US2576542A - Method of producing sealed bags - Google Patents

Description

Nov. 27, 1951 w SCHQEN 2,576,542

METHOD OF PRODUCING SEALED BAGS Filed March 22, 1948, 2 SHEETS-SHEET l Nov. 27, 195] w. A. SCHOEN METHOD OF PRODUCING SEALED BAGS 2 SHEETS-SHEET 2 Filed March 22, 1948 /A/ new rim. Z0. Q .ra ciom/ 5/ Mal/52% v ATTORNEYS.

Patented Nov. 27, 1951 METHOD OF PRODUCING SEALED BAGS Walter A. Schoen, Milwaukee, Wis., assignor to Milprint, Inc., Milwaukee, Wis., a corporation of Wisconsin Application March 22, 1948, Serial No. 16,333

3- Claims.

My present invention relates generally to improvements in the art of manufacturing bags or bag-like receptacles and relates more particularly to an improved sealed bag provided with an external end pocket and to an improved methd of and apparatus for producing the improved structures.

A primary object of the invention is to provide an improved commodity receiving bag which is extremely simple and durable in construction and which may be quickly and easily produced and effectively sealed in accordance with an improved method.

It has heretofore been proposed to provide a sealed commodity receiving bag formed with an external pocket in one end thereof providing a convenient means for easily applying the bag to a hook upon a display rack in stores or the like where the commodities are merchandised. Since the commodities thus packaged are frequently edible food products, it is desirable to provide these bags with seals which are as tight and durable as possible. Furthermore, these bags are generally sold in large lots and in empty unsealed condition by the bag manufacturer to the producer of the commodity who performs the final packaging and sealing operation, and it is therefore also desirable to provide bags of unitary construction which may be readily and effectively sealed in a simple manner by novices without need for special expensive equipment. One of the more successful bags of this general type heretofore proposed has an external pocket formed directly in the sealed bottom end of the bag between the folded back end portion or bot-:

tom closure flap and the bag itself, the sealing being performed by application of heat and pressure to the folded end portion while a medial portion of the end flap is maintained separated or spaced from the adjacent outer Wall of the bag by a special tongue or the like to form the pocket. However, although commodity receiving bags of this type have enjoyed some commercial success, it has heretofore been found necsary to employ special relatively expensive equipment for the heat-sealing operation of the end closure of the bags in order to provide a suitable external pocket, since it was necessary in the prior structures to maintain the pocket-forming portion of the flap entirely separated from the'adjacent bag wall during the sealing operation. Furthermore, this use of special .equipment required considerable care by more or less experienced operators of heat sealing devices to insure proper placement of the separating tongue,

and the operation was accordingly time-consuming, tedious and expensive.

It is therefore a more specific object of the present invention to provide an improved commodity receiving bag which may be readily provided with an external pocket in a heat-sealed end thereof in accordance with an improved method of production which obviates the disadvantages of prior methods.

Another specific object of my invention is to provide an improved method of producing a sealed commodity receiving bag having an external end pocket which may be provided simultaneously with the heat-sealing of'the bag end without requiring the use of special equipment.

Another specific object of this invention is to provide an improved bag which may be readily manufactured in large quantities and at minimum cost in accordance with my present method, and which maybe quickly and easily filled with a desired commodity and heat-sealed by a novice with an external hook-receiving pocket being automatically provided at the sealed end during the sealing operation without necessitating separation of theend flap from the adjacent bag wall.

A further specific object of my present invention is to provide an improved unitary heat sealed commodity receiving bag having an external end pocket and a method of economically and rapidly producing the same from a web of sheet material with a'minimum number of simple operations.

An additional specific object of the present invention is to provide improved simple and highly efiicient apparatus for effecting automatic utilization of the present bag producing method, and for manufacturing the improved bags in an expeditious and reliable manner.

These and other specific objects and advantages of the invention will be apparent from the following detailed description.

A clear conception of the various features constituting the present improvement and of the several steps involved in the improved method of producing the new heat-sealed bags and of 'typical apparatus for effecting commercial exploitation of the method, may be had by referring to the drawings accompanying and forming a part of this specification, wherein like reference characters designate the same or similar parts in the various views.

