Container and blank for constructing same

Abstract: A liquid-carrying, thermoplastic-coated paperboard container includes a top end closure 12, a four-sided body portion 14, and a bottom end closure 15. Various end closure panels (54, etc.) are folded so as to abut against one another to become sealed thereagainst. To effect the sealing, a pressure sensitive, food grade adhesive is applied to at least one of each two abutting surfaces and the abutting surfaces are pressed together without the application of heat or high frequency vibration. The adhesive may be applied to the blank 10 during the converting process, or while the blank is being formed into a container on the forming, filling and sealing machine.

Description: TECHNICAL FIELD This invention relates generally to thermoplastic coated liquid carrying paperboard containers and, more particularly, to a blank and a container formed from the blank with improved sealing features. BACKGROUND ART Containers for beverages such as milk, cream, other dairy products, juices, and the like are conventionally constructed from thermoplastic coated paperboard. One type of these containers includes a top end closure with a folded gable roof having a vertically projecting seal at the roof ridge for sealing the container and providing a readily available pouring spout when the contents of the container are to be dispensed. Thermoplastic coated paperboard blanks for constructing such a container are made on converting machines similar to those disclosed by US-A-2,682,208 and 3,731,600. After construction, the blanks are processed by forming, filling and sealing machines, such as those disclosed by US-A-3,303,761; 3,918,236; 3,398,659 or 4,193,833, to produce the formed, filled and sealed containers of the type referred to above and shown and described in US-A-3,270,940 and 3,120,335. Typically, as shown and described in the forming, filling and sealing machines of the above referenced US-A-3,303,761; 3,918,236 and 3,398,659, there are heating stations included on the machines to heat the various thermoplastic coated surfaces so that they can then be sealed together under pressure. Alternatively, as disclosed in US-A-4,193,833, sealing may be accomplished by ultrasonic or high frequency vibration. For particular applications, a so-called thermoplastic "hot melt" may be applied as a sealant for various panel surfaces, or to serve as a sealant for crevices that may occur between the adjacent edges of co-planar panels after closing. In still other prior art liquid carrying container arrangements, such as that shown and described in Wyberg U.S. Patent Nos. 4,813,548 and 4,756,426, a fillet comprising a thin strip of stiff material coated with or adjacent to a layer of adhesive, which may be a type of pressure sensitive adhesive approved for food contact, is attached to the gable rib panels which form the spout. These arrangements contemplate the application of the usual heat sealing process to establish a conventional thermoplastic-to-thermoplastic bond. DISCLOSURE OF THE INVENTION An object of the invention is to provide an improved sealing arrangement for liquid carrying thermoplastic coated paperboard containers. Another object of the invention is to provide a container sealing arrangement which does not require either heat or a high frequency vibration, or the application of a hot melt material. A further object of the invention is to provide a pressure sensitive, food grade (FDA approved) adhesive for sealing liquid carrying thermoplastic coated paperboard containers, in lieu of having to apply heat or use ultrasonic or high frequency vibration to effectuate the sealing process, as has heretofore generally been the case. According to one aspect of the present invention, there is provided a liquid-carrying, thermoplastic-coated paperboard container, comprising a top end closure, a four-sided body portion and a bottom end closure, wherein panels thereof have pairs of thermoplastic-coated, paperboard portions of the panels lying face-to-face with each other and these pairs of thermoplastic-coated, paperboard portions are sealed face-to-face with each other in a liquid-tight manner. Such a container is known from, for example, US-A-3 118 586. The present invention is characterized in that thermoplastic surfaces of each of said pairs of thermoplastic-coated paperboard portions are sealed together by a layer of pressure-sensitive, food-grade adhesive rather than having been sealed together by a melting effect. According to a second aspect of the present invention, there is provided a thermoplastic-coated paperboard blank for forming into a container for carrying liquid, comprising top end closure panels, first to fourth body portion panels and bottom end closure panels, wherein panels thereof are for folding so that pairs of thermoplastic-coated paperboard portions of the panels lie face-to-face with each other and wherein these