US2438981A - Packaging method - Google Patents

Description

April 6, 1948. v H. F. WATERS PACKAGING METHOD 3 Sheets-Sheec l.

- Original Filed Oct. 5, 1940 FITTO RNEY BYv April 6, 1948. H, F, WATERS 2,438,981

PACKAGING METHOD Original Filed Oct. 5, 1940 3 Sheets-Sheet 2 INVENT OR.

HTTORNE Y April 6, 1948. H. F. WATERS 2,438,981

PACKAGING METHOD Original Filed Oct. 5, 1940 5 Sheets-Sheet 5 IN VENTOR.

HTTORNEY N .BY Wm Patented Apr. 6, 1948 Harry F. Waters, New York, N. Y.

` Application August 16, 1941, Serial No. 406,496, which is a division of application Serial No.v 359,823, October 5, 1940. Divided and this application October 6, 1945, Serial No. 620,773

4 Claims.

.which application isa `division of application Serial No. 359,823 iiled October 5, 1,940,` now Patent 2,252,106 of August 12, 1941.

, The product with which the present invention is primarily concerned is a container of generally moisture-proof and Vfluid-,tight character comprising an outer cartonhaving at least some iiexibility and strength and an inner bag or liner fluid-tight and heat fusible at least on the inner face thereof.1 I have `found that in containers of the described character it is ,desirable to provide a bag which is bigger than the inner space of the carton so that in the iilled andsealed condition of the bag it will be supported by the carton throughout the entire surface thereof. In `other Words, the liner may be` of a relatively Weak material provided it has good fluid-tight qualities since the stresses occurring during transportation and storage are taken up by the `outer carton.` `Containers of the described character have obtained great importance in the packaging art and are disclosed, for example, in my copendingapplication Serial No. 191,860, iiled February 23, 1938, Whichhas become abandoned.

Heretofore, fluid-tight containersV of the` described character have been generally made by separately forming a liner bag of the desired size and attaching such bag in its original flat or collapsedI` condition to a carton blank. Another method disclosed in my` co-pending application Serial No. 329,254 Viiled April 12, 1 940 (now Patent No. 2,228,647) ,involved attaching a iiat liner sheet to the carton blankand simultaneously forming a tubular carton structure and a tubular or envelope-like liner structure Within this carton, In `both of these instances the container was formed in-its fiat or collapsed condition and was subsequently erected prior to i`1lling. Various problems Werel encountered in forming fluidtight containers by means of these methods particularly when it Was desired to use a four-sided carton. As those skilled inthe art know, it is diicult, if not impossible, to directly and adhesively secure a collapsed envelope or bag to a `collapsed four-sided tubular carton due to the fact that upon erection a container of this type develops substantial stresses in the bottom seam thereof. 'This can be avoided only by leav- (Cl. Bft-3.6.01) t ing the liner open at both ends which are sealed only after the container has been erected. This, of course, involves performing bag making operations at the filling station` and to some extent complicates the `use of thisA type `ofcontainer.

It is an object of the'presentinvention to provide a packaging method which completely eliminates these disadvantages fand inconveniences of prior procedures'.`

It is another objectlof `thepresenti` invention to provide a continuous method ofpackaging `which starts out ifrom `a heat-fusible: and fluid-tight liner material and form or erects such material about a mandrel.

i It is a further object of the present invention to provide a novel andlimproved method of forming duid-tight, duplex containers` involving heat sealing a` fluid-tight sheet material on a mandrel and thereafter combining such erected and uid-tight bag withfa carton either by pushing the erected bagintov an erected carton or by wrapping the, 'carton blank around the erected bag while it is still on the mandrel.

. It is also Vwithin the contemplation of the invention to provide a method oflforming fluidtight and hermeticallysealed lpackages which operates in a direct and continuous manner starting from the `sheet-like liner material and fromthe iiatcarton blank and converts such materials into anished'and hermetically sealed fluid-tight package.

Still another object of the present invention is liner or bag integrally formedfrom a single sheet of material; x L 1 f Fig. 2 depicts a longitudinal sectional view taken on line 2--2 of Fig. 1; a i A Fig. 3 shows a `perspectiveview of a mandrel having a, fluid-tight liner material wrapped around it and sealed ,along its longitudinal edges;

Fig. `4 is a horizontal sectional viexvsomewhat` fragmentary in character, andstake'n online 4 ,4 0f Fig. 3;;

Fig. 5 illustrates a perspective vient, `having portions of the bag ilattened a somewhat reduced scale adapted to be combined Fig. 7 shows a perspective view of the liner supported by a mandrel after it has been combined with a carton;

Fig. 8 is a similar view of the nished Yand lined carton in its erected condition during the filling operation;

Fig. 9 illustrates a perspective View V of the top portions of the filled container. with the ',rriouth o le p 'rie dened by the upper hinge lineslv `Jf lthe earch; K Y

Fig. 10 is a similar View of the top part of the container in the position in which the collapsed mouth portions of the liner bag are hermetically Sea1ed;.

