US2944715A - Package - Google Patents

Description

July 12, 1950 J. G. vERGoBBl 2,944,715

PACKAGE Filed Sept. 10, 1957 3 Sheets-Sheet 1 July 12, 1960 J. G. vERGolBl PACKAGE 3 Sheets-Sheet 2 Filed Sept. l0, 1957 INVENTOR.

F ig. 7

. frraR/YEY United States,

PACKAGE John G. Vergohbi, Quincy, Mass.; assignor to Pneumatic Scale Corporation, Limited, Quincy, Mass., a corporation of Massachusetts Filed sept. 1o, 1957, ser. No. 583,184v 1 claim. (ci. 229-14) This invention relates to a package andmore particu- Alarly to a liner bag for a package.

The invention has for an object to provide a novel seams wherein'provision is made for preventing leakage through the side seam portions occurringv at thev end closure seams in a manner such as to produce impervious end closures.

A further object of theA invention is to provide a novel and improved method of Vforming agliner bag of the character specified in a novelA manner such as to provide an impervious end closure.

With these general objects in view and such others asv may hereinafter appear, theinvention consists in the package embodying a leakproof linerfbag and in the method of making the same as hereinafter described and particularly defined in the claims at the end of` this specification. Y

ln the drawings illustrating the preferred embodiment of the invention: Y

Fig. 1 is a plan view of a sheetof liner bag material from which the present liner bag is produced;

' Fig. 2 is a perspective view illustrating the sheetiof bag forming material wrapped about a mandrel Vand provided wtih a longitudinal faceto-face side seam to form a rectangular tube;

Fig. 3 is a cross sectional -view taken through the side seam on the line 33 of Fig. 2 and illustrating a feature of the present invention;

Fig. 4 is aview similar'to Fig'. 3 showing the faceto-- face side seam' folded flat againstthev wall of the liner bag; l 'I Fig. Sis a perspective view'of the bottom 'end closure' of the liner bag; "f

Fig. 6 is a' cross sectional view 'through a portion 'of the bottom end closure as taken Yon the line' 6L'- 6fof FigqS; i s Fig. 7 is a front elevation'of the portion ofthe end closure as seen from the line 7--7 of Fig. 6; 'f

Y Fig. 8 is a perspective view of the completed bottom endclosure; w f1 j Y Fig. 9 is a perspective view of the liner bag placed vina carton; .7 M. 1

Fig.V 10 is a perspective view of the upper 'portion of the lined carton showing 'the top end closure partiallyv ffermed; Y Y fr Fig.' 11 is a similar view showing the Acompletely formed fonemi closure; and l j Fig.vv 12 is a perspective view of the c ornpletely'sealed vpackage ln" general`the'` present invention contemplates a novel and improved leakproof package and a method of makthe adjacent innerface of the opposing wall of the heatl ing the same'comprising a liner bag and aY carton where-` sealed face to face'by the application of heat and pres' sure. In the illustrated embodiment of the invention the sheet material provided with the thermoplastic coating is folded to form a rectangular tube having alongif Ytudinally extended -face-to-face side seam sealed .by the application of heat and pressure. The top and bottom end closures of the liner bag are also formed byelongated face-to-face heat sealed seams to produce a completely sealed liner bag.

In practice it has been foundv that in the formationof the longitudinally extended face-to-face side seam a relatively small longitudinal groove or gap is formed on the inner surface of the liner bag defined by a slight separation or break in continuity of opposed portions of the bag form-ing material at the bottom or inner endA of the side seam, andwhen the end portions of the bag areA subsequently folded and heat sealed in face-to-face relationV with extended portions of the side seam it was found that a relatively small and substantially triangular channel was formed in each end closure defined bythe side seam groove in one wall of the end closure and sealed end closure through which nely divided or liquid and semiliquid material may leak. In accordance` with the present invention provision is made for closing such relatively small channels in the end yclosures in a novel manner'whereby'to renderl the package leakproof and capable of being used for packaging finely divided and liquid or semiliquid products.