Fig. l is a diagrammatic side view of a portion of a typical installation adapted to accomplish the initial step .of-printing and application of heat-scalable material to the continuous web of sheet material;

Fig. 2 is a similar diagrammatic side view of the portion of the installation adapted to perform the remaining steps in producing the empty bags from the web of material;

Fig. .3 is a plan view of a fragment of the web with some of the heat-sealable material applied thereto, the view being taken in the zone marked 33 in Fig. 2;

Fig. 4 is a similar plan view of a fragment of the web as it passes the tube former, :the view being taken in the zone marked 4-4 in Fig. 2;

Fig. 5 is a plan view of one of the completed empty bags produced by the apparatus shown in Figs. 1 and 2 in accordance with the improved method; and V Fig. 6 likewise is a plan view of one of the completed bags, showing the same in final completely sealed condition after insertion of the commodity.

While the improvements have been specifically shown and described herein as being advantageously applicable in the production of flat commodity receiving :bags .of 'a particular type having portions thereof coated with thermoplastic and sealed ;by application of heat and pressure and with the external pocket formed in the top end portion thereof, it not my desire or intention to thereby unnecessarily limit the scope or :utility of the invention; since the improvements might be advantageously applied to fbag sof other types and other :forms of .sealing materials may "also the utilized with provision ibeing made for the :pocket at either .or both ends of the bag.

In accordance with my present improved method of producing the new bags, .I initially print and apply local laterally-spaced :spots of adhesive .such as thermoplastic to one face of a continuous .ribbon 'or web :of relatively thin and flexible .sheet stock. Then, I dry the continuously moving ribbon :by subjecting the same to a controlled heat and apply transverse strips of thermoplastic material to the opposite surface of the ribbon at approximately the same areas as the local thermoplastic spots, after which the ribbon may be rolled up. Next, the roll of initially printed and thermoplasticized sheet material is reversed and a longitudinal adhesive strip is continuously applied to an edge portion of the ribbon which may then be folded over to form a tube and simultaneously sealed along the overlapping longitudinal edge portion thereof. Thereafter, the tube may *be severed into the desired lengths in proximity to the thermoplastic transverse strips and local spaced spots so that these strips and spots are located at one open end of each tube length or section. Finally, transverse strips of glue or thermoplastic may :be applied to "the end of each :of the-tubular sections remote from the initially applied thermoplastic spots and strips, and this remote tube end may then be folded and sealed to provide a closed bottom for the :completed empty bag. After subsequent insertion of the commodity within the bag, the open end, having an inner transverse strip and adjacent outer local spots of thermoplastic, need merely to be folded over upon the adjacent :bag wall and heat and pressure applied thereto to seal the same and simultaneously provide a pocket between the spots of laterally spaced thermoplastic and the fold and outer adjacent surface of the bag wall.

In carrying on commercial exploitation of my seam atthe overlapped ribbon stock edges.

at one open end of each tube section 26..

improved bag producing method, an installation substantially as shown diagrammatically in the drawings may preferably be utilized to rapidly, automatically and effectively construct the successive bags, illustrated herein as being of a particular type on which indicia is printed in three different colors. Referring particularly to Figs. 1 and 2 of the drawings, the initial thin and flexible ribbon H] of any suitable relatively durable sheet stock may be supplied from a rotatably supported roll H from which the ribbon 10 may be continuously withdrawn by a set of draw rolls I2 and printed successively on one side thereof with indicia of different colors by the respective sets of printing rolls 13, I4, I5, with local laterally-spaced spots of thermoplastic or other adhesive being applied to the same side of the ribbon by a set of rolls I6. To dry the printed material and the adhesive spots in a fairly rapid manner and within a confined space, the ribbon 1 0 may be continuously advanced over a series of rollers :11 .or the like through an oven 18 wherein the advancing :ribbon is subjected to a controlled heat; and after leaving the oven 1 8, the ribbon It is supplied with transverse strips of thermoplastic or other adhesive on the opposite side thereof and at approximately the same areas as the thermoplastic spots by means of rolls .119, the ribbon 18 then bein .rolledup as indicated .at 29. The roll 20 of initially printed and thermoplastized sheet material may then :be