Eig llis a similar. VieW '.offt'he finished lled anseeled glaackage, the. top flaps oi the carton being zonen. i or clarity' .of 3illustration ;v

Figlzyigllustrates a tcp elevational view of a melted baefadapted to -be used in the method Ojbe invention;l

ligplY depicts a ltrans.'ferse sectional view taken on line I3--l3 .of Fig. I2;

Eig. 1 4 vshows the bag illustrated in Figs. 12 and '13 erected o na mandrel;

Fig. `15 is a top eleyatibnal vlewof a'six-sided carton blank adapted to "be combined viththe erected bag;

Fig. 16 is, aperspective view ofthe erected bag combined with the carton;

Fig. 1'7 represents the carton kand bag removed frojmthe mandrel `upon which they were formed and ina collapsed condition in which they may be stored. and shipped prior Vto use; and

Fig. 18 is a perspective view'of the carton and bag in its erected form during the vfilling operation.

Generallyv speaking, the containers ycontemplated by my invention have to `'satisfy certain importantconsiderations. 4First of all, it is of great importance that in theerected and filled conditionof 'the'packaga vthe inner fluid-tight bag should be greater than the inner space "of the carton ksu that the relatively weak material of the bag is supported by the carton-walls throughout the entire surface thereof rthat Vis the'inner'liner orfba'gris bigger than the buter carton and'after fllli'ngi'and sealing of the package Vis 'fully "supported by the cartn throughout the'entirej surface thereof. Another important condition "of `prvi'di-ng Ia completely fluidtight and le?akage-'prcic'if V'container is that the inner bag should be formed as farvas possible exclusively by means of completely flat 'seams so lthai-,in thesealedfregions not more than two layersfof-'material are placedina face to face position. 'Experience hasdemons'trated 'that in the, eventthatreentrant folds, intervening layers 'of materlalsand'similar regionsv are present in which there are more than two layers ef the liner material included. such regions will be greatly subject to the danger Iof leakage dueto the nonunifiormA` thickness of the liner materials therein. g Y

In' accordance wlthmyfinven-tion, I first provide'a 'liner or "envelope'preferably formed! of a single sheet of' material which i'suid-tightfand fusible at least on one face thereof. Preferred examples of- `:these `fusible or 'thermoplastic Ina- 1 Sides and-attire tou-.bm isbtaineu. Tn

terials are a sheeted rubber hydrochloride product known by the name Pliolm, synthetic resinous materials sold under the name Koroseal, Vinylite, and the like. These sheets may be employed in the form of a self-sustaining lm or layer or in the form of a layer Coated en or laminated `to a sheet of fexible material, such as paper. rThe latter procedure has the advantage that the liner material may be made fusible on one face and is non-fusible on the other so Ythat heat and pressure may be applied to the 'fusible portion through the unfusible portion whereby adherence of the material to the heat `sealing members is prevented. A bag or envelope may be 'formed in flat form by means ol folding `-av s'hetu of such laminated material about ainedi'al line and heat sealing the resulting structure at least at two lateral edges thereof whereby an envelope closed at three sides and open at one side is obtained. The result is a liner bag Aor envelope in flat form ha'vinga continuous "coating of fluid-tight material throughout the Aentire 'inner surface'ther'eof, vfin which bag or envelope Vcan be 'squared-upand erected upon a mandrel. This erecte'dbag which is closed at the bottom and is v'open-'alt the top may now beipus'he'd into an erected tubular carton, or a'cartonblar'ik of suitable fch'aracter and of appropriate diiiensions may be wrapped around the bag yand lmaybe adhesively Asecured thereto vwhile the bag is still on lthe mandrel After the mandrel is withdrawn, a siiuare'd-up carton having a squared-up linertherin is p'rcvided `and may be fuled'with a'ccinmdity in any conventional 'mannen After "llin'g`-, the mouth portions'of the linerbr bag 'are collapsed and are hermetically 'sealed p'referably by `|the application of heat and pressure 'along fa `trans.- verse strip. Thereafter, the resulting 'tabs of :the liner or'bag may be'foldedinto `th`e 'in ner space of the carton and the'aps'inay be'ilosd'ther'eabout. Y v n i Referring now more particularly to the draw'- ing's, Figs. 1 and -2 'illustrate a bag Icirenvelope of thefsocalled seamless bottomtype employed in the method of the-present invention. 'It will be noted that 'this -`bag `essentiallychilipris'esy 'a Sheet l 'Strip "l Of 'x'blellatral 'Sbl "a't least on" theinner face'the'reof. This sheet-is folded' about'a transveselnedial litre i2 tob'l'ir'ig its edges "into registering positin. The Aesulting structure Iriaybefsea-ledby thefapplicatlnof heat and pressure "to two lateralargihalfstrips 3 thereof, Ahereby "an "enve-ldpeclsed j'zvttthe may now be erectedr'squared-u Aen "af d 'whereby the structure illustrated 'in 1F;

