US2968432A

US2968432A - Gusseted pasted valve bags

Info

Publication number: US2968432A
Application number: US782783A
Authority: US
Inventors: Craighead Prevost
Original assignee: BANCROFT BAG FACTORY Inc
Current assignee: BANCROFT BAG FACTORY Inc
Priority date: 1958-12-24
Filing date: 1958-12-24
Publication date: 1961-01-17
Anticipated expiration: 1978-01-17

Description

I Jan. 17, 1961 P. CRAIGHEAD 8,432

GUSSETED msmn VALVE BAGS 5 Sheets-Sheet 1 Filed D90. 24, 1958 1961 P. CRAIGHEAD 2,968,432

GUSSETED PASTED VALVE BAGS Filed Dec. 24, 1958 3 Sheets-Sheet 2 ATTORNEY Jan. 17, 1961 P. CRAIGHEAD cusss'rsn PASTED VALVE BAGS 5 Sheets-Sheet 3 Filed Dec. 24, 1958 R m V m 3 V 3 m a 2/ V Q vl, d/ X 9? a HM Q l 1 2 1 I 1 I 1 1 1 I I I I 1 m wl l lwi l l 1 I I I I I 1 1 I II P Unite States Patent 2,968,432 GUSSETED PASTED VALVE BAGS rando 195s, Ser. No. 782,783

3 Claims. or. 229-625) invention relates to bags formed from paper .or ,other flexible sheet material, and more particularly to :gusseted' 'rnultiwall valve bags having pasted end closures,

" "l Ieretofore, it has been suggested .to provide multiwall bags for packaging .finely divided materials, the ends pasting, sewing or stapling the th j s be n lo by iQltle d olltlpqljtlQl'lSof the bag -tube. It has also been suggested to provide valve bags wherein each end of the gussetedbag tube is formed with oppositely disposed adapted to be adhesively secured in over-lapping "relationship and sealed with a cover sheet. While the aforementioned priorart arrangements 'areno doubt satisja ctoryior packaging certain types of particulate mate- ]rials', they are open toobjection as a packaging medium ffor veryfine or dusty materials, since by reason of their :construction there is a tendency for such materials to siftthrough unsealed channelsor crevices, when the filled ha sare being handled or shipped.

ltwill be appreciated that with various materials in divided form, for example, carbon black, pigments and-chemicals, leakage from the bags not only results in contamination .of merchandise in surrounding areas, but when the packaged material is of a combustible nature, creates a serious fire hazard. Additionally, leakage or sift age represents loss of material, and .it also detracts from the appearance of the bag, which is undesirable ',f oripackagingff or consumer sales.

After considerable research and experimentation, in con'nectionwith the manufactured gussetedopen mouth bags 'havingpastedfor sewn bottoms, and satchel bottomed pasted open mouth bags, I have found that gusseteid'open mouth bags having pasted bottoms are more ;s"iftpro of, andare characterized by a stronger bottom structure, than-bags having satchel bottom arrangements, and' ac'cordingly, these desirable features of the g'usseted operi"mouth pasted bottom bagsare incorporated in the "irnproved-bag structur e of the present invention.

In accordancewith the' present invention the bags are formed from gusseted tubes comprising one or'more pliesof paper or other suitable material, the tubes being provided with animproved integral, non-sift pasted closure assembly at either or both ends thereof, and a preformed valve or tuck-in sleeve,to facilitatefilling of the jbags, having one end portion adhesively secured within one o'fthe closure assemblies. The use of a gusseted tiibe, in conjunction with a tuck-in sleeve and pasted 'bo'ttom closure,- is particularly well adapted 'for' valve filling', for the'reason that as the gussets are forcedoutwar'dly'by the material entering the bag, the bottom of -.the Y bag is simultaneoiisly forced downwardly into-' fully opened. position, thus permitting the materialto settle in the corners of the bag without need of manual or mechan'i'cal assistance. In the filling of the bags havin'ga satchel type "b'ottom difiiculty is frequently encountered sin'c'e itlie material tends to settle on a knee formed by the inner half of the side wall of the fiat tube where the '-.bottom foldsback against the face of the .bagfand on tsuch i occurrenCe'manuaL assistance must be given during 'opens automatically as breakage is experienced onsatchel bottom paper tube having pasted end closures.