thermoplastic-coated, paperboard portions are for sealing face-to-face with each other in a liquid-tight manner, characterized in that at least one thermoplastic surface of each of the pairs of thermoplastic-coated paperboard portions has applied thereto a layer of pressure-sensitive, food-grade adhesive. According to a third aspect of the present invention, there is provided a method of forming a container for carrying liquid, comprising bringing face-to-face with each other pairs of thermoplastic-coated paperboard portions of thermoplastic-coated, paperboard material and sealing together thermoplastic surfaces of each of said pairs of thermoplastic-coated, paperboard portions in a liquid-tight manner, by a step comprised of pressing each pair of thermoplastic surfaces together, to form a top end closure, a body portion and a bottom end closure, characterized in that a layer of adhesive is applied to at least one of each pair of said thermoplastic surfaces before said pairs of thermoplastic-coated paperboard portions are brought face-to-face and in that the layers of adhesive are caused to seal their pairs of thermoplastic surfaces together through said pressing rather than through a melting effect. In order that the invention may be clearly understood and readily carried into effect, reference will now be made, by way of example, to the accompanying drawings, in which:- Figure 1 is a fragmentary layout view of the inside surface of a coated paperboard container blank used to construct a container having end closures for being sealed; Figure 2 is a fragmentary layout view of the outside surface of the container blank in Figure 1; Figure 3 is a fragmentary layout view of the outside surface of a container structure after it is side seamed from the container blank illustrated in Figures 1 and 2; Figure 4 is a fragmentary perspective view showing the side seamed container blank illustrated in Figure 3 in an open ended top end view prior to the closing of the top closure structure; Figure 5 is an enlarged fragmentary perspective view showing the container evolved from the side seamed blank of Figure 3 in a partially closed condition; Figure 6 is a fragmentary perspective view showing the Figure 5 container in a completely closed condition; Figure 7 is a fragmentary perspective view showing the container after the seal of Figures 5 and 6 is broken, and with the pouring spout in an intermediate step of the opening process; Figure 8 is a fragmentary perspective view showing the container of Figure 7 after the pouring spout has been fully opened; Figures 9 and 10 are fragmentary layout views of the inside and outside surfaces of an alternate top end closure for being sealed; and Figures 11 and 12 are fragmentary layout views of the inside and outside surfaces of an alternate bottom end closure for being sealed. BEST MODE OF CARRYING OUT THE INVENTION Referring now to the drawings in greater detail, Figure 1 illustrates a thermoplastic coated container blank 10 interior surface. The container blank 10 is generally divided into three sections including a top end closure 12, a body portion 14, and a bottom end closure 15. The latter may be similar to that shown and described in US-A-3,120,335, and incorporated herein by reference. A staggered lower top horizontal score line 16 extends transversely across the container blank 10 and separates the top end closure 12 and the body portion 14. Similarly, a bottom staggered horizontal score line 17 extends transversely across the container blank 10 and separates the bottom end closure 15 and the body portion 14. The body portion 14 comprises a plurality of integrally connected body panels, namely, a side panel 18, a front panel 20, a side panel 22 and a back panel 24, and a side seam flap or narrow fifth panel 26 formed adjacent the panel 24. The container blank 10 is defined on its longitudinal sides by its edges 28 and 30. The body panels 18, 20, 22 and 24, and the side seam flap 26 are defined by vertical score lines 32, 34, 36 and 38. The top end closure 12 comprises roof panels 40 and 42. The panels 40 and 42 are connected integrally to the upper ends of the body panel members 18 and 22, respectively. A triangular gable or spout panel 44 and a triangular gable or closure panel 46 are connected integrally to the body panels 20 and 24, respectively. A staggered upper top horizontal score line 48 extends transversely from the blank edge 28 to the blank edge 30, substantially parallel to the horizontal score line 16. The roof panel 40 is divided basically into two portions by the horizontal score line 48. A lower closure panel 50 is defined by the score line 32 and the edge 28. An opening assist score line 52 extends substantially from the intersection of the score line 16 and the score line 32 to a point on the score line 48 that is closer to the score line 32 than to the edge 28. An upper closure panel 54 of the outer roof panel 40 