obtained. The netseaied. rgles fsf are lattened inthe pllaiie'of fthe two `sid`e walls mandrel andfrithe?'saineV direeticn wherb e are convertediirito long 'udnal -nsr'jf''absf will beprovided attirer ena df tnejside' transfer the erected bag and maybe?subsequently'vflled inWal'ds'ir-ito the-'Diaria `f the fbdttdmfwaill -"f`='ille= bag.' Y A inte which it y"was irisrted..V The tr-asenx dlfllcultywas` Obvious. "1in-'or' r t'o f the sneetjoftne bagfma 'menaient adi be'tfgntiy wrappedareunu tnefmandrei and sineetne'uivinensions of the mandrel had to be necessarily smaller than the dimensions of the carton into which mandrel and bag were subsequently inserted, the bagwas necessarily at least slightly smaller than the inner space dened by the erected carton. Thus, after the bag was lled with a fiowable or fluid commodity, the inner pressure on the inner walls of the bag was unable to obtain supportfrom the walls of the carton. As aresult at least a portion of the inner liner remained unsupported by the outer carton, causing frequent rupturing or tearing of the bag and loss of the contents during transportation and storage. I have now discovered that this diiliculty may be eliminated in an extremely simple manner by means of heat sealing the liner material on a mandrel in such a way that the heat sealed region is at a substantial distance from the mandrel surface. I have found that when the resulting seam is flattened into the plane of one of the walls of the erected bag, a structure is obtained which is capable of relative displacement and of an increase in size until the bag is fully supported by the carton Walls. This seam structure which operates in the manner of an expansion joint or slip joint will be best understood from the contemplation of Figs. 3 and 4.

Asit will be observed in Fig. 3, sheet I which is fluid-tight and fusible on at least the inner surface thereof, may be preformed into bag or envelope shape, or it is wrapped about mandrel 4 in such a manner that its longitudinal edges are brought into a face to face position. Thus, liner I has been converted into an erected structure having main panels 1 and 8 and end panels 9 and I0. Two fins 5, corresponding to ns 5 in Fig. `5, are obtained, extending along the medial lines of end panels 9 and IIJ of the bag. The two layers of liner material in these fins may be permanently secured to each other by applying heat and pressure along a longitudinal marginalstrip thereof. This is preferably accomplished by means of heatsealing members II and I2 extending in longitudinal direction parallel with the end panels of mandrel 4 and of the bag. Preferably, one of these heat sealing members I2 is heated by means of an electric resistance or heating element (not shown) to 'a temperature at which the coating or laminating material of the liner is fusible. The other member II is preferably constituted of an at least partially resilient material such as rubber. It will be readily noted that sealing members II and I2 operate along a strip of the bag material which is remote from the end walls of the erected bag on mandrel 4, the distance being denoted by reference character I3 in Fig. 3. Thus,y after the sealing operation is completed, the sealing members are withdrawn, and the resulting fins 5 are flattened into the plane of end panels 9 and I0, there will be an unsealed strip incorporated into the fins corresponding to distance I3 in Figs. 3 and 4. The result will be that the two halves of end walls 9 and I0 of the bag may be displaced to a moderate extent from each other under the effect of internal pressure whereby a slip joint or expansion joint-like effect is obtained. In other words, after the bag is inserted into a carton of appropriate dimensions and is filled with a fluid material, the bag is capable of slight expansion under the pressure of the contents, this expansion not exerting any appreciable pressure on the material but being taken up by the said yslip or` expansion joint. This expansion continues until 6 the" inner filled bag is completely supported by thefouter carton throughout the entire surface thereof. Y

