US 2353605 A
Description (OCR text may contain errors)
- July 11, 1944. H. F. WATERS BAG ` Filed May 14, 1940 11-1,!-lll #HR/W E rif/475195 ATTORNEY.
`July 11, 1944. H. WATERS BAG Filed May 14, 1940 4 Sheets-Sheet 2 FWS/64E APHESYE' INVENTOR. HHRFY/-TWHTEHS l Maa 7K7 fron/ver July 11, 1944. F WATERS l 2,353,605 f BAG Filed May 14, 1940 4 Sheets-Sheet 3 INVENTOR.
M' #HHH VFW/WER;
`Fuly l1, 1944.
H. F. WATERS BAG Filed May 14, 1940 4 Sheets-Sheet 4 INVENTOR. H/qRRYFW/qTE-S Patented July 11, 1944 OFFICE BAG Y muy F. water-New York. N. Y. n Application May 14, 1040, serai No'. 335,045
The presentinventlon relates to improvements in the bag making art and, more particularly. to an improved form of bag of the type having automatically opening bottoms, and to a method oi producing the same.
As those skilled in the art know, in themanufacture of ybags used for packaged products, particularly food products, bags were used to a substantial extent which were provided with those automatic opening types of bottoms sometimes referred to in the art as ABC and satchel or dia- The manipulations of mondfold bottom bags. the material in these types of bags make it exbottom which is sift-proof. In the pastvarious attempts were madeto make the bottom of these types of bags sift-proof, either by usinga supplemental patch kmember or'by providing additional folds in Vthe bottom` to obtain the Asame result.
' I'hese attempts Vwere not satisfactory due tothe fact that they were expensive and in theA latter instance resulted in theV utilization of more material than can economically 'be allowed for such purposes. Moreover. the methods involved Yin these procedures were rather complicated and could not be carried out by means of conventional machinery. Althoughffrom time'to-time .various `other suggestions, and proposals .were
made to solve the outstanding problem,f none,
ias far as I am aware, yof these prior sggestions `to provide a bag having a bottom of the autotremely diilicult, if not impossible, to produce a 1 of predetermined yregions on the fusible surface Y of a bag having a non-fusible layer or coating thereon which in the formed-up condition ofjthe bagprevents such regions from fusing andV adhering to each other upon the application of heat and pressure thereto.
It is also within the contemplation of the present invention to provide a novel and improved method for the quantityproduction of sift-proof bags of the automatic opening bottom type which is simple in character and which may be carried out with great facility on a practical and industrial scale by means Vof existing machinery without requiring any complicated and expensive changes. Y A Y ,v
Other andV further objects and advantages Vof i .the invention will become apparent from the -folmatically opening type in which complementary Y "lines of adhesive are provided along pre-deter mined lines of the material of the bag which is subsequently going, to form the bottom in such a manner that these lines of adhesive are brought into cooperating relation and form a continuous dam or ,wall interposed between the folds of the bottom and the exterior of the bag.
It is a further object of the present4 invention to provide a sift-proof and substantially fluidtight bag having lines of asuitable adhesive provided in predetermined regions thereof, said adhesive being adapted to be fused after the formation of the bottom structure to convert it into a sift-proof and in some vcases substantially fluidtight structure.
