 ,  46 . One of the gluing stations  44  is particularly adapted for applying the adhesive to at least one and preferably both of the opposite faces  36   a,    36   b  of each of a number of layers of corrugated paperboard  36 . The other gluing station  46  is likewise adapted for applying adhesive to each of the opposite faces  40   a,    40   b  of a layer of reinforcing insert  40 . The gluing stations  44 ,  46  are schematically shown in cross section in FIG. 7 in which a pair of feed rollers  48 ,  48  are rotationally driven in counter rotation to one another to feed therebetween one of the layers  36  or  40  toward of counter-rotating adhesive application rollers. The outer periphery of each of the adhesive application rollers  50 ,  50  is ribbed and in contact with wetting roller  52 ,  52 . Each wetting roller  50 ,  50  is likewise at least partially submerged in a reservoir  54  of adhesive so that upon rotation of the adhesive application roller  50 , the wetting roller likewise rotates in contact with the outer periphery thereof. The adhesive is picked up from the reservoir  54  by the wetting roller and is likewise transferred to the outer ribbed surface of the adhesive application roller  50  for application to one of the faces  36   a,    36   b,    40   a,  or  40   b  of the layer of paperboard or reinforcing insert  36 ,  40 . A pair of counter-rotating discharge rollers  56 ,  56  advance the layer  36  or  40  with adhesive thereon from the gluing station  44 ,  46 . In one embodiment, the adhesive gluing stations  44 ,  46  are commercially available from Osama Technologies, Wood Working Machinery in San Gimignano, Italy.  
         [0039]    As a result of this invention, the quantity of adhesive applied during the manufacture of the runners  12  is reduced to approximately two to three pounds per thousand square feet from approximately seven to eight pounds per thousand square feet in prior manufacturing operations. In addition to the reduction in the amount of adhesive utilized, the effectiveness of the adhesive is significantly increased because delamination and separation of the adjacent layers of paperboard is eliminated.  
         [0040]    An additional feature of the gluing stations  44 ,  46  according to this invention alternatively includes foaming the adhesive prior to or in conjunction with application to the layers  36 ,  40  to further reduce adhesive consumption. Alternatively, the adhesive may be sprayed, drizzled or otherwise applied to the faces  36   a,    36   b,    40   a,    40   b  of the layers  36 ,  40  within the scope of this invention.  
         [0041]    Referring once again to the system of FIG. 6, in one embodiment the gluing stations  44 ,  46  are oriented approximately 90° from one another in conjunction with a set up station  60  at which the individual layers of paperboard  36  and reinforcing insert  40  are arranged into a billet of layers to be adhesively bonded together. The set up station  60  is located downstream from the gluing stations  44 ,  46  and upstream from a transfer mechanism  62  in the form of a conveyor having a plurality of rollers or carts  75  movable on rails  73  on which the billets  32  are transferred to be positioned adjacent one of a number of pressing stations  64  of the system  42 . The individual billets  32  are transferred from each cart  75  by a pusher  79  movably mounted on a pair of bars  77 ,  77  on each cart  75 .  
         [0042]    To facilitate the efficient manufacture of a large quantity of runners  12 , a number of pressing stations  64 , six of which are shown adjacent the conveyor  62  in FIG. 6, are included in the system  42 . However, it will be appreciated that any number of pressing stations  64  may be utilized within the scope of this invention. The billets  32  are transferred by the carts  75  along the rails  73 ,  73  to be adjacent one of the pressing stations  64  and are each then transferred by the pusher  79  to the respective pressing station  64  for processing. Each pressing station  64  may take one of a variety of forms for applying pressure to substantially the entire surface area of the upper and lower layers  36 ,  40  to achieve intimate face-to-face contact between the adjacent layers  36 ,  40  in the billet  32 . Typically, the pressing station  64  may include a lower stationary platen  66  and an upper movable platen  68  for applying pressure to the billet  32  positioned therebetween. Movement of the upper platen  68  and the pressure P 2  applied thereby to the billet  32  may be generated from one or more pneumatic cylinders  70  mounted on a frame  72  in the station  64 .  
         [0043]    In an alternative embodiment of this invention, the pressing stations  64  are arranged vertically one upon another and the billets  32  are delivered by lifts, conveyors or the like to the respective pressing stations  64 . The vertical arrangement (not shown) of the pressing stations  64  is particularly advantageous for sites having limited floor space for the system  42 .  
         [0044]    In one embodiment, each pressing station  64  delivers P 2  of approximately 30 pounds per square foot of pressure to the billet  32  to thereby overcome the warp or curvature in the layers of paperboard  36  and achieve appropriate face to face contact and bonding between the respective adjacent layers  36 ,  40 . Previously, pressure P 1  in the amount of as much as 400 pounds per square foot of pressure was applied by platens  66   a,    68   a  to the stack  34  of billets  32  as shown in FIG. 4 and the warp of the paperboard was not flattened out leaving gaps  74  preventing appropriate contact with the adjacent layers of paperboard and reinforcing insert  36 ,  40  for proper bonding. However, according to this invention, the pressing stations  64  and associated method apply pressure to a single billet  32 , limited number of billets  32  or layers  36 ,  40  to appropriately achieve face-to-face contact while avoiding gaps  74  and overcoming the warp to thereby appropriately bond the layers  36 ,  40  together. Typically, each billet includes the layers of paperboard and reinforcing insert appropriate for a single runner.  