'Whether the bag is rst formed flat and then erected on amadrel or it is directly made in erected form on a mandrel, the structure illustrated in Fig. 5 is obtained. In order to obtain a completely satisfactory reinforced huid-tight package, it` is necessary to combine the erected bag with a carton. `This may be accomplished in various Ways. Thus, in the simplest case an erected carton of suitable dimensions may be formed and the bag may be pushed into the carton While it is `still on the mandrel. After withdrawal of the mandrel, the package is ready for lling. Another possibility is to provide a carton blank 23 of thetype shown in Fig. 6 having main panels 'Ia and 8a and end panels 9a. and lila corresponding `in dimensions and arrangement to similar panels 1, 8, 9 and` I0 of the erected bag. Main panels 'la and 8a are 'provided with top and bottom iiaps I4 and" I5, IE and I1, respectively, while similar flaps I8 and I9, 20 and 2| are provided for end panels 9a and. IIIa. A conventional glue flap 22 is provided at one end of the carton blank. In carrying this modification of my method into practice, carton blank 23 is wrapped around the erected bag and lglue flap 22 is secured to the corresponding portion of end panel 9a. If desired. the carton and the bag may be adhesively secured to each other although in most cases this is not necessary. The resulting structure Will be best observed in Fig.,7 which clearly shows the tubular carton with its` top and bottom flaps extending in opposite directions and mandrel 4 Within the bag.

The next step in my novel packaging method involves closing the bottom flaps of the carton around tabs 6 of the bag `which are likewise folded into the inner space of the carton. The erected bag may nowlbe filled through a lling device 24 with a predeterminedlquantity of the commodity to be packaged. Hereafter, the mouth portions of the inner bag extending beyond vthe main body portion of the `carton may be collapsed or brought into a face to face position and may be hermetically sealed by the application of' heat and pressure across a transverse strip thereof.

As ithas been pointed out in the foregoing, in order to provide a positively fluid-tight and leakage-proof package, it is desirable tohave a structure comprising only completely flat seams. The principles governing this type of seams are disclosed in my copending application Serial No. 329,254 referred to in the foregoing. I have found that in a carton and bag structure having lateral fins` flattened into the plane of one or more panels of the bag, certain conditions have to be satisfied in order to permit the provision of a completely fiat transverse top seam with. a minimum of liner material. In order to obtain this result it is necessary to flatten mouth portions 30 of the bag into the plane defined by the hinge lines of the top flaps of the carton and in the direction in which the fins extend. This will be best observed in Fig. 9 in which mouth portions 39 of the bag are showncollapsedA against each other and brought into a substantially horizontal position'. A flat top seam may be applied 4 to the mouth portions of the inner bag already from center line 26 of the package. (Fig. 10.)

gassosi in this. .position the collapsed mouth portions are readily accessible to Ia :heat sealing device :of suitable character and a transverse heat seal or seam 27 may beapplied thereto hermetically .sealing the inner 'bag'. Thereafter, the resulting talos 2.8 jand V29 may be' folded as Vshown lin Fig. .11, and top aps 1d, i6, ISB andi!! .closedthereabout and secured in Asuch Yclosed position by means of a-suitable iquick drying adhesive Whereb'ya fluid-V tight .package is obtained vsatisfying /all iof the important considerations :set forth in the foregoing.

While lin the foregoing .a bag fof the 'seamless bottom type has vbeen described, .'Figs. V`1:2 `to 18 illustrate my .novel .method .of :packaging applied to `a ybag .having fan fL-shaped continuous seam incorporated therein. .A bag .of this type may .be made .in at form by providing sa sheet '31, fluidtight vand fusible :on iat least ione face thereof, which is folded over :about ailongitudinal medial line 32 `to bring .its edges into .registering position. L-:shaped marginal area :3-3 extending 'along one of the longitudinal edges `and, one vof the transverse .edges Aof this folded `structure 4convert-,s `the san-ie intosa dat bag closed .at three A:sides .and .open at one side.

