US2428440A - Packaging method - Google Patents

Description

Oct. 7, 1947.

H. F. WATERS PACKAGING METHOD 4 Sheets-Sheet 1 Original Filed Oct. 5, 1940 lllllllllllllll |.III.||-

INVENTOR HHRRV E WH TERS WBY M4@ JMW:

HTTR/VEY oct. 7, 1947. l H, F, WATES 2,428,440

PACKAGING METHO D original Filed oct. 5, 1940 4 sheets-shet 2 l lnllvxsbrroR.

'H/qRRY/I-WHTERS BY 4f-u HTTQRNEY OGL 7 1947- H. F. WATERS v 2,428,440

PACKAGING METHOD n Original` Filed Oct. 5, 1940 4 Sheets-Sheet 3 INVENTOR .HHRRYF W/qTE-RS I BY ,Maw L-,M

FITTORNEY Oct 7, 1947. H. F. WATERS 2,428,440

PACKAGING METHOD Original Filed Oct. 5, 1940 4 Sheets-Shet 4 mvmox HHRRYE' WHTERS BY WMM JW HTTOR NEY Patented Oct. 7, 1947 UNITED sTA'rEsPATENT oFFlcE l Originailpliaxiite: SYerial No.

Divided and this application August 12, 1941, Serial No. 406,496

The present invention relates to the art of packaging, and more particularly, to a novel method of forming fluid-tight containers and of packaging commodities therein.

The product with which the present invention is primarily concerned is a container of generally moisture-proof and fluid-tight character comprising an outer carton having at least some flexibility and strength and an inner bag or liner iiuid-tight and heat-fusible at least on the inner face thereof. I have foundthat 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 filled and sealed 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 uid-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 co-pending application Ser. No. 191,860, filed February 23, 1938. Y

Heretofore, iluid-tight containers 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 collapsed condition to a carton blank. Another method disclosed in my co-pending application Ser. No. 329,254 led April 12, 1940, involved attaching a flat liner sheet to the carton blank and 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 at or collapsed condition and was subsequently erected prior to filling. Various 'problems were encountered in forming fluid-tight containers by means of these methods particularly when it was desired to use a four-sided carton. As those skilled in the art know, it is difficult, 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 inthe bottom seam thereof. This can Claims. (Cl. 93-3) liner material and forms or erects such material be avoided only by leaving the liner open at vide a packaging method which completely elimabout a mandrel.

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

It is also within the contemplation of the invention to provide a method of forming fluidtight and hermetically sealed packages which' operates in a direct and continuous manner starting from the sheet-like liner material and from4 the flat carton blank and converts such materials intol a finished and hermetically sealed iluidtight package.

Still another object of the present invention is to provide an apparatus for carrying the method of the invention into practice.

fThe invention also contemplates a packaging method which is simple in character and which.

may vbe employed on a practical and industrial scale for the quantity production of uid-tight and hermetically sealed packages.v

Other and further objects and advantages of the present invention will become apparent from the following description taken in conjunction with the accompanying drawings in which:

Fig. 1 illustrates a top elevational view` of a liner or bag integrally formed from a single sheet of material:

Fig. 2 depicts a longitudinal sectional view taken on line 2-2 of Fig. 1;

Fig. 3 shows a perspective view of a mandrel having a fluidtight liner material wrapped around it and sealed along its longitudinal edges;

Fig, 4 is a horizontal sectional view, somewhat fragmentary in character, and taken on line 4-4 of Fig. 3;

Fig. 5 illustrates a perspective view, having parts broken away for reasons of clarity, and showing the longitudinal seams or iins of the liner material flattened into the plane loi? two panels or walls thereof;

Fig. 6 depicts a plan view of a carton blank on a somewhat reduced scale adapted to be combined with the erected bag appearing in Fig. 5;

mouth portions of the liner bag are hermetically sealed; u I

Fig. 11 is a similar view of the finished lled and sealed package, the top flaps of the -carton being open for clarity of illustration;

the name Pliolm, synthetic resinous materials sold under the name Koroseal, Vinylite, and the like. Theseisheets may be employed in the form of a self-sustaining `film or layer or in the form of a layer coated on or laminated to a sheet of flexible material, such as paper. The latter procedure has the advantage that the liner material may be made fusible on one face and is non-fusible on the other so that heat and pressure may be vapplied to the fusible portion through the unfusible portion whereby adherence of the mate- '-rial to the heat sealing members is prevented.

