Flexible container, closure means therefor, and manufacture thereof
United States Patent 2271279

This invention relates to flexible containers and wrappers, more particularly those of the envelope, pouch and like types, especially those intended for use as retail or dispensing holders and containers for commodities, merchandise, etc. It aims to provide an attractive, inexpensive and otherwise...

Thomas, Errold B.
Application Number:
Publication Date:
Filing Date:
Thomas, Errold B.
Primary Class:
Other Classes:
206/245, 206/260, 206/268, 229/79, 383/43, 383/86, 383/210
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This invention relates to flexible containers and wrappers, more particularly those of the envelope, pouch and like types, especially those intended for use as retail or dispensing holders and containers for commodities, merchandise, etc.

It aims to provide an attractive, inexpensive and otherwise improved container of the class mentioned, together with novel closure means and devices for containers of that class and with special emphasis upon the provision of a simplified and more efficient sealing closure capable of repeated resealing throughout a normal use period.

While efforts have heretofore been made to produce a commercially satisfactory resealable envelope or pouch, any such of which I am aware have employed an inherently tacky material for the walls of the container itself and have either treated the material to render it non-tacky throughout except at a sealing location, generally an inside face of the wall, or have made some portion of the tacky material subject to restoration to a more or less tacky condition by special action such as the application of pressure sufficient for example to fracture a non-tacky layer or coating of pulverant material such as starch, tale or the like and so rendering operative an underlying normally sticky substance or composition such as uncured rubber; or else said envelopes or pouches have lacked the hinging and associated novel features of my invention as herein disclosed.

But in accordance with my invention there is coordinated with the flap or fold-piece of such envelope-type container a closing device or closure comprising an attachable strip preferably preslotted to define an aperture at the container mouth and foldable as a hinge, such strip providing a vehicle for cohesive material for sealing and resealing purposes. In combination with the material of the container body and flap this closure means of the invention affords a relatively stiff or semi-rigid character for the mouth of the container, aiding the latter to maintain its original form and shape for display and 4 packing purposes and throughout its use and cooperating as a reinforcement and stay to give strength not only in the otherwise weak regions of its mouth and the crease of its flap but also to the container as a whole. Additionally, my 1 closure makes it much easier to manipulate the container to open and close it, so that such.action may be substantially semi-automatic and accomplishable by but one hand of the user; opposite pressure of the fingers at the ends of the 5t semi-rigid hinge closure springs the closure slot and container mouth or opening to an elliptical shape while upon release of the pressure reclosing is effected, whereupon downturning of the flap hinges together the cohesive surfaces of the closure, so that little or no additional pressure beyond the effort of so turning down the flap completes the closing and sealing or resealing operation.

In the accompanying drawing illustrating by way of example certain -embodiments of the invention: Fig. 1 shows in perspective an envelope or pouch type of container, in an opened condition and as if subject to opposite pressure at its ends, as by the user's fingers, as indicated by the oppositely directed arrows; Fig. 2 is a plan of the main portion, vehicle or body of my novel closure or closing device, apart from the container as a whole; Fig. 3 is a longitudinal section of the pouch and closure structure such as that of Fig. 1, either as upon the flap portion or upon the adjacent wall of the body portion of the container, the thickness of the several sheets or films being exaggerated in the interest of clearness, as is also the case in Fig. 1; Figs. 4 and 5 are similar sectional views as Fig. 3, showing modifications; and Fig. 6 illustrates largely diagrammatically a method of manufacture of a container such as the pouch or envelope of Fig. 1.

Referring to the drawing in further detail the body, bag or .commodity-receiving portion of the " container is represented at A. For the purposes of explanation the illustrated container may be regarded as for tobacco, for which purpose it is admirably suited. Hence it will generally herein be referred to as a pouch, it being understood 10 however that this term has no limiting significance as to the content of the package which, as above indicated, is adapted for a wide range of uses, while the foldable closure structure per se may be applied to packages and containers ' of various sizes, forms and types.

The container, including both the bag or pouch proper A and the folding flap B, may be formed of any suitable flexible sheet material, including those known commercially as "Cellophane," 0 "Pliofilm," "Vinylite" resin film, "Vinylite" resin treated papers, and such like, and including treated paper, cloth or other textile material, either of cellulosic or non-cellulosic nature or combinations. In other words, the material is 5 selected from the numerous flexible sheet structures available, as appropriate to the particular package and use and having the particular characteristics, as to weight, thickness, strength, transparency, moisture resistance or proofness, flexibility, crackle, crack resistance, odor, color and others, as may be desired for the circumstances of content and use. Fuller disclosure of and claims for a novel and specially treated cotton-fibre-base material peculiarly suited to certain of the uses of the present invention, and the method of manufacture of said material are for a related application by me.

