Patent Publication Number: US-6213388-B1

Title: Dispensing assembly for a lined carton and process and apparatus thereof

Description:
RELATED APPLICATION 
     This application is a continuation-in-part of application Ser. No. 09/150,966 filed Sep. 10, 1998 which is a continuation-in-part of application Ser. No. 09/050,533 filed Mar. 30, 1998, now U.S. Pat. No. 6,062,467, which claims priority from Provisional application Ser. No. 60/069,859 filed Dec. 17, 1997, all of which are incorporated herein by reference. 
    
    
     BACKGROUND 
     This invention relates to the packaging of dry particulate foods such as ready-to-eat (“RTE”) cereal. More specifically, this invention relates to lined cartons of the type known as a bag-in-a-box with reclosable dispensing means connected to the liner or bag in such a way that a portion thereof is separated from the liner upon initial opening of the dispensing means to provide access to the contents of the carton. 
     The use of cartons with liner bags for dry particulate products such as RTE cereal is well known. Such cartons are usually formed from a blank of paperboard or similar material comprising sidewalls with top and bottom flaps. The liner is a plastic or coated paper bag which holds the particulate product. The liner can be filled and sealed before or after being placed inside an open carton, the flaps of which are then folded and sealed. 
     Access to the contents of such cartons involves breaking the seal between the top flaps of the carton and pulling open the sealed liner bag. Resealing is often difficult and incomplete leading to a loss of freshness of the product. RTE cereal, for example, has a low moisture content and readily absorbs moisture from the air leading to a loss of crispness. 
     Dispensing devices such as pour spouts have been proposed to control the discharge of particulate product and minimize exposure to the atmosphere. However, when a carton with a pour spout contains a filled and sealed liner bag, the bag must be manually torn or cut with a knife or scissors when the spout is first opened. This arrangement has several drawbacks not the least of which is manually cutting or tearing of the liner bag. Once opened, and as the contents are depleted, the liner bag and its contents slide and shift positions in the carton which can cause the opened portion of the liner to become misaligned with the pour spout opening thereby hindering dispensing of product from the carton. This also causes product to drop between the carton and the liner. 
     U.S. Pat. No. 2,998,788 relates to bag-in-a-box packaging where a liner is sandwiched between a metal spout and a precut flap in the carton side wall. A cut-out in the side wall above the flap allows the insertion of a knife to cut the liner and open the spout. The liner is bonded to the spout and the carton flap using a heated anvil which is inserted into an empty, lined carton. 
     SUMMARY OF THE INVENTION 
     The present invention is directed towards an improved bag-in-a-box container where the bag or liner in the box is filled with product and sealed. The box has a dispensing flap and while the filled, sealed liner is in the box the liner is sealed to the flap in such a way that the bag remains sealed but upon initial opening of the flap, that portion bonded to the flap separates from the liner to provide access to the contents of the container. 
     A preferred carton has a pivotable pour spout mounted to a dispensing opening or flap. A front panel of the pour spout is bonded to a portion of the liner bag while it is filled and sealed without braking the seal and, when initially opened, that portion partly separates from the rest of the liner thereby providing access to the contents of the carton. Thus, as the pour spout is manually opened for the first time, the liner bonded to the front panel separates to create an opening while remaining integral with the liner along the pivot axis. 
     Because the portion of the liner that separates corresponds to the size of the dispensing opening, reclosure of the pour spout fills the opening to minimize contact of the contents with the outside atmosphere. Moreover, the liner stays connected at the bottom of the dispensing opening to maintain alignment. 
     It is preferred to heat seal the liner along the top and side edges of the flap or front panel in a way that creates weakened tear lines in the liner, but without breaking the seal of the liner, to facilitate initial opening of the flap or pour spout. The liner can also be bonded adjacent the dispensing opening or flap to further maintain alignment and prevent product from falling between the bag and the box. The present invention is also directed to an improved one-piece pour spout assembly including a fitment defining a dispensing opening with upper and lower margin portions adjacent thereto, and a pour spout having side panels and a front panel integral with the lower margin portion such that when the pour spout is folded over the fitment, the front panel overlies (or is in register with) the dispensing opening. A preferred fitment has side members and a cut-out piece corresponding to the dispensing opening which is bonded to the front panel of the pour spout. The cut-out piece can have vertical edges that extend into the side pieces at right angles to the front panel of the pour spout. This provides for a tight fit on reclosing the spout to minimize exposure to the outside atmosphere. 
    