serves as a sealing panel, as will be explained. The roof panel 42 is divided into two parts by the score line 48. The inner part of the roof panel 42 comprises a lower closure panel 56 which is defined by the horizontal score lines 16 and 48 and the vertical score lines 34 and 36. An opening assist score line 58 extends from the intersection of score lines 16 and 34 to a point on the score line 48. The last mentioned intersection on the score line 48 is closer to the score line 34 than to the score line 36, and it is substantially the same distance from the score line 34 as the opening assist score line 52 is from the score line 32 along the score line 48. The roof panel 42 includes an upper closure panel 60 which is integral with the closure panel 56, and it is separated therefrom by the score line 48. The triangular spout panel 44 is connected to a pair of inner roof or fold-back panels 62 and 64 by diagonal score lines 66 and 68, respectively. The fold-back panels 62 and 64 connect the triangular spout panel 44 to the closure panels 56 and 50, respectively. A pair of pouring panels or infold lips 70 and 72 are integrally connected to the fold-back panels 62 and 64, respectively, and they are defined by a portion of the horizontal score line 48, the vertical score lines 32 and 34, and a vertical score line 74. The triangular closure panel 46 is integrally connected to a pair of inner roof or fold-back panels 82 and 84 by diagonal score lines 86 and 88, respectively. The fold-back panel 82 integrally connects the triangular closure panel 46 to the extension of the fifth panel 26. A pair of closure panels or infold lips 90 and 92 are connected to the fold-back panels 82 and 84, respectively, and they are defined at their lower ends by the score line 48 and at their outer edges by the score lines 38 and 36, respectively. The closure panels 90 and 92 are separated from each other by a vertical gable score line 94. The triangular base angles of the closure panel 46 as well as of the spout panel 44, are normally formed so as to be equal. Referring now to Figure 2, there is shown the exterior surface of the container blank 10 of Figure 1. The respective exterior panels are identified the same as for their interior counterparts shown in Figure 1. A pressure sensitive food grade (FDA approved) adhesive is preferably applied to the blank 10 while the blank is being scored and printed on the usual converting machine, such as that disclosed in the above referenced Patent Nos. 2,682,208 and/or 3,731,600, prior to being cut into individual blanks. However, such adhesive may be applied to the various surfaces of the blank while it is being formed into a container on a forming, filling and sealing machine, such as those disclosed in the above referenced patents modified to include one or more adhesive-applying stations. More specifically, the food grade adhesive is applied to the following areas, shown as stippled areas in Figures 1 and 2: (a) The full exterior (Figure 2) infold lips 70, 72, 90 and 92; (b) The full interior (Figure 1) infold lips 90 and 92, and outer left and right edge portions 100 and 102 of the respective interior infold lips 70 and 72, adjacent the respective closure panels 60 and 54, leaving clear areas 104 and 106; and (c) The full interior (Figure 1) closure panels 60 and 54, except for respective rectangular portions 108 and 110 at the lower, central section of each of the respective right and left halves of the panels 60 and 54, adjacent the score line 48. As such, the food grade adhesive is applied adjacent the left, right and upper edges of each of the rectangular portions 108 and 110, as shown in Figure 1. The clear areas 104, 106, 108 and 110 are reserved for the application, if it is required, of a suitable abhesive material of a type and for a purpose well known in the art, as will be explained later. The container blank 10 illustrated in Figures 1 and 2 is first formed into a side seam blank by rotating the body panel 24 and the side seam flap 26 as a unit about the vertical score line 36, and having the inside surfaces of the body panel 24 come into contact with the inside surface of the body panel 22, with the vertical score line 38 positioned next to the vertical score line 34, and with the inside surface of the side seam flap 26 contacting the inside surface of the body panel 20 adjacent the vertical score line 34. The body panel 18 is then rotated about the vertical score line 32 to bring its inside surface into contact with the inside surface of the body panel 20. The inside surface of the body panel 18 along the edge 28 comes into contact with the outside surface of the side seam flap 26, and the edge 28 is positioned parallel and aligned with the vertical score line 38. The various members of the top end closure 12 and the bottom end closure will make similar movements. The container blank 10 is then sealed where the inside area of the body