..voi ds at the ends oredges of thepackage'.

the filling operation, in order to flip or force the bottom down so that material being deposited in the bag will fill all corners at the bottom of the bag. As aboveindicated, valve filling of my improved .bag is easily and .quickly accomplished withoutneedof manualor mechanical assistance. By reason of its novel design fthe'b'ag the material is deposited therein during the filling operation. 1

It is customary with industries using valve filled bags to compress thefilled package forfreig'ht rate advantages, particularly with ov'rse'asishipments. 'Whether the com- 'pression is accomplished by means of hydraulic orroller presses, the filled bag package .of the presentinvention is well suited for compressing. The bag is" fillcd uriiformly and rectan'gularly" because of the preformed corners 7 along the side ,Walls and the box like form of the result-aht support .the gusset area to form a [rectangular package.

In feeding satchel bottomjor sewn type bags through these compressing machines, the gusset area protrudesand must be forced into a rectangular shape. Considerable or sewn type bags by the gusset area catching or hanging on the side belts or gusset guides of the compressing machine, as the p c ent he m neof satchel bottom type bags in themachine dueto contortion of the bag walls as the material is being forced into a rectangular shape. My improved bag lends itself perfectly to roller pressing because the package is rectangular when it enters .the' machine, and consequently, ,thegusset area does not protrude so as to hang on the gusset guides or sidebelts. Breakage is minimized inthe machine because thejpa'ckageis already rectangular when it enters the machine, andsince the material withinthe package has been pre-shaped, "itiis readily pressed into the desired size and shape without undue stress and onthe paper bagwalls.

object of my invcntionis to providean improved valve bag, and method of producing the same fr'om'a gusseted tube having pasted end closures.

' Another object of my invention is to provide an improved valve bag formed from a ,gl sseted, multiwall Still another object of my invention is to provide a .bag

formed from a'gnsseted, multiwall tube having improved a ed en os e a se bfi sa d'a pre ormed fill ng sleeve incorporated in one of the assemblies.

"Yetanotherobject of my invention is to provide an improved valvebagadapted toautomatically open as the material with which it is to be .filled is deposited therein, .thefilledbagbeing of rectangular box-like shape.

A further object of myinventionisto provide an improved valve bag adapted for packaging finely divided and dusty materials of the character of carbon black,

p ment an the i wh r h fil e pa ma be subjected to roller or hydraulic compressionto corn- ..pactthe contents, without undne stress orstr-ain on the .paper walls of the bag.

" Yet a further object of my invention is to provide. an

. improved valvebag adapted to'form a rectangular shaped box-like package .after it has been filled, withont A still further object of my invention is-to provide an improved valve'ibag which is strong and 'rugged in Sllbjctedto rou h han ng e i with theseand other objects i v viewrwhichfimaylbe There is also breakage incident to my improvements, the invention consists in the parts and combinations to be hereinafter set forth and claimed, with the understanding that the several necessary elements, comprising my invention, may be varied in construction, proportions and arrangement, without departing from the spirit and scope of the appended claims.

In order to make my invention more clearly understood, I have shown in the accompanying drawings means for carrying the same into practical effect, without limiting the improvements in their useful applications to the particular constructions, which for the purpose of explanation, have been made the subject of illustration.

In the drawings: 4

Figure l is a plan view of a multi-ply bag blank used in forming a gusseted tube, in accordance with one embodiment of the present invention;

Fig. 2 shows the bag blank of Fig. 1 after it has been arranged in tubular form and pressed into flat rectangular shape;

Fig. 3 shows the arrangement of the closure assembly elements formed at each end of the tube, and an associated filling sleeve;

Fig. 4 shows a filling sleeve at the valve end of the tube, with one of the closure flaps folded thereover;

Fig. 5 shows the completed bag after the flaps at the ends of the tube have been folded inwardly and adhesively secured in over-lapping relationship.