    
     DESCRIPTION OF THE DRAWINGS 
     The present invention will be more fully understood from the following description and the accompanying drawings wherein: 
     FIG. 1A is a plan view of a pour spout of the invention opened up and laid flat. 
     FIG. 1B is a plan view of the other side of the pour spout of FIG.  1 A. 
     FIG. 2 is a plan view of the assembly of FIG. 1B turned over with the pour spout folded over a fitment which defines a dispensing opening shown in phantom. 
     FIG. 3 is a perspective view of the pour spout assembly of FIG. 2 shown folded and partly open. 
     FIG. 4 is a perspective view of a carton with access to a dispensing assembly of the invention. 
     FIGS. 5 and 6 are perspective views of a dispensing assembly of the invention partly open and fully open. 
     FIG. 7 is a plan view showing the assembly of FIG. 1A with the pour spout folded under a fitment (FIG. 2 turned over) and positioned on the interior of a flat carton blank. 
     FIG. 8A is a perspective view, broken away, of the interior of a dispensing assembly of the invention. 
     FIGS. 8B and 8C are cross-sectioned views taken along lines  8 B— 8 B and  8 C— 8 C of FIG.  8 A. 
     FIG. 8D is a cross-sectional view of laminated foil used to promote bonding. 
     FIGS. 9 and 10 are perspective views of an alternate dispensing assembly show closed and open. 
     FIG. 11 is a front view of the assembly of FIGS. 9 and 10 shown fully open. 
     FIG. 12 is a cross-sectional view taken along line  12 — 12  of FIG.  9 . 
     FIG. 13A is a diagrammatic view of apparatus for sealing a liner to the pour spout assembly. 
     FIG. 13B is a cross-sectional view along line  13 B— 13 B of FIG.  13 A. 
    