Noting particularly Fig. 1 of the present drawing, the body or bag portion A may .be formed by folding a flat sheet of the selected flexible material as upon the line F-F' up to the line E-E' and sealing together the outer edges or side portions FE, F'E' as by cementing, by application of heat, or otherwise. The flap or cover portion B desirably is comprised as a continuation of the initial sheet member, adapted for folding at or above the top of the body A, as upon the line E-E', to form a crease or fold formation.

The novel closure means C of the invention, one form of which is shown separately in Fig. 2, comprises an initially separate single-ply or plural-ply section or strip of sheet material which inherently or by special treatment is of such weight and degree of stiffness that when applied to the flap and adjacent wall of the envelope container it will provide in combination therewith a structure of the semi-rigid or self-supporting character previously mentioned. That is, in cases where the material of the pouch or container proper is of such flexibility as to be nonself-supporting oring substantially so-and it is an important feature of the invention that relatively flimsy, soft or easily torn materials are hereby made available for the purpose-the material of the hinge closure means is afforded, or is selected to have, a greater rigidity as compared with the container material, desirably at least sufficient to provide a staying or form-maintaining effect and to afford for the package as a whole the semi-automatic pressure-effective spring opening and closing capacity earlier referred to. In some instances the closure means or element C may be comprised of one or more plies of the self-material of the pouch or like container stiffened by special treatment where necessary to afford the 67 desired degree of rigidity or semi-rigidity.

The material of the closure device or closing strip C accordingly may be a relatively heavy paper, cloth or other textile product, such as buckram, or combinations of such materials. 5 Desirably a single section or strip of the particular material is used, whether single or plural ply, of a length at least substantially equalling that of the fold or crease of the container flap and of a width for folding the strip lengthwise g6 upon itself to provide adjacent hingedly connected portions adapted respectively to overlie a wall portion of the bag or body A and a corresponding portion of the flap B, said wall and flap portions or areas being selected so as to match p when the flap is turned down. That surface or those surface portions of this hinging closure device C which appear in open or exposed position in Fig. 1 but which provide the in-facing or hingedly contacting areas in the folded and 7 sealing position of the closure will herein be termed for convenience in reference the inner faces of the closure. By means of coating or impregnation at least said "inner" surface presents a cohesive sealing substance having a tacky or sticky nature adapted to be maintained over long periods, the substances suitable for this purpose including uncured rubber, merely as one example among various such substances available. Such substance if necessary may be modified as by the addition of inert fillers, to afford a degree of cohesive action such that when two surface areas so constituted are brought into firm contact with each other they will form an effective sealing bond but nevertheless will be readily capable of being pulled apart to unseal, and of being resealed by renewed mutual contact.

The reverse side of this hinging closure element, that is, the side or face to be affixed to the pouch or like container, and for convenience referred to as the outer, under or affixing face or side, may for that purpose be coated with a general use adhesive adapted to be activated by the application of moisture or solvent or by heat, at the time said element is to be affixed. It will be understood that the particular adhesive is selected as appropriate to the material of the container and of the closure element and the projected use. In this respect it is to be noted that adhesives of the solvent type must allow for release of the solvent of the interposed wet film in order to effect an optimum bond. With such adhesives said closure would be constructed of buckram or some such open-meshed or somewhat porous but relatively stiff fabric, to allow for such solvent release.

As previously stated the closure or closing device C desirably has a slot or through slit D, as indicated by the dash line in Fig. 2, along its intended line of hinging and at a location adapting it to register with the fold or crease for the flap B in the completed condition of the container, as represented in Fig. 1. While in some instances this sealing closure C, at least as to one or another of the plies of a plural-ply form of this device, may be composed of two or more longitudinal pieces disposed side by side in hinging relation, preferably a unitary strip is employed and its aperture or opening-defining formation is provided by means of a slot such as D terminating short of the ends of the strip, desirably leaving at each end of the latter an integral uncut transverse end portion as at H, H' of an extent, in the direction of the slot, desirably at least substantially equal to the width of the sealed marginal side portions of the container body portion A, for example as indicated by the terminal points G and G' of the slot in Figs. 1 and 2.