Fig. 6 shows the rectangular box-like shape of the bag of Fig. 5, when it is expanded;

Fig. 7 is a plan view of a modification of the bag blank shown in Fig. 1;

Fig. 8 is a view of the bag tube formed from the blank of Fig. 7, showing the arrangement of the elements of the tube of the closure assemblies at each end of the tube;

Fig. 9 shows the completed bag expanded into rectangular box-like form;

Fig. 10 is a detail view of a modified form of closure flap at the valve end of the tube; and

Fig. 11 is a detail view, showing the flaps of Fig. 10 secured in over-lapping relationship.

Referring to the drawings, and more particularly to Fig. 1, the bag blank is comprised of

plies

1, 2 and 3, formed from paper or other suitable flexible material having slits 1', 2' and 3, of graduated length formed therein at the upper and lower margins 4 and 5, respectively of the blank, the gusset portions being designated generally by numeral 6, which portions are defined by fold lines 7 and an intermediate fold line 8. The

plies

1, 2 and 3 are arranged in superposed relation, and stepped as shown, so that when the blank is folded into the tubular form of Fig. 2, the joints at the over-lapping portions of the plies will be in vertical staggered relationship. In the process of arranging the plies in superposed stepped relation, they are spot pasted to prevent relative movement therebetween during the folding of the blank into tubular form, and during the subsequent steps of securing the over-lapped ends of the plies, folding the slitted portions of the plies and the end portions of the blank, in connection with the formation of the flaps, and panel members of the closure elements at the ends of the tube.

As will be seen in Fig. 3, the closure assembly at each end of the tube or bag blank, comprises inwardly folded rectangular shaped end flaps 9, an isosceles trapezoidal shaped side flap 10, having re-entrant triangular shaped portions 10' adjoining the end flaps, and a second side fiap 11, embodying a pair of stepped, re-entrant trapezoidal shaped portions 11a, and a contiguous overlying stepped rectangular shaped portion 11b, the side flaps 10 and 11, being adapted to be turned inwardly in over-lapping relationship about

fold lines

12 and 13, respectively. It will be noted that the gussets are defined by the

fold lines

7 and 8, together with the triangular shaped inturned portions 14 at the top and bottom of the tube, and that when the tube is expanded it is of rectangular cross-section, the rectangular shaped ends of'the tube being defined by the

fold lines

12 and 13, and the bases 15 of the triangles 14. It will be further noted that the free end portion 11b of the side flap 11 is of rectangular shape, and that it is formed by folding the plies inwardly at the bottom ends of the slits 1', 2' and 3 (Fig. 2), along the

diagonal lines

16 and 17, whereby the exposed areas of the individual plies are in stepped relation. A filling sleeve 18, formed from paper or other flexible material, is interposed between and adhesively secured to the upper exposed surface of one of the inturned end flaps 9, and to the exposed portion 10 of the side flap 10 which overlies the sleeve. The flap 10 is then folded over the previously inturned flap 10 and is adhesively secured thereto, and to the valve sleeve and to the oppositely disposed end flap 9, as shown in Fig. 5.

In connection with the closing and sealing the ends of the tube, the adhesive or paste is applied to the exposed stepped areas of the plies constituting the flaps 11, and to portions of the end flaps 9, (Fig. 3), said pasted areas being designated generally by

numerals

19 and 20. It will thus be seen that a tight closure is effected by reason of the seal formed by the stepped areas of the side flaps 11, the end portions of the plies thereof being severally adhesively secured in over-lapping relationship with respect to end flaps 9 and flap 10, whereby a substantially siftproof closure is obtained.

The use of a gusseted tube, in conjunction with a preformed filling sleeve and the improved closure assemblies as above described, provides a bag structure which is particularly well adapted for valve filling.

During the filling operation, the gussets are forced outwardly by the material entering the bag, and the bottom is simultaneously forced downwardly into fully opened position, whereby the material settles in the corners of the bag and completely fills the same, without requiring manual or mechanical assistance. When the bag is filled, it is in the form of a box-like container of rectangular cross-section, as shown in Fig. 6, thus providing a package which lends itself to easy handling. Additionally, the rectangular shaped package is ideally suited for roller pressing, by reason of its smooth rectangular shaped lateral faces, and the fact that the material within the container has already been pre-shaped before the package enters the pressing machine. The rectangular shape of the container also permits the package to be set in an upright position while the sleeve is being tucked in, or while tape is automatically applied as the container moves away from the filling machine, in event that a different type of filling opening is provided. It will be further noted that the rectangular portions of flaps 11 (Figs. 5 and 6) extend a substantial distance over the flaps 10, and are adhesively secured thereto along their peripheral edges and body portions, thus providing a tight sift-proof seal between the elements of the closures, without requiring the use of separate cover sheets for the bottoms.