The invention also contemplates the provision e structure;
lowing description taken in conjunction with the accompanying drawings inwhich: Y Y
Fig. 1 illustrates a lplan view, somewhat fragmentary in character, of a continuous web or strip of paper showing the manner in which the lines of adhesive are applied thereto before :it isl made into bags;
Fig. 2y depicts an end view of the tube formed from the web illustrated in Fig. 1; Y
Fig. 3 shows a perspective view of the endor bottom portionof the bag during the initial step of forming the bottom; Y
Fig. 4 is'a perspective view showing a further step in making the bottom structure of the-bag;
Fig. 5 is a similar view of the resulting bottom Fig. 6 illustrates a plan view of a webk of ilexible material .having lines of adhesive provided thereon, for the provision of a sift-proof bottom structure; Y f,
Fig. 7 depicts a plan view of the lother side of the web illustrated in'Fig. 6; Y
, Fig, 8 shows the portions of the bag forming the bottom in their partially completed form;
Fig. 9 is a similarview of the bottom portion of the bag shown in Figs. 6to 8 in its completed form prior to folding over the resulting tabs;
Fig. 10 illustrates a plan view of a pair of webs employed in the .manufacture of a modified embodiment of the invention involving a bag of the duplex type; Fig. 11 depicts a fragmentary perspective view of the end portions of the superposed strips of sheet material employed in making theV duplex bag of the invention;
lig. 13 is a similar view of the bottom structure of the bag as shown in Figs. to 12 prior to its completion; and
Fig. 14 is a perspective view of a finished bagV Vregions of adhesive will be brought into a con-l tacting or cooperating relationship and a co` tinuous dam or wall will be interposed between the folds of the bottom and the exterior of the bag. This desirable result may `be accomplished in various ways. Thus, when for simplicity of manufacture it is preferred to provide all of the may be provided with longitudinal'strips of ad- Vhesive adjacent to theslde edges thereof. These g longitudinal lines of adhesive are supplemented by a continuous line orstrip of adhesivev extending across the web in suchfa mannerl that upon the formation of the bottom structure vthese lines of adhesive will be brought `into complementary or lcooperativerelation and into a single plane. .After the bottom has been formed, these cooperating lines ofadhesive may be fused by theV Y Vapplication of a heated pressure surface against the exterior ofthe bottom structure whereby aV continuous dam of fused` adhesive will be interposed between the interior and the exterior ofthe bag. Asa modification of this concept, a web of non-fusible sheet material may be provided with Y,reactivable adhesive in predetermined regions of both sides thereof, said regions being constructed and arranged tobe automatically brought into registering iand cooperating position during the formation ofthe bottom structure: It is also possible to apply the principle of the invention. to.
bags of the so-called duplex type, in which gen,- erally a non-fusible external sheet or lweb, and
Ait fusible internal liner web are arranged in vsuperposed position. In these types of bags the complete innersurface ci the bag is fusible and in orderto obtainthe desired selective adhesion,
it is necessary to render predetermined regions thereof Vnon-fusible. This may be accomplished in various ways such as -by applying a layer or coating, of non-fusible material to such'reglons'.
V,This non-fusible layer may be constituted by'a "patch of paper, or of a coating material which is either non-fusible or,in case it is fusible, has a melting point which is higher than that of the fusible linermaterial. In this case', when after the formation of the bottom structure a heated pressure surface is applied to the bottom surface, only those regions willrbe'fused together where a dam or fusion seam is desired while the other regions of the inner surface of the bag remain unaffected. It will be noted that in all of these various forms of my invention the essential conadhesive regions on one side of the web, the web assaeos ofthe drawingaa preferred embodiment of the invention will be described. A web I of suitable,
ynon-fusible sheet material having a width determined by the dimensions ofthe bag to be produced is provided with longitudinal lines of a suitable adhesive 2.adjacent to the lateraledges thereof. In addition, a transverse line lof similar adhesive extends across the complete'fwidth of web I and connects longitudinal lines of adhesive 2. As it will be noted in Fig. l, this transverse `line of adhesive has horizontal portions 4 and l extending. across 'the portions of the web subsequently forming the'end panels of the finished `bag and similar horizontal vlines 8 and 1 extend ,across the portions of the' web which are going to form the main panels thereof. These horizontal lines of adhesive are connected by means of longitudinal lines of adhesive 9, III, II and I2. The object of these lines of adhesive will be more fully explained as the description proceeds. Conventional incisions or cuts I2 and I4 are provided in the terminal regions of the main panels and are adapted to form tabs I5 and I8, the object of which iswell known to Athose skilled in the art. Although in practical operation these incisions are generally provided-at a later stagein the manufacture of the bag, their provision has been shown already in web I for convenience of description and illustration.