    
     DESCRIPTION 
     It is preferred to use a conventional paperboard carton with a separate or integral pour spout made of plastic or paperboard and a conventional plastic liner bag that is filled and sealed before or after being inserted into an open top carton. Numerous apparatus and processes using such materials and techniques for packaging RTE cereal are known and available. 
     In carrying out the present invention, a portion of a filled and sealed liner bag is brought into contact and bonded with the front panel of a pour spout or a flap mounted in a dispensing opening in a side panel or end wall of a carton. Reduced pressure means such as a vacuum enclosure can be used to bring about sealing contact between the liner and a flap or front panel of the pour spout. 
     An activatable hot melt adhesive is positioned in the desired pattern between the liner and the flap or front panel and externally activated by delivering bonding energy to the interface such as by induction heating. This can be done by including a heat generating substance in or with the hot melt adhesive that will generate heat to activate the adhesive. Such substances include metal foils such as aluminum foil laminated on one or both sides to a hot melt adhesive, metal salts such as magnesium chloride, chromium nitrate, aluminum chloride and the like, mixed with a hot melt adhesive or metal particles such as iron or aluminum powder mixed with or flocked onto a hot melt adhesive applied in the desired pattern to the flap or front panel. 
     When using magnetizable particles such as iron, a magnet can be employed to orient the particles and promote bonding with the liner. Metal salts and metal particles are used in amounts sufficient to activate the adhesive when external bonding energy is applied. 
     Hot-melt adhesives are 100% solids and are applied in hot, molten form. They set fast when heat is removed and can be preapplied and reactivated later by the application of heat. Hot melt adhesives are typically formulated with a backbone polymer such as ethylene-vinyl acetate or polyethylene. The main polymer is usually let down with a diluent such as wax to improve melt flow properties. Antioxidants are a component since the adhesive is applied hot and is subject to oxidation. Tackifiers improve hot tack and viscosity. Other materials influence melt temperature. Added colorants can make the adhesive more visible. 
     Hot-melt adhesives are readily available from numerous sources. INSTANT LOK® hot melt adhesives from National Starch and Chemical Corporation of Bridgewater N.J. 08807 are suitable for use in the invention. 
     Metal foil laminates are preferred for ease of application and activation. 
     A typical metal foil laminate includes aluminum foil, generally vacuum metalized aluminum on a polyester film, with a linear low density polyethylene adhesive on one or both sides. Curwood Inc., of Oshkosh, Wis. 54903, provides CURLAM® Grade 5432 film with adhesive on one side. It is preferred to coat both sides of the film with an adhesive which enables the use of induction heating to bond the foil laminate to the front panel and the liner at the same time. 
     Induction heating equipment is widely used in the packaging field and suitable units for use in the invention are available from Lepel Corporation of Edgewood, N.Y. 11717 and Amertherm, Inc. of Scottsville, N.Y. 14546. 
     The intensity and duration of the induction field required to bond the liner to the front panel depends on the composition of the heat activatable adhesive. For example, an aluminum foil laminated with linear, low density polyethylene generally achieves its sealing temperature in 0.9 to 1.2 seconds when exposed to a Lepel, LEPAK, Jr. 750 watt induction sealer. An adhesive including a resin base with about 5 to 10 weight percent metallic salt, such as chromium nitrate or aluminum chloride, generally reaches its sealing temperature in under 2.0 seconds when placed in an 800 watt GE microwave oven operating at 900 to 1100 kHz. 
     Other induction heating systems and heat activatable adhesives can be adopted to the present invention. For example, an induction heating system for sealing packages using magnetic susceptible particles and heat softenable adhesives and high frequency alternating magnetic fields is disclosed in U.S. Pat. No. 3,879,247 which is incorporated herein by reference. Polymer systems for sealing containers which can be activated by electromagnetic energy frequencies of 0.1-30,000 MHZ, including radio frequency and microwave heating, are disclosed in U.S. Pat. 4,787,194 which is incorporated herein by reference. RF sealable, non-foil acrylate based polymers for packaging applications are disclosed in U.S. Pat. No. 4,660,354 (Example 1) and WO 95/03939 which are also incorporated herein by reference. 
     Heat sealing the liner to a flap or the front panel of the pour spout is done in a way to locally weaken the liner to facilitate separation of a portion of the liner upon initial opening of the pour spout or flap. In one embodiment, this can be accomplished by attaching a metal foil laminate to the front panel of the pour spout or to the fitment which defines the dispensing opening. The foil can be configured so as to concentrate heat at the edges of the dispensing opening which crates a weakened or thinned tear line without breaking the seal of the bag. 
     A preferred liner is biaxially oriented, laminated high density polyethylene film. Such films will tear easily in the longitudinal or machine direction and to impart better tearability in the transverse direction, fillers such as finely divided calcium carbonate, silica, diatomaceous earth and the like can be added to the film. A suitable film can have two high density polyethylene layers containing 15% by weight finely divided silica in the inner layer and 10% in the outer layer. 