Accordingly, in the complete container, the hinging action of said element or closure device C is performed at said opposite end portions H and H', as along the lines EG and G'E', in registry with the flap fold. Thus what I have found generally to be the weakest points and those most subject to wear in a pouch or like container of 0 the flap type are materially strengthened structurally and as an attendant cooperative feature of the provision for sealing and resealing. In addition the novel closure means as here shown and described by way of example further serves not only to avoid tearing at the lip or opening of the container such as the illustrated pouch but also provides for the latter a lip of a semi-rigid character. Moreover the hinge portion on the flap B 0 strengthens and affords rigidity for the latter, better adapting it to serve in the manner of a tray or dispensing chute for the contained commodity.

As previously noted, the container or pouch of '65 Fig. 1 is there shown in an open or partly opened position and as if being held under opposite and inward pressure at the sides or ends, as by a pressing action of the user's fingers, this being indicated by the arrows. Thus the container is slightly distorted at its opening and along the semi-rigid hinge closure, thereby opening the slot to allow for content removal. On release of such pressure it will be seen that the closure automatically will return to and assume the original substantially fiat state, thereby closing the slot. The flap B may then be folded over onto the body A, bringing the upper and lower sections of the closure element C into registering contact with each other at their then inner faces whereupon said contacting faces, depending upon the degree of their tackiness, either automatically cohere in sealing relation in the normal manipulation of the container or do so by a slight additional and naturally applied squeezing action.

With reference particularly to the structure in the region of the flap fold, one construction for the illustrative pouch of Fig. 1, as seen in section, may be such as represented diagrammatically in Fig. 3. There the flexible sheet material of the pouch or container itself is indicated by the lowermost layer or web B, the view being assumed as taken along the flap adjacent its fold line. The body strip or vehicle of the semi-rigid closure is indicated at C. The latter is affixed to the flap B by a film of cementitious or like material as indicated by the film section labeled "cement." The upper face ("upper" in the position of Fig. 3 and referred to as the "inner" face with reference to the hinging action) of said closure element C presents a coating or impregnation of the cohesive material such as previously described, represented by the top stratum in Fig. 3 and so labeled.

Figs. 4 and 5 similarly show modifications, thicknesses again being exaggerated as in Fig. 3.

In Fig. 4 the three lower strata of the diagram may be the same as in Fig. 3, namely, reading upwardly, the bag material B, the adhesive or cement means and the body or base element C of the closure structure. In this case however it is assumed that said closure base C is of a flexible sheet material in itself of insufficient relative rigidity for the purposes of the invention, being for example identical with the container material B or even more flexible. Accordingly the cohesive substance for effecting the sealing and resealing of the closure is first applied to a suitable web adapted to act as a vehicle for said substance, such for example as a gauze carrier strip coated or impregnated with the cohesive substance, the latter being available at both faces of the gauze carrier and serving, with some modification if necessary, as the attaching bond between said upper element of Fig. 4, marked "cohesive carrier and substance," and the closure base or body layer C. It will be understood that this Fig. 4 c form of sealing and resealing means-at that face of the complete closure strip which is exposed at its top when the hinge is open and which I designate as the "inner" face due to its inside position when the hinge is closed-may be employed in a other instances and irrespective of the particular material or degree of initial flexibility of the closure body C which latter, for example, may be as in the forms of Figs. 3 or 5.

In the fuither exemplary modification of Fig. 5 7 the separately applied cementitious layer between the flap material B and the adjacent superposed layer is omitted. Here the body element or vehicle C for the semi-rigid closure is itself initially treated as with thermo-plastic impregnants so 7 that its underface is adapted for affixing directly upon the pouch or bag material B by the application of heat or heat and pressure, while its upper or "inner" sealing face is afforded the cohesive character inherently having the describd capacity for sealing and resealing in use.

Since this package is primarily considered as an original merchandise container its cost must be very low. Therefore, the usual papers or wrapping films customarily used in packaging are recommended for the pouch body. But it is charateristic of such materials that their tearing strength is low and they are comparatively flimsy and without rigidity, so that they are non-selfsupporting and, in the absence of the semi-rigid hinge-like closure and seal of the invention, an envelope constructed on the economic lines shown in the drawing would be impracticable for the uses here suggested. However with the incorporation of my stiffening hinge closure means these deficiencies are overcome while simultaneously introducing a convenient and necessary original seal capable of continuous resealing.

Secondly, and again from low cost consideration, the device has been conceived in relation to mechanical package construction wherein accordingly it may be easily introduced without penalizing the rate or-cost of package production.

Accordingly in Fig. 6 I have indicated diagrammatically a typical mechanical system and process of producing a package of the invention.