fThe first step in converting web I into a bag is to fold it Valong a plurality of longitudinal lines Il, I8, I9, 20, 2| and 22 and thereby to convert it` into a tube having main panels 23 and 24 andreentrant end panels 25 .and 26. YAi: the same time longitudinal lines of adhesive 2 will be brought into a face to face relation and may be fused` by means of a heat-sealing device. The
general appearance' of the tube thus formed will lbe readily seen in Fig. 2 of the .drawings showing main panels 23 and 24, reentra'nt end panels 25 and 26, and turned-down longitudinal fin 21 provided by the union of adhesive lines 2.v After the 4tube having the dimensions of thedeslred bag is obtained, its terminal regions are squaredup to form the structure shown in Fig. 3, this be ing part'of the conventional procedure in forming a bag-oi' the automatically opening bottom type. The terminal portions of end walls 25 Aand -2l may now be folded down fiat towards each other. This will result in the structure illustrated in Fig.r4 showing the terminal regions of end -walls 25 and 26 folded towards each other and the terminal portions of main' panels 2l and 24,1including tabs I5 and I8, extending ilat into opposite directions.
y ture, adhesive lines 6 and I of the mainpanels cept isto provide an automaticallyk opening bot-,. l
tom ina bag which is originally'not sift-proof and to finally convert this imperfect bottom structure into a completely sealed and sift-.proof bottom structure by the application of heat and pressure to predetermined regions of the finished bottom surface. l
Referring now more particularly toFlgs. 1 to 5 will be in a cooperating and contacting relation with adhesive lines IUand II, and I2 and 9, respectively.y Likewise, `adhesive lines 4 and l extending across the terminal edges of end panels '25 and 28 -will be brought into a cooperating and contacting position and may be turned down flat to form a bottom fin 28. In other `words, all of these cooperating lines of adhesive have been Y brought into a'single plane, to wit: that of the main panels. After these preliminary steps have been accomplished, tabs I8 and I5 may be folded into an overlapping position and may be secured together by a spot of adhesive 29 provided on the larger tab I5, This step completes the bottom structure and provides a conventional automatically opening bottom of the so-called ABC type depicted in'Fig. 5. Of course, this bottom would not be any more sift-proof or leak- It will be readily apprecivated that in this position of the bottom strucproof-than that of a bag made by theconvem tional procedure. However, this bag. having-ans imperfect closure at the bottom region thereof may be converted in a simple and-completely sat- Y isfactory 'manner intoa bag having a completely and positively sift-proof bottom structure bythe application of heat and pressure to thefupper surface of the bottom structure. YThis `may be accomplished in various ways well known to those `skilled in the art such as, for example, by apoperating lines of adhesive together and Vthese- 1 fused lines of adhesive will form positivelyleakproof and sift-proof seams between the folds of the bottom. It will be readilyunderstood that these seams will positively seal the bottom structure and will prevent the leakage of material from the bag.
Figs. 6 and 9 illustrate a modified embodiment vof the invention. While in the embodimentdescribed in the foregoing allof the lines offusible adhesive have been applied to one face of the web from Which'the bag'. is formed, in the embodiment now to be described a portion of the adhesive lines is provided on one face of the web and another portion thereof is provided on the other face of the web. The appearance of the web is shown in Figs. 6 and?! illustrating a portion of the web inproximity to the terminal regions thereof. Of course, in Yactual` practice Y the web isprovided in substantial lengths and the lines of adhesive arranged in the proper and suitable configuration are repeated at predetermined distances corresponding to the length of the individual bags to be formed.' As it will be notedin Fig. 6, essentially a web 3 i of nonfusible sheet-like and flexible material is provided. In the terminal regions of web 3|, I provide U-shaped lines 32 and not' an adhesive ofy 'suitable character, the horizontalI portions Vof which 34 and 35,- respectively extend transverselyacross the portionsof web 3i which. are subsequentlyrforming main panels and 31. The longitudinally or downwardly extending portions of the U-shaped adhesive lines are denoted by reference characters 38, 39,' 40 and 4|. Conventional incisions 42 and 43A are provided in the4 terminal regions of main panels 34 and l1 and provide conventional tabs 44 and 45. A deposit or coatingl of fusible adhesiveris also'provided on the inner surface of tab 44. Due to the fact that this type of bag is contemplated with a lap type seam, one of the longitudinal lines of adhesive i! appears Vat the right lateral extremity.
of the web but will be brought into a position in which it will form continuation of adhesive line 84 after web 3l has been converted into a tube.