Fig. 12 illustrates a top elevational view of a t modified bag adapted to be used in the method of the invention;

Fig. 13 depicts a transverse sectional view taken on line 13-13 of Fig. 12;

Fig. 14 shows the bag illustrated in-Figs. 12 and 13 erected on a mandrel;

Fig. 15 is atop elevational view of 'a six-sided carton blank adapted to be combined with the erected bag;

Fig. 16 is a perspective view of the erected bag combined with the carton;

Fig. 1.7 represents the carton and bag removed from the mandrel upon which they were formed and ina collapsed condition in which they may be stored and shipped prior to use; n

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

Fig. 19 is a perspective view illustrating an alternative procedure for forming the heat fusible, fluid-tight liner on a mandrel;

Fig. 20 is a similar view showing the liner sheet on a mandrel sealed along its longitudinal edges; Fig. 21 is a similar perspective view showing vthe formation of ythe transverse or bottom edge of the liner on the mandrel; and

Fig. 22 is a similar view of the liner after it.

has been converted into an erected heat sealed bag ready lfor insertion into a carton.

Generally speaking, the containers contemplated by my invention have to satisfy certain important considerations. First of all, it is of great importance that inthe erected and filled f condition ofthe package, the inner fluid-tight bag should be greater than the inner space of the carton so that the relatively weak material of the bag is supported by the carton walls throughout the entire surface thereof. Another important condition of providing a completely fluid-tight and leakage-proof container is .that the inner bag should be formed as far as possible exclusively byv means of completely at seams so that in the sealed regions not more than two layers of material are placed in' a face to face position. Experience has demonstrated that in the event that reentrant folds, intervening layers of materials and similar regions are present in which there are more than two layers of the liner materialv included, such regions willy be greatly subject to the danger of leakage due to the non-uniform thickness of the liner materials therein.`

In accordance with my invention, I first provide a lineror envelope preferably formed of a single sheet of material which is duid-tight and'fusible at least on one face thereof. Preferred examples ofthe'sefusible or thermoplastic materials are a l therein is provided and may be 'lled with a comv least on the inner face thereof.

A bag or envelope may be formed in at form by means of folding a sheet f such laminated material about a medial line and heat'sealing the resulting structure at least at two lateral edgesthereof whereby an envelope closed at three .sides and open at `one side is obtained. lAs an alternative, the bag may be heat sealed on a l mandrel by means of folding a piece or strip of erected tubular carton, or a carton blank of suitable character and of appropriate dimensions maybe wrapped around. the bag and may be adhesively secured thereto while the bag is still on the mandrel. After the mandrel is withdrawn, a squared-up cartonv having a squared-up liner modity in any conventional manner. After filling, the mouth portions of the liner lor bag are collapsed and are hermetically sealed preferably by the application of heat and pressure along atransverse strip. Hcreafter, the resulting tabs of the liner or bag may be folded into the inner space of the carton and the aps may be closed thereabout. y

Referring now more particularly to the drawings, Figs. 1 and 2 illustrate a bag or envelope of the so-called seamless bottom type employed in the method of the present invention. It will be noted that this bag essentially comprises a sheet or strip I of exible material fusible at This sheet is folded about a transverse medial line 2 to bring its edges into registering position. The resulting structure may be sealed bythe application of heat and pressure to two lateral marginal strips 3 thereof, whereby an envelope closed at the sides and at the bottom is obtained. This bag may now be erected or squaredup on a mandrel 4 whereby the structure illustrated in Fig. 5 is obtained. The heat sealedV regions 3 are attened in the plane of the two side walls ofthe mandrel and in the same direction whereby they are converted into longitudinal ns 5. Tabs 6 will be provided at the end of the side walls of the erected bag and may be subsequently folded inwards into the plane of the bottom wall of the bag.

