US2537462A - Method of making automatic bottom bags - Google Patents

Description

Jan. 9, 1951 A. B. HASLACHER 2,537,462

METHOD OF MAKING AUTOMATIC BOTTOM BAGS Filed Nov. 16, 1944 2 Sheets-Sheet l j Fz il.

Jan. 9, 195 1 A. B. HASLACHER 2,537,462

METHOD OF MAKING AUTOMATIC BOTTOM BAGS Filed NOV. 16, 1944 2 Sheets-Sheet 2 1269b 350 354 300 Ayrecl Bjfaslaclzez p @Ema 550 fiw Patented Jan. 9, 1951 UNITED STATES rATENr OFFICE AlfredB. Haslacher, San Francisco, Calif. Application November 16, 1 944, Serial-i No, 563,128

9 Claims, 1

This is a. division of myicopending, application Serial No; 451,343, filed July 17, 1942,.now Patent No. 2,317,005, dated. May 29, 1945, and relatesto method of making automatic bottom bags,

It is an object of this invention to provide: a mouth structure for a gusseted bag having. an inner ply of heat-fusible material: in. which the heat-fusible ply may be seaied in. any desired manner and the outer ply may be formed into; a closure attractive in appearance.

It is a further object: of my invention to provide a bag having a mouth structure as above. indicated but in which the bottom structure is not altered" by the exigencies of the mouth. structure.

It is a further object of my invention to improve the structure of the bag bottom disclosed I in my copending application Serial No. 395,393,

filed May 26, 1941 (:now' abandoned), particul'arl-y for the purpose of facilitating heat sealing and to relate this improvement in the bottom structure tomy improvement in themouth structure so-that' either or both improvements may-be from the following descriptions taken in connectionwith the annexed drawing in which:

Fig. 1 illustratesmy treatment of the paper preparatory to formation of my improved bags;

Fig. 1A is identical with Fig. I except that it shows the treatment applied to a center-seam bag instead of a side seam bag Fig. 2 is aperspective view showing my improved bag opened and filled with the parts in position for sealing of the heat-fusible ply;

Fig. 3 is aperspective View showing one method of arranging theheat-fusible pl y for-heat sealing;

Fig; 4 is a perspective view showing an intermediate step in completing the package;

Fig. 5 is a perspective view of the completed package;

Fig. 6 is a plan view of a web of paper showing finai disposition of. theparts preparatory to. the final sealing step;

8 isa view similar to Fig; 6 and illustrating a modified form.- for: the application of my improved bottom structure;

Fig.- 9 is a perspective view similar to; Fig. 7. 11-. lustrati-nga bag iormedirom the web of rib. 8;

Fig. 9a. 1558; section. on theline AA of Fig. 9 but with the parts in final sealing position;

Fig, 9b is a section; similar: to Fig. 9a but; taken on: the line: 3-3; of; Fig. 9..

Fig. id is. a. schematic; plan view of the apparatus. for carrying. out: my improved. method.

7 Fig--11 i anelevatiorr corresponding to. Fig. lit; Fist. i2:is a section. on the: line l.2': [:1 of. Figs 1:1; Fig: 1351s a section ontheline [3 -1.3- of Fig. I1; Fig. 14; isea plan view of a bag, formed; inaccordance' with my application aforesaid, just prior to. the final; forming step; and,

Fig. 15 is a. plan view or. the completed: bag bottom- It is to be understood that any desired form of bottom. may be applied. tothe bag disclosed herein; Preferably, however, abottom: should be of th typedisclosediim copend'ing application leerial No 395,303,. filed May: 26 1 941. That is; it should be of the preformed or automatic type hermetically closed accordance withmy aforesaid application.

Throughout thi specification theword paper includes any and: alt flexible webs which do not have heat-fusible. or thermoplastic; characteristics, and the: term heat-fusible web or piy the arrangement of slits and. die cuts for the production of both my improved bottom and improved mouth structures. Fig. '7 is a perspective view showing a two-ply tube, the outer ply of which is formed from the i neludesnot only sheets or webs formed of in herently heat-fusible or thermoplastic material but also: sheets or webs: surfaced with such'material'. 1

This invention is particularly concerned with the hermetic sealingof flexible walled bags. Generally speaking, it is not difiicu-lt for the bag manufacturer to produce a perfect hermetic seal of' the bottom of the bag. If, however, thefunction of" the bag is that of a hermetically sealed package, the closure of the mouth, which is accomplished. at the point of use. of equal. importance with, the. closure. of the bottom. The diificulties of this problem are intensified-by the fact. that the user may have equipment: varying from elaborate; fully automatic machinery to semi-automatic equipment amounting to;- little more than a handtool. Accordingly, it-isdesir- Fi'g. 7b is a view similar to .Fig.. 70.. showing the as able that: at the mouth or the. bag the utmost latitude be given the user so that Y whatever sealing equipment may be; he will have-, ne.v-.

between lines [8 and 25.