The first step 1in V,this modi-ned packaging method iis to erect the bag' on a mandrel T34 whereby the `structure illustrated in Fig.. i4 is obtained. It will be noted that upon erection the bag will-have .a `pair of main panels .35 :and 3o and apairfof end panels 3l and 38. The L-shaped seam 33 Will-be converted into a longitudinal fin 39 and a transverse bottom -fin 4U. In addition, vertically depending tabs YM and l2 vare:obtained at the places Where the end panels merge With the bottom panel of the erected bag. erected'fbag on the mandrel vmay vbe combined 'with a Ycarton of suitable dimensions and 'having least the same number of panels, or Walls, fas the erected bag. vThis may be accomplisl'iedZ for example, by simply pushing the bagz While it is still on vthe mandrel, into an `'erected four-sided carton. Another possibility, whichlis preferred in some cases, involves `vvi'rapping a carton of appropriate shapearound the erected bag. This" `carton maybe a four-sided carton-of tlie'type shown in Fig. 15 `having main panels 35d and 36d, end ,panels 31a and 36a corresponding in dimensions and arrangement to panelsSli, 36, 31 andSB of the bag. Main panelsv 35a and are provided with conventional -top and bottom flaps v11? and 4E, '45 and do, respectivelywhileend panels 31a and 33a are provided with similar top and bottom " flaps 4l and 48, 49 and '59, respectively. A conventional glue ilap 5I is connected to main tpanel 36a and is adapted to cooperate With the corresponding .portion of end panel 31a to'` convert theicarton into a tubular structure. Adhesive lines 52 are provided on the main and end panels'and have the object tosecure Athe bag' tothe carton.

In the event that after combining the carton with the bag th? 'fesfil'fig .S''ulcfdlef .isf imma; diately lled'and sealed, these adhesive'lines may be omitted. On the other hand, ifit lis proposed to remove .the container .comprising Vthe carton and Vthelinner bag and to ship it in collapsed form to a filling station, one can prpvide medial Score .lines -53 ,and .54 in @dreads Sie and 38a @webdvdx-webbe@ a Six-sided' Structure yIn thiscase the duplex container may be collapsed on these medial score lines53 Iand reduced. The carton and inner ibas may .also

bo collapsed on .corner fold lines. I

The structure. obtained. after combining the carton with the bag is .shown in'Fg. T6 illustratng the carton and bagwhile they are stil-1 on mandrel 34. Upon Withdrawal of themandrel, the container may he. `either collapsed on medial fold lines 533 and "54,l as this is shown in Fig. 17., or :the 'bottom aps 'of the carton may be: closed and the inner bag maybe filled With-a1eommodity through a conventionaliilling .device '5.5. .After filling, the mouth .portions of the inner bag are collapsed into. a face to face position and are hermetically sealed by applying heat and pressure. to a transverse marginal strip thereof.

In forming this top `closure or seal .for the in.- ner bag` the 4same lconditions have to be oonsidered as were explained in connection rwith the previous embodiment .of my invention. In other Words, in view -of the presence rof 4a longitudinal 1in .39 in one of the end .panels of the bag, the closed top portions of the bag must lbe first folded into the plane deiined by the top hinge lines of the .carton .and in the direction determined by the fin. Hereafter, heat and pressure may fbe applied to the mouth portions of the bag across fa transverse `strip thereof jor .these flatten-ed mouth portions may be first folded vertically upwards .in which postion they .are more accessible to a heat sealing device. After the top closure has been made, the resulting tabs of the bag vare folded into the carton and the top flaps ofthe carton are closed thereabout. The procedure vfollowed in making this top closure is practically identical with the .manipulations illustrated in Figs. k9 to 1l, .the 'only diiference Vbeing that While in Figs. .9, 1'0' and 11, tabs 28 and 23 are of equal length due tothe presence of a lateraln in both end panels',

the tabs resulting in the closure of the bag shownIV in l'ig. 18 rare of unedualflength since there is onlyone lateral 'n 33 present. Due tothe eX- treme similarity of VVthese* procedures, no detailed description offforrhing a'closure for' the structure oflig. 18 is :believednecessaryI YIn the foregoing, .I haveexplained the yvarious steps 'of my novel packaging methodby means of which a `pri-:formed dat baghaving an L-.shap'ed seam may be oonvertedinto a lflnished and hermetically sealed package.

1t willb'e noted that my novel packaging method provides important advantages for packaging commodities of various character and is especially advantageous for packaging fluids `which have to be hermetically sealed, and commodities desiredto be `sealed in a vacuous atmosphere such as coffee. The principal advantage of mynovel method resides in that Ythe packaging `materials such as ner sheets and :carton blanks may be converted intofajfinished and hermetically sealed package .ina simple, direct and continuousmanner.