Instead of forming the bag in a flat or collapsed form and subsequently squaring it up on a mandrel, it is also possible to wrap or fold a sheet or strip of the liner material around a mandrel of suitable shape 'and then heat seal the marginal regions of such strip. In fact, in some cases this type of operation is to be preferred sheeted rubber hydrochloride product known'by since in this case the bag is directly formed in an erected shape and the intermediate step of erecting';a fiat bag may be dispensed with. It was'already suggested to heat seal a suitable sheet or strip on a mandrel or former and thereby to convert it into an erectedbag.l These prior procedures, however, were incapable of providing a bag which was potentially greater in all of 6 to distance I3 in Figs. 3 and 4. The result will be that the two halves of end walls 9 and I0 of its dimensions than the inner space of the carton into which it was inserted. The reason .for this difficulty was obvious. In order to form the sheet of the bag on a mandrel it had to be tightly wrapped around the mandrel and since the dimensions of the mandrel had to be necessarily smaller than the dimensions of the carton rinto which mandrel and bag were subsequently iniserted, the bag was necessarily atfleast slightly smaller than the inner space defined by the erected carton. Thus, after the bag was filled with a flowable or uid commodity, the inner pressure on the inner walls of the bag was unable to obtain support from the waus of 'the cartn. As'a. result at least a portion of the inner liner remainedunsupported by the outer carton, causing frequent rupturing or tearing of the bag and loss of the contents during transportation and storage. As a result of the great difficulty, as far as I know, this procedure was never employed commercially I have now discovered that this diillculty may be eliminated in an extremely simple manner by vmeans 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 struc'- ture 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 understoodfrom the contemplation of Figs. 3 and 4.

As it will be observed in Fig. 3, sheet I, which is fluid-tight and fusible on at least the inner surface thereof, 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 'I and 8 andend 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 I0 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 marginal strip thereof.

'I'his is preferably accomplished by means of heat sealing members II and I2 extending in longitudinal direction parallel with the end panels of mandrel 4 and of thev bag. Preferably, one of these heat sealing members I2 is heated by means of anelectric resistance or heating element'l (not shown) toI 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 I I 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, 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 ns corresponding 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 iiuid 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 slip or expansion joint.

This expansion continues until the inner filled l trated in Fig. 5 is obtained. In order to obtain vformed 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 Iblank 23 of the type shown in Fig. 6 having main panels 1-a and 8a and end panels 9a and Illa 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, I6 and I1, respectively, While similar flaps I8 and I9, 2li and 2| are provided for end panels 9a and Illa. 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 glue aps 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' folded into the inner space of the carton. 'I'he erected bag may now be filled through a filling device 2'4 with a predetermined quantity of .the commodity to be packaged. Hereafter. the mouth portions of the inner bag extending beyond the main body portion of the carton may be col- 1 lapsed or brought into la face to face position and may be hermetically sealed by the application of heat and pressure across'a transverse A strip thereof.

As it has been pointed out in the foregoing, in order to provide a positively fluid-tight and leakage-proof package, it is desirable to have a structure comprising only completely flat seams. The principles governing this type of seams are disclosed in my copending application Ser. No.

have to be satisfied in order to permit the provision of a completely flat transverse top seam with a. minimum of liner material. In order to 'obtain this result itis necessary to iiatten mouth t0n into a tubular structure.

7 portions 39 of the bag into the plane defined by the hinge lines of the top flaps of the carton and in the directionv in lwhich the ns extend. This readily accessible to a heat sealing device of suitable character and a transverse heat seal or seam 21 may be applied thereto hermetically sealing the inner bag. Thereafter, the resulting tabs 28 and 28 may be folded in and top aps Il, I8. I8 and 2n may be closed thereabout and secured in such closed position by means of a suitable quick dryingA adhesive whereby the duid-tight package shown in Fig. 11 is obtained satisfying all of the important considerations set forth in the foregoing.

While in the foregoing a bag of the seamless bottom type has been described, Figs. 12 to 18 illustrate my novel method of packaging applied to a bag having an L-shaped continuous seam incorporated therein. A bag of this type may be made in flat form by providing a sheet 3|, fluid-tight and fusible on at least one face thereof, which is folded over about a longitudinal medial'line 32 to bring its edges into registering position. L.shaped marginal strip 33 extending along one of the longitudinal edges and one of the transverse edges of this folded structure converts the same into a flat bag closed at three sides and open at one side.