3 ertheless, an opportunity to make the type of closure best adapted to that equipment.

In Fig. 1, I show a web of paper ldadvancing in the direction of the arrow A. Lines l2, l4 and 16 indicate the ultimate location of one set of gusset folds, while lines I8, 20 and 22 represent the opposite set. These lines are located in Fig. l for the formation of a side seam bag in which the margin of the web iii adjacent the line 22 will be folded over the opposite margin of the web it to form a seam.

As the web advances I form a transverse slit 24 extending between lines 12 and i and a second transverse slit 32 parallel to the slit 24 and extending between the same lines. I also form a transverse slit 2? somewhat to the rear of the slit 24 and extending between linesl i and 16.

On the line i2 I form a longitudinal slit 30 connecting the outer extremities of the transverse slits 2 and 32. On the line [4 I form a longitudinal slit 28 connecting one extremity of the transverse slit 2'i with the center of the rearward transverse slit 32, and on line it I form a longitudinal slit 25 connecting the inner extremities of the transverse slits 2t and 21.

The slits above described define the shaded area 3Q which I remove from the web. This leaves a tongue or flap 3G defined by slits 21, 28 and 32.

Simultaneously with the above described steps I form a transverse slit 38 in alignment with the slit c -land extending between lines [8 and 22,

and a transverse slit 12 in alignment with the transverse slit 32 and also extending between lines I8 and 22. I :46 in alignment with the slit 2's" and extending I then form a longitudinal slit 43 on the line 22 andconnecting the outer extremities of the transverse slits 38 and 42; a longitudinal slit 48 on the line 2|] and 0011- necting one extremity of the transverse slit 46 with the center of the transverse slit 42, and a longitudinal slit in on the line it connecting the inner extremities of the transverse slits 38 and 4E. The slits just described define the shaded area 52 which I remove from the web in the manner .of the area 35.

While the relative locations of slits 27 and 28 in area 3d and of slits ift and 43 in area 52 may be varied from those shown in Fig. 1, the slits 21 and 46 should always be spaced from slits 25 and 38, respectively, a distance equal to the spacing of slits 28 and 48 from lines it and [8, I8 vspectively, in order to form the sightly closure shown in Fig. 5. V

The line XX indicates the line at which the cut off of a bag length will take place and the areas 34 and52 will be adjacent the mouth of the finished bag. The web lei superimposed upon a web of thermoplastic material, the superimposed webs are formed into a continuous gusseted tube and consecutive bag lengths are severed therefrom along the line XX as above described.

In Fig. l-A I show a web of paper I00 advancing in the direction of the arrows B and have indicated by lines )6, I68 and H0 the fold lines of one set of gussets and by lines H2, H4 and H6 the location of the opposite sets. Areas I02 and 164 correspond with areas 34 and 52, respectively, of Fig. 1 and the line of cut off is indicated by the line YY. Fig. l-A differs from Fig. 1 only in that the gusset fold lines are arranged to bring the longitudinal seam at the center of the back wall instead of at the side..

also form a transverse slit 4 Once the tube is formed, however, it is immaterial whether the bag be of the side seam or the center seam type.

Referring again to Fig. 1 it is to be noted that the distance between slits 21 and 32 is equal to the distance between the gusset lines 12 and i6 and the distance between slits 46 and 42 is equal to the distance between the gusset lines is and 22. Accordingly, the distance between transverse slits 25 and 32 and 38 and 42 substantially exceeds the width of the gusseted walls.

