US2140178A - Sealed carton and method of manufacture - Google Patents

Description

Dec. 13, 1938. A. WESSELMAN 2,140,178

SEALED CARTON AND METHOD OF MANUFACTURE Filed July 11, 1955 Patented Dec. 13, 1938 UNITED STATES PATENT OFFICE SEALED CARTON AND METHOD OF MANUFACTURE Albert Wesselman, Cincinnati, Ohio Application July 11, 1935, Serial No. 30,886

6 Claims.

' or adhesive which must be used, in practice,to

efiect rapid sealing of the containers.

Another object of the invention is to provide a practically effective seal for containers formed of impervious material, the proper sealing of which has long been a .vexatious problem to manufacturers and packers.

The foregoing and other objects are attained by the means described herein and disclosed in the accompanying drawing, in which:

Fig. 1 is a perspective view of .the improved con- 3 tainer, showing the new method of glue or adhesive application.

Fig. 2 is a cross-sectional view taken on line 2-2 of Fig. 1. l

Fig. 3 is a perspective view of a glueing apparatus.

Fig. 4 is a diagram of a modified glueing apparatus.

In the packaging of food products and the like, it is particularly desirable to employ a container designed and constructed to exclude moisture and foreign substances with which the container may come into contact, and to maintain within the container the original freshness, aroma and wholesomeness of the packaged product. Heretofore, this has been accomplished to a satisfactory extent by the use of relatively expensive containers. Some of the containers-have been of metal, while others have been of the double or lined box construction commonly employed in the packaging of products such as breakfast foods and the like. The lined box construction requires the use of an inner waterproof container generally having a parafline coating, or impregnated with parafline, whereby to provide a substantially sealed container which in turn is placed within an outer container. The outer container is not sealed against moisture, air, and dust, except that the flaps thereof are glued in place with no particular degree of care, the package being considered complete so long as it holds together.

Packages of the kind just described are obviouslyr'nore expensive to manufacture than were the single walled boxes or cartons used previously. Moreover, they require the installation of additional folding and assembling machines, and double the amount of stock that is necessary for production of a carton.

In the attempt to produce a single walled container equal in effectiveness to the double container, it was necessary first of all to treat paper and cardboard to render it substantially impervious to moisture, air, vermin, etc. This has been accomplished, and no difliculty is experienced in procuring cardboard and heavy paper so treated. Practical problems, however, have interfered with the satisfactory commercial use of cardboard or paper containers so treated, because the producer and packer have been unable to provide an efiective sealing of the joints or corners at the time of closing the carton or container upon the contents thereof. The various difficulties above related have been effectively overcome by the practice of the invention disclosed herein.

- With reference to the drawing accompanying this description, the character 3 indicates any kind-of a paper or cardboard box, preferably, although not necessarily, one that has been treated with any of the common preparations for rendering the material thereof impervious to moisture, air, vermin and other extraneous elements that might otherwise enter the box or container. The container illustrated includes the opposed side walls 4, 5, 6 and I, and a series of flaps v integral with the side walls for closing the opposite ends of the container. The flaps 8 and 9 on the opposed walls 5 and 1, respectively, are referred to as the initially turned flaps which, during closing of the container, are directed inwardly and exposed to theinterior of the container. The larger flap II! which is integral with sidewall 4', is known as an intermediate flap which is turned upon said initially turned flaps, so that its free marginal edge I2 assumes a position close to the score line l3 of the outer or cover flap I 4. The outer or cover flap overlies the intermediate flap, and its forward marginal edge l5 may abut-the, upper face of flap I0, if desired.

In some constructions, the edge l5 may over-hang the side wall 4 and be suitably fastened thereto in any known manner such as bymeans of a quick-setting adhesive. It is to be understood that both ends of the container may be closed by means of flaps as above explained.

The side wall 4 may include a connecting tab l 6 which extends longitudinally of said wall, which tab is adapted to be secured to the inner face of and means hereinafter set forth for effecting a perfect sealing