The first step in this modied packaging method is to erect the bag on a mandrel 34 whereby the structure illustrated in Fig. 14 is` obtained. It will be noted that upon erection the bag will havea pair of main panels 35 and 36 and a pair of end panels 31 and 38. The L-shaped seam 33 will be converted into a longitudinal 1in 39 and a transverse bottom fin 40. In addition, vertically depending tabs 4| and 42 are obtained at the places Where the end panels merge with the bottom .panel of the erected bag. The erected bag on the mandrel may be combined with a 8 filled and sealed. Vthese adhesive lines may be omitted. On the other hand, if it is proposed Ito remove the container comprising the carton'and the inner bag and to'ship it in collapsed form to a filling station, one can provide medialV score lines 53 and 54 in end'panels ,31a and 38a respectively, t0 obtain a six-sided structure. In this case the duplex container may be collapsed on these medial score lines 53 and 5I and may be l0 shipped and stored in such collapsed form where'- by the space requirements are greatly reduced,

' the carton and inner bag may also .be collapsed on corner fold lines.

The structure obtained after combininglthe 15 carton with the b ag is shown in Fig. -16 illustrating the carton and bag while they are still on mandrel 3l. Upon withdrawal fof the mandrel, the container may be either collapsed on medial fold lines 53 and-54, as this is shown in Fig. 17,

or the bottom aps of the carton may be closed and the inner bag may be .lled with a commodity through a conventional filling device 55. After filling, thel mouth portions of the inner bag are collapsed into a face to face position and v are h'ei'emetically sealed by applying heat and pressure to a transverse marginal strip thereof.

In forming this top closure or seal for the inner bag the same conditions have to be'considered as were explained in connection with the I previous embodiment of my invention. v In other words,`in view of the presence of a longitudinal fin 39 in onefof the end panels of the bag, the closed top portions of the bag must be first folded into the plane defined by the top hinge lines o f the carton and in the direction determined by 40 in which position they are more accessible to a heat sealing device. After the top closure has been made, the resulting tabs of the bag are folded into the carton and the top flaps of the carton are closed thereabout. The procedure followed in-making this top closure is practically identical with the manipulations illustrated in Figs. 9 t0 1l, the only difference being that while in Figs. 9, 10 and 11, tabs 28 and 29 are of equal length due to the presence of a lateral n in both end panels, the tabs resulting in the closure of the carton of suitable dimensions and having at least bysimply pushing the bag, while it`is still on the mandrel, into an erected four-sided carton. Another possibility, which is preferred in some cases, involves wrapping a carton of 'appropriate shape around the erected bag. This carton may be a four-sided carton of the type shown in Fig. 15 having main panels 35a and 36a, end panels 31a and 38a corresponding in dimensions and arrangement to panels 35, 36, 31 and 38 of the bag. Main panels 35a and 36a are provided with conventional top and bottom flaps 43 and 44, 45 and 46, respectively, Vwhile end panels 31a and 38a are provided with similar top and bottom iiaps 41 and 48, 49 and 5i), respectively. A conventional glue iiap 5l is connected to main panel 35a and is adapted to cooperate with the corresponding portion of end panel 31a to convert the car- Adhesive lines 52 are provided on the main and end panels and have the object to secure the bag to the carton.

bagshown in Fig. 18 are of unequal length since there is only one lateral fin 39 present. Due to the extreme similarity of these procedures, no detailed description of forming a closure for the structure of Fig. 18 is believed necessary.

In the foregoing, I have explained the various steps of my novel packaging method by means of which a preformed flat bag having an L-shaped seam may be converted into a finished and hermetically sealed package. Instead of forming a bag fiat and then subsequently/ erecting the same on a mandrel it is also possible to form a bag directly on a mandrel by means of heat sealing operations. This modification' of my method will be best understood from Figs. 19 to 22.

procedures, however, invariably resulted in the provision of a bag which had exactly the same In the event that after combining the carton with l sarily at least slightly smaller than the inner the bag the resulting structure is immediately dimensions as the mandrel and which w-as incapable of subsequent expansion. When abag of this type formed on the mandrel was lpushed into an erected carton, the bag had to be necesspace cf the carton. Upon mung the bag with a fluid commodity, the inner pressure of thecontents exerted substantial pressure o n the inner walls of the bag and such substantial pressure was likewise exerted in the sealing region, which is generally the weakest portion of a heat sealed ported by the carton throughout the entire surface thereof, such expansion having no appreciable eifect on the sealed regions. In other words, I succeeded in forming a bag on a mandrel which in actual operation has a considerably greater volumetric contentthan the volume dened by the mandrel.