In Fig. 2 I show a bag having the paper Web ID as its outer ply and a heat-fusible web 60 as its inner ply. In this view the bag is standing on a preformed bottom 10 formed in accordance with my copending application aforesaid. The

portion 52 of the rear wall of the paper ply lying between slits 32 and 42 (Fig. l) and the mouth of the bag has been bent down into the horizontal plane and the equivalent portion 54 of the front wall has similarly been bent down to expose the entire mouth portion of the heatfusible ply 6B. Flaps 36 and 50, being attached to the front wall portion 54, have been drawn out from between the gusset folds and are similarly placed in the horizontal plane. It is to be understood that the essential feature is to clear the paper away from the heat-fusible ply. The portions 52 and 54 are shown in the horizontal plane for purposes of illustration, but can be bent to any position which will give satisfactory access to the mouth of the heat-fusible ply 60.

In Fig. 3 I illustrate one very satisfactory method for sealing the mouth of the heat-fusible ply. Here the exposed walls of the ply 66 have been drawn out into a common plane so as to form a fin 6| and this fin may be subjected to heat and pressure throughout its length to form a seat seal. This type of closure is particularly advantageous when the heat-fusible ply consists of coated material. It will be noted that this closure results in the formation of ears 6! at each end of the fin, said ears lying in the plane of the top of the bags contents.

In Fig. 4 the fin Bl has been suitably folded into the plane of the bags contents and the ears 6| have been folded over so as to lie Within the cross section of the bag. The folded fin Si is so placed as to lie to the left of Figs. 3 and l.

The portion 52 of the rear wall is then superimposed upon the collapsed and sealed inner pl 60, the extremity 52' of the portion 52 being doubled back upon itself. This has the effect of compensating the right-hand side of the bag for the folded up portions of the ply 60 so as to bring the top surface into as level and even a condition as possible.

In Fig. 5 I show the finished package in which the front wall portion 54 has been pulled across the top of the bag with its free edge 54 folded upon and suitably secured to the opposite vertical wall of the bag and the flaps 36 and at the sides of the portion 54 have been folded upon and secured to their respective gusseted walls. This produces an extremely sightly closur since the top of the bag has a completely uninterrupted surface which may be suitably printed and has excellent stacking characteristics.

The closure of the heat-fusible ply 6E3 neednot always be as shown in Fig. 3 though that type is probably best Where the heat-fusible ply is a coated sheet. For certain heat-fusible materials it may be better to reform the gussets so as to collapse the mouth of the heat-fusible ply intoa plane of the, same width as the width of thepackage: In suchcase theflaps as as should bewithdrawn from the gussets'; but portions 52" and 54 of the rear and front walls may usefully be carried up over the collapsed mouth of the heat-' fusible ply so as to protecttl'ie heat-fusible material during the imposition of heat and pressure; When the closureisthus formed the resulting from the heat sealing operation may be and the paper webthen rewoun-d before being superimposed on a heat-fusible web for the purpose: of tubing.

In Fig. 6 show a web-of paper iEQ'adVancinginthedi rection of the arrow W. Lines #52, i54 and I'E Findicateone setof gusset fold lines. while I158, F98 and it?- indicate the opposite set. Th'e'transverse line indicates theultini-ate line oi cut offof'each tube length. Area tallying between lines E52, E56 and the cut off line S-S corresponds exaetlyto the area 33 illustrated in Fig. 1-, while area tSE, lying between lines 58-, i672 and; the out off line 8-8 corresponds exactly to the area 52 of Fig. i. To the left of the line S -S I providethe cutareas 5%, lid and 12.. The areas [68- and H2 extend farther to the-left of. the' cut oir line S-S than does the area He and; are preferably of twice the width of the area I10. The area i5 5 extends along the line SS from the margin of the web l5i3 a distance equal to that bet can the line Hi2 and the oppositemangin of the web" 95?} and when the tube is formed the area $58 will coincidewith the lower end of the area W2 so to lie within the longitudinal seam of theba'g;

The lengthsof the-die out areas Ni] and i 12 may be varied within certain limits. The-tongues 28b and 292 forming the ends of thediamond foid are entirely conventional. They are termed in the fl attene'rl' tube by pairs of slitsin the front and rear wallswhich permits opening of the:d-ia-, mond" fold as shown in Figs. 7 and 9. This di amond fold' structure is old andwell known-and is now almost universally used in bottoms of the preformed type. These tongues may be mutual 1y of the same width and in the particular em"- bodiment equality is probably" preferable. There is, however, no reason why one tongue shouldnot be made somewhat narrowerthan the other; as shown, forexample; in Fig. 14.