     In another embodiment, a fitment defining a dispensing opening, preferably with a cut-out piece, is positional between the liner and the front panel of a pour spout. This defines a focused seal area around the periphery of the dispensing opening and consequently a weakened seal line which facilitates separation from the liner. 
     Other methods of scoring a liner include applying a metal containing substance, such as a metal foil or a metal ink, directly to the liner, and then exposing the liner to an induction field. 
     Referring now to FIGS. 4-6 of the drawing, the dispensing assembly of the invention, shown generally by reference numeral  3 , is mounted to a dispensing opening in carton  1 . Carton  1  includes side walls  42 , end walls  43  and top flaps  40  and  41 . The carton bottom is defined by similar flaps which are folded over and adhered to each other (not shown). 
     A sealed plastic liner bag  15  with particulate product such as RTE cereal is in carton  1 . Access panel  5 , which is perforated on three sides from end wall  43  so as to pivot around axis  2 , carries the pour spout which includes front panel  6  and side panels  7  (FIG.  3 ). Access to pour spout  3  can be gained by removing strip  5  between perforated lines  4  via pull tab  5 ″ thus exposing an upper portion of front panel  6  (FIGS.  4  and  5 ). Alternatively, panel  5  can abut a cut line in end wall  43  which can be covered by a peal off tape which can be removed for initial opening of the pour spout  3 . Resealable peel-off tape can cover panel  5  and the surrounding areas to insure freshness. 
     In the embodiment shown in FIGS. 1-3, the pour spout assembly has side panels  7  joined to front panel  6  along fold lines  31 . Side panels  7  have stepped portions  7 ″ and ears  38  which interact with end wall  43  and cuts  2 ″ to define the open and closed positions of the pour spout. Side panels  7  have curved embossed areas  7 ′ to stiffen or reinforce the panels  7  for closing the pour spout and diagonal embossed lines  8  to allow the stepped portions  7 ″ to flex if necessary to fit between side wall  42  and end wall  43  at  2 ″. 
     Front panel  6  in integral with fitment  100  via panel  104 . Fitment  100  has upper and lower margin portions  111  and  105 , respectively, side members  102  and a cut-out piece having a central section  126  and vertical side pieces  127  which extend into side members  102  (FIG. 1B) to define dispensing opening  109  along line  131 ′ as shown in dotted lines under bonding member  9  (FIG.  2 ). 
     Front panel  6  has a tab  306  which releasably interlocks with tab  112  and panel  114  having slits  114 ′ of upper margin portion  111  when spout panel  6  is folded over fitment  100  (FIG.  2 ). 
     In one embodiment, upper margin portion  11  can have laterally extending flexible tabs (now shown) that interact with stepped portions  7 ″ and cut-outs adjacent ears  38  (not shown) to hold the spout in the open and closed positions. Ears  38  prevent pull-out of the spout. Stepped portions  7 ″ slide through cuts  2 ″ in end wall  43 . 
     When the pour spout is folded over fitment  100  (FIG.  2 ), connecting panel  104  ties on top of lower margin portion  105  and front panel  6  covers central section  126  of cut-out  126 / 127  and pivots at line  6 ″ which is aligned with the bottom of opening  109 . Oval cut-out  104 ′ along line  6 ″ facilitates flexing and bending of the pour spout. Side members  127  are folded at right angles to panel  6  and cut-out  126 / 127  fits into dispensing opening  109  defined by fitment  100  when the pour spout is closed. 
     The pour spout and fitment can be spot or hard glued to the interior of carton end wall  43  via upper portion  111  and lower portion  105 . One side member  102  can be wider to provide an area  102 ′ (FIGS. 1A and B) to spot or hard glue to the interior of carton side  42  before the carton is erected. This insures that side members  102  will stay flat against the interior side walls of the carton when erected so as not to interfere with the insertion of a filled and sealed bag. 
     The top of opening  109  is V-shaped and the upper corners provide areas of reduced resistance to initiate separation of the liner bonded to cut-out  126 / 127  from liner  15  itself. 
     A preferred bonding member  9  (FIGS. 1A and 2) is a metal foil laminate having an outer member  131  and an inner member  133 . As shown in FIG. 8D, a preferred member  9  includes a layer of metal foil  9   a  such as aluminum foil or vacuum metalized aluminum adhered to polyester layer  9   b . Adhesive layers  9   c  and  9   e  flank both sides of the polyester/foil laminate. Linear low density polyethylene adhesive layers define the outermost layers  9   d  and  9   f . The overall thickness of member  9  is about 5 mils. 
     Bonding member  9  can be adhered to fitment  100  in a number of ways. It can be fully glued in place using a pressure sensitive, heat activated or other adhesive. It can also be spot glued for later full gluing by actuating adhesive layer  9   d  or  9   f  at the same time the other layer is bonded to liner  15 . 
     Margin portions  111  and  105  and side members  102  surround opening  109 . Inner member  133  corresponds to opening  109  and is connected to outer member  131  via perforation line  131 ′ about the periphery of opening  109 . 