The other side of web Il' whichis subsequently going toform the outer surface of the bagis depicted in Fig. 7. It will be noted that the web is provided with transverse lines of adhesive extending throughout the width of the web with the exception of tabs 45 and' 44. Thus, transverse line of adhesive 46 extends across end panel 41 and a portion of main panel 31. A similar transverve line of adhesive 48 extends across the remaining portion of main panel 31, the complete width of end panel 49 'and part of the width of connection Vwiththe previousembodiment of the invention, no detailed 'description thereof will be main panel 36.` Adhesive line 50 extends through 75 the `remaining portion yof main panel il; Adhesive.l line 4l is somewhatnarrower thangglines 4l l plurality of`longitudinal lines 5I, l2; 5l, 54, ll and II k=to form-a tube having main panels "f and 31 vand end panels 41and 49, repectively, and
Ythelateral marginal portions. thereof are secured together in the form of .a lap seam by means of a longitudinal line `of adhesive 51. n `this adhesive may be ofany suitable type, such asrordinaryglue, and does not have to be `of a fusible character. Due to the fact that the Asteps in forming the bag and its bottom structure from the web vare identical with those described in necessary. It is sufficient to state that after folding `the terminal regions of ythe end panels together and folding the terminal portions ofthe main'panels into opposite directions, .the struc- -Y ture in Fig. 9v is obtained. 'I'he arrangement and the'cooperation of the various stripsof fusible adhesive will be best understood vfrom Fig. 8V
showingportions'of the bottom structure lifted Vup for the sake of clarity. It V"will be noted that in this assembled position of the bottom structure, the transverse portions 34 and 350i. the U-shaped lines of adhesive have been brought into a face to face relation'with their corresponding longitudinal portions 38 and 39. and 4l and 4l, respectively. Likewise, the transverse strips of adhesive 48, 48 and Snare brought into adjacent positions and are exposed to the exterior. Preferablyf the length of these portions Vis so determined that the marginal portions bearing the adhesive lines 48 and 50 slightly overlap line 48 and are resting on the narrow and'clear stripil. This will pre-l vent any adhesive leaking into the interior of the bag during rthe'subsequent heat-sealing operation. Hereafter, the extensions of .mainpanels I6 Vand 31 ending in tabs 44 and 45, respectively, are folded into an overlapping position to vcomplete the bottom structure and .may be secured in such position' by means of Va spot of adhesive provided on the inner surface of tab 45. In this completed position of the bottom structure. the portions of adhesive lines 48 and beyond fold lines SII and 6| will cover the portions of such adhesive lines between said fold lines and thereby will be Abrought into face to face relation therewith. Thus, all of the folds ln the bottom structure are provided with cooperating linesof adhesive at the terminal regions Vthereof and such cooperative linesfof adhesivev may be fused together by the application of a hea-ted pressure' surface against-theouter surface of the finished bottom structure. This will provide a plurality ofheat-sealed seams and willconvert the-bottom.
structure into one of positively leak-proof and sift-proof character.a
While the two foregoing.Y embodiments of they invention are concerned kwith bags constituted of a non-fusible material such as paper and provide' bags which although positively sift-proof are not completely huid-tight, it is also possible tofincorporate 4*the principlesA of the invention into bags whichare oa positively fluid-t'ght char-'j ing a fluid-tight inner surface for the bag either Of course,
by coating the material thereof v.with flexible, fluid-tight and fusible material or by securing an internal fusible lining of fluid-tight character to an external vnon-fusible sheet. Figs. to 1'4 illustrate a practical embodiment of the invention into a duplex bag havingan external non-fusible layer Yandv an internal liner of a fluid-tight and fusible character, such as, for example, Pliofilm.