It is to be noted that in Fig. 6 areas H1? and [6E and the areas H2 and it'd are, in effect, merged and all of the matenal may be removed in a single operation. If, however, his desired to dispense with. the mouth closin features represented by the areas We and 556, these may .be eliminated and all. of the die Cutting will take place to the left of the out off line S-S'. It is, moreover, possible in any event to eliminate either the area i it? or the areas" 1'68 and F52 as will be. hereinafter described. If, however, such elim' inati'on is to take. place thedie cut area whichis used should be the relative depth indicated for areas [Edand i1 2.

As the web i553 advances consecutive sets of diev cu-t areas as above described are formed therein, each set being spaced from the next bythe length or a tube to be severed therefrom; The web tfifi isthen superimposed upon a weboff'he'ats fusible material and the superimposed webs: are; formed intoa gusseted tube; each web: hating: its own independent longitudinal seai'm- Censored-- ti ve lengths are then severedfrom the: continuou'sly term-ed tube and at thebottom end or each; a diamond is: opened by separating the flaps 2'0'il and 282-, the edges of the material interme-= diiate these flaps being brought intoupsta-nd iace-toiace contact as disclosed; my copendmg application aforesaid Due to the presence oi? thedie out areas 168, H3 and" E 1 2, the heatfusible material 264 in the meeting: portion of" the edges is entirely exposed. This effect: is clearly shownin Fig. 7a where the meeting edges-1 21 m of the heat-fusible ply 25% formanupstanding seam which may be subjected to heat sealing without any danger of blocking the: bottom oi? the bag. At one side of the edges: 21-9 theedge I510 of the area We comes toth-e baseoi thefin, On the other side the edge in of the area fl i' fallsshort ofthe base or" the edges 210 by an amount equal to the height of the upstanding The reason for this will be made clear from- Fig. Z'b in which the fin formed bythe edge 21:9 has been folded into the plane of the bag bottom. Atthistime the bottom is: subjected totransverse seals along the lines Qw-Qj and as'descri bed in my aforesaid copending application, of Fig.1, but due to the gap between: the edges it'd and i 72 there is no differential of thickness to inter".- fere with or prevent perfection of the heat seal. It will be noted in connection with Fig. 6v that the web I56 is completely severed by the various die cut areas except for thoseportions which will ultimately become the tongues 28d and. 2202.. For certain grades of paper this is not objectionable". Where, however, certain grades of. paper and cer tain tubing operations are used this is. objectionable. Where a light grade of paper is to be used or where the web is to be subjected to considerable handling, as where the die cutting operation is performed as part of a preprinting opera.-

tion and the web is re-wound before being tubed,

the weakness occasioned by the presencev of die cuts; may be serious and to. take care of suchsituations I have devised the alternative disclosed in Figs. 8, 9, 9a and 9b.

In Fig. 8 I. show a web 3% advancing in. the direction of the arrow Z. Lines 382 364 and 396 7 indicate the location of one set of gusset folds,

while. lines 388, 3H] and 3l2 indicate the opposite set; The transverse line T-T indicates the 111- timate line of cut ofi. Area 3M lying behind lines 302 and 3% and the transverse line T--T correspondsexactly with area 3 3', Fig. 1, while die cut area 31 8 lying behind the lines 398, 3!.2 and. the transverse line TT corresponds exactly withv arc-a 52 of Fig. 1. To the left of the line T'T I provide a pair of die cut areas 3 i8 extending outwardly from lines 302 and 3535, a pair of die cut areas 32!) extending outwardly from lines 398 and 312', and a die cut area 320" extending inwardly from the upper margin of the web 3%. Whenv the web is tubeol the area 320 will coincide with the marginal one of area 328 and will thus lie wholly within the longitudinal seam.

The portion of the web lying between the inner margin of the area 3213' and the outer margin of the uppermost one of area 3 i8 will in the final bag bottom define a tongue339, while the material between the outer margin of the lowermost area 318 and the adjacent margin of the uppermost area 320 defines atongue 3'32 forming the opposite of the diamond fold, as shown in Fig. 9. For rea-' sons which will be made clear hereinafter, the areas 320 and 320' should extend approximately twice as far to the left of the line T-T in Fig. 8 as do the areas 3l8.

