CA1172487A - Method of forming a corner on a paperboard carton blank - Google Patents
Method of forming a corner on a paperboard carton blankInfo
- Publication number
- CA1172487A CA1172487A CA000401906A CA401906A CA1172487A CA 1172487 A CA1172487 A CA 1172487A CA 000401906 A CA000401906 A CA 000401906A CA 401906 A CA401906 A CA 401906A CA 1172487 A CA1172487 A CA 1172487A
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- Canada
- Prior art keywords
- carton
- carton blank
- blank
- sealing
- panels
- Prior art date
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Abstract
Abstract of the Invention A one-piece T-shaped carton blank is disclosed which is utilized to form a rectangular cross-sectional container having its top and bottom end panels sealed in a plane substantially perpendicular to its sidewalls. The carton blank is formed having a definite dimensional relationship between its end panels and side panels to provide improved nesting of multiple carton blanks upon paperboard sheet stock in an alternating inserted side-by-side relationship. A pair of end sealing tabs extend along the top and bottom edges of the blank side panels. One of the end sealing tabs is separated from the top end panel and from a side sealing tab to prevent tearing and to permit the complete welding of the side sealing tab up onto the top end closure panel of the carton blank. This separation of the end sealing tab in combination with displacement of the hinge line of the top end closure panel downward provides a liquid-tight corner seal for the carbon. Further, an improved method of scoring and bending of the carton blank is provided.
Description
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ac~ro~nd-of the Invention The ~resent invention relatPs to paperboard ~` 5 containers for potable liquid and more paxticularly to rectangular cross-sectional containers formed from a one-piece substantially T-shaped blank of polyethylene coated paperboard. Such containers are generally of the type shown in ~nited States Patent No. 3,749,3309 granted 10 July 31, 1973, to Charles W. Jones, United ~tates ~Patent No. 4,084,489, ~ranted April 18, 1978, to ;`~Matovich, Jr., and Canadian Patent ApPlicatio~-Serial No. 316,8B2 f~led November ~7, 1978, b~ Josef Buschor.
The distinguishing charactexistics of these cartons are 15 their inclusion of a straw element within the interior of ~he carton blank which, during opening of the carton, may ke ro~ated to expose one end of the straw element from which the contents of the carton may be drawn, and the deposition of the top and bottom end p2nels of 20 the carton substantially perpendicular to the sidewalls. Such characteristics provide convenience and sanitary usage of the contents of the container while permitting more efficient use of paperboard ma~erial and yielding improved carton stac~ing for 25shipment.
Although these containers have provided a ~ignificant improvement over prior art gable top container ~esigns, they have possessed certain stxuctural and fabrication deficiencies which have prevented their widespread use 30in the industry. These deficiencies have focused upon mat~rial loss or waste in the nesting of multiple carton blanks upon the sheet stock from which they are derived, ~ tendency for leakage at the top corner ~eals of the ~arton, and damage to the carton blank paperboard 35during the scoring and bending of the carton blank.
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ac~ro~nd-of the Invention The ~resent invention relatPs to paperboard ~` 5 containers for potable liquid and more paxticularly to rectangular cross-sectional containers formed from a one-piece substantially T-shaped blank of polyethylene coated paperboard. Such containers are generally of the type shown in ~nited States Patent No. 3,749,3309 granted 10 July 31, 1973, to Charles W. Jones, United ~tates ~Patent No. 4,084,489, ~ranted April 18, 1978, to ;`~Matovich, Jr., and Canadian Patent ApPlicatio~-Serial No. 316,8B2 f~led November ~7, 1978, b~ Josef Buschor.
The distinguishing charactexistics of these cartons are 15 their inclusion of a straw element within the interior of ~he carton blank which, during opening of the carton, may ke ro~ated to expose one end of the straw element from which the contents of the carton may be drawn, and the deposition of the top and bottom end p2nels of 20 the carton substantially perpendicular to the sidewalls. Such characteristics provide convenience and sanitary usage of the contents of the container while permitting more efficient use of paperboard ma~erial and yielding improved carton stac~ing for 25shipment.
Although these containers have provided a ~ignificant improvement over prior art gable top container ~esigns, they have possessed certain stxuctural and fabrication deficiencies which have prevented their widespread use 30in the industry. These deficiencies have focused upon mat~rial loss or waste in the nesting of multiple carton blanks upon the sheet stock from which they are derived, ~ tendency for leakage at the top corner ~eals of the ~arton, and damage to the carton blank paperboard 35during the scoring and bending of the carton blank.
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With reference to the material wastage during fabrication of the carton blanks, the prior art, such as Matovich, Jr.~ Pat. No. 4,084,489, has disclosed a 5 carton blank in which the width across the side panels and end sealing tabs has been substantially greater than the combined width of the end closure panels.
This dimensional relationship has required the carton blanks to be nes~ed upon ~he shee~ s~ook from ~hich they 10 are produced, in a manner whereby the carton blanks are ~eparated from one another. By such separation r voids are formed between adjacent carton blanks upon the sheet ~tock~ which results in substantial sheet stock waste and decreases machine cutting speed operation.
The corner leakage tendency of the prior art cartons has been caused primarily due to the inclusion of V-shaped notches upon the sealing tabs of the blank which has resulted in the raw cut edges of the sealing tab beiny located at the corner junctions of the side 20 panels with the end closure panels of the container~
These raw cut corners are subject to being wetted by the contents of the carton and yield small discontinuities in the sealing surfaces which has been found to prohibit the effective sealing of the end closure panels thereto~
25 Thus, the prior art carton has ~een subject to moderate leakage at the top corner junctions between the end panels and side panels~
Additionally, the prior art carton blank design has heretofore prohibited the side sealing tab from being 30 sealed onto both the top and bottom end closing panels of the carton. As such, during the subsequent end sealing operation of the end closure panels to the side panels, a ~mall inconsistency'or flow channel ha~ been present in the corners of the carton adiacent the end panel/side 35 sealing tab junction which often allowed small amounts of the ~ontents of the carton to be released during shipping and handling.
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To facilitate fo~nation of the carton, the p:rior art carton blank has been pre-scored to provide preferred bending line~ about which the carton is articulated.
~er~tofore, the bending of the carton blank was accomplished in a direction away from the scoring line, i. e., such that the carton blank breaks away from the score lines. This bending produced a bulging effect at the corners of the container and 10 res~lted in the rupturing of the paperboard fiber during tha bending process which detracted from the overall appearance of the container~ as well as o~tentimes fracturing the p~lyethylene coati~g of the caxton blank making the container subject to absorbtion 15 of the contents therein.
Thus, there exists a present need in the art for a carton blank wherein material wastage is mai~tained at a minimum, the coxner areas of the carton are eliminated from raw cut edges, and the scoring and bending of 20 the carton blank is adapted to eliminate rupturing of the fibers of the paper stock material.
Summ~y of the Pr~ t ln~cl~lc~
The present in~ention comprises a carton blank and an improved ~ethod of forming a carton of the type 25 hereinbefore identified, which significantly eliminates the structural and fabrication deficiencies of the prior art. Particularly, the carton blank of the present invention and carton formed therewith, is ~pecifically designed to obtai~ maximum content volume with a minimum 30 usage of paperboard stock. In this regard, the carton blank of the present invention is formed having a definike dimensional reIationship between the side panels and sealing tabs of the carton blank to the end closure panels which permits multiple carton blanks to nest 35 together in an inverted side-by-side orientation upon the paperboard stock and be cut therefrom, with a minimum . .