         [0045]    After the pressure is applied to the billets in the individual pressing stations, typically for a duration of about 120 seconds, the individual billets  32  are then transferred to a roller conveyor  62  or an alternative transfer mechanism for transfer to and processing in a cutting station  80 . The duration of the pressure on the billets  32  is highly dependent upon the type of adhesive used and should be adjusted appropriately as is know by those skilled in the art. The cutting station  80  includes a series of circular saw blades (not shown) spaced one from another, the spacing of which is determined by the height of the runner, typically 3.5 inches. At least one and preferably multiple runners  12  are severed by the cutting blades from the billet  32  along cut lines  58  as shown in FIG. 7. The cut lines  58  and oval cut-outs in the billet  32  are arranged for cutting the billet  32  to produce the notches  30  in the runner  12 . According to the billet  32  shown in FIG. 6, nine runners  12  are to be cut from the billet  32 , each with two notches  30  to provide the four-way entry into the runner  12  or resulting pallet  10 . Alternatively, the ovals  30 a may be appropriately positioned so that they do not intersect the cut lines  58  and portals in the runners  12  are generated according to an alternative embodiment of this invention.  
         [0046]    Referring to FIG. 9, an alternative embodiment of a system  42   a  for manufacturing the runner  12  according to this invention is shown. Features of the system  42   a  of FIG. 9 that are common to the system  42  of FIG. 6 are identified by like reference numerals. The system  42   a  includes the pair of gluing stations  44 ,  46  arranged up stream from the set up station  60  at which the individual layers of paperboard  36  and reinforcing insert  40  are arranged into the billet  32  of layers to be adhesively bonded together.  
         [0047]    Downstream from the set up station  60  of the system  42   a  is a pressing station  64   a  in the form of upper and lower belts  82   a,    82   b  between which the individual billets  32  are serially feed for pressing and processing. Each belt  82   a,    82   b  is trained around a pair of end rollers  84  at least one of which is rotationally driven to pass the belt in an endless loop and advance the billets  32  through the pressing station  64   a  while being pressed. In one embodiment, each belt  82   a,    82   b  is driven at a rate of about 25 feet/minute, is 60 inches wide and the associated end rollers  84  are spaced 20 feet apart. A number of intermediate rollers  86  are also provided in the pressing station  64   a  between each of the pair of end rollers  84 . The rollers  84 ,  86  for each belt are mounted for rotation in a frame that includes a pair of side rails  88  at the opposite ends of the rollers  84 ,  86 . The spacing of the side rails  88  of the upper belt  82   a  is fixed and preferably adjustable relative to the side rails  88  of the lower belt  82   b.  Preferably, each roller  86  for the upper belt  82   a  is mounted for rotation on a shaft  90  that extends through a slot  92  in each of the associated side rails  88 .  
         [0048]    The rollers  86  of the upper belt  82   a  are weighted to apply the requisite pressure to the billets  32  passing between the belts  82   a,    82   b.  The spacing between the upper and lower belts  82   a,    82   b  is determined by the thickness of the billets  32  being manufactured and the rollers  86  of the upper belt  82   a  are movable vertically relative to the lower belt  82   b  on the shafts  90  in the slots  92  to accommodate variations in billet thickness and maintain pressure on the billet  32 . Additionally, weights  94  can be added to the outboard portions of the roller shafts  90  of the upper belt  82   a  to increase the pressure being applied to the billets  32 . Once the billets  32  pass through the pressing station  64   a  they are transferred to the cutting station  80 .  
         [0049]    The system  42   a  and associated pressing station  64   a  affords the continuous production of billets  32  without operator involvement as an additional feature of the invention compared to the system  42  of FIG. 6. Additionally, the transfer of the billets from the set up station  60  and to the cutting station  80  is more easily and efficiently accomplished in the system  42   a  of FIG. 9.  
         [0050]    Therefore, as a result of the system  42  or  42   a  and associated method for manufacturing reinforced paperboard pallet runners  12  of this invention, the reliability and effectiveness of the manufacturing operation is increased because runners  12  that separate or delaminate from one another are eliminated. Additionally, less force is required during the compression cycle of the manufacturing operation and consumption of adhesive is significantly reduced compared to prior manufacturing operations for runners of corrugated paperboard having warp along with a reinforcing insert.  
         [0051]    From the above disclosure of the general principles of the present invention and the preceding detailed description of at least one preferred embodiment, those skilled in the art will readily comprehend the various modifications to which this invention is susceptible. Therefore, I desire to be limited only by the scope of the following claims and equivalents thereof.