Referring to said Fig. 6, the roll of packaging material M slit to proper width is unwound at intervals to synchronize with the several operations. The outer edge portions of this material, as defined by the dotted lines, may be first coated with an adhesive cement, conveniently applied and dried, at the time of slitting. At station I said coated edge portions are activated as at the spaces KL and K'L' for a distance appropriate for the subsequent pouch or like container formation; or, if said edge portions have not been previously coated, an adhesive or cement is applied at said station I. In case the material M shall be "heat sealable" station I generally is unnecessary and so may be omitted. It will be understood that the stations are numbered merely for identification and without particular reference to their location along the machine or to their sequence in time. The whole process may be continuous throughout the entire extent of the material M so that a given step for one pouch or like container may be performed simultaneously with another step for a succeeding or preceding container, the various operating stations being located upon the machine or duplicated along it as best to promote operating efficiency.

At station 2 a folding operation is performed whereby the packaging material is folded over o0 at FF' so as to carry its previously leading edge up to potential crease line EE', the outer edges FE and F'E' being joined under pressure by the activated cement film or other adhesive referred to. Where the material M is of a thermo-plastic 15 or of a "heat sealable" nature as above mentioned such as "Pliofilm," all adhesions may be effected by means of heat, with such pressure if any as is appropriate.

A closure device C, prepared as previously 0 described and slotted as at D between points G, G' is introduced as at station 3, at right angles to the flow of operations, to the position on the packaging material indicated at C', slot D then registering exactly over the potential 5 crease line EE'. The cemented or other adhesive under or attaching face of said closure device C is engaged flatwise with the underlying material of the container portions A and B and there pressed into permanent position.

At station 4 there is represented the further operation of cutting off the flexible packaging material as on the line between points KK', at the appropriate location to furnish the desired flap, thus completing the structure. Subsequent folding, filling, sealing, labeling, stamping or 1 other operations may be performed mechanically or manually.

In cases where the adhesions are heat-effected, as in the use of "Pliofilm" or the like mentioned above, the closure device C may be introduced at 11 and beneath the leading edge-of the material M at station 2 of Fig. 6, with the engaging side of said device up and with its slot D registering with the leading edge of the material. The part of the strip device C thus underlying the material M 2 is then fused to it as by a heated bar or roller..

Following this the folding as at F, F' may proceed as previously described, slot D being made to register at the potential crease line E, E'. At station 3 edge margins FE and F'E' are fused to- 2 gether and the previously unattached leading part of the closure C, now having its engagingag side down, is fused to the potential flap B, these operations being effected as by heated bars or rollers.

While I have particularly illustrated the adapt- 3 ability of my device to a continuous, integrated and automatic process of package and container manufacture, wherein manufacturing costs would be very low, it will be understood that this hinge and closure means can be conveniently and eco- 3 nomically applied in a package-making system wherein only part or none of the operations are mechanized. Again, while this device has been suggested chiefly for tobacco packages or pouches, the style and dimensions of which are more or less limited, no limitation in those or like respects is intended or implied, the scope of the invention being pointed out in my claims as follows: I claim: 1. In a flexible container, in combination, a sheet folded and secured to provide a container body having a fold flap, a separately formed strip fixed at the inner face of the flap and overlapping an adjacent wall of said body to afford a hinge formation thereat, and a slot in said strip defining the container opening, said hinge formation being of sufficient rigidity to exert a permanent shaping influence upon the container.

2. In a flexible container, in combination, a sheet folded and secured to provide a container body having a fold flap, a separately formed strip fixed at the inner face of the flap and overlapping an adjacent wall of said body to afford a hinge formation thereat, and a slot in said strip defining the container opening, said hinge formation being of sufficient resilience to facilitate the opening and closing of the container in response to application and release of slight pressure at the ends of the hinge.

3. In a flexible container, in combination, a sheet folded and secured to provide a container body having a fold flap, a separately formed strip fixed at the inner face of the flap and overlapping an adjacent wall of said body to afford a hinge formation thereat, and a slot in said strip defining the container opening, said strip formed of a material of a strength adequate in combination with that of the container to provide an effective tear-resistant structure for the region of said hinge formation, 4. In an envelope-type container, in combination with the envelope body and its cover flap, a separately formed sealing closure strip having relatively hinging portions secured respectively to matching areas of the flap and an adjacent wall of the envelope body, a slot formation in said strip for access to the envelope body, and means at the mutually contactable inner faces of said hinging strip portions for cohesively in0 terengaging and repeatedly reengaging them to seal and reseal the container.