Referring now to Fig. 19, the rst step in forming the liner material into a bag is to wind a. sheet 58 about a mandrel 34 so that its longitudinal edges are brought into a registering position. Heat and pressure may be applied to these registering portions of the liner material by means of a pair of heat sealing membersvSl and 58. Preferably, one of these heat sealing members, for example 51, is constituted of a metal and has an electric heating element (not shown) whereby it may be maintained at a temperature at which the fusible portion of the liner material becomes plastic. The other heat sealing member 58 may be constituted of a resilient or yielding material such as rubber, in order to apply a uniform and equalized pressure to the regions to be heat sealed. It will be noted that in Fig. 19 heat sealing members 51 and 58 are located at a substantial distance 59 from the surface of the mandrel in order to obtain the ex-f pansion joint effect already explained in the foregoing particularly in connection with Figs. 3 and 4.

After the liner material has been provided with a longitudinal seam and thus has been converted into a tube preliminary to providing the b'ottom or transverse seam, the tube is pushed down on the mandrelto a suitable extent .in order to free the portions to be heat sealed for, displacement towards each other (Fig. 20).

Prior to forming the bottom seam, lateral seam 60 is iiattenedlnto the plane of the end panel of the tube. Thereafter the bottom portions of the tube are collapsed and folded in the direction determined by the flattened nn. The procedure followed is exactly the same in forming this bottom closure as that explained in Figs. 9, 10, and l1 in connection with forming the top closure. That is, first' the collapsed mouth portions are folded into a horizontal plane and in the direction in which the flattened lateral fin is pointing. Thereafter, the collapsed mouth portions are' folded vertically downward along a line at a substantial distance 'from the center line of the package vand a transverse heat seal is applied by means of a pair of transverse heat sealing members 60 and 6|, at least one of which is heated to a heat sealing temperature by means of an electric heating element. After this bottom seam has been provided, the resulting tabs 62 and 63 are folded inwardly providing the structure shown in Fig. 22 in which position the bag may be com- It will be noted thatvmy novel packaging methv od provides important advantages for packagv ing commodities of various character and is especially advantageous for packaging fluids i which have to be hermetically sealed, and commodities desired'to be sealed in a vacuous atmosphere such as coffee. The principal advantage of my novel method resides in that the'pack.- `vaging materials such .as liner sheets and carton blanks may be converted into ay finished andl yhermetically sealed package in and continuous manner.

It is also to be observed that while the va-ri, ous steps of my method have been explained for the sake of simplicity as hand manipulations, obviously, all of the steps are preferably carried out by means of machinery. In fact.' practically all of the steps involved in my method maybe carried out by some of the conventional packaging machines without requiring any complicated or expensive changes.

Furthermore, the packaging method of my inlvention provides a finished package which employs all of the important structural elements which I have found indispensable for the provision of a practical and commercial hermetically sealed in accordance with my method, the inner liner is bigger than the outer carton and after filling and sealing is fully supported by the carton throughout the entire surface thereof. Moreover, all of the sealed regions have only two layers or liner material incorporated therein and reentrant folds, intervening layers and similar danger points of leakage are completely avoided. All of theseams. including the seam in the top' closure, are fiat and if in a package made in accord-` ance with my method the completely sealed bag would be withdrawn and the fluid contents removed therefrom, for example through a small hole, the bag could be completely collapsed into a fiat envelope sealed by means of flat seams at three edges -and closed by a. fold line at the fourth .equal or similar results.

edge. In this manner, a heretofore unobtainable packaging structure and a closure of a' completely and permanently hermetic character are obtained. Y