" An example of theproducts which may be contained in the present package includes a dehydrated food prod- 'sion of relatively thick auxiliary strips of thermoplastic adhesive applied to` the liner sheet at the end closure portions of the subsequently formed heat sealedV side seam and end closures which serve to close the relatively small openings during the formation of the liner bag. The present package is capable of being produced in a high speed packaging machine wherein the liner bag is formed by wrapping the liner sheet about a'mandrel and forming the face-to-face heat se'aledside seam and a bottom closure whereupon a prescored carton blankv is folded about the mandrel and the liner bag and s'ealed along/aside seam.' The bottom flaps of the carton are' then folded and sealed while supported on the mandrel. The lined carton is then removed from the mandrel and filled with the product being packaged whereupon the lining bag top closure is for-med and the top closure flaps of the carton are folded and sealed to complete the package. Y

Referring now to the drawings, 10 represents'a' sheet f flexible fibrous lining bag material which mayand preferably` will comprise a moistureproof material provided with a relatively thin coating of thermoplastic adhesive on one facethereof 'comprising the inner face of Vthe applicationv of heat and pressure. As shownin Fig2;

the liner sheet 10 may be wrapped about a mandrel 12 Patented July 12 19 60 being brought'togeth'er in face-'to-face relation andnsealed Y by the application of heatk and pressure to provide a longitudinally extended n type sealedfsde seam'l.V

In thefprodiictionof the bag then'rtype. seal isrformedfV by aPQir of cooperating pressure bars, at least one of which is heated, and which are clampedV against qoppcsed sides of thel seam'to effect the heatl seal. `In. practice the inner or. bottom Vportion of Vthe seam, where the flexible bag formingl material is bent upwardlyV at right angles to the block, defines arelatively small groove or gap indicated at 20- in Figs. 2 and 3.

Theiin type sideV seam 18 is subsequently folded flat against the side wall of the tube, as shown in Fig. 4, and thereafter the extended portions of the tubular structure are folded, as shown in Fig. by spreading the extended end walls 24, 26 outwardly and folding the opposed extended side . walls 28, 30 inwardly in face-to-face relation providing an elongated end closure which is also subjected to heat and pressure to form an adhesive seam 32. It will be observed that one of the extended side walls 2Sincludes a portion of the side seam 1S, and when the side walls 28, 30 are brought face to face the side wall 30 extends acrossthe small groove or gap 2t) forming with the groove a substantially triangular channel indicated at 34`in the sealed closure seam 32, resulting in a small opening from the interior of the bag to the atmosphere.

The vertical dottedrlines shown in Fig. 1 represent the lines upon which the unscored lining sheet is folded to produce a tubular container having a iin type side seam, land the horizontal dotted lines shown in Fig. l represent the fold lines produced when the top and bottom end closures are Yformed to provide the iin type end closures. Thus, the vertical dotted lines 13, 15, 17, 19 represent the fold lines produced when the lining-sheet is wrapped about longitudinal edges of the forming block, as shown in Fig. 2, and the Vertical dotted lines 21, 23frepresent the fold lines produced when the marginal edges 14, 16 are folded into face-to-face relation to provide the longitudinally extended side seam 18. The horizontal dotted line 2S shown at the lower end of the lining sheet disclosed inFig. 1 represents the fold lines Vproduced when the extended portion ofthe tubular container isfolded to produce the lining bottom closure while supported upon the forming block, and the horizontal line V27 represents the, folds produced when the lin type seam 32 is formed. Similarly, the corresponding lines 29, 31 at the upper end of the lining sheet are produced when thertop closureV isformed. The angular fold lines 33 andthe relatively short vertical fold lines 35 represent the lines produced whenfthe triangular end tabs are formed in the top and bottom end'clorsures as illustrated in Figs. 5 and l0 respectively.

The above description of the formation of the liner bag conforms substantially to the manner of producing the fin typesealed linerbags of the prior art, and in accordancelwiththe present invention in order to effectively seal such end closure opening 34 during the formation of the liner bag, the liner sheet is provided with relatively small and thick auxiliary strips 36, 38 and 40, 42 of a thermoplastic adhesive, preferably a so-called hot melt adhesive applied on top of the thermoplastic coating. The auxiliary strips of hot melt adhesive are applied adjacent the corners of the sheet in a selected location such that when the longitudinal side. seam 18 is formed a portion yof opposed hot melt adhesive strips 36, 38 at the outer orbottom closure end of the tube will be inconfronting relation between the folds of the side seam 18, and likewise a portion of opposed strips 40,A 42 at the top closure end of the tube will also be in confronting relation between the folds of the side seam 18. AsV shown in Fig. l, the auxiliary strips 36, 40 areplaced at right angles to the subsequently formed fold line 21, and extend equidistantly'on both sides of said fold line. Likewise, the auxiliary strips 38, 42 ,are similarly disposed relative to the subsequently formed fold line 23. Thus, when heat and pressure is applied to Seal the side seam 18 by virtue of the thermoplastic coating on the inner face of the sheet, the confronting portions of the hot melt adhesive will be melted to flow into and partially close the groove 20 at each end of the seam as indicated at 44 inFig, 3g The remaining portions of the hot melt adhesive strips which are in contact with the unheated mandrel will remainintheir hardened and unmelted condition, as `indicated in Fig. 3, and the melted portions 44 partially filling the groove will set up into its s olidform substantially immediately upon removal of the heat sealing apparatus.