l VReferring nowto Figs. 10 and 11, a web structure Y of'dupiex character is shown comprisingy any ex- This heated pressure surface will fuse Ithe eooperating portions of the inner liner into a fluidtight structure having seams fluid-tightly bonding the overlapping edges of the liner and also fusing the resulting tabs Il, Il oi' the liner to said seam due to the presence of cut-out portion 1I which permits direct contact' of the intermedlate portion of seam l. with its terminal portions. In this flnal operation it will be noted that the provision of non-fusible regions 1I and 8l in main panels 1| and 1I prevents fusion of the inner surface ofthe liner tube together under the ellectof the heat when the bottom structure is sealed. Without the provision of these non- Yfusible regions when applying the heated pressure surface against the regions to be heattively securedftogether to provide a tube having Y main panels 10 and 1I and end panels 12 and 13.
' Generally speaking,1it is preferred to employ an ordinary adhesive for securing the edges of the external web together, and to employ fusion by heat and pressure to secure theedges of the internal web together. Conventional cuts 14 and 15 are made in main panels 10 and 1I eitheras a .preliminary step inmaking the bag orV after the tube isformed and provide tabs -16 and'11. The relative arrrangement of websil and 63 will Y "be best observed in Fig. 11 which also clearly vshows that web 62 isy provided-with a cut-out marginal portion`18, extending transversely along part 'oi' main panel 1l, end panel 12, and apor- Inner fusible liner 6l is Y tion of main panel 1l. Y 1 also provided with non-fusible regions 18 and lll in thejcentral portions of vmain panels 10 and.1| subsequently formed therefrom.v The object of non-fusibleregions 1I, Il and of cut-out portion vr18 will be further .explained as the description proceeds. f 'f Omitting the 4various intermediate `stages of the procedure followed in converting webs' G2 and 63 intoa tube and informing-a flattened rectangular bottom structure, which is closely similarto the one followed in the previous embodixnents'of the invention, the structure illustrated in- Fig. 13 is obtained. This ligure shows the bottom'already formed and closedbut tabs The cooperationof the various layers in this position will be best seen in Fig. 12, showing `the terminal portions of thebottom structure bent up to make the arrangement ofthe innercliner readily discernible. It willbe noted in Fig. 12 that in this conditionof the bottom structure the terminal edges of the inner liner will be brought into an overlapping position and provide a closure for the interiorV of the bag. `On the other hand, the terminal and overlapping portions of the inner liner are not completely covered but are exposed to the exterior due-to the presence of cut-out portion 1l. VWhen the bottom strucy10 and11still extending into opposite'directions.`
ture so formed is now folded together along fold lines Il and 82, tabs 1t and 11V are folded one above the other andare adhesively securedV and complete the bottom structure of the bag. However, it is .obvious-thatfthelfolds of the Vbottom structure would Abe farffrom being sift-proofor fluid-tight and `thevalue ofthe 'bag would be;
hardly superior to that .of a conventionalxag.
A simple heat-sealing operation will convert this structureinto one of a'completely sift-proof and' fluid-tight character. This operation consists in the application of a heated pressure vsurface against a narrow strip ofthe bottom structure indlcated'by referencel character in Fig.- 13.
sea1ed,the inner walls of ythe liner would be fused together in the same region and would render the bag practically useless. VNon-fusible regionsls and lll on the fusible liner may be provided in various ways, such as, for example, by adhesively securing a patchmember of paper, andthe like, thereto or by coating or printing such regions with a suitable material? which is either non-fusible, or, if fusible, has a melting point which is higher than that of the liner. Examples Vof such materials are nitrocellulose and cellulose acetate,V although, of course, a great variety of equivalent'materials are known to Vthose skilled in the'art.