It is also toibe observed that While the-various steps of mymethodhave been explained for the sake of simplicity ashand manipulations, obviously, `all ofthe-:steps vare preferably carried out by means -of machinery. In fact, practically all of the steps involved in my method may be' carried yout bvsome of the conventional' packaging machines Without requiring any complicated or expensive changes.

Furthermore, the packaging method of my inyentionprovides a finishedpackage which emnloys al1 of .the important structural elements which I :have found indispensable for the {provision of a practical and commercial hermetically sealed fluid-tight package. In the packages prepared in accordance with my method, the inner liner is bigger than the outer carton throughout the entire surface thereof. Moreover, all of the sealed regions have only two layers of liner material incorporated therein and reentrant folds, intervening layers and similar danger points of leakage are completely avoided. All of the seams, including the seam in the top closure, are flat and if in a package made in accordance with my method the completely sealed bag would be withdrawn and the iluid contents removed therefrom, for example through a small hole, the bag could be completely collapsed into a flat envelope sealed by means of iiat seams at three edges and closed by a fold line at the fourth edge. In this manner, a heretofore unobtaina-ble packaging structure and a closure of a completely and permanently hermetic character are obtained.

In addition, the packaging method of my invention is extremely simple and inexpensive to use so that it is readily adaptable to packaging relatively low-priced commodities on a practical and commercial scale.

Although the present invention has been de-l scribed in connection with a few preferred embodiments thereof, variations and modifications may be resorted to by those skilled in the art Without departing from the principles of my in Vention. Thus, while in the foregoing it was disclosed that the filling operation is performed after the bag has been combined with the erected carton, it is also possible to fill the erected bag with the commodity to be .packaged and thereafter to insert the filled bag into an erected carn ton, with equal or similar results. I consider all of these variations and modifications as within the true spirit and scope of the present invention as disclosed in the foregoing description and dened by the appended claims.

I claim:

1. 'I'he method of producing fluid-tight containers which comprises providing a collapsed envelope fluid-tight and fusible on at least the inner surface thereof and including the same number of layers throughout, erecting said envelope on a mandrel, combining said erected envelope with a carton having two pairs of opposed panels and medial score lines in one pair of said panels, withdrawing the resulting lined container structure from said mandrel, and then collapsing said structure on said medial score lines of said carton whereby a fluid-tight container in knocked-down form is obtained adapted to be erected to form a lined packaging medium.

2. The method of producing collapsed erectable fluid-tight containers which comprises providing a iiat bag fluid-tight and fusible at least on the inner surface thereof and having at least one heat-sealed longitudinal marginal area, erecting said bag on a rectangular mandrel to convert it into a rectangular bag having two pairs of opposed panels and a medial iin in at least one of its panels, adhesively combining said erected bag with a carton blank having panels corresponding to those of said bag and medial score lines in a pair of opposed panels, withdrawing the resulting lined container structure from said mandrel, and then collapsing said structure on said medial score lines of said carton whereby a fluid-tight container in knocked-down form is obtained adapted to be erected to form a lined packaging medium.

3. The method of producing fluid-tight containers which comprises providing a fiat bag integrally formed of a sheet presenting a continun ous fluid-tight and fusible inner surface and having an L-shaped heat sealed region extending along two adjacent marginal areas thereof, erecting said bag on a mandrel, flattening said sealed region into unidirectonally extending longitudinal and transverse ns, slipping said erected bag into a carton having two pairs of opposed panels and medial score lines in one pair of said panels, withdrawing the resulting lined container structure from said mandrel, and then collapsing said structure on said medial score lines of said carton whereby a fluid-tight container in knocked-down form is obtained adapted to be erected to form a lined packaging medium.

4. The method of producing fluid-tight containers which comprises providing a ilat bag having a continuous fluid-tight and fusible inner surface and parallel sealed regions in two longitudinal marginal portions thereof, erecting said bag on a rectangular mandrel to convert it into a bag having four panels, wrapping around and adhesively securing to said erected bag a carton |blank having four panels corresponding to those of said bag and having medial score lines in a pair of opposed panels thereby flattening said sealed marginal portions into a pair of longitudinal fins extending in the same direction, withdrawing the resulting lined container structure from said mandrel, and then collapsing said structure on said medial score lines of the carton whereby a fluid-tight container in knocked-down form is obtained adapted to be erected to form a lined packaging medium.

HARRY F. WATERS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,048,122 Howard July 21, 1936 2,114,621 Bergstein Apr. 19, 1938 2,162,263 Lindholm et al. June 13, 1939

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