reversed as shown in Fig. 2 and continuously supplied to a center seam glue wheel 2| where ra longitudinal adhesive strip is applied to an edge portion of the ribbon to; the ribbon being drawn over a tube-forming "unit '22 by a set of draw rolls 2-3 for conversion into :a iconstantlycadvanoing :flat tube having a longitudinal glued The tube may thereafter be continuously drawn past a cut-ofi knife assembly '24 :by another set of draw rolls 25, the knives .24 severing the continuous tube into successive tube sections 26 :in proximity to the thermoplastic inner transverse strips and the -.exterior local laterally-spaced spots so that these strips and spots are located The successive tube sections 26 are then delivered by .a .set of accelerating rolls 2'! from the severing zone to the upper rear portionof thesperiphery of a rotating bag blank conveying and bottom forming clamp cylinder or rotor 28 having a bottom adhesive-applying and tucker cylinder .29 associated therewith, the cylinder 29 functioning to apply transverse strips of glueor thermoplastic to the end of each tubular section 26 remote from the initially applied thermoplastic spots and strips and folding and sealing such end to provide a closed bottom for each of the'completed empty bags which are ifinally successively stacked as at '30.

During normal operationof the bag producing equipment hereinabove described, the draw rolls I 2 are operating to constantly withdraw .flat ribbon stock In from the supply roll ll, the-successive printing rolls [3, I4, I15 are functioning to apply colored indicia to one side of theadvancin ribbon, and the roll 16 is functioning to apply local laterally spaced spots of adhesive to the same side of the ribbon II] as the printed indicia, these local spots being illustrated on the ribbon :0 by means ofnumerals 31 in Fig. 3. The printed material and adhesive spots 31 are thereafter dried while the ribbon :l-O is subjected to controlled heat as it is continuously advanced apply transverse strips of adhesive, illustrated by means of numerals 32 in Fig. 3, to the opposite side of the dried ribbon H) at approximately the same areas as the thermoplastic spots 3|. The ribbon is then reversed on the roll 20 and the roll or wheel 2| functions to continuously apply an adhesive strip, shown at 33 in Fig. 4, to a longitudinal side edge portion of the advancing ribbon,

. while the forming unit 22 folds the ribbon ID, as

it is drawn therethrough by the rolls 23, and converts the same to a continuous elongated flat tube having a central seam 34, as illustrated in Fig. 4, the local thermoplastic spots 3| being located on the exterior surface of the tube and the thermoplastic strips 32 being located interiorly of the tube by virtue of the reversal of the ribbon ID. The knives 24, herein illustrated as producing a serrated cut, se er the tube into sections 26 as it is drawn by the rolls 25 past the knives,

the tube being severed in proximity of the thermoplastic spots 3| and transverse strips 32 so that each tubular section 26 is provided, at one open end thereof, with a pair of these exterior laterally-spaced adhesive spots 3| and an adjacent interior transverse adhesive strip 32 as shown in Fig. 5. The tube sections are then successively supplied by the rolls 21 in an accelerated manner to the cylinder 28 where the roll or cylinder 29 functions to apply adhesive and fold and seal the opposite end of each section 26-as shown at 35 in Figs. and 6, thus completing the empty bags which may be stacked as shown at 30 in Fig. 2.

It is apparent that the improved bag producing method may thus be carried on continuously, efficiently and automatically with the aid of relatively simple equipment to rapidly and successively provide improved bags 36, such as shown in Fig. 5, which may be quickly and easily supplied with a commodity and finally effectively sealed at the open end thereof by a novice by merely folding the end portion, as at 31 in Fig. 6, and applying heat and pressure entirely across the folded portion, thereby providing a sealed end having an external pocket formed between the fold and the adjacent bag wall and between the laterally spaced adhesive spots 3 I. The improved bag 36 comprises, in general, a flat tubular body having a longitudinal adhesively-united seam 34, one end of the tubular body being sealed as at 35 and the opposite end thereof being open, the open end of the tubular body being provided with external laterally-spaced spots 3| of adhesive and an internal transverse adhesive strip 32 adjacent the spots 3| so that when the open end is folded and sealed the tubular body will be closed entirely across the interior of the latter end and the folded portion of this end will be united to the exterior of the body only at laterally-spaced spots to provide an external suspension pocket.