In the modification shown in Figs. 7, 8, and 9, the bag blank (Fig. 7) is the same as shown in Fig. 1, except for the location of the slits 1a, 2a, and 3a, at the lower margin 5 of the blank. By arranging the slits in the plies, as shown, the closure assemblies are formed in apposed relation, that is to say, on opposite sides or faces of the tube, in lieu of forming them on the same side or face as previously described. The closure assemblies are identical, except for the difference in location, as those of the first described embodiment of the invention, and they are folded and sealed in the same fashion.

By arranging the bottoms in apposed relationship, more printing area is provided for advertising purposes, the bags can be pressed more effectively, and movement of the bag into and out of the printing press is facilitated, since the trailing bottom is down, and accordingly, can not snag on the printing mechanism or other parts of the press.

Referring to Figs. 10 and 11, there is shown a modified form of flap arrangement at the valve end of the bag.

xii 968 :482

Inthismodification, it will-be notedithatthe lengths of the ,stepped portions 1a, 2'12 and: 3':a have been de; creased, and accordingly, foldline 17 of the, inturned panel 9 at the valve corner ofthe tube is substantially longer than the corresponding fold lines 17 of the bag tubes shown in Figs. 4 and 8. It will thus be seen that when flap 11 is folded into over-lapping relationshipwith respect to flap (Fig. 11) the fold lines 17' and 21 of the side flaps form a triangle with fold line as a base, the vertex 22 of the triangle being at the inter-section of the fold lines. The purpose of this arrangement is to provide reinforcement in the vicinity of the filling end of the bag, and to minimize the possibility of tearing flap 11 during the filling operation. In this connection, it will be appreciated that while various filling techniques are employed, it is customary practice to introduce the filling nozzle into the sleeve a sufficient distance to enable the bag to be supported thereon, while the bag is being filled. By constructing the flap at the valve corner of the bag, as above described, the forces created as the bag is being filled are distributed along diagonal lines, and a reinforced area of contact is provided be tween the filling tube and the flaps.

In making a bag, in accordance with the present invention, the plies are spot pasted, slit, and brought together, as shown in Fig. 1, and after adhesive has been applied to the seam margins of the plies, the bag blank is folded and pressed into the tube form of Fig. 2. It will be noted that the resultant open-ended tube comprises three separate tubes, one tube from each ply, and that the marginal over-lapping edges of each ply are bonded by inter-lineal pasting, thus providing a strong and rugged multiwalled tubular unit. The bag tube is now creased at the fold lines 12, 13 and 13, at the end of the tube opposite the valve end, which end of the tube is then opened (Fig. 3), flaps 10 and 11, and end flaps 9 formed, the side flap 11 and end flaps 9 being pasted in accordance with the paste patterns designed generally by

numerals

19 and 20. The end of the tube is now closed by folding flap 10 about fold line 13, and then folding flap 11 about fold line 12 into over-lapping engagement with flap 10.

The valve end of the bag is closed in substantially the same fashion as above described, that is to say, the tube is creased at the fold lines 12, 13 and 13', the end of the tube is opened and paste applied to side flap 11 and end flaps 9, however, the paste pattern at the valve or sleeve corner is modified by decreasing the pasted area of the end flap 9, whereby to provide a pocket to receive the tucked-in free end of the filling sleeve. After the end of the tube is opened, and side flaps 10 and 11, and end flaps 9 are formed and portions thereof pasted, sleeve 18 is positioned on the inturned end flap 9 at the valve corner as shown in Fig. 3, the inner end 18' of the sleeve projecting beyond the inner edge 9 of the end flap. Thereafterwards, the valve end of the bag is closed by folding flaps 10 and 11 inwardly about their respective fold lines, as explained in connection with the steps of closing the bottom end of the tube.

It will thus be seen, that by reason of the construction and arrangement of the flaps and panels at the ends of the tube, in conjunction with the paste patterns associated therewith, the elements of the closure assemblies are adhesively secured in such manner as to assure a substantially sift-proof closure.