' The finished bottom structure of the bag may be seen in Fig. 14, showing a perspective view of the finished bag with its bottom turned up. It will be observed that the bottom structure has a conventional appearance but, of course. provides characteristics of sift-proofness and iluid-tightnesswhich were impossible to obtain prior to the present invention.L
'Ihe materials employed inthe bags embodying the invention may be of various character according to the packaging problem contemplated; The non-fusible web is generally constituted ofY paper although other materials of a non-fusible character, such as metal foils, may
be employer-1v with equal or similar results. The fusible adhesive `may be constituted of a suit- `ablerubbery material, such as rubber hydrochloridefa chlorinated rubber compound sold under the `name Plioi'ilm, and various synthetic Vresins of which a vinyl resin sold under the name OfVin'yIite is an example. These fusible Kadhesives are preferably applied to the surface of the non-fusible web by means of a printing, coating or spreading process in the form of a solution in a volatile solvent. The preferred materialfor the fusible liner of the duplex bag embodying the invention is Plioillm.
vIt will be noted'that the present invention provides various novel types of bags of the automatically opening bottom type having a completely sift-proof and in many cases even fluidtight character. Of course, these important new results and advantages could not; be obtained by means of conventional bagsof ythe automatically opening bottom type all of which yare'subject to leakage to a lesser or greater extent. c Y
Other importantadvantages of the present invention reside in the circumstance that as far as actual mechanical manipulations of the sheetlike material are concerned, these are similar to the manipulations followedY in making conventional bags o1' Vthe automatically opening bottom typegso that existing machinery may be used with slight changes. 'I'he critically important difference residesin the provision of my adhesive Therefore, my novelbags may be readily manufactured on a quantity production scale with'existing machinery which only has to be supplemented with a heat sealingdevice of appropriate character. v
Although the present invention has been described in connection with a few preferred embodiments thereof, variations and modifications may be resorted to by those skilled in theart without departing from the principles of the present invention. Thus, although Il have shown principally bags having reentrant end walls,
' which are generally referred to in the art as ABC bags, obviously, thesame inventive concept may be employed for bags of the type in which the end walls are folded outwardly along their medial lines and which are referred to in the trade as satchel type or diamond-fold type bags. I consider all of these variationsand modifications as within the true spirit and scope of the present invention as described in the foregoing description and defined by the appended claims.
I claim: Y
l. A bag of the automatically opening'bottom type which comprises in combination a tube constituted of flexible sheet material folded longitudinally along a plurality of lines to form front and rear walls and end walls connecting the same, a preformed fiat bottom structure at the lower end of said tube including a squared-up portion of said walls flattened down in the plane of said front and rear walls, and lines of reactivable adhesive provided on the marginal portions of said tube forming said bottom structure, said lines of adhesive being contacted with each other after said bottom structure has been formed and reactivated to connect the bottom ends of said tube with a substantially continuous and siftproof seam.
2. A bag of the automatically opening bottom type which comprises in combination a tube of flexible material folded longitudinally along aA plurality of lines to form end walls in the form of reentrant folds connecting the front and the rear walls of the tube, a preformed flat bottom structure at the lower end of said tube integrally' connected with said front and rear and end walls and flattened down in the plane of one of said walls, and lines of a fusible adhesive provided on the bottom marginal portions of said tube incorporated into said bottom structure, said lines of adhesive being contacted with other like portions thereof after the bottom structure has been formed and the contacting lines of fusible adhesive fused by the application of a single heated pressure surface applied against the outer surface of said preformed bottom to form a substantially continuous and sift-proof dam.
3. A bag of the automatically opening bottom type which comprises in combination a tube constituted of non-fusible flexible material folded longitudinally along a plurality of lines to form reentrant end .walls and front and rear walls lines of a fusible adhesive provided in the portions of said tube incorporated into said bottom structure, said lines of adhesive` being contacted with other like portions thereof after the bottom structure has been formed, said cooperating and registering lines of adhesive being interfused to a substantially continuous and fluid-tight seam sealing the bottom of said tube. Y
4. A bag of the automatically opening bottom type which comprises in combination aweb of non-fusible flexible material,- a strip of fusible adhesive on each longitudinal marginal portion of said web bonded bythe application of heat and pressure to form a tube, said tube'being folded longitudinally along a plurality of lines to form reentrant end walls and front and rear walls connected to said endwalls, a preformed j quadrangular bottom structure flattened in the plane of said front and rear walls constituted of the lower terminal vportions of said end walls folded towards each other and of the resulting tabs including the lower portions of said front and rear walls being folded towards each other, transverse lines of fusible adhesive provided at the bottom ends of said front'and lrear wallsand.