Thereafter, when'the elongated'end closure seam 32 comprising the bottom closure is formed by the application of heat and pressure, the remaining hot melt adhesive portions extended 4betweenthe Avfolds of -the seam 32 Will be activated to iow into the groove-20 and merge with the previously activated portion 44and completely iill the channel 34 to providein effect a plug of adhesive 45 to form an impervious end closure as indicated in Figs. 6 and 7. The bottom closure seam 32A is then folded flat against the bottom wall of the liner bag and the laterally extended tabs 46 48 formed by the end closure operation are preferably folded against the end Walls of the bag as shown in Fig. 8.

A prescored carton blank 49 provided with the usual end closure flapsis then'wrapped about the mandrel and the liner bag'v carried thereby and sealed along overlapping marginal poltions to provide a side seam in the usual manner whereupon the ybottomilaps ofthe carton are folded andsealedrto complete the 4bottom closure. The lined carton is then removed from the mandrel in the condition shown in Fig. 9 andndelivered to a filling machine where the product being packaged is deposited into the lined carton. The extended mouth portions 47 of the liner bag are then folded and sealed in the same manner as the lining bottom closure to provide a top closure havingan elongated face-toface heat sealed seam 50 wherein the remaining portions of the second pair of cooperating hot melt adhesive strips 40, 42 extended between the folds of the seam 50 are melted and caused to flow into the channel opening to provide a hermetic seal for the mouth of the bagV as illustrated in Fig. 10. The seam 5t? is then folded flat, vand the laterally extended tabs 52, ,54 are folded inwardly on top of the bag, as shown in Fig. l1, whereupon the top closing flaps lof the carton are folded and sealed toproduce the completely sealed package shown in Fig. l2.

In practice the moistureproof liner bag material may be provided with a relatively thin thermoplastic coating such as a vinyl plastic coating which` servesV to produce leakproof heat sealed seams at all sealing points where the material is brought together in face-to-face relation without any intervening breakin continuity of the seam, such as occurs when the ends of the sideseam 18 are included in the end closure seams. In other words, there is no leakage laterally through the seams thus produced, and the channel formed by the side seam portion occurring in the end closure portion is effectively sealed by the provision' of the relatively thick auxiliary strips of hot melt adhesive as described. In practice the melting point of the vinyl plastic coating andthe melting point of the hot melt adhesive is preferably about the same, although some variation in the` melting point of the different adhesives may occur within a limitedV range. For example, it was found in practice that a selected vinyl thermoplastic coating having a melting point between 300" and 325 F. used with a selected hot meltV adhesive having a melting point between 275 andA 300 F. served to produce hermetically sealed liner bagseams,

the relatively lower melting point -ofv the hot melt ad- 'van hesive serving to assure free ilowing of the same into the channel opening during the heat sealing operation.

From the above description it will be seen that the present package embodying a hermetically sealed liner bag provides a novel structure preventing leakage through the channels formed by the side seam portions included type end closure seams form channels which may be effectively sealed by the provision of auxiliary strips of adhesive in the manner described. It will also be apparent that the present liner bag may be used alone as a container if desired. The invention also contemplates the use of a paran coated bag forming material halving fin type seams formed by fusing of the paran coating and provided with auxiliary strips of hot melt adhesive for sealing the channels in the end closure seams as described.

While the preferred embodiment of the invention has been herein illustrated and described, it will be understood that the invention may be embodied in other forms within the scope of the following claims.

Having thus described the invention, what is claimed A package comprising a liner bag formed from a sheet having a relatively thin coating of thermoplastic material on the inner face thereof and having a heat sealed face-to-face longitudinal side seam and a heat sealed face-to-face transverse end closure seam in which a portion of the side seam occurring in the end closure seam forms a channel opening defined by the inner ends of the side seam fold in one wall of the end closure and theA inner face of the opposing wall of the end closure,

said sheet being provided with opposing relatively thick strips of thermoplastic adhesive applied to the inner face thereof adjacent the side seam portions occurring in said end closure seam, the completed end closure seam having a plug of thermoplastic material closing said channel opening formed by melting and owing of said auxiliary strips of adhesive during the heat sealing operations.

References Cited in the ile of this patent UNITED STATES PATENTS

Images