panel 18 comes into contact with the outside surface of the side seam flap 26. The sealing is accomplished by applying the food grade adhesive to one or both the outside surface of the side seam flap 26 (Figure 2) and the adjacent mating surface, represented at 111 (Figure 1), of the body panel 18. After the side seam blank is opened up into a squared condition, the bottom end closure is formed and a product, such as milk or juice, is inserted in the container. Thereafter, the various parts of the top end closure 12 are folded about the various score lines in the following manner so as to form the top end structure. The triangular spout panel 44 is moved around the horizontal score line 16 over the end of the filled container and towards its center, as shown in Figure 5. At the same time, the triangular closure panel 46 is moved toward the middle of the filled container around the horizontal score line 16. The spout panels 70 and 72, and the closure panels 90 and 92 will have their outside surfaces rotated towards each other around the vertical score lines 74 and 94, respectively. The respective surfaces of the lip 72 and the lip 90 contact the sealing panel 54, while the respective surfaces of the lip 70 and the lip 92 contact the closure panel 60, as may be noted from Figures 5 and 6. The sealing of the last mentioned elements of the top closure 12 is accomplished by applying a predetermined minimum pressure to the exterior surfaces of the upper closure panels 54 and 60, thereby causing all adjacent surfaces carrying the food grade adhesive to become sealed together, without requiring the application of heat and without any possible contamination of the enclosed product. Figure 6 illustrates the positions of the various elements of the top end closure 12 once the sealing thereof has been effected, i.e., with the sealing panels 54 and 60 being disposed in a position perpendicular to a plane perpendicular to the side panels 18, 20, 22 and 24 to form a top seal. Depending upon the type of pressure sensitive food grade (FDA approved) adhesive used, the upper closure panels 54 and 60, which are secured to each other as shown in Figure 6 by the above mentioned application of pressure, may be prevented from forming a difficult-to-open seal with the inner seal lip associated with the front triangular gable panel by applying an abhesive material in the well known manner to portions of the infold lips 70 and 72, as well as to portions of the laterally adjacent upper closure panels 54 and 60 and as shown by the clear areas 104, 106, 108 and 110. If used, this abhesive coating may be made of any suitable material, such as a silicone based material, that prevents a difficult-to-open sealing between different portions of the container and permits the sealed top end closure to be more easily opened from its closed condition of Figure 6 through the step shown in Figure 7 to its open condition of Figure 8 where the pouring spout is provided. With respect to the sealing of the bottom end closure 15 (Figures 1 and 2) and the well-known panel configuration thereof, a food grade adhesive would preferably be applied to at least one of each pair of adjacent panel portions adapted to overlap one another, including the following: Figure 1 interior: panel portions represented as an extension 112 extending beyond the adjacent edge 113, except for a triangular central portion 115 thereof, triangular portions 114, 116, 118 and 120, an extension 122 beyond the adjacent edge 113, triangular portions 124, 126, 128 and 130, and side seam flap end segment 131, except for a triangular inner edge portion 132, with diagonal score lines 117, 119, 127 and 129 defining the triangular portions 118, 120, 128 and 130, respectively. Figure 2 exterior: panel portions represented as an extension 133 extending beyond the adjacent edge 113, and triangular portions 134, 136, 138, 140, 142 and 144, with the score lines 117, 119, 127 and 129 separating the triangular portions 144/142, 140/142, 138/136 and 134/136, respectively. The respective overlapping or abutting panel portions would then be pressed together on the forming, filling and sealing machine at a predetermined minimum pressure to complete the sealing therebetween. Referring now to Figures 9 and 10, there are shown, respectively, the outside 146 and inside 148 surfaces of flat top closure blank 150 disclosed in US-A-4,582,246, incorporated herein by reference; and the surface portions thereof to which the food grade adhesive is applied, and which will be sealed by pressure in forming the closed container (not shown) therefrom. These surface portions are identified by stippling. The surface portions of the inside top closure surfaces 146 (Figure 9) to which the adhesive is applied are represented as triangular panels 151, 152, 154, 156, 158, 159, 162 and 164, a lift tab type extension 155 formed at the outer edge of the panel 154, an extension 160 extending