in the portions of said bottom structure forming extension of said end walls, longitudinal lines of fusibleadhesive connecting said transverse lines connected thereby, a preformed bottom structure f flattened in the plane of said front and rear walls constituted of the lower terminal portions of said end walls folded towards each other and of the resulting tabs folded towards each other, and 'I5 of adhesive to a continuous line, said lines of adhesive being so constructed and arrangedthat a portion thereof will cooperate with and will face another portion thereof after the bottom structure has been formed and being fused to a substantially continuous and fluid-tight seam sealing the bottom of said tube.
5. A bag ofthe automatically opening bottom type which comprises in combinations. web of non-fusible flexible material, astrip of fusible adhesive on each longitudinal marginal portion of being folded towards each other, transverse lines of fusible adhesive provided on the bottom ends of said front and rear walls and in the portions of said bottom structure forming extensions of said end walls, and longitudinal lines of fusible adhesive connecting said transverse lines of adhesive to a continuous line, said lines of adhesive being so constructed and arranged that the transverse lines of adhesive at the ends of said front and rear walls will be brought into a face to face relationship with said longitudinal lines of adhesive and the transverse lines of adhesive at the end of the extensions of'said end walls will be brought into a face to face relationship with each other after thebottom structure has been fonned, said cooperating lines of adhesive being fused to a substantially continuous and fluid-tight seam sealing the bottom of said tube and having a structure characterized by the application of a heated pressure plate against the external surface ofsaid preformed and flattened bottom.
6. A bag of the automatically opening bottom type which comprises inycombination, a tube constituted of flexible sheet material folded longitudinally along a plurality of lines to form front and rear walls and end walls connecting the same, a preformed flat bottom structure at the lower end of said tube `including a squared up portion of said walls flattened down in the plane of said front and rear walls, and lines of adhesive provided on the marginal portions of said tube forming said bottom structure, said lines of adhesive being applied in adhesive contactrwith each other after said bottom structure has been formed and connecting the bottom ends of said tube with a substantially'continuousand sift-proof seam.
wards each other and of the resulting tabs including thelower portions of said front and rear walls being folded towards each other, transverse lines of adhesive provided at the bottom en'ds of said front andrear walls and in the portions of said bottomstructure forming extension of said end walls.; longitudinal lines of adhesive connecting said transverse lines of adhesive to a continuous line, said lines of adhesive being so constructed and arranged that a portion thereof will cooperate with and will face anotherportion thereof after the bottom sttructure has been formed and being consolidated to a substantially continuous and fluid-tight seam sealing the bottom of said tube.
8..A bag of the automatically opening bottom type. which comprises in combination a web'A of non-fusible flexible material, a strip of adhesive on each longitudinalmarginalportion of said web, the said adhesive strips being juxtaposed in registry and bonded by the application of pressure to` form a tube, said tube being folded longitudinally along a plurality of lines to form reentrantend y walls and front and rear walls connected to said `end walls, 'a preformed quadrangular bottom structure flattened in the plane of said frontand rear walls constituted of the lower terminal portions of said end. walls folded towards each other and of the resulting tabs including the lower portions of said front and rear walls being folded towards each other, transverse registering lines of adhesive provided on the bottom ends of said front and rear walls and in the portions of said- `bottom structure forming extensions of said end walls, and longitudinal lines of adhesive connecting said transverse lines of adhesive to.a continuous line, said lines of adhesive being so constructed and arranged that the transverse lines of adhesive at the ends of said front and rear walls will be brought into a face to face relationship with said longitudinal lines of adhesive and the transverse lines of adhesive at the end of the extensions of said end walls will be brought into a face to face relationship with each other after the bottom structure has been formed, said cooperating lines of adhesive being coalesced to a substantially continuous and fluidi-tight seam sealing the bottom of said tube.
HARRY F. WATERS.