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of material scrap and a maximum cutting machine operation ` speed. As such, an optimum num~er of carton blanks may be produ~ed from the paperboard sheet stock using existing machine technologyO
In addition, the presen~ invention eliminates the V-shaped notches previously formed on the sealing tabs of the ~arton blank. Rather, ~he sealing t~bs of ; ~he carton blank of ~he present invention are formed 10 continuou~ throughout their length and diagonally scored ; in the vicinity of the corner fvlds of the side panels, thereby bein~ adapted to be folded inward to reside within the interior o~ the carton. By ~uch a design, the end closure panels may be ~ealad directly to the unbroken ; 15 perimeter edges of the sealing tabs even in the sidawall corner areas of the container, rather than upon ~he raw edges her~tofore utilized in the prior art. It has been found that such corner formation greatly increases the strength of the seal in ~he corners of the container, : 20 thU5 yielding a liquid-tight carton-Furtherr in ~he present invention, the side sealing tab is relocated upon th~ opposite end of the carton blank (com~ared to that disclosed in Matovich~ Jr., Pat. No~ 4,084,489, and is increased in length over the 2S prior art configuration to extend partially onto both end ' closure panels. By ~uch a configuration~ the side sealing tab may be sealed throughout its full length and onto both the top and bottom closing pane~s which, during the subsequent ~ealing of the end closure panels to the side panels, has been found to eliminate'the rear corner leakage experienced in ~he prior art designs.
In contradistinction to the methods heretofore utilized throughout the'industry, the'pre~ent invention contemplates' the'novel method of forming scoring lines upon the in~erior of the carton blank and subse~uently bending ~he'carton blank to break into the'score line.
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r : 5 This inside breaking of the carton blank eliminates the unsightly bulging effect at the oorners caused by the rupturing of the fiber of the paperboard stock 2nd yields a crisp corner whexein the fibers of ~he paper stock are compressed within the score line.
In addition, the present invention discloses a displaced hinge line for the top end closure panel of the car~on which ~urther eliminates the tendency of the 10 car~on to leak in its rear corners, as well as discloses alternative embodiments for the actual carton produced : . by the improved carton blank of the present invention which are specifically suitable for various li~uid and powdered contents.
Descri~tion of the Drawin~s These and o~her features of the present invention : become more apparent upon reference to the figures .~ wherein:
~igure 1 is a plan view of the improved carton 20 blank of the present invention illustrating its preferred configuration and the location of the scoring lines thereon;
Figure 2 is a plan view of a portion of the sheet - s~ock web from which the carton blank o Figure 1 is 25 derived showing the improved nesting of multiple ~arton blanks thereon;
Figure 3 is an enlarged perspective view of the top end portion of the carton formed from the carton blank of Figure 1 with ~he top end closure panel raised above .
30 the continuous sealing tab;
Figure 4 is an enlarged partial cross-sectional view of the upper rear corner of the carton of Figure 3 ; depicting the orientation of the end closure panel, side panel, end sealing tab, and side sealing tab prior to 35 the end sealing process;
Figuxe 4A is a partial perspective view of one of the forward corners of the car~on blank produced fxom the .~
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: .6 . . , .. ~ carton blank of Figure 1 depicting the inward folding of a portion o~ ~he continuous end æealing tab;
. Figure 4B is an enlarged partial cross-sectional 5 view of the upper rear corner of the cæ~on blank of Figure 3 illustrating the configuration of the junction of the end closure panel, side panel, end sealing tab, and side sealing tab subsequent to the end sealing process;
Figure 4C i5 a partial perspective view of the orward corner of the carton blank in Figure 4A depicting îts configuration subse~uent to the end sealing process;
Figure 4D is an enlarged parspective view of the ~arton formed ~rom the carton bl~nk o~ Figuxe 1 showing ~ 15 the displaced hinge line of the top end closure panel;
:` Figure 5~ is a cross-sectional ~iew of a portion of a carton blank illustrating the formation of a scoring line heretofore utilized in the prior art;
Figur~ 5B is a cross-sectional view o the prior art .~ 20 method of bending of the carton blank of Figure 5A about the scoring line;
Figure 5C is a partial cross-sectional view of a : portion of a carton blank illustrating the formation of a scoring line thereon as utilized in the present invention;
Figure 5D is a cross-sectional view o the present invention's method of bending of the carton blank of Figure 5C about the scoring line;
Figure 6A is a perspective view of the carton produced with the preferred carton blank of Figure 1 ha~ing a straw element and tape seal applied thereto;
Figure 6B is an alternative e~bodiment for a carton having a straw element and tape seal disposed on its top end closure panel;
Figure 6C is an ~lternative embo~iment for a carton having a tape seal disposed on its top end closure panel;
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Figure 6D is a perspective view of the car~on of the present invention formed withbut a s~raw elemen~ or tape ' seal thereon.
Detailed Description of the Preferred Embodiment .
Referring to Figure 1, there is shown ~he carton blank 10 of the present invention preferably formea from - thin paperboard stock, coated with a layer of polyethylene ': material which is impervious ~o the o3ntents ~o be placed 10 in the container~ The carton blank 10 is formed in substantially T-shaped configuration having an elongate , central portion 12 and a pair of end panels 14 and 16 ~hich are integrally connected to the elongate section : 12 adjacent one end thereof.
The elongate section 12 is composed of four sidewall ,. panels 20, 22, 24~ and 26, which are delineated by a plurality of scoring lines 28 extending transversely across the section 12. These scoring lines 28 are preferably formed as indentations on the side of 20 the carton blank 10 which will subsequently form the interior sux~aces of the container~ and selectively weaken the carton hlank to yield preferential folding lines about which the carton blank may be articulated.
A pair of end sealing tabs 30 and 32 extend 25 continuously along the opposite end edges of the side panels 20, 22, and 24 and are formed by the respective ~coring lines 34 and 36. The side panel 20 is additionally provided with a side sealing tab 38 at its distal edge, formed by the scoring line 40 which 30 extends throughout the length of the side panel 20. In the pxeferred embodimen~, the end sealing tab 32 is integrall~ connected at its opposite ends to the end ,~ ~losure panel 16 and side sealing tab 38,,whereas the end sealing tab 30 is separated or severed from the ena 35 closure panel 14 and side sealing tab 38 by cuts or ~
slits 42 a~ 43., respe~i~ely, extending throughout the height of the end sealing tab 30.
Each of the end sealing tabs 30 and 32 are provided : with a plurality of diagonally extending score lines 44 which initiate at the intersection of the scoring lines 28 with the scoring lines 34 and 36, ~espectively, and terminate at the distal edge of the sealing tabs 30 and 32. A~ sho~n, these diagonal scoring lines 44 on the end sealing tab 3~, are formed only on the side panels 20 and 24, whereas for the end sealing tab 30, they are provided 1~ on each of the ~ide panels 20, 22, ænd 24. ~inally, the side panel 26 may additionally be provided with an aperture 48 which provides access to the interior o:E
the carton ~ and ~ealingly receives the straw element and tape length ~shown in Figure 6A).
The end panels 14 and 16 are integrally connected to the side panel 26 at opposite ends thereof, and are formed in a generally square configuration. The end closure panel 16 is delineated from the. side panel 26 b~
a scoring line 50 which extena~ from the edge 25 of the 20 side panel 26 terminating at a location spaced fxom the aperture 48, and is aligned with the scoring line 36 fonming the en~ sealing tab 32. The end closure panel 14 is delineated from the side panel 26 by a scoring line 52 which extends only through the central portion of the 25 5ide panel 26 terminating short of the edge 25 and short of the scoring line 28 formed between the side pane~s 26 and 24. As will be noted, the scoring line 52 is not aligned with the scoring line 34 which forms ~he end ~ealing tab 30, but rather is displaced inwardly a 30 short distance E along the length of the side panel 26.
The end closure panel 14 is addi$ionally formed slightly larger in size than the end panel 16 extending a short distance F outward beyond the edge 25 and score line 28 of the side panel 2S. The oversized portion 3s of the end panel 14 extending beyvnd tne ed~e 25 of the carton blank foLms a protruding section 54; the length of which extends inboard beyond the edge of the sealing tab 4 ~ ~
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g 30 represented by the distance "G" in Figure 1.