beyond the triangular panels 158 and 159, but separated from the panel 158 by a strip 161, a side seam flap end segment 165, except for a triangular inner edge portion 166, a lift tab 167, and a body side panel edge portion 168 and a top closure panel edge portion 168'. The surface portions of the outside top closure surfaces 148 (Figure 10) to which the adhesive is applied are represented as triangular closure panels 170, 172 and 174 with score lines 177 and 179 separating the triangular portions 170/172 and 174/172, respectively; a panel edge portion 176 extending across the score line 169, a section 178 adjacent the edge portion 176 coinciding with the contoured portion of the extension 160 (Figure 9), a central portion 180 spanning between the score lines 171 and 173 and outwardly therefrom, the side seam flap end segment 182, the full length side seam flap 184, and an off-centre rectangular segment 185 at the upper end of a side panel coinciding with the shape of the lift tab 167 (Figure 9). Referring now to Figures 11 and 12, there are illustrated, respectively, the inside 186 and outside 188 surfaces of the modified bottom end closure blank 190 disclosed in US-A-4,341,340, incorporated herein by reference, which may be used in lieu of the bottom end closure 15 shown in Figures 1 and 2. In this bottom end closure arrangement, there results a substantial saving in the amount of thermoplastic coated paperboard required, in that the free cut edges of the four closure panels are shaped to include 45° angled edges, rather than the horizontally oriented edges shown in Figures 1 and 2. As indicated by phantom lines in Figure 12, the saving results from the adjacent interdigitated panels of a web or sheet from which the blanks are cut. The surface portions of the outside surfaces 188 (Figure 12) of the blank 190 to which the food grade adhesive is applied, and which will be sealed to an adjacent similarly shaped surface by pressure in forming the closed container (not shown) therefrom are identified by stippling as edge portions 192, 194, 200 and 202, adjacent strips 196, 198, 204 and 206 separated, respectively, from the portions 192, 194, 200 and 202 by score lines 195, 197, 203 and 205; a trapezium-form end portion 207 corresponding to a shape to be described, a substantially square side seam extension 208, and the full length of the side seam flap 209. The surface portions of the inside surfaces 186 (Figure 11) to which the food grade adhesive is applied, and which will be sealed by pressure in forming the closed container (not shown) therefrom, are identified from left to right in Figure 11 as pairs of edge portions 210/212,211/213,214/216, and 215/217, a side seam extension portion 218 adjacent the edge portion 217, an edge portion 220 of the side wall which the side seam flap is adapted to abut, and the extension 222 thereof which extends to the edge portion 210. The edge portions 211, 213, 215 and 217 are defined by the score lines 195, 197, 203 and 205, respectively. The respective widths of the edge portions 196, 198, 204, 206, 210, 212, 214 and 216 are the same as the width of any of the like edge portions 192, 194, 200, 202, 211, 213, 215 and 217. As indicated above for the Figures 1 and 2 embodiment, the respective overlapping or abutting panel portions of the Figures 9 and 10 and Figures 11 and 12 arrangements, to which the food grade adhesive have been applied, would require being pressed together while being processed on the forming, filling and sealing machine to complete the sealing therebetween. INDUSTRIAL APPLICABILITY It should be apparent that the invention provides novel means of sealing a liquid carrying container without requiring a thermoplastic hot melt, and without requiring the application of heat or high frequency vibration to the usual polyethylene coated outer and inner surfaces. It should also be apparent that the food grade adhesive could be applied to either or both the abutting surfaces of any top and/or bottom end closure configuration, as well as to the usual side seam flap and the abutting side wall edge portion to effectuate the sealing thereof. It should be further apparent that the food grade adhesive is applicable to either gable or flat top end closures, as well as to the flat bottom end closure. It should also be apparent that, by utilizing different types of pressure sensitive food grade (FDA approved) adhesive, a bottom end closure may be sealed so completely that it cannot be opened without causing paper tear, whereas a top end closure may be sealed without substantial paper tear and without the need for an abhesive material to facilitate the easy opening thereof, particularly since the thermoplastic surfaces adjacent thereto do not require being heated and sealed. While but one embodiment of the invention has been shown and described, other modifications thereof are possible within the scope of the following claims.