While I have shown and described the preferred embodiment of my invention, I wish it to be understood that I do not confine myself to the precise details of construction herein set forth by way of illustration, as it is apparent that many changes and variations may be made therein, by those skilled in the art, without departing from the spirit of the invention or exceeding the scope of the appended claims.

What is claimed:

1. A valve bag of the character described, formed from a gusseted, multi-ply 'bag tube having an outer ply side panel of the tube, the slits in the inner ply being inwardly spaced from and shorter than the slits in the outer ply; an integral, sift-proof, pasted'closure assembly at each end of the tube, comp rising a pair of oppositely disposed, inwardly folded rectangular-shaped end-flaps, an isosceles trapezoidal-shaped first side flap having reentrant, triangular-shaped portions adjoining the end flaps, the said first side flap, at one end of the tube, being folded inwardly along a base fold line, the triangularshaped portions thereof being adhesively secured to the subjacent surfaces of the end flaps; and a second side flap, embodying a pair of stepped, re-entrant, trapezoidalshaped portions and a contiguous overlying stepped, rectangular-shaped portion, folded inwardly in overlapping relation with the first side flap, the stepped, re-entrant trapezoidal portions and overlying the stepped, rectangular shaped portion of said second side flap being ad- 'hesively secured to the exposed, subjacent surfaces of the end flaps and the first side flap; a preformed flexible filling sleeve adhesively secured to one of the end flaps at the opposite end of the tube, the first side flap at said opposite end of the tube being folded inwardly into overlapping relation with the end flaps and adhesively secured to the subjacent surfaces of the filling sleeve and the opposite end flap, the second side flap being folded inwardly into over-lapping relation with the first side flap, and adhesively secured to the exposed subjacent sur faces of the first side flap, the filling sleeve, and the end flap opposite the sleeve.

2. A valve bag of the character described, formed from a gusseted, multi-ply tube having an outer ply and at least two inner plies, said tube, when expanded, being of rectangular cross-section and having rectangularshaped side and end panels, each of said plies having a pair of parallel, longitudinal slits at each end of a. side panel of the tube, the slits in the inner plies being inwardly spaced from and progressively shorter than the slits in the outer ply; an integral sift-proof, pasted closure assembly at each end of the tube, comprising a pair of oppositely disposed, inwardly folded rectangular-shaped end flaps, an isosceles trapezoidal-shaped first side flap having re-entrant, triangular-shaped portions adjacent the end flaps, the said first side flap, at one end of the tube, being folded inwardly along a base fold line, the triangular-shaped portions thereof being adhesively secured to the subjacent surfaces of the end fiaps; and a second side flap, embodying a pair of stepped, re-entrant, trapezoidal shaped portions and a contiguous overlying stepped, rectangular-shaped portion, folded inwardly into overlapping relation with the said first side flap, the stepped, re-entrant trapezoidal-shaped portions and the contiguous overlying stepped, rectangular-shaped portion of said second side flap being adhesively secured tothe exposed, subjacent surfaces of the end flaps and the first side flap; a preformed flexible filling sleeve adhesively secured to one of the end flaps at the opposite end of the tube, the first side flap at said opposite end of the tube being folded inwardly into overlapping relation with the end flaps, one of the re-entrant triangular-shaped portions of said first side flap being adhesively secured to the subjacent surface of the filling sleeve, and the remaining triangular-shaped portion of said side flap being directly, adhesively secured to the subjacent surface of the opposite end flap, the second side flap being folded inwardly into overlapping relation with the first side flap, the stepped, re-entrant trapezoidal-shaped portions and the contiguous overlying stepped, rectangular-shaped portion of said second side flap being adhesively secured to the exposed subjacent surfaces of the first side flap the filling sleeve, and the end flap opposite the sleeve.

3. A valve bag according to claim 2; in which the References Cited in the file of this patent UNITED STATES PATENTS 1,782,738 Martin Nov. 25, 1930 8 Taggart May 29, 1934 McNulty Mar. 5, 1935 Gelbcke Oct. 22, 1957 Duflin Mar. 3, 1959 FOREIGN PATENTS Belgium Nov. 30, 1951