The web, after removal of the several die cut areas, is superimposed upon a web of heat-fusible material and then superimposed webs are formed continuously into a gusseted tube, each web having its own independent longitudinal seam. Consecutive bag lengths are severed from the tube and are bottomed by first opening a diamond fold as indicated in Fig. 9. The edges of material between the flaps 33B and 332 are brought into face to face contact in a plane at right angles to the plane of the diamond fold, as described in my aforesaid copending application. Due to the presence of the die cut areas SIB, 320 and 320, the paper does not cover the heat-fusible material at the extremities of the upstanding seam formed by the meeting edges. This fin while upstanding is heat sealed to avoid the possibility of blocking the bag bottom and is then folded into the plane of the bag bottom as illustrated in Figs. 9a and 92). Fig. 9a is a section taken within that portion of the fin where the paper and the heat-fusible material are coextensive. The heat-fusible ply 355! has its edges 352 fused along the line 355 to form a fin faced on each side by paper. After the formation of this fin transverse heat seals are to be applied as illustrated and described in connection with Fig. 7. Fig. 9b is taken along the line bb of Fig. 9 and illustrates the condition of the parts in the area where the transverse seal is to be applied. Due to the presence of the die cut areas 3I8, 326 and 329, the material of the heat-fusible ply 350 in the region of its edges 352 is exposed and is not subjected to differences of thickness or heat transmissibility by the presence of the paper ply 388. Accordingly, a perfect transverse seal may be obtained.

It is optionally possible to eliminate either the die out area 3(8 or the areas 325 and 329' but if one set is eliminated the remaining set should be of the depth indicated in Fig. 8 for areas 326 and 326' in order to avoid having paper underlie the edges 352 at the point of transverse sealing, as will be clear from Fig. 9b. If in Fig. 8, for example, the area 3 i3 be eliminated, the right-hand edge of paper in Fig. 91) would cover the uppermost one of the edges 352 of the heat-fusible ply 350. This might be desirable where the nature of the material of the heat-fusible ply 35B is such as to make the shielding action of the paper desirable.

If the bag is made up of an outer ply of paper and an inner ply of paper coated on its inner surface with thermoplastic material, the form shown in Fig. lb, without change, is preferred.

In Figs. 10 to 13, inclusive, I illustrate an alternative treatment of the central seam oi the diamond fold in a bag of this class. This treatment may be used in connection with a web die cut as illustrated in Fig. 6 and is applicable to the form of that figure even though only one effective die cut area, such as that comprising the areas I68 and I72, be provided.

In Fig. 10 I show a two-ply bag 493, the bottom of which has been die out in accordance with Fig. 6, eliminating, however, the area iii Flaps 4G2 and 66 at the bottom end have been opened into a diamond fold. The edges i538 and 408 of the material intermediate the flaps have, however, been brought into simple overlapping relatiOnShip, instead of being brought into the up- The bag advances in the direction of the arrow N and encounters the leading end MD of a member 4l2. At the leading end 4H] of the member 4l2 there is a plowshare 4M which as the bag 400 advances lifts the edges 4% and 408 into upstanding condition. As these edges pass beyond the plowshare they encounter a pair of folding members M6 and M8. The folding member 416 lies in advance of the member 618 and brings the edge 4% back into the plane of the bag bottom, while the member lfi superimposes the edge 408 upon the edge 486, with the member H2 lying under the superimposed edges. It is to be noted in Fig. 12 that the bag 408 is composed of a paper ply 4M and a heat-fusible ply 403 and that as a result of the die cut, the paper ply 4ill terminates short of the edge 4% of the heat-fusible material. As a result, after the action of the folding members 416 and M8 the parts are in the relationship shown in Fig. 13, with the heat-fusible portion of the edge 498 superimposed on the exposed portion 585 of the heat-fusible material in the opposite edge. The member 412 is hollow and is supplied with cooling air by a duct 42!). The air emerges from the member 412 through openings H3 in its upper surface. Additional openings may be provided in the sides and the lower surface, if desired. This is an optional feature necessary in connection with certain types of heat-fusibie material and unnecessary in connection with certain other types. The cooling feature should be used whenever the heat-fusible ply has the characteristic of remaining soft and tacky for an appreciable time after having been subjected to a heat sealing operation. In such case the cooling medium moving through the member M2 acts not only to expedite the setting of the heat-fusible material but also in the nature of a lubricant to facilitate sliding of the material over the member 4|2.