Claims: A liquid-carrying, thermoplastic-coated paperboard container, comprising a top end closure (12), a four-sided body portion (14) and a bottom end closure (15), wherein panels (18,24,40,42) thereof have pairs of thermoplastic-coated paperboard portions (26/111, 90/92, 116/118, 152/154, 213/214, 209/220,) of the panels (18,24,40,42) lying face-to-face with each other and these pairs of thermoplastic-coated, paperboard portions (26/111, etc.) are sealed face-to-face with each other in a liquid-tight manner, characterized in that thermoplastic surfaces of each of said pairs of thermoplastic-coated paperboard portions (26/111, etc.) are sealed together by a layer of pressure-sensitive, food-grade adhesive rather than having been sealed together by a melting effect. A container according to claim 1, wherein said layer of adhesive comprises respective coatings of said adhesive on the thermoplastic surfaces of each of said pairs of thermoplastic-coated paperboard portions (26/111, etc.). A container according to claim 1 or 2, wherein said top end closure (12) comprises a triangular fold-in spout panel (44) formed on the upper end of one (20) of the four sides (18-24) of said body portion (14), a triangular fold-in closure panel (46) formed on the upper end of a second (24) of the four sides (18-24) of said body portion (14), first and second oppositely disposed lower closure panels (50,56), first and second sets of triangular fold-back panels (62, 64, 82, 84) connecting said spout panel (44) and said fold-in closure panel (46), respectively, with said respective lower closure panels (50,56), and being folded against the latter, first and second upper closure panels (54,60) extending vertically from the respective first and second lower closure panels (50,56), and first and second infold lips (70,72,90,92) extending vertically from the respective first and second sets of fold-back panels (62,64,82,84) and being folded toward one another and sealed between said first and second upper closure panels (54,60), the thermoplastic surfaces sealed together by said adhesive being the exterior surfaces of at least one infold lip (70,72,90,92) of each of said first and second infold lips (70,72,90,92), the interior surfaces of at least one (90,92) of said second infold lip (90,92), at least one of the extreme left and right edge portions (100,102) of the interior surfaces of said first infold lip (70,72), and the interior surfaces of one of said first and second upper closure panels (54,60) except for portions (110,108) thereof directly opposite portions (106,104) of said first infold lip (72,70) not covered with adhesive. A container according to claim 1 or 2, wherein one of the top and bottom end closures (12,15) comprises first and second triangular fold-in panels formed on the respective adjacent ends of respective opposite sides (20,24) of said body portion (14), first and second oppositely disposed closure panels, first and second sets of triangular fold-back panels connecting said first and second triangular fold-in panels with said closure panels and being folded against the latter, the thermoplastic surfaces sealed together by said adhesive comprising substantially triangular areas (114,116,118,120,124,126,128,130; 151,152,154,156, 158,159,162,164) of the interior surfaces of said first and second oppositely disposed closure panels and of said first and second sets of triangular fold-back panels and the exterior surface (134-144; 170-174) of at least one of said closure panels. A container according to claim 1 or 2, wherein said bottom end closure (15) comprises first to fourth closure panels having edges converging towards the middle of the bottom end closure (15), the thermoplastic surfaces sealed together by said adhesive comprising interior and exterior surface portions (192,194,196,198,200,202,204,206,210-217) of the zones of those converging edges. A thermoplastic-coated paperboard blank for forming into a container for carrying liquid, comprising top end closure panels (12), first to fourth body portion panels (14) and bottom end closure panels (15), wherein panels (18,24,40,42,) thereof are for folding so that pairs of thermoplastic-coated paperboard portions (26/111, 90/92, 116/118,; 152/154, 213/214, 209/220,) of the panels (18, etc.) lie face-to-face with each other and wherein these thermoplastic-coated, paperboard portions (26, etc.) are for sealing face-to-face with each other in a liquid-tight manner, characterized in that at least one thermoplastic surface of each of the pairs of thermoplastic-coated paperboard portions (26/111, etc.) has applied thereto a layer of pressure-sensitive, food-grade adhesive. A blank according to claim 6, wherein said body portion panels comprise front and back panels (20,24) and a pair of lateral panels (18,22), said top end closure panels (12) comprise first and second oppositely disposed