From the foregoing detailed description, it will be apparent that my present invention provides an improved sealed bag adapted to be manufactured from relatively inexpensive stock and provided with an external pocket adjacent one or both of the sealed ends thereof to provide suspension means for the bag. The improved commodity receiving bag is extremely simple and durable in construction and may moreover be quickly and easily produced in accordance with my improved method. By utilizing the improved method in the manufacture of these bags, the speed or rate of production may be enhanced to a maximum at 6 a minimum cost; and the apparatus diagrammatically shown and described herein is highly efiicient and reliable in operation and may obviously be modified and adjusted to produce bags of various shapes and sizes. Bags manufactured in accordance with my improved method may be readily sealed with an external hook receiving end pocket being automatically formed during the sealing operation without necessity of utilizing special equipment, and these bags may therefore be quickly and easily filled with the commodity and heat-sealed by a novice. The invention has, in fact, gone into extensive and highly successful commercial use, and commercial bags produced in accordance with the method have proven very satisfactory for purposes of packing and merchandising diverse commodities. The bags may be produced in accordance with my improved method from a web of suitable sheet material in a rapid and economical manner with a minimum number of simple operations without necessitating use of positive means for. separating the end flap from the adjacent bag wall during the sealing operation to form the external pocket; and the improved bags may obviously be decorated by printing or otherwise applying suitable indicia in various colors.

It should be understood that it is not desired to limit this invention to the exact steps of the method disclosed or to the precise details of construction of the bags, herein shown and described, for various modifications within the scope of the appended claims may occur to persons skilled in the art to which this invention pertains; and it is also contemplated that specific descriptive terms used herein be given the broadest possible interpretation consistent with the disclosure.

I claim:

1. The method of producing bags from a web of sheet material, which comprises, initially applying local laterally-spaced spots of heat-sealable material to one face of a continuous web of sheet stock inwardly of the side edges thereof, continuously advancing the web and applying transverse strips of heat-scalable material to the opposite face thereof and entirely thereacross at approximately the same areas as said local spots, thereafter applying a continuous adhesive strip to a longitudinal edge portion of the web and folding the web to form a tube adhesively united along the longitudinal edge portion to 'form a longitudinal seam and with said local spots on the exterior surface of said tube on opposite sides of the seam, severing said tube in proximity to each set of said local spots and transverse strip to provide tube sections each having a set of exterior laterally-spaced spots of heat-scalable material and an interior transverse heat-sealable strip adjacent one end thereof, closing and sealing the end of each tube section remote from said spots and strip to provide a bag, and finally supplying the bag with commodity and folding the open bag end back upon itself with said local spots located interiorly of the fold and applying heat and pressure thereto entirely across the fold to produce a seal at the transverse strip-and an external suspension pocket between the local spots.

2. The method of producing bags from a web of sheet material, which comprises, initially applying local laterally-spaced spots of adhesive to one face of a continuous web of sheet stock inwardly of the side edges thereof, continuously advancing the web and applying transverse strips of adhesive to the opposite face thereof at approximately the same areas as said local spots, thereafter forming the web into a longitudinally seamed tube with said local spots on the exterior surface thereof on opposite sides of the seam,

upon itself. with said local spots located interiorly of the foldand applying sealing pressure thereto-entirely across the fold to produce a seal atthe. transverse strip and an external susp sion pocket between the local spots- 3, The method of producing bags from a web ofisheet material, which comprises, initially applying local laterally-spaced spots of adhesive to one face of a continuous web of sheet stock in wardly of the side edges thereof, continuously advancing the web and applying transverse strips of adhesive to the opposite face thereof at approximately the-same areas as said local spots, thereafter forming the web into a longitudinally seamed tubewith said localspots on the exterior 8 surface thereofon opposi v i es of the seam, severing said tube in proximity to each set of said localspots and transverse strip to provide tube sections each having a set of exterior laterally-spaced spots of adhesive and an interior transverse adhesive strip adjacent one end thereof, folding the bag end containing said local'spots back upon itself with said local spots located interiorly of the fold and sealing the folded end along said transverse strip and local spots,.and finally closing and sealing the end .of each tube section remote from said spots and strip to complete a bag.

WALTER A. SCHOEN.

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

UNITED STATES PATENTS Number Name Date 1,983,291 Haskell Dec. 4, 1934 2,048,122 Howard July 21, 1936 2,060,451 Steen Nov. 10, 1936 2,146,308 Maxfield Feb. 7, 1939 2,146,831' Maxfield Feb. 14, 1939 2,339,304 Von Haase Jan. 28, 194 2,409,621 Geimer et a1. Oct. 22, 1946 2,439,584 Shumann Apr. 13, 1948

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