Above the member M2 is mounted a duct 450 supplied with heated gas by a pipe 45L On the side of the duct 450 adjacent the member 4l2 there is a narrow orifice 452. When hot gas is supplied under pressure it emerges from the orifree 452 with considerable velocity. The heat content of the gas serves to heat the portion of the bag immediately thereunder and the Velocity of the gas serves to press the parts together as described in my copending application Serial No. 438,161, filed April 8, 1942 matured into patent No. 2,353,402, July 11, 1944, and the duct 450 is of sufiicient length to enable a satisfactory seal to be formed. As shown in Fig. 10, the cooling member 4l2 extends substantially beyond the trailing end of the heating member 450. This is to enable the cooling member to set the heatfusible material before being withdrawn. Any possibility of blocking is thereby eliminated. Thereafter transverse heat seals may be formed across the ends of the diamond as hereinabove described. Due, however, to the exposure of the heat-fusible material 4136 uniform thickness and heat transmissibility is aliorded for the formation of these transverse seals.

While I prefer to utilize a blast of hot gas for sealing purposes, this is not an indispensable feature. For example, anti-friction support in the form of rollers could be used in the upper surface of member M2 and the heat and pressure could be applied by means of pressure bars, traveling chains or rollers. While the top closure illustrated in Figs. 1 to 5 inclusive, is applicable only to a gusseted bag, the bottom structures illustrated in Figs. 7 to 13. inclusive, are equally applicable the tautomatici-bottom of -a gussetedbagorato he. ;sa-tchel.."- bottom ioflafinonegusseted bag. s iln sieithercasef the bottom when 2 the bag1is set-np-fis itrectangular and this 'rectangularrareazzis what. I :refer to. as: the ultimate: bottom.

Figs. 14 and :15 illustrate generally the bag. dis- '2 closedrin my: application'F-SeriaL No 395,303,; filed ,JMEYQG; 1941.: :IrrFig. .14 I showa tube ilflfl having :tuckedein ,gussetsr5il I i Theitubehas a diamondicfold rxbottomxof which-some 'endaisa-a tongue: 502 formed from the front'iwalli5il3fofthe tubea 500, z: and :the other: endJis a' somewhat narroweritongue -i-504formed fromitherear wall .5llfiiofitheitube 500. "'fThes entire interior. surface-t'ofthei tube 500 tis Fiormed 'of thermoplasticanateria1; and-'theizdia- ,zsnondfold bottom "is :so 'zproportioned thattxthe margins of the1=materia1;of-i:thetubeaeSUflaihtermecasdiatethertongues 51321arid 594 maybe'brought into i -face to'nface:contact; rforming i a" fin 506:which: is .c-heatasealedvand.folded;asshownin-Fig; 14,: into .tthe: plane'trof the: diamond. This zsame-feffectiis lustratedi'ior. thebags herein'in' Figs. 'lbyQw-and 39b. "'fTransverse heat-seals are then applied-across zthesshadedrareasf X1 and :Y. The entire-shaded rvarear may be sealed; but? thetsealing shofuld"'not =1 transgressupon-the rectangularnltimate bottom prof theb'aa andthe sealrtm ay beizlimitediin rwidth ext-lengthwise of th ebag) to the portionsrcnlycfithe rareas'Xe-and Y; 'bnt mustext nd entirely across :isthese trapezoidal *areas. Following. the sealing. of eAareasX-and-YJthe tongue 'E'Ht'and the trapezoidal warea? Y. are foldedru'oon the rectangular :bottom of: the ibag and the tongue '5 E 2 and theitrapezoi'dal 1'; area' Xare folded :tonver ie' the: folded tongue 504. =liOrdinary adhesive is t ap lied 3-;to* secure the tongues toaether.l:=?l3his is without 'efle'ctunon' the khermetic character :of t e :bottom seal. ltsisole oeflectis'mechahical; Theanpearancerofthe bag ;s='b0l7tUmin 15-:is identical with the' appearance f every zbag -b ott mwi scl-os d in t isan'plicati on. 1 IR isrto' bet noted iithatl the structure' anrl' the hermetic seal of the bottomi would :be una'ltered :i'ifithe gussetsrlii! l' were thrust :outward-lvtsoias to wm'ake the:' ba'9,i'T-'0fi" the so-called'"satcheFbottom retyzpe and, :"unless otherwise snecific'al y'rset f rth, the claimsare tozbe taken asreadable'upon either -a 'gusset d or non-g sse ed tube having. a bottom oflanv of the tvnes herein tdisclosed.