triangular gable panels (44,46) connected to the adjacent ends of said front and back panels (20,24), first and second oppositely disposed lower closure panels (50,56) connected to the adjacent ends of said lateral panels (18,22), first and second sets of fold-back panels (62,64,82,84) interconnecting said respective first and second triangular gable panels (44,46) and lower closure panels (50,56) for being folded against the latter, first and second upper closure panels (54,60), connected to said respective first and second lower closure panels (50,56) and having a first abhesive pattern (110,108) selectively formed on each interior surface thereof, and first and second infold lips (70,72,90,92) connected to each of said respective first and second sets of fold-back panels (62,64,82,84) for being folded toward one another between said first and second upper closure panels (50,56), and a second abhesive pattern (104,106) formed on the inside surfaces of one of said first and second infold lips (70,72,90,92) so as to be directly opposite said first abhesive pattern (110,108) once the blank is folded, the thermoplastic surfaces sealed together by said adhesive being the exterior surfaces of each of said first and second infold lips (70,72,90,92), the interior surfaces of said second infold lip (90,92), extreme left and right edge portions (100,102) of the interior surface of said first infold lip (70,72), and the interior surfaces of said first and second upper closure panels (54,60) except for portions (110,108) thereof adapted to be opposite the portions (106,104) of said first infold lip (70,72) not covered with adhesive once the blank is folded. A blank according to claim 6 or 7, and further including a side seam flap (26) and a side seam flap bottom extension, said bottom end closure panels (15) comprising four foldable rectangular bottom closure panels, two of which are each divided by diagonal score lines (117,119,127,129) into a central and two adjacent side triangular portions, and the other two of which each have a contoured extension formed thereon, the thermoplastic surfaces sealed together by said adhesive being the interior surfaces (118,120,128,130) of at least one of either of said two adjacent side triangular portions of said two panels divided by diagonal score lines (117,119,127,129), or to each of similar side triangular areas (114,116,124,126) of each of the other two rectangular bottom closure panels; and the exterior surfaces (134,138,140,144) of at least one of each of said two adjacent side triangular portions of said two panels divided by diagonal score lines (117,119,127,129), or to each of said central triangular portions (136,142). A blank according to claim 8, wherein the thermoplastic surfaces sealed together by said adhesive are the interior surfaces (178,120,128,130) of each of said two adjacent side triangular portions of said two panels divided by diagonal score lines (117, etc.), and similar side triangular areas (114,116,124,126) of each of the other two rectangular bottom closure panels, the full exterior surface (134-144) of each of said central and two adjacent side triangular portions of each of said two panels which are divided by said diagonal score lines (117, etc.), the interior surfaces (112,122) of each of said contoured extensions, except for a central triangular portion (115) of one of them, the exterior surface (133) of the latter contoured extension, and both the interior and exterior surfaces (131) of the side seam flap bottom extension except for an inner triangular portion (132) of the interior surface of the side seam flap bottom extension. A blank according to claim 6, and further including a side seam flap and a side seam flap top extension, said top end closure panels (150) comprising four foldable, substantially rectangular, flat top closure panels, one of which is longer than the other three, two of the other three of which are each divided by score lines (171,173,177,179) into a central and two adjacent side triangular portions, a single diagonal score line (169,175) forming a single side triangular portion on each of the fourth and the longer panels, a lift tab extension formed on one adjacent side triangular portion of one of said two divided panels, and a lift tab formed on an edge of said longer top closure panel, the thermoplastic surfaces sealed together by said adhesive comprising the interior surfaces (154,156,162,164) of at least one of each said two adjacent side triangular portions, or the interior surface (152,158) of each of said single side triangular portions and similar shaped side triangular areas (151,159) of said fourth and longer panels; the exterior surfaces (170-174) of at least one of the central and the side triangular panels of the other divided panel not bearing said lift tab extension (155); at least one of the interior surface (160) of said longer