In the preferred embodiment, a definite dLmensional ; relationship is maintained between $he length "A" and "B"
of the en~ panels 14 and 16 to the length "C" ffl the side .` panels 20, 22, 24, and 2~ and the length ~D" of the end sealing tabs 30 and 32~ In particular~ t~e carton blank :~ 10 is formed such that the sum of the distances A and B
which the end panels 14 and 16, respectivel~, extend 10 beyond the edges of the end sealing tabs 30 and 32, is e~ual to the sum of the length dimension C of the side panels 20, 22, 24, and 26, and the height dimension D
of each of the end sealing tabs 3 0 and 32 . That is, : A ~ B = C ~ 2D. By this particular dLmensional 15 relationship, the carton blank 10 may ~e nested and cut from a web of sheet stock material with minimum material wastage yielding o~timum utilization of material stock.
The improved nesting ~haracteristics made possible -- by the carton blank 10 of the present invention may be ~; 20 seen upon reference to Figure 2 wherein a plurality of ~arton blanks 10 are disposed in a patterned array upon ~ a web of shee~ stock material 60. The carton blanks 10 are pre~erably arranged in a plurality of horiæontally extsnding rows, e~g., in Figure 2, blanks lOA, lOB and 25 lOC being in one row, while blanks lOD and lOE are in a ~econd row, and blanks lOF, lOG, and lOH are in a third i row. Adjacent carton blanks lOA, 10B, and lOC, in each row, are disposed in a side-by-side orientation with their respective end closure panels 14 and 16 abutted along a 30 single cutting line 62~
A9 shown, the CartQn blank rows are arranged vertically along the sheet stock 60 to form a plurality of nested pairs of rows, with the second carton blank row in each pair (comprising carton blanks lOD and lOE in 35 Figure 2) being inverted with respect to the fir~t carton ; blank row (comprising blanks lOA, lOB, ~nd lOC). A5 ~uch, ad~acent carton blanks lOA, 10D, lOB, lOE, and lOC in each ~ ~7~&~
-pair of rows are alternativPly upright and .inverted along the web of sheet stock 60.
Due to the combined width (C and 2D) of the side panels 20, 22, 24, and 26 and sealing tabs 30 and 32 being equal to the combined width of the end closure panels ~A and B~ ~ the elongate sections 12 sf each of the carton b}ank~ 10 arranged in the inverted rows, a~ut each other along the lines 64A and ~4B, 64C and 64D, which 10 may be xeferred to as an abutment axis.
: In addition to the inverted alternative row orientation of the carton blanks~ each horizontal pair ~ of rows is positioned upon the web 60 such that the : protruding portion~ 54 of the end closure panels 14 in 15 the second inverted row of one pair abut the protruding portions 54 of the ~irst row in the next pair along a common diagonal edge 72. This abutment at the edge 72 causes each pair of rows to be hori20ntally offset or staggered from the next pair of rows by a distance "0"
20 equal to twice the distance "G" that the protrudin~
section 54 extends inward beyond the edge o the sealing tabs 30.
By this alternate inverted xow and offset carton blank ne~ting pattern, the carton blanks 10 lie tightly 25 nested in a side-by-side orientation thereby eliminating the substantial voids formed on the sheet s~ock 60 b~
the prior art carton blank configurations. As suchr the scrap material on the web 60 of the present invention consists only of the minimal material 66 and 68 lying 30 adjacent the end closure panels 16 of each of the carton blanks 10 which rspresents the size differential "F"
(Figure 1) between the end closure panels 14 and 16 as well as a small border ~ection 70, fonmed along the edges of the webbing 60 which can be reduced substantially to nothing 35 by proper selection of the web siæe. Considering that the carton blanks 10 form non-reusable containers9 and will typically be supplied in vast quantities, such savings in the amount of scrap or waste material :Erom the web of sheet stock 60 is very important from the standpoint of overall cost effectiveness of the carton.
As will be recognized, by the specific nesting configuration depicted in Figure 2, the individual - carton blanks 10 may be fabricated from a roll stock . webbing 60 with a minimum of material wastage as well : as a ninimum of cuttings upon the sheet stockD Thus, ` as the webbing 60 is fed into one of the well~known stamping apparatus (not shown), a maximum number of car on blanks may be produced for a particular webbin~
and machine operational speed.
Referring to Figure 3, the improved sealing : characteristics made possible by the carton blank 10 : 15 of the present invention will now be described~ As will be recognized, ~he car~on depicted in Figure 3 is formed from the carton blank 10 by a series of folding~ bending, and sealing steps. The first of these steps is the bending of the side panels 20, 22, 24, and 26 about the .`. 20 scoring lines 28 as well as ~he bending of the side sealing tab 38 about the scoring line 40 to reside on . the interior surface of the side panel 26, Once in this :~ configuration, the side sealing tab 38 may be sealed as by way of the application of heat,to the interior of the side panel 26 thereby maintaining the open ended sguare tubular configuration, depicted in Figure 3.
It i8 an important featuxe of the carton blank 10 of the present invention that the side sealing tab 38 is bonded or sealed throughout its entire length including the ~mall portlon 38A which extends upward onto the interior surface of the top end closure panel 14 and a corresponding small portion 38B ~Figure l) which similarly extends onto the interior surface of the bottom end closure 16~ In the preferred em~odiment, the side sealing operation is performed on an interior mandrel tnot shown) which is additionally utilized to permit the bottom end closure panel ~ 6 (not shown in : Figure 3) to be sealingly bonded across khe lower end ~ealiny tab 32 (Figure 1) which has been previously folded inward the end closure panel 16 thus forming the bottom surface (not shown~ of the carton 10. The apparatus and method or forming the carton blank 10 into such a configuration i5 disclosed in Canadian Patent A~plic-ation, Serial Number 356,428, filed July 17, 1980, by . the same applicant entitled MæTHOD AND APPARATVS FOR
13 FORMING A CONTAINER FOR LIQUIDS. It should be recognized tha~ the size differential ~etween the : bottom and top end closure panels 16 and 14, resPectively, the differing locations of the diagonal scoring lines 44 on the botto~ and top sealing tabs 32 and 30, and the inclusion of the slits 42 only on the top sealing tabs 30, are specifically designed to augment the . interior mandrel sealing of the bottom end pan~1 ~6 as opposed to the exterior mandrel sealing of the top end panels 14, since the many structural ana formational problems encountered in exterior mandrel sealing are not present in interior mandrel sealing.
Subsequent to the side sealing and bottom end sealing o~ the carton blank 10, the top end sealing tab 30 is folded over to reside withLn the ~nterior of the square tuhular carton configuration and extend generally perpendicular to the upper portion of the side walls 22, 24, and 26 ~shown in Figure 41. Due to the top end sea~ing tab 30 being separated from the end closu~e panel 14 and side sealing tab 38 by the cuts or slits 42 and 43 ~Figure 3), the sealing tab 30 may be folded over throughout its length without tearing and without : disturbing the seal betwe~n the end closure panel 14 and the upper portion 38A of the side sealing tab 38.
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As shown in Figure 4A, during.this fold-~ver process, the diagonal score lines 4~ formed at the intersection of the sealing tab 30 with the corner-forming score lines 5 28, permit the portion 31 of ~he sealing tab 30 lying between adjacent diagonal score lines 44 to be p~shed -. inward below the main plane of the sealing ta~ 30. By such a design, the top sealing tab 30 is maintained continuous throughout its length having a miter-like 10 interface 41 at its corner junctions with the sidewalls 20, 22t and 24. With this miter-like interface, the present invention eliminates the prior art's raw cut edge in the immediate vicini~y of the corner junction of the s~aling tab 30 which heretofore was subject to 15 being wetted by the contents of the container and substantially weakened the top end seal.