Oth r modifications'fof 'the' 'forms 'herein derasealingthemontacting portions oi -said heat-insia-blep-ly while shielding th undersiderof said over- .-.lapped portions-againstblocking.

.2. I n-. the-process of forming bag= botto-mmthe aste-ps comprising sproviding a length of: flattened tube-having anrou-ter ply of paper: and an inner plyesof heat-fusible material, said? .tube length .-having -an:-opened diamond fold atone endy-said adiamonclfoldi having, at its longitudinallextremities, flaps defi-nedbypairs ofslits in-both plies rl5-of opposed walls 01? saidtube length, the inner a: surfaceecf (one margin of-the .inner 'ma-teri-ar intermediate -said-r fiapshbeing-in overlappedpondition on the outer surface oithe opposed-)ma-rgin ..of-theinneri-material,andthe paperply at one .--,Of.- SLlCh margins being shorter 'than themeatfusible :ply --to expose said heat-fusible ply wadvanc ng said tube-length in the--direction.of.;-its length wand/over -a--p1oughshare folder totlift asuch overlapped. margins out of-the' plane 0f.:the

'; 25. diamond fold and'restoring'saidmarginseto oner- ---lapped-conditiomwhile bringing ashield-ingmemberthereunder; control ing said-restoring steptto i bring the exposed margin of atheheatefusible ply iunderlthe oppos te margin; and forming'aslongi- 30, tudinal heatseal throughoutthe=-1ength-:of.:said

- over.lapped marg-ins -whi1e --ma-inta-ining i rsaid shielding member thereunder.

3. A method-of makingebags which com-prises -advanci-nga webof paper and "removing 'therev from 'consecutive areas ;spaced-apartiai distance corresponding etc 'a .wbag length isuperimposing Unsaid web of paper upon a web of heat-fusiblemalterialaanditubing the superimposed websl-with-rthe heat-fusible web onthe interior of the tube sevlosering consecutivebag lengths'from said tubewith oneaofathe aforesaid areas-at one -end'--'of each length; forming fa diamond fold: at that. endcof weaeh-e length, said vdia-mond fold :having; at- ;its 1. lengthwise extremities; flaps defined-by :pairswof s-s its bothplies of the innensurface of 'one wall wOf said tube; bringing the inner SllIffiJCG-Ofxfll'lfi ma-rgin ,of the i-nner material intermediatew said flaps into overapped: condition on theicuter surwface of t-he opposecl m argin of the "inner: matescribedrw ill' occurttoithose ski-l edt'inztheg b d- "rial in the rla'nebf the: diamondfoldythe aforerilrzdolnot'intendito bezl-imite'cl? to the nre'cise forms and proportions here n describd bmonlwas set toithtin theisubioinedafclaims which are to be broadly construed.

What is claimed 'is: 1. A: method :of: making: bagswhich 'comprises advancing a web of paper and removing-therefrom consecutive areas spaced-apart a distance corresponding to a bag Iengthjsuperimncsing said web of paper upon a-vveb of heat-fus blematerial and tubing the superimposed webs eizith -the 'heat fusible web -on the' interior of the tube; .ssevering consecutive baglen'gths from said tube With-one of theaforesaid areas at one end of-each each length, said diamond fold having, at its lengthw se extremities, fla s defined by pairs of slits in both plies of opposed walls of said tube; bringing the inner surface of one margin of the inner material intermediate said flaps into overlapped condition on the outer surface of the opposed marginof the inner material in the plane of the diamond fold, the aforesaid area of removal of the paper being so located as to expose the heat-fusible ply throughout the length oi one iengthf forming-adiamond foid at that end of" esaid ia-rea of removal of "the paper being: so 2 10- cated as to expose the heat-fusible plyithrcug h- !out'-.the"length of one" such margin; and sotfcontroi-ling thei bringing "ofrsaid margins f intoi's'uch overlapped condition I as to "bringisa'id' (exposed margin :of" s'aid*=heat'-fusible ply beneath 't'he'oprposite= margin, and then heat sealing: the icon- Jtacting portions -':of said heat fusible'iplyawhile shielding theru-nderfsi'de' of said- "overlapped' por- 41750115 againstirblocking; thereafter removing said -'shieIdingmember-and' forming a transvers "seal adjacent'one zsi'deofi thei'ultimate be *tomp-sai'd' transverse: heat seal: intersecting' 'said islongitudinal: heatseal.