panel and the exterior surface (176) of the fourth panel; and at least one of the interior surface (167) of said lift tab or and the exterior surface (185) of an off-centre portion of the end of the body panel adjacent the divided panel bearing the lift tab extension (155). A blank according to claim 10, wherein the thermoplastic surfaces sealed together by said adhesive comprise the interior surface (154,156,162,164) of each of the four adjacent side triangular portions, the interior surface (152,158) of each single side triangular portion and similar side triangular areas (151,159) of each of said fourth and longer panels, the exterior surface (170-174) of one of said two divided panels adjacent said side seam flap extension, the interior surfaces (155,167) of said lift tab extension and said lift tab, both the interior and exterior surfaces (165,168') of the side seam flap extension, except for an inner triangular portion (166) of the interior surface thereof, the interior surface (160) of the edge portion of the longer top closure panel, the exterior surface (176) of the edge portion of the fourth panel, the exterior surface (180) of a central edge portion of said one of said two divided panels and the exterior surface (185) of an off-centre portion of the upper end of the body panel adjacent said last-mentioned one of said two divided panels. A blank according to claim 6 and further comprising a side seam flap and a side seam flap extension, said bottom end closure panels (15) comprising four foldable bottom closure panels connected to said side seam flap extension, each of said bottom closure panels having converging outer edges, and two of said bottom closure panels each having two diagonal score lines (195,197,203,205) formed thereon defining a central triangular panel portion and adjacent edge portions with the respective converging outer edges, said thermoplastic surfaces sealed together by said adhesive comprising the interior surfaces (210-217) of at least one of the edge portions of adjacent bottom closure panels, and at least one of the edge portions of extreme right and left bottom closure panels; and the exterior surfaces (192,194,200,202) of at least one of each of said adjacent edge portions beyond said respective diagonal score lines (195,197,203,205), and an area (196,198,204,206) on the opposite side of each of said diagonal score lines (195,197,203,205) of the same width as said respective adjacent edge portions. A blank according to claim 12, wherein said thermoplastic surfaces sealed together by said adhesive comprise the exterior surfaces (192,194,200,202) of said adjacent edge portions, portions (196,198,204,206) of the exterior surface of each of said central triangular panel portions adjacent each diagonal score line (195,197,203,205) of the same width as said adjacent edge portions, the exterior surface (208) of said side seam flap extension, the interior surfaces (210-217) of the edge portions of each of the four bottom closure panels of widths equal to said adjacent edge portions, and the interior surface (218) of a triangular half of said side seam flap extension adjacent one of the latter edge portions. A blank according to any one of claims 8 to 13, wherein the thermoplastic surfaces sealed together by said adhesive include at least one of the exterior surface of said side seam flap (26) and the interior surface (111) of the edge portion of the body panel (18) farthest away from the side seam flap (26) and to a width equal to the width of the side seam flap (26). A method of forming a container for carrying liquid, comprising bringing face-to-face with each other pairs of thermoplastic-coated paperboard portions (26/111, 90/92, 116/118,; 152/154,; 213/214, 209/220,) of thermoplastic-coated, paperboard material (10) and sealing together thermoplastic surfaces of each of said pairs of thermoplastic-coated, paperboard portions (26/111, etc.) in a liquid-tight manner, by a step comprised of pressing each pair of thermoplastic surfaces together, to form a top end closure (12), a body portion (14) and a bottom end closure (15), characterized in that a layer of pressure-sensitive adhesive is applied to at least one of each pair of said thermoplastic surfaces before said pairs of thermoplastic-coated paperboard portions (26,111) are brought face-to-face and in that the layers of adhesive are caused to seal their pairs of thermoplastics surfaces together through said pressing rather than through a melting effect.

Inventors: DAUZY BRUCE CALVIN, ESPER LEO JOSEPH, JORGENSEN DAVID CHARLES, MURRAH HOWARD ELWOOD, PHILIPS RAYMOND MICHAEL, SCHNEIDER MICHAEL GEORGE, DAUZY, BRUCE CALVIN, ESPER, LEO JOSEPH, JORGENSEN, DAVID CHARLES, MURRAH, HOWARD ELWOOD, PHILIPS, RAYMOND MICHAEL, SCHNEIDER, MICHAEL GEORGE
Applicants: ELOPAK SYSTEMS, ELOPAK SYSTEMS AG
Application year: 1991
Main classification: B65D5
IPC codes: B65D5