     Inner member  133  has score lines  134  and  134 ′ in the shape of inner member  133  to concentrate heat for bonding around the periphery of line  131 ′. This creates a weakened seal line in the area of line  131 ′ to facilitate initial opening of the pour spout, especially at the upper comers of opening  109  where cut-out members  126  and  127  meet along fold line  101 . 
     Outer member  131  has a series of graduated fingers or cuts  132  which help to distribute bonding heat over the area of member  131  and away from the outer edges to prevent the formation of weak spots when liner  15  is bonded to the area surrounding opening  109  to maintain alignment of the liner with the pour spout. Fingers  132  also cooperate with score lines  134  and  134 ′ to concentrate bonding heat along line  131  &#39;to form a thinner or weakened tear line in liner  15 . In the embodiment shown in FIG. 7, liner  15  is bonded to outer member  131  in an area between fingers  132  and line  131 ′ and to inner member  133  in the areas defined by line  131 ′ and score lines  134  and  134 ′. In order to bring liner bag  15  into contact with pour spout  3 , referring to FIGS. 13A and B, a filled carton is passed through enclosure  70  via air locks  72  and  73  which maintain an area of reduced pressure in enclosure  70  via vacuum pump  71 . Because sealed liner bag  15  contains atmospheric air, the application of a vacuum has the effect of inflating liner bag  15  forcing it tightly against the interior of the carton and fitment  100 . See, FIGS.  7  and  8 -A-C. While in this state, the carton  1  enters a heat sealing zone provided with an induction heating device  21 . A suitable induction heater is a Model XP20 made by Ameritherm Inc. 
     To insure that liner  15  reaches into the comers formed when cut-out side members  127  are folded at a right angle to center section  126  along line  101  (FIGS.  1 A and B), means can be employed before a carton enters vacuum enclosure  70  to put pressure on the product in liner  15  to cause it to settle neatly into the comers. For example, plunger means can be used to force the sealed liner into the recesses of the carton before closing the top or bottom of the carton. Such liners are normally filled with product leaving such head space which allows the use of a plunger without damaging the product. 
     After a carton is sealed it can be placed on edge, pour spout down, and passed thru a shaking station such as a conveyor belt running over a series of eccentric rollers or wheels. This is effective to cause the product to settle and push the liner into the recesses of the pour spout assembly. 
     A sealed carton can also be squeezed at the sides before or in enclosure  70  using the head space to protect the product and force the liner into the corners of the pour spout assembly. 
     Heat delivered via induction heater  21  heats inner and outer members  131  and  133  which in turn activates adhesive layers corresponding to layers  9   d  and  9   f  of FIG.  8 D. Adhesive layer  9   d  adheres member  9  to cut-out  126 / 127 , side members  102  and margin portions  105  and  111 . See FIGS. 1A and B. Because heat generated by foil layer  9   a  becomes concentrated as shown and described in FIG. 7, a thinning of liner  15  occurs at  128  (FIGS. 8B and C) around the edges of cut-out  126 / 127  to facilitate initial opening of the pour spout. While liner  15  is thinned along line  131 ′, the seal of the bag is not broken until the pout spout is opened by the consumer. 
     To open the pour spout of FIGS. 1-7, tab  5 ″ is pulled to remove section  5 ′. This exposes tab  306  of front panel  6  which extends above access panel  5 . Insertion of one or more fingers behind tab  306  will cause the liner to begin to tear at the upper comers of center section  126  where they join side sections  127  along fold line  101 . Continued pulling separates panel  5  along lines  2 ′ and the liner along line  131 ′ until it reaches the bottom comers of center section  126  when the spout is fully open. Liner  15  remains connected to outer member  131  where it is attached to side members  102  and margin portions  105  and  111 . 
     In the embodiment shown, spout side panels  7  pivot in and out between a narrow space defined by side members  102  and carton side walls  42  without coming into contact with liner  15 . 
     Upon closing of the spout, cut-out  126 / 127  fits neatly back into dispensing opening  109  defined by side members  102  and margin portions  105  and  111  of fitment  100  to minimize invasion of exterior air. When closed, recess  7 ″ of the side panels slip behind cuts  2 ″ to maintain closure of the spout. For added holding power, tab  306  interlocks with members  112  and  114  providing a “snap” closure to insure freshness. 
     To demonstrate that the embodiment shown can maintain freshness, moisture gain tests were conducted with Froot Loops® in a standard, top entry bag-in-box package and in a pour spout package of FIG.  5 . All packages used the same liner used for standard package Froot Loops®. Accelerated tests were conducted at 100° F. and 70% relative humidity for 2 weeks. Three samples were used for each test. 
     The standard package liners were well reclosed (folded over as many times as possible and creased); fairly reclosed (folded over as many times as possible but not creased); and poorly reclosed (pushed back in the package and left partially open). 
     All packages were samples initially for moisture content and again after 1, 2, 4, 7, 10 and 14 days to simulate how a consumer would consume the cereal. The percent of moisture gain was measured against the initial moisture content and is reported in the following table: 
     