5. An envelope-type container comprising, in combination, a sheet folded and secured to provide an envelope body having a fold flap, a separately formed closure strip fixed at the inner face of the flap and overlapping an adjacent wall of said body in the manner of a hinge, and a slot in said strip defining the container opening.

6. As a separate article of manufacture, a Sclosure device for a container having a folding cover flap, said device -comprising a strip of flexible sheet material adapted for adhesive attachment flatwise partly on the in-turning face of a container flap and partly on an adjacent wall of the container, said strip having a longitudinal slot for access to the container and being adapted for hinging on the line of or one parallel to the slot, interengageable inner face -portions of the strip presenting a cohesive medium for mutually 0 intersealing said portions with capacity for repeated opening and resealing.

7. An envelope-type container comprising, in combination, a sheet folded and secured to form an envelope body having a cover flap, a sepa15 rately formed closure strip fixed on the flap and on the envelope body so as to hinge at the flap fold line, a slot in said strip defining the container opening, and cohesive means on the strip whereby its hingedly contacting portions in the closed flap position may be sealed, released and resealed repeatedly.

8. In an envelope-type container, in combination, a flexible sheet folded and secured to provide a commodity-receiving body having an i opening at one edge and having a projecting cover flap adapted for folding against the body along a crease formation adjacent said opening, and a separately-formed closure strip fixed partly on the inner face of the flap and partly on an no adjacent wall of the body and adapted for hipging in registry with said crease formation, said strip having a slot defining the container opening and having at the opposed faces of its relatively hinged portions means rendering said. por55 tions separably cohesive In the closed position ,of the flap thereby to seal the container with capacity for repeated opening and resealing, and said strip further cooperating with the flap and body to afford semi-rigidity for the container at no the region of its. opening.

9. The method of making a resealable envelope-type container which comprises the steps of folding a sheet transversely on itself and securing it laterally to form anenvelope body hav'"5 ing a projecting flap portion for folding onto said body along a selected transverse fold line, providing a sealing strip of a length approximately that of the transverse dimension of the sheet, supplying a cohesive sealing and resealing medium at one face of said strip, forming a longitudinal slot in the strip, and superposing and affixing said strip partly on said flap portion and partly on an adjacent wall of the envelope body, 76 in position transverse of the latter and with its slot in substantial registry with the selected fold line of the flap portion.

10. That method of making a repeatedly selfsealable flap-closure envelope-type container which comprises the steps of providing a separate sealing strip having self-cohesive properties for at least one face, longitudinally slotting the strip, and affixing it to the inner face of the container flap and an adjacent wall of the envelope with its slot in substantial registry with the flap fold line.

11. That method of making a repeatedly selfsealable flap-closure envelope-type container which comprises slotting a strip of sheet material to present a container mouth and adhesively securing it flatwise for folding in the manner of a hinge at the inner face of the envelope flap and an adjacent wall of the envelope and rendering said strip self-adhesive at hingedly contactable areas thereof. 12. In the class of flap-closure dispensing envelopes and pouches adapted for repeated opening and closing by the user, a semi-rigid transversely hinged flap-sealing device of sheet material, said device having cohesively and resealably interengageable inner faces and adapted for adhesive attachment at its respective outer faces to the under face of an envelope flap-closure and the adjacent flap-sealing wall, and said device having a mouth-defining opening formation paralleling the flap-closure hinge line when the device is so attached.

13. For application under the closure flap of envelope and pouch type dispensing packages subject to repeated opening and closing by the user, a semi-rigid closure strip hinged and slotted longitudinally and having a cohesive inner surface formation capable of producing and reproducing a sealing tension between hingedly contacting areas thereof attendant on repeated opening and closing of the package, the longitudinal hinge line of said strip adapted to coincide with that of the closure flap of the package and the longitudinal slot of said element extending a major portion of its length and adapted to align substantially with a free edge of a wall of the package to define the mouth of the latter.

14. As a new article of manufacture, for use in connection with envelope and pouch type dispensing containers having a hinged closure flap and subject to repeated opening and closing by the user, a generally rectangular combined hinge and mouth device of flexible sheet material constructed and arranged for folding lengthwise upon itself to provide hingedly connected portions for attachment flatwise at their outer faces respectively against'the inner face of the closure 'flap of such container and against an underlying opening-defining wall area of the container, said portions of the device having interengageable inner areas thereof rendered mutually cohesive and capable of sealing and resealing together repeatedly; and said device having throughout a major extent of its length a slot adapted to present a mouth for access to the container opening when said device and the closure flap are swung to an open position and to be covered by and to seal said closure flap in the closed condition of the latter.