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

l Although the present invention has been describedin connection with a few preferred embodiments thereof, variations and modifications maybe resorted 4to by those skilled in the art without departing-from the principles of my invention. 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 a` simple, direct In the packages prepared` I claim: Y 1. The method of producing a huid-tight bag for packaging commoditieswhich comprises folding a sheet of exible material fusible at least on orieface thereof around a mandrel with its fus- 1 ible face within to bring at least two marginal edges of the sheet into 'registering face to face position, to form completelyflat fins, applying heat and pressure to heat-seal the edge portions only of said margins parallel with the faces of said mandrel with the heat-sealed area spaced from the mandrel and the sheet material between said mandrel andthe heat-seal maintained free from heat and pressure during the heat sealing operation and thereby forming fin-seams to convert said sheet into an erected bag open at the top, flattening said marginally heat-sealed iini seams into the plane of the corresponding panels of said mandrel, and then withdrawingsaid mandrel whereby an erected Ibag withv a continuous fusible inner surface is provided having potential dimensions substantially `greater than corresponding dimensions of said mandrel.

2. The method of producing a fluid-tight bag for packaging commodities which comprises folding a sheet of4 flexible material fusible at least on one face thereof around a mandrel with its fusible face within to bring two parallel marginal and longitudinal edges of said sheet intoA registering face to face position, applying heat 4and pressure to heat-seal said edge portions only of said margins parallel with the faces of said mandrel, with the heat sealed area spaced from the mandrel and the sheet material between said mandrel and the heat seal maintained free from heat and pressure during the heat-sealing operation and thereby forming fin-seams to produce a pair of fluid-tight iin seams and to co-nvert said sheet into an erected bag having a seamless i bottom and an open top, flattening said heatsealed seams into the plane of the corresponding panels of said mandrel, and then withdrawing said mandrel whereby an erected bag is obtained than corresponding dimensions of said mandrel. I

3. The method of producing a fluid-tight bag for packaging commodities which comprises folding a sheet of iiexible material fusible at least on one face thereof around a mandrel with its fusible face within to bring the longitudinal edges of said sheet into registering face to face position, applying heat and pressure directly to said edges parallel with the side surface of said mandrel with the heat sealed area spaced from the mandrel and the sheet material between said mandrel and the heat seal maintained free from heat and pressure during the heat sealing operation and thereby forming iin-seams to produce a longitudinal seam and to convert said sheet into a tube, displacing said tube on said mandrel to free the terminal portions of said tube for displacement towardseach other, collapsing said terminal portions into a face to face position, applying heat and pressure to said collapsed terminal portions'parallel with the bottom sur- `face of said mandrel, with the heat sealed area spaced from the mandrel and the sheet material between said mandrel and the heat-seal maintained free from heat and pressure during the heat sealing operation and thereby forming nseams and then withdrawing said mandrel whereby an erected bag is obtained having potential dimensions substantially greater than corre` sponding dimensions of said mandrel.

4. The method of producing a fluid-tight conhaving potential dimensions substantially greater i 12 tainer for packaging commodities which comprises folding a sheet of flexible material fusible at least' on one face thereof around a mandrel with its fusible face within to bring at least two edges of the sheet into registering face to face position, applying heat and pressure to said'edges parallel with the faces of said mandrel with the heat seal area spaced from the mandrel and the sheet material between said mandrel and the heat seal maintained free from heat 'and pressure during the heat sealing operation and thereby forming fin-seams to convert said sheet into an erected bag open at the top, flattening said heatsealed n-seams into the plane of the corresponding panels of said mandrel to form unidirectionally extending fins, introducing said erected bag into a carton, and then withdrawing said mandrel whereby a uid-tight container is obtained comprising an outer reinforcing carton and an inner fluid-tight bag having potential dimensions substantially greater than corresponding inner dimensions of the carton.

5. The method of producing a fluid-tight container for packaging commodities which comprises folding a sheet of ilexiblematerial fusible at least on one face thereof around a mandrel. with its fusible face within to bring at least two.

edges of the sheet into registering face to face parallel with the faces of said mandrel with the heat seal area lspaced from the mandrel and the sheet material between said mandrel and the heat seal maintained free from heat and pressure during the heat sealing operation and thereby forming fin-seams to com vert said sheet into an erected bag open at the top, flattening said heatsealed n-seams into the plane of the corresponding panels of said mandrel to form unidirectionally extending fins, wrapping a carton blank around said erected bag and securing the ends thereof together, and then withdrawing said mandrel whereby a huid-tight container is obtained comprising anouter reinforcing carton and an inner fluid-tight bag having potential dimensions substantially greater than corresponding inner dimensions of the carton.