       
         
           
               
               
               
             
               
                   
                 TABLE 
               
               
                   
                   
               
               
                   
                 Package 
                 Moisture Gain 
               
               
                   
                   
               
             
            
               
                   
                 Standard package poorly reclosed 
                 4.0% 
               
               
                   
                 Standard package fairly reclosed 
                 3.3% 
               
               
                   
                 Standard package well reclosed 
                 2.9% 
               
               
                   
                 FIG. 5 pour spout package reclosed 
                 2.7% 
               
               
                   
                 with recesses 7″ and Tabs 112 and 
               
               
                   
                 306 
               
               
                   
                 FIG. 5 pour spout package reclosed 
                 2.9% 
               
               
                   
                 with recesses 7″ only 
               
               
                   
                   
               
            
           
         
       
     
     Thus, without using closure tabs  112  and  306  (which is the normal way of reclosing the pour spout of the invention), moisture gain equals the most careful way of reclosing a standard package. The FIG. 5 pour spout package using the closure tabs is better then all three ways of closing a standard package. 
     FIGS. 9-12 show an alternate embodiment wherein pour door  202  with a recessed center section  203  snaps into frame  204  which is mounted to a dispensing opening  214  in end wall  43  of carton  1 . 
     Metal foil laminate  205  (similar to member  9 ) is perforated along line  205 ′ and is adhered to the interior of end wall  43  over opening  214 . 
     Liner  15  is adhered via laminate  205  using the process of FIG. 19 to the interior end wall  43  surrounding opening  214  and to recessed portion  203  of door  202 . When pour door  202  is lifted up the first time, portion  15 ′ separates from liner  15  along line  205 ′ providing access to the contents thereof. Initial separation of portion  15 ′ takes place where opening  214  is pointed (at  206 ) which offers less resistance than trying to tear an entire side at one time. 
     Liner  15  and its contents remain aligned with opening  214  because the liner  15  is adhered via member  205  to end wall  43  around opening  214 .