Subsequent to the inward ~olding of the seallng tab 30, the sealing tab 30, as well as the extreme upper portion of the sidewalls 20, 22, and 24, are beveled 20 outward to lie exteriorly of the remaining portion of the sidewalls 20~ 22, and 24 through a short distance of approximately 1~8 of an inch ~designated by the distance "H" in Figure 4B). As will be recognized, this outward beveling is accommodated in the vicinity of the - 25 forward corners of the carton by the sealing tab 30 and the upper portion Gf the sidewalls of the carton stretching outward due to an internal thinning flow of the paperboard carton material. As shown in Figur~
4C, this thinning flow causes the miter~like interace 30 41 to be inwardly spaced by a distance S from the outermost edge of the ~orward corners, which, as will be exp}ained in more detail below, per~its an effective top seal to be formed across the sealing tab 30, even in the vicinity of the forward corners of the carton 35 blank. Additionally, this outward be~el~ng permits the upper end of the carton blank 10 to be supported by an exterior mandrel 80 ~represented by the phantom ~ ~ 2~&~
line in Figure 4B) which may be positioned along the three sides of the carton ~lank 10 corresponding ~o the side panels 20, 22, and 24. Additionally, as shown in 5 Figure 4B, during this beveling process, the portion of the sealing tab 31, lying between the diagonal score lines 44, is folaed further beneath the sealing tab 30, assuming a position generally parallel to the angular plane of the sealing tab 30 located on the side panel 10 20.
With the carton blank 10 supported against the exterior anvil 80, the top end closure panel 14 may be forced downward to lie in a plane subs~antiaily perpendicular to the open end of the carton blank 10 15 as by way of a die 82 (represented by the phantom lines in Figure 4B). By the application of this downward force, the perimeter edges 14A of the end : panel 14 are beveled angularly upward between the die 82 and the anvil 80 to ext~nd along and overlay 20 the length of the sealing tab 30, wherein they may be sealingly bonded ~hereto by the application of heat.
Further, due to the miter-like interface 41 being spaced from the outer edge of the sealing tab 30 (shown in Figure 4C), a portion of the perimeter edges 14A of 25 the end closure panel 14 extends outward beyond the interface 41 to positively seal against the sealing tab 30 and close off the inter~ace 41 thereby significantly reducing the possibility of forward corner leakage.
Referring conjunctively to Figures 3 and 4D, it is shown that during the fold-over and end closure panel 14 sealing process, the end closure panel 14 pivots about the scoring line or actual hinge line 52 which, : a~ previously mentioned, is displaced or dislocated downward along the length of the sidewall panel 2 6 35 from its natural or apparent h~nge line 53 (represented by the phantom lines in Fi~ures 3 and 4D). Due to this displaceme~t, the natural hinge line 53 is positioned ;' .~ ~ 72~
- ~orward and above the relatively broad ~ealing surface ~f the end sealing tab 30. Additionally, the slits .~ ~2 and 43 located at the interseetion of ~he top end ~ealing tab 30 with the end closure panlsl 14 are forced forward to be displaced from the-actual rear corner of the carton and lie upon the sealing tab 30O
As such, the slit8 42 and 43 may be tightly ~closed off" between end closure 14 and sealing tab 30 by the 1~ pressure exexted between the anvil 80 and die B2 .~ during the end sealing procedure~
Additionally, due to the upper portion 38A of thle side sealing tab 38 being previou~ly sealed onto the end closure panel 14 during the fold~over procedure, 15 the portion 38A overlays the cut or slit 42 formed on the sealing tab 30. Thus, the raw cut edge of the cut or slit 42 is covered by the continuous length of th~.
portion 38A which extends from the ~idewall panel 26 onto the end sealing tab 3 O.
By this particular top end carton arrangement~ the application af heat during the sealing process causes all of the elements located in the right rear corner (as viet~ed in Figure 3), i~e~, the sealing tab 30, peri~eter edge 14A, upper portion 38A, and the u~per 25 end o~ the sidewall 20, to be sealingly joined together.
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Addi~ionally, due to the end sealing tab 30 being continuous throughout its length and including the miter-like interface 41 (Figure ~C) at the top frontal S corners of the carton, a liquid-tight seal between the perimeter edge 14A of the end Closure pa~el 14 and the sealing tab 30 may be facilitated, ~s s~ch, the top : seal leakage tendencies of the pxior art flat top cartons is substantially ellminatedo In addition to the improved ~ealing capabili~ies made possible by the improved carton blank 10, the present invention additionally diScloses a nov~l me~hod o~ scoring and bending of the carton blank which produces a crisp c~rner and eliminates damayë to the carton blank duriny fabrication.
In Figures SA and 5B~ an enlarged~ partial cross-sectional view of the method o~ sc~ri~g (Figure 5A) and bending (Figure 5B) a carton blank 100 in the prior art is depicted. AS shown, the carton blank 100 is scored by an indentation 102 which produces a corresponding protrusion 104 on the reverse side of the carton blank 100. Subsequently, the car~on blank 100 i8 bent away from the scoring line 102 in a direction indicated by the arrows in Figure 5B, yielding a corner coniguration ~imilar to that shown in Figure SB. As will be recogniæed, in this configuration~ the corner bulges outward at 103 beyond the exterior plane o~ the carton blank 100 due to the internal fibers of the carton blank material rupturing upon encountering the tension exerted during the ben~ing proce~3~ This rupturing of the fibers substantially weakens the carton blank 100 at the area of ~he bend and, in severe instances, causes a fracturing of the polye~hylene m~t~rial on the in~erior of the corner thereby subjecting thc car~on blank to absorbtion of thé ~luid contents.
In contradistinction, the present i~ve~ion contemplates the ~coring and bending of the c~r~on blank 100 in a 7 ~
manner depicted in Figures 5C and 5D wherein the scoring line 102 is formed on the opposite ~urface Si.e.~ the surace that will form the interior of the carton) of the carton blank 100 yielding an attendant protrusion 104 on the exterior side of the blank.
Subsequently, the carton blank 100 is bent inwardly about the score line 10~ in ~he direction indicated in Figure 5D. By ~his proceaure, the corner is formed substantially, as shown in Figure 5D, with the internal fibers of the carton blank material being compressed to reside within the indentation 102 while the outer corner ; configuration assumes the general preformed cuxvature of the protrusion 104. As such, a more crisp corner is provided which additionally eliminates the weakening of the carton blank 100 and the ~racturing of the polyethylene coatiny material on the interior of the carton blank 100.
In Figures 6A, 6B, 6C, and 6D, altexnative embodiments of the container, derived from the carton blank lQ of the present invention, are shown. In Figure 6A, a container 200 is shown which is fahricated ~rom the carton blank 10, shown in Pigure 1. As sh~wn, the aperture 48 po~itioned on the sidewall 26 is provided with the straw element 202 and sealingly covered by a length of tape 204~ In this embodiment, the tape 204 is preferabl~ ~ormed from a Mylar strip which is coated on its undersurface by a film of polyethylene. Due to the different melting temperatures between Mylar and 3a polyethylene, the tape length 204 may be heated to simultaneously ~eal against the exterior of the side panel 26 as weIl as a portion of the straw element 202.
Subsequently, when a user desires to open the container 200, the end portion of the tape length 204 may be grasped by the user and be peeIed or torn from $he side panel 26 whe~eby the straw element 202 is rotated upward and in position to withdraw the contents from the oontainer 200. As will be recognized, such a carton 200 is specifically sui able for pot~able liquids such as milk or fruit juices which are conveniently packed in single serving sizes and disposable after usage~ A more detailed discussion of ~he opening operations of such a carton is di~closed in Canadian Patent Application Serial No. 316,882 filed November 27, 1978, by Toseph Buschor.
In Figure 6B, an alternative embodiment for the container of Figure 6A is shown, wherein the aperture 48 is relocated upon the top end closure panel 14 and includes a straw element 212 disposed therein. In this embodiment, however, the straw element 210 is preferably sealed to the interior of the sidewall 26 and includes a resilient upper portion 214 which is disposed in a plane perpendicular to the remainder of the element. A length of tape 210 sealingly covers the aperture 48 and prevents the upper portion 214 of the straw element 212 from ~lexing outward from the container. In use, a user may peel off the tape length 216 from the end closure panel 214 thereby all~wing the resilient upper portion 214 of the ~traw element 212 to spring upward from the container whereby a user may easily withdraw the liquid from the container 210 or alternatively remove the straw element 212 and utilize the aperture 48 as a pouring spout. As such, with the carton 210 depicted in Figure 6B, a user may consume the contents directly from the carton 210 or alternatively pour the contents into a drinking glass or the like.
In Figure 6C, an additional embodiment of a carton 200 formed by a carton blank 10 of the present invention is shown, wherein the aperture 48 is disposed centrally upon the top end closure panel 14. As in the ~ther embodiments, the aperture 48 is sealed by a tape length 222 which is removable by the user. In this particular ~2~
, ;~ 19 embodiment, howevar, the straw element has been eliminated with the aperture 48 being used exclusively as a pouring spout. Thi~ particular embodiment of the carton ~20 is 5 suitable for large.size containers, such as that ~ypically uti}ized in the inaus~ry for marketing quart and half~gallon sizes of milk.
. AlternativeIy, in Figure 6D, a carton 230 is disclosed .~ wherein the aperture 48 has been completely eliminated.
By this design, the carton blank 230 is specifically adapted for various dry products which preferably are maintained in a safety container which may not be easily opened by the user~.
It will be understood that although the foregoing speci~ication has disclosed particular materials from which the carton blank is fabricated, alternative materials may be utilized withou~ departing ~rom the spirit of the present invention.r Also, while the description reers to certain orientation as ~he top and bottom, it will be 20 evident that this is only for convenience in description and does not lim~t the orientation.
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With reference to the material wastage during fabrication of the carton blanks, the prior art, such as Matovich, Jr.~ Pat. No. 4,084,489, has disclosed a 5 carton blank in which the width across the side panels and end sealing tabs has been substantially greater than the combined width of the end closure panels.
This dimensional relationship has required the carton blanks to be nes~ed upon ~he shee~ s~ook from ~hich they 10 are produced, in a manner whereby the carton blanks are ~eparated from one another. By such separation r voids are formed between adjacent carton blanks upon the sheet ~tock~ which results in substantial sheet stock waste and decreases machine cutting speed operation.
The corner leakage tendency of the prior art cartons has been caused primarily due to the inclusion of V-shaped notches upon the sealing tabs of the blank which has resulted in the raw cut edges of the sealing tab beiny located at the corner junctions of the side 20 panels with the end closure panels of the container~
These raw cut corners are subject to being wetted by the contents of the carton and yield small discontinuities in the sealing surfaces which has been found to prohibit the effective sealing of the end closure panels thereto~
25 Thus, the prior art carton has ~een subject to moderate leakage at the top corner junctions between the end panels and side panels~
Additionally, the prior art carton blank design has heretofore prohibited the side sealing tab from being 30 sealed onto both the top and bottom end closing panels of the carton. As such, during the subsequent end sealing operation of the end closure panels to the side panels, a ~mall inconsistency'or flow channel ha~ been present in the corners of the carton adiacent the end panel/side 35 sealing tab junction which often allowed small amounts of the ~ontents of the carton to be released during shipping and handling.
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~248~
To facilitate fo~nation of the carton, the p:rior art carton blank has been pre-scored to provide preferred bending line~ about which the carton is articulated.
~er~tofore, the bending of the carton blank was accomplished in a direction away from the scoring line, i. e., such that the carton blank breaks away from the score lines. This bending produced a bulging effect at the corners of the container and 10 res~lted in the rupturing of the paperboard fiber during tha bending process which detracted from the overall appearance of the container~ as well as o~tentimes fracturing the p~lyethylene coati~g of the caxton blank making the container subject to absorbtion 15 of the contents therein.
Thus, there exists a present need in the art for a carton blank wherein material wastage is mai~tained at a minimum, the coxner areas of the carton are eliminated from raw cut edges, and the scoring and bending of 20 the carton blank is adapted to eliminate rupturing of the fibers of the paper stock material.
Summ~y of the Pr~ t ln~cl~lc~
The present in~ention comprises a carton blank and an improved ~ethod of forming a carton of the type 25 hereinbefore identified, which significantly eliminates the structural and fabrication deficiencies of the prior art. Particularly, the carton blank of the present invention and carton formed therewith, is ~pecifically designed to obtai~ maximum content volume with a minimum 30 usage of paperboard stock. In this regard, the carton blank of the present invention is formed having a definike dimensional reIationship between the side panels and sealing tabs of the carton blank to the end closure panels which permits multiple carton blanks to nest 35 together in an inverted side-by-side orientation upon the paperboard stock and be cut therefrom, with a minimum . .
~17~48~
of material scrap and a maximum cutting machine operation ` speed. As such, an optimum num~er of carton blanks may be produ~ed from the paperboard sheet stock using existing machine technologyO
In addition, the presen~ invention eliminates the V-shaped notches previously formed on the sealing tabs of the ~arton blank. Rather, ~he sealing t~bs of ; ~he carton blank of ~he present invention are formed 10 continuou~ throughout their length and diagonally scored ; in the vicinity of the corner fvlds of the side panels, thereby bein~ adapted to be folded inward to reside within the interior o~ the carton. By ~uch a design, the end closure panels may be ~ealad directly to the unbroken ; 15 perimeter edges of the sealing tabs even in the sidawall corner areas of the container, rather than upon ~he raw edges her~tofore utilized in the prior art. It has been found that such corner formation greatly increases the strength of the seal in ~he corners of the container, : 20 thU5 yielding a liquid-tight carton-Furtherr in ~he present invention, the side sealing tab is relocated upon th~ opposite end of the carton blank (com~ared to that disclosed in Matovich~ Jr., Pat. No~ 4,084,489, and is increased in length over the 2S prior art configuration to extend partially onto both end ' closure panels. By ~uch a configuration~ the side sealing tab may be sealed throughout its full length and onto both the top and bottom closing pane~s which, during the subsequent ~ealing of the end closure panels to the side panels, has been found to eliminate'the rear corner leakage experienced in ~he prior art designs.
In contradistinction to the methods heretofore utilized throughout the'industry, the'pre~ent invention contemplates' the'novel method of forming scoring lines upon the in~erior of the carton blank and subse~uently bending ~he'carton blank to break into the'score line.
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r : 5 This inside breaking of the carton blank eliminates the unsightly bulging effect at the oorners caused by the rupturing of the fiber of the paperboard stock 2nd yields a crisp corner whexein the fibers of ~he paper stock are compressed within the score line.
In addition, the present invention discloses a displaced hinge line for the top end closure panel of the car~on which ~urther eliminates the tendency of the 10 car~on to leak in its rear corners, as well as discloses alternative embodiments for the actual carton produced : . by the improved carton blank of the present invention which are specifically suitable for various li~uid and powdered contents.
Descri~tion of the Drawin~s These and o~her features of the present invention : become more apparent upon reference to the figures .~ wherein:
~igure 1 is a plan view of the improved carton 20 blank of the present invention illustrating its preferred configuration and the location of the scoring lines thereon;
Figure 2 is a plan view of a portion of the sheet - s~ock web from which the carton blank o Figure 1 is 25 derived showing the improved nesting of multiple ~arton blanks thereon;
Figure 3 is an enlarged perspective view of the top end portion of the carton formed from the carton blank of Figure 1 with ~he top end closure panel raised above .
30 the continuous sealing tab;
Figure 4 is an enlarged partial cross-sectional view of the upper rear corner of the carton of Figure 3 ; depicting the orientation of the end closure panel, side panel, end sealing tab, and side sealing tab prior to 35 the end sealing process;
Figuxe 4A is a partial perspective view of one of the forward corners of the car~on blank produced fxom the .~
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: .6 . . , .. ~ carton blank of Figure 1 depicting the inward folding of a portion o~ ~he continuous end æealing tab;
. Figure 4B is an enlarged partial cross-sectional 5 view of the upper rear corner of the cæ~on blank of Figure 3 illustrating the configuration of the junction of the end closure panel, side panel, end sealing tab, and side sealing tab subsequent to the end sealing process;
Figure 4C i5 a partial perspective view of the orward corner of the carton blank in Figure 4A depicting îts configuration subse~uent to the end sealing process;
Figure 4D is an enlarged parspective view of the ~arton formed ~rom the carton bl~nk o~ Figuxe 1 showing ~ 15 the displaced hinge line of the top end closure panel;
:` Figure 5~ is a cross-sectional ~iew of a portion of a carton blank illustrating the formation of a scoring line heretofore utilized in the prior art;
Figur~ 5B is a cross-sectional view o the prior art .~ 20 method of bending of the carton blank of Figure 5A about the scoring line;
Figure 5C is a partial cross-sectional view of a : portion of a carton blank illustrating the formation of a scoring line thereon as utilized in the present invention;
Figure 5D is a cross-sectional view o the present invention's method of bending of the carton blank of Figure 5C about the scoring line;
Figure 6A is a perspective view of the carton produced with the preferred carton blank of Figure 1 ha~ing a straw element and tape seal applied thereto;
Figure 6B is an alternative e~bodiment for a carton having a straw element and tape seal disposed on its top end closure panel;
Figure 6C is an ~lternative embo~iment for a carton having a tape seal disposed on its top end closure panel;
and .
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Figure 6D is a perspective view of the car~on of the present invention formed withbut a s~raw elemen~ or tape ' seal thereon.
Detailed Description of the Preferred Embodiment .
Referring to Figure 1, there is shown ~he carton blank 10 of the present invention preferably formea from - thin paperboard stock, coated with a layer of polyethylene ': material which is impervious ~o the o3ntents ~o be placed 10 in the container~ The carton blank 10 is formed in substantially T-shaped configuration having an elongate , central portion 12 and a pair of end panels 14 and 16 ~hich are integrally connected to the elongate section : 12 adjacent one end thereof.
The elongate section 12 is composed of four sidewall ,. panels 20, 22, 24~ and 26, which are delineated by a plurality of scoring lines 28 extending transversely across the section 12. These scoring lines 28 are preferably formed as indentations on the side of 20 the carton blank 10 which will subsequently form the interior sux~aces of the container~ and selectively weaken the carton hlank to yield preferential folding lines about which the carton blank may be articulated.
A pair of end sealing tabs 30 and 32 extend 25 continuously along the opposite end edges of the side panels 20, 22, and 24 and are formed by the respective ~coring lines 34 and 36. The side panel 20 is additionally provided with a side sealing tab 38 at its distal edge, formed by the scoring line 40 which 30 extends throughout the length of the side panel 20. In the pxeferred embodimen~, the end sealing tab 32 is integrall~ connected at its opposite ends to the end ,~ ~losure panel 16 and side sealing tab 38,,whereas the end sealing tab 30 is separated or severed from the ena 35 closure panel 14 and side sealing tab 38 by cuts or ~
slits 42 a~ 43., respe~i~ely, extending throughout the height of the end sealing tab 30.
Each of the end sealing tabs 30 and 32 are provided : with a plurality of diagonally extending score lines 44 which initiate at the intersection of the scoring lines 28 with the scoring lines 34 and 36, ~espectively, and terminate at the distal edge of the sealing tabs 30 and 32. A~ sho~n, these diagonal scoring lines 44 on the end sealing tab 3~, are formed only on the side panels 20 and 24, whereas for the end sealing tab 30, they are provided 1~ on each of the ~ide panels 20, 22, ænd 24. ~inally, the side panel 26 may additionally be provided with an aperture 48 which provides access to the interior o:E
the carton ~ and ~ealingly receives the straw element and tape length ~shown in Figure 6A).
The end panels 14 and 16 are integrally connected to the side panel 26 at opposite ends thereof, and are formed in a generally square configuration. The end closure panel 16 is delineated from the. side panel 26 b~
a scoring line 50 which extena~ from the edge 25 of the 20 side panel 26 terminating at a location spaced fxom the aperture 48, and is aligned with the scoring line 36 fonming the en~ sealing tab 32. The end closure panel 14 is delineated from the side panel 26 by a scoring line 52 which extends only through the central portion of the 25 5ide panel 26 terminating short of the edge 25 and short of the scoring line 28 formed between the side pane~s 26 and 24. As will be noted, the scoring line 52 is not aligned with the scoring line 34 which forms ~he end ~ealing tab 30, but rather is displaced inwardly a 30 short distance E along the length of the side panel 26.
The end closure panel 14 is addi$ionally formed slightly larger in size than the end panel 16 extending a short distance F outward beyond the edge 25 and score line 28 of the side panel 2S. The oversized portion 3s of the end panel 14 extending beyvnd tne ed~e 25 of the carton blank foLms a protruding section 54; the length of which extends inboard beyond the edge of the sealing tab 4 ~ ~
:
:
g 30 represented by the distance "G" in Figure 1.
In the preferred embodiment, a definite dLmensional ; relationship is maintained between $he length "A" and "B"
of the en~ panels 14 and 16 to the length "C" ffl the side .` panels 20, 22, 24, and 2~ and the length ~D" of the end sealing tabs 30 and 32~ In particular~ t~e carton blank :~ 10 is formed such that the sum of the distances A and B
which the end panels 14 and 16, respectivel~, extend 10 beyond the edges of the end sealing tabs 30 and 32, is e~ual to the sum of the length dimension C of the side panels 20, 22, 24, and 26, and the height dimension D
of each of the end sealing tabs 3 0 and 32 . That is, : A ~ B = C ~ 2D. By this particular dLmensional 15 relationship, the carton blank 10 may ~e nested and cut from a web of sheet stock material with minimum material wastage yielding o~timum utilization of material stock.
The improved nesting ~haracteristics made possible -- by the carton blank 10 of the present invention may be ~; 20 seen upon reference to Figure 2 wherein a plurality of ~arton blanks 10 are disposed in a patterned array upon ~ a web of shee~ stock material 60. The carton blanks 10 are pre~erably arranged in a plurality of horiæontally extsnding rows, e~g., in Figure 2, blanks lOA, lOB and 25 lOC being in one row, while blanks lOD and lOE are in a ~econd row, and blanks lOF, lOG, and lOH are in a third i row. Adjacent carton blanks lOA, 10B, and lOC, in each row, are disposed in a side-by-side orientation with their respective end closure panels 14 and 16 abutted along a 30 single cutting line 62~
A9 shown, the CartQn blank rows are arranged vertically along the sheet stock 60 to form a plurality of nested pairs of rows, with the second carton blank row in each pair (comprising carton blanks lOD and lOE in 35 Figure 2) being inverted with respect to the fir~t carton ; blank row (comprising blanks lOA, lOB, ~nd lOC). A5 ~uch, ad~acent carton blanks lOA, 10D, lOB, lOE, and lOC in each ~ ~7~&~
-pair of rows are alternativPly upright and .inverted along the web of sheet stock 60.
Due to the combined width (C and 2D) of the side panels 20, 22, 24, and 26 and sealing tabs 30 and 32 being equal to the combined width of the end closure panels ~A and B~ ~ the elongate sections 12 sf each of the carton b}ank~ 10 arranged in the inverted rows, a~ut each other along the lines 64A and ~4B, 64C and 64D, which 10 may be xeferred to as an abutment axis.
: In addition to the inverted alternative row orientation of the carton blanks~ each horizontal pair ~ of rows is positioned upon the web 60 such that the : protruding portion~ 54 of the end closure panels 14 in 15 the second inverted row of one pair abut the protruding portions 54 of the ~irst row in the next pair along a common diagonal edge 72. This abutment at the edge 72 causes each pair of rows to be hori20ntally offset or staggered from the next pair of rows by a distance "0"
20 equal to twice the distance "G" that the protrudin~
section 54 extends inward beyond the edge o the sealing tabs 30.
By this alternate inverted xow and offset carton blank ne~ting pattern, the carton blanks 10 lie tightly 25 nested in a side-by-side orientation thereby eliminating the substantial voids formed on the sheet s~ock 60 b~
the prior art carton blank configurations. As suchr the scrap material on the web 60 of the present invention consists only of the minimal material 66 and 68 lying 30 adjacent the end closure panels 16 of each of the carton blanks 10 which rspresents the size differential "F"
(Figure 1) between the end closure panels 14 and 16 as well as a small border ~ection 70, fonmed along the edges of the webbing 60 which can be reduced substantially to nothing 35 by proper selection of the web siæe. Considering that the carton blanks 10 form non-reusable containers9 and will typically be supplied in vast quantities, such savings in the amount of scrap or waste material :Erom the web of sheet stock 60 is very important from the standpoint of overall cost effectiveness of the carton.
As will be recognized, by the specific nesting configuration depicted in Figure 2, the individual - carton blanks 10 may be fabricated from a roll stock . webbing 60 with a minimum of material wastage as well : as a ninimum of cuttings upon the sheet stockD Thus, ` as the webbing 60 is fed into one of the well~known stamping apparatus (not shown), a maximum number of car on blanks may be produced for a particular webbin~
and machine operational speed.
Referring to Figure 3, the improved sealing : characteristics made possible by the carton blank 10 : 15 of the present invention will now be described~ As will be recognized, ~he car~on depicted in Figure 3 is formed from the carton blank 10 by a series of folding~ bending, and sealing steps. The first of these steps is the bending of the side panels 20, 22, 24, and 26 about the .`. 20 scoring lines 28 as well as ~he bending of the side sealing tab 38 about the scoring line 40 to reside on . the interior surface of the side panel 26, Once in this :~ configuration, the side sealing tab 38 may be sealed as by way of the application of heat,to the interior of the side panel 26 thereby maintaining the open ended sguare tubular configuration, depicted in Figure 3.
It i8 an important featuxe of the carton blank 10 of the present invention that the side sealing tab 38 is bonded or sealed throughout its entire length including the ~mall portlon 38A which extends upward onto the interior surface of the top end closure panel 14 and a corresponding small portion 38B ~Figure l) which similarly extends onto the interior surface of the bottom end closure 16~ In the preferred em~odiment, the side sealing operation is performed on an interior mandrel tnot shown) which is additionally utilized to permit the bottom end closure panel ~ 6 (not shown in : Figure 3) to be sealingly bonded across khe lower end ~ealiny tab 32 (Figure 1) which has been previously folded inward the end closure panel 16 thus forming the bottom surface (not shown~ of the carton 10. The apparatus and method or forming the carton blank 10 into such a configuration i5 disclosed in Canadian Patent A~plic-ation, Serial Number 356,428, filed July 17, 1980, by . the same applicant entitled MæTHOD AND APPARATVS FOR
13 FORMING A CONTAINER FOR LIQUIDS. It should be recognized tha~ the size differential ~etween the : bottom and top end closure panels 16 and 14, resPectively, the differing locations of the diagonal scoring lines 44 on the botto~ and top sealing tabs 32 and 30, and the inclusion of the slits 42 only on the top sealing tabs 30, are specifically designed to augment the . interior mandrel sealing of the bottom end pan~1 ~6 as opposed to the exterior mandrel sealing of the top end panels 14, since the many structural ana formational problems encountered in exterior mandrel sealing are not present in interior mandrel sealing.
Subsequent to the side sealing and bottom end sealing o~ the carton blank 10, the top end sealing tab 30 is folded over to reside withLn the ~nterior of the square tuhular carton configuration and extend generally perpendicular to the upper portion of the side walls 22, 24, and 26 ~shown in Figure 41. Due to the top end sea~ing tab 30 being separated from the end closu~e panel 14 and side sealing tab 38 by the cuts or slits 42 and 43 ~Figure 3), the sealing tab 30 may be folded over throughout its length without tearing and without : disturbing the seal betwe~n the end closure panel 14 and the upper portion 38A of the side sealing tab 38.
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8~
As shown in Figure 4A, during.this fold-~ver process, the diagonal score lines 4~ formed at the intersection of the sealing tab 30 with the corner-forming score lines 5 28, permit the portion 31 of ~he sealing tab 30 lying between adjacent diagonal score lines 44 to be p~shed -. inward below the main plane of the sealing ta~ 30. By such a design, the top sealing tab 30 is maintained continuous throughout its length having a miter-like 10 interface 41 at its corner junctions with the sidewalls 20, 22t and 24. With this miter-like interface, the present invention eliminates the prior art's raw cut edge in the immediate vicini~y of the corner junction of the s~aling tab 30 which heretofore was subject to 15 being wetted by the contents of the container and substantially weakened the top end seal.
Subsequent to the inward ~olding of the seallng tab 30, the sealing tab 30, as well as the extreme upper portion of the sidewalls 20, 22, and 24, are beveled 20 outward to lie exteriorly of the remaining portion of the sidewalls 20~ 22, and 24 through a short distance of approximately 1~8 of an inch ~designated by the distance "H" in Figure 4B). As will be recognized, this outward beveling is accommodated in the vicinity of the - 25 forward corners of the carton by the sealing tab 30 and the upper portion Gf the sidewalls of the carton stretching outward due to an internal thinning flow of the paperboard carton material. As shown in Figur~
4C, this thinning flow causes the miter~like interace 30 41 to be inwardly spaced by a distance S from the outermost edge of the ~orward corners, which, as will be exp}ained in more detail below, per~its an effective top seal to be formed across the sealing tab 30, even in the vicinity of the forward corners of the carton 35 blank. Additionally, this outward be~el~ng permits the upper end of the carton blank 10 to be supported by an exterior mandrel 80 ~represented by the phantom ~ ~ 2~&~
line in Figure 4B) which may be positioned along the three sides of the carton ~lank 10 corresponding ~o the side panels 20, 22, and 24. Additionally, as shown in 5 Figure 4B, during this beveling process, the portion of the sealing tab 31, lying between the diagonal score lines 44, is folaed further beneath the sealing tab 30, assuming a position generally parallel to the angular plane of the sealing tab 30 located on the side panel 10 20.
With the carton blank 10 supported against the exterior anvil 80, the top end closure panel 14 may be forced downward to lie in a plane subs~antiaily perpendicular to the open end of the carton blank 10 15 as by way of a die 82 (represented by the phantom lines in Figure 4B). By the application of this downward force, the perimeter edges 14A of the end : panel 14 are beveled angularly upward between the die 82 and the anvil 80 to ext~nd along and overlay 20 the length of the sealing tab 30, wherein they may be sealingly bonded ~hereto by the application of heat.
Further, due to the miter-like interface 41 being spaced from the outer edge of the sealing tab 30 (shown in Figure 4C), a portion of the perimeter edges 14A of 25 the end closure panel 14 extends outward beyond the interface 41 to positively seal against the sealing tab 30 and close off the inter~ace 41 thereby significantly reducing the possibility of forward corner leakage.
Referring conjunctively to Figures 3 and 4D, it is shown that during the fold-over and end closure panel 14 sealing process, the end closure panel 14 pivots about the scoring line or actual hinge line 52 which, : a~ previously mentioned, is displaced or dislocated downward along the length of the sidewall panel 2 6 35 from its natural or apparent h~nge line 53 (represented by the phantom lines in Fi~ures 3 and 4D). Due to this displaceme~t, the natural hinge line 53 is positioned ;' .~ ~ 72~
- ~orward and above the relatively broad ~ealing surface ~f the end sealing tab 30. Additionally, the slits .~ ~2 and 43 located at the interseetion of ~he top end ~ealing tab 30 with the end closure panlsl 14 are forced forward to be displaced from the-actual rear corner of the carton and lie upon the sealing tab 30O
As such, the slit8 42 and 43 may be tightly ~closed off" between end closure 14 and sealing tab 30 by the 1~ pressure exexted between the anvil 80 and die B2 .~ during the end sealing procedure~
Additionally, due to the upper portion 38A of thle side sealing tab 38 being previou~ly sealed onto the end closure panel 14 during the fold~over procedure, 15 the portion 38A overlays the cut or slit 42 formed on the sealing tab 30. Thus, the raw cut edge of the cut or slit 42 is covered by the continuous length of th~.
portion 38A which extends from the ~idewall panel 26 onto the end sealing tab 3 O.
By this particular top end carton arrangement~ the application af heat during the sealing process causes all of the elements located in the right rear corner (as viet~ed in Figure 3), i~e~, the sealing tab 30, peri~eter edge 14A, upper portion 38A, and the u~per 25 end o~ the sidewall 20, to be sealingly joined together.
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1 ~2~3~
. 1~
Addi~ionally, due to the end sealing tab 30 being continuous throughout its length and including the miter-like interface 41 (Figure ~C) at the top frontal S corners of the carton, a liquid-tight seal between the perimeter edge 14A of the end Closure pa~el 14 and the sealing tab 30 may be facilitated, ~s s~ch, the top : seal leakage tendencies of the pxior art flat top cartons is substantially ellminatedo In addition to the improved ~ealing capabili~ies made possible by the improved carton blank 10, the present invention additionally diScloses a nov~l me~hod o~ scoring and bending of the carton blank which produces a crisp c~rner and eliminates damayë to the carton blank duriny fabrication.
In Figures SA and 5B~ an enlarged~ partial cross-sectional view of the method o~ sc~ri~g (Figure 5A) and bending (Figure 5B) a carton blank 100 in the prior art is depicted. AS shown, the carton blank 100 is scored by an indentation 102 which produces a corresponding protrusion 104 on the reverse side of the carton blank 100. Subsequently, the car~on blank 100 i8 bent away from the scoring line 102 in a direction indicated by the arrows in Figure 5B, yielding a corner coniguration ~imilar to that shown in Figure SB. As will be recogniæed, in this configuration~ the corner bulges outward at 103 beyond the exterior plane o~ the carton blank 100 due to the internal fibers of the carton blank material rupturing upon encountering the tension exerted during the ben~ing proce~3~ This rupturing of the fibers substantially weakens the carton blank 100 at the area of ~he bend and, in severe instances, causes a fracturing of the polye~hylene m~t~rial on the in~erior of the corner thereby subjecting thc car~on blank to absorbtion of thé ~luid contents.
In contradistinction, the present i~ve~ion contemplates the ~coring and bending of the c~r~on blank 100 in a 7 ~
manner depicted in Figures 5C and 5D wherein the scoring line 102 is formed on the opposite ~urface Si.e.~ the surace that will form the interior of the carton) of the carton blank 100 yielding an attendant protrusion 104 on the exterior side of the blank.
Subsequently, the carton blank 100 is bent inwardly about the score line 10~ in ~he direction indicated in Figure 5D. By ~his proceaure, the corner is formed substantially, as shown in Figure 5D, with the internal fibers of the carton blank material being compressed to reside within the indentation 102 while the outer corner ; configuration assumes the general preformed cuxvature of the protrusion 104. As such, a more crisp corner is provided which additionally eliminates the weakening of the carton blank 100 and the ~racturing of the polyethylene coatiny material on the interior of the carton blank 100.
In Figures 6A, 6B, 6C, and 6D, altexnative embodiments of the container, derived from the carton blank lQ of the present invention, are shown. In Figure 6A, a container 200 is shown which is fahricated ~rom the carton blank 10, shown in Pigure 1. As sh~wn, the aperture 48 po~itioned on the sidewall 26 is provided with the straw element 202 and sealingly covered by a length of tape 204~ In this embodiment, the tape 204 is preferabl~ ~ormed from a Mylar strip which is coated on its undersurface by a film of polyethylene. Due to the different melting temperatures between Mylar and 3a polyethylene, the tape length 204 may be heated to simultaneously ~eal against the exterior of the side panel 26 as weIl as a portion of the straw element 202.
Subsequently, when a user desires to open the container 200, the end portion of the tape length 204 may be grasped by the user and be peeIed or torn from $he side panel 26 whe~eby the straw element 202 is rotated upward and in position to withdraw the contents from the oontainer 200. As will be recognized, such a carton 200 is specifically sui able for pot~able liquids such as milk or fruit juices which are conveniently packed in single serving sizes and disposable after usage~ A more detailed discussion of ~he opening operations of such a carton is di~closed in Canadian Patent Application Serial No. 316,882 filed November 27, 1978, by Toseph Buschor.
In Figure 6B, an alternative embodiment for the container of Figure 6A is shown, wherein the aperture 48 is relocated upon the top end closure panel 14 and includes a straw element 212 disposed therein. In this embodiment, however, the straw element 210 is preferably sealed to the interior of the sidewall 26 and includes a resilient upper portion 214 which is disposed in a plane perpendicular to the remainder of the element. A length of tape 210 sealingly covers the aperture 48 and prevents the upper portion 214 of the straw element 212 from ~lexing outward from the container. In use, a user may peel off the tape length 216 from the end closure panel 214 thereby all~wing the resilient upper portion 214 of the ~traw element 212 to spring upward from the container whereby a user may easily withdraw the liquid from the container 210 or alternatively remove the straw element 212 and utilize the aperture 48 as a pouring spout. As such, with the carton 210 depicted in Figure 6B, a user may consume the contents directly from the carton 210 or alternatively pour the contents into a drinking glass or the like.
In Figure 6C, an additional embodiment of a carton 200 formed by a carton blank 10 of the present invention is shown, wherein the aperture 48 is disposed centrally upon the top end closure panel 14. As in the ~ther embodiments, the aperture 48 is sealed by a tape length 222 which is removable by the user. In this particular ~2~
, ;~ 19 embodiment, howevar, the straw element has been eliminated with the aperture 48 being used exclusively as a pouring spout. Thi~ particular embodiment of the carton ~20 is 5 suitable for large.size containers, such as that ~ypically uti}ized in the inaus~ry for marketing quart and half~gallon sizes of milk.
. AlternativeIy, in Figure 6D, a carton 230 is disclosed .~ wherein the aperture 48 has been completely eliminated.
By this design, the carton blank 230 is specifically adapted for various dry products which preferably are maintained in a safety container which may not be easily opened by the user~.
It will be understood that although the foregoing speci~ication has disclosed particular materials from which the carton blank is fabricated, alternative materials may be utilized withou~ departing ~rom the spirit of the present invention.r Also, while the description reers to certain orientation as ~he top and bottom, it will be 20 evident that this is only for convenience in description and does not lim~t the orientation.
/JBB: pb
Claims (2)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A method of forming a corner on a paperboard carton blank without damaging the internal fibers of said carton blank comprising:
scoring said carton blank to form an indentation line on one surface of said carton blank and a corresponding protrusion line on the other surface of said carton blank; and folding said carton blank inwardly about said indentation line so that the one surface of said carton blank forms the interior surface of said corner and the other surface of said carton blank forms the exterior surface of said corner.
scoring said carton blank to form an indentation line on one surface of said carton blank and a corresponding protrusion line on the other surface of said carton blank; and folding said carton blank inwardly about said indentation line so that the one surface of said carton blank forms the interior surface of said corner and the other surface of said carton blank forms the exterior surface of said corner.
2. The method of Claim 1, wherein said folding step causes the internal fibers of said carbon blank to be compressed within said indentation line.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000401906A CA1172487A (en) | 1980-01-21 | 1982-04-28 | Method of forming a corner on a paperboard carton blank |
Applications Claiming Priority (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US113,487 | 1980-01-21 | ||
| US06/113,487 US4300716A (en) | 1980-01-21 | 1980-01-21 | Paperboard carton |
| CA000368540A CA1156200A (en) | 1980-01-21 | 1981-01-15 | Paperboard carton |
| CA000401906A CA1172487A (en) | 1980-01-21 | 1982-04-28 | Method of forming a corner on a paperboard carton blank |
Related Parent Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000368540A Division CA1156200A (en) | 1980-01-21 | 1981-01-15 | Paperboard carton |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1172487A true CA1172487A (en) | 1984-08-14 |
Family
ID=27166934
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000401906A Expired CA1172487A (en) | 1980-01-21 | 1982-04-28 | Method of forming a corner on a paperboard carton blank |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1172487A (en) |
-
1982
- 1982-04-28 CA CA000401906A patent/CA1172487A/en not_active Expired
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| Date | Code | Title | Description |
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| MKEX | Expiry |