- 6. The method of producing a fluid-tight bag for packaging commodities which comprises folding a sheet of liiexible material fusible at least on one fac e thereof around a mandrel with its fusible face within to bring at leasttwo edges ofthe sheet into registering face to face positin, applying heat and pressure to said edges parallel with the faces of said mandrel with the heat seal area spaced from the mandrel and the sheet material between said mandrel and the heat seal maintained free from-heat and pressure during the heat sealing operation and thereby forming fin-seams to convert said sheet into an erected bag open at the top, iiattem'ng said heatsealed iin seamsinto the plane of the corresponding panels of said mandrel, and then withdrawing said mandrel whereby an erected bag having a continuous fusible inner surface is pro- "f ing a'sheet of exible material fusible at least on one face thereof around a mandrel with its fusible face within to bring two parallel marginal and longitudinal edges of said sheet into regis- Itering face to face position, applying heat and pressure to said edges in a region parallel with 13 the faces of said mandrel with the heat seal are spaced from the mandrel and the sheet material between said mandrel and the heat seal maintained free from heat and pressure during the heat sealing operation and thereby forming finseams to produce a pair of fluid-tight fin-'seams and to convert said sheet into an erected bag having a seamless bottom and an open top,

flattening said heat-sealed iin seams into the plane of the corresponding panels of said mandrel, and then withdrawing said mandrel where'- by an erected bag having an expansion jointlike seam structure is obtained capable of moderate increase of its volumetric content under the effect of internal pressurerwithout exposing said seams to appreciable stresses.

` 8. The method of producing a fluid-tight bag for packaging commodities which comprises folding a sheet of flexible material fusible at least on one face thereof around a mandrel with itsfusible face within to bring the longitudinal edges of said sheet into registering face to face position, applying heat and pressure to said edges along a strip parallel with the side surface of said mandrel with the heat seal area spaced from the mandrel and the sheet material between said mandrel and the heat seal maintained free from heajJ and pressure during the heat sealing opera` tion and thereby forming fin-seams to produce longitudinal fin-seams and to convert said sheet into a tube, displacing said tube on said mandrel to free the terminal portions of said tube for displacement towards each other, collapsing said terminal portions into a. face to face position, applying heat and pressure to ,said collapsed terminal portions parallel with the bottom surface of said mandrel with the heat seal area spaced from the mandrel and the sheet material between said mandrel and the heat seal maintained free from heat and pressure during the heat sealing operation and thereby forming fin-seams, and then withdrawing said mandrel whereby an erected bag having an expansion joint like botposition, applying heat and ypressure to said edges parallel with the faces of said mandrel with the heat seal area spaced from the mandrel and the sheet material between said mandrel and the heat seal maintained free from heat and pressure during the heat sealing operation and thereby forming iin-seams to convert said sheet into an erected bag open at the top, flattening said heat-sealed edges into the plane of the cor- 14 responding panels of said mandrel to form unidirectionally extending fins, introducing said erected bag into a carton, and then withdrawing said mandrel whereby a :duid-tight container is obtained comprising an outer reinforcing carton and an inner fluid-tight bag, said bag ybeing capable of moderate expansion in the sealing region to conform to the surface of said carton throughout the entire surface thereof. I

10. The method of producing a fluid-tight container for packaging commodities which comprises folding a sheet of flexible material fusible at least on one face thereof around a mandrel with its fusible face within to bring at least two edges of the sheet into registering face to face position, applying heat and pressure to said edges parallel with the faces of said mandrel with the heat seal area spaced from the mandrel and the sheet material between said mandrel and the heat seal maintained free from heat and pressure during the heat sealing operation and thereby forming iin-seams to convert said sheet into an erected bag open at the top, flattening said heatsealed strips into the plane of the corresponding panels of said mandrel to form unidirectionaliy extending fins, wrapping a carton blank around said erected bag and securing the ends thereof together, and then withdrawing saidy mandrel whereby a fluid-tight container is obtained comprising an outer reinforcing carton and an inner fluid-tight bag, said bag being capable of moderate expansion in the sealing region` under the pressure of the contents to conform to and to be supported by said carton throughout the entire surface thereof. i

HARRY F. WATERS.

`file of this patent:

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Palmer Feb. 25,v 1914s

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