' heat azil-n'ilther-process of forming b'ag'bottOms the I diamond fold having, at its longitudinal extremion the outer surface of the opposed margin of the inner material, and the paper ply at one of such margins being shorter than the heat-fusible ply to expose said heat-fusible ply; advancing said tube length in the direction of its length and over a ploughshare folder to lift said overla ped margins out of the plane of the diamond fold and restoring said margins to overlapped condition while bringing a shielding member thereunder;

controlling said restoring step to bring the exposed margin of the heat-fusible ply under the I :opoosite margin; and forming a longitudinal heat seal throughout the length of said overlapped margins while maintaining said shield ng member thereunder, thereafter removing said shield:

ing member and forming a transverse heat seal adjacent one side of the u timate bag bottom. said transverse heat seal intersecting said longitudinal heat seal.

1 5. A method of making bags which com rises advancing a web of paper and removing there'-- from consecutive areas spaced apart a distance corresponding to a bag length; superimposing said web of paper upon a web of heat-fusible material and tubing the superimposed webs with the heat-fusible web on the interior of the tube; severing consecutive bag lengths from said tube with one of the aforesaid areas at one end of each length: forming a diamond fold at that end of each length, said diamond fo d having, at its lengthwise extremities, flaps defined by pairs of slits in both plies of the inner surface of one wall of said tube: bringing the inner surface of one margin of the inner material intermediate said flaps into overlapped condition on the outer surface of the opposed margin of the inner material in the plane of the diamond fold, the aforesaid areas of removal of the paper being so cated as to expose the heat-fusible ply throughout the length of one such margin; and so controlling the bringing of said margins into such overlapped condition as to bring said exposed margin of said heat-fusible ply beneath the opposite margin,

' and then heat sea ing the contacting portions of I said heat-fusible ply while shielding the under side of said overlapped portions against blocking,

thereafter removing said shielding member and forming transverse heat seals adjacent each side of the ultimate bag bottom, said transverse heat seals intersecting said longitudinal heat seal, and thereafter mutually superimposing said flaps on the bag bottom and securing them in such relationship.

6. In the process of forming bag bottoms the steps comprising: providing a length of flattened tube having an outer ply of paper and an inner p y of heat-fusible material, said tube length having an opened diamond fold at one end, said diamond fold having, at its longitudinal extremities, flaps defined by pairs of slits in both plies of opposed walls of said tube length, the inner 1 surface of one margin of the inner material intermediate said fiaps being in overlapped condition on the outer surface of the opposed margin of the inner material, and the paper ply at one of such margins being shorter than the heat-fusible ply F to expose said heat-fusible ply; advancing said tubelength in the direction of its length and over a ploughshare folder to lift said overlapped "margins out of the plane of the diamond fold,

and restoring said margins to overlapped condition while bringing a shielding member thereunder; controlling said restoring step to bring l the exposed margin of the heat-fusible ply under the opposite margin; and forming a longitudinal "heat seal throughout the length of said overlapped margins while maintaining said shielding member thereunder, thereafter removing said shielding member and forming transverse heat seals adjacent each side of the ultimate bag bottom, said transverse heat seals intersecting said longitudinal heat seal, and thereafter mutually superimposing said flaps on the bag bottom and securing them in such relationship.

'7. A method of making bags which comprises advancing a web of paper and removing therefrom consecutive areas spaced apart a distance corresponding to a bag length; superimposing said web of paper upon a web of heat-fusible material and tubing the superimposed Webs with the heat-fusible material on the interior of the tube; severing consecutive bag lengths from said tube with one of the aforesaid areas at one end of each length; forming pairs of corresponding slits in opposed walls of said length at said end, said slits passing through both plies thereof; forming a diamond fold at said end of each length, each of said pairs of slits defining therebetween a flap at a lengthwise extremity of said diamond fold; bringing the margins of the material inter- .mediate said flaps into overlapped condition in the plane of the diamond fold, with that margin of said heat-fusible material exposed throughout the area of removal aforesaid lying beneath the opposite margin of said heat-fusible material, and heat sealing the marginal contacting shielding member.

ALFRED B. HASLACHER.

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

UNITED STATES PATENTS Number Name Date 2,254,510 Bergstein Sept. 2, 1941 2,353,311 Karlson July '11, 1944 2,353,402 Hasl-acher July 11, 1944 2,353,605 Waters 1.. July 11, 1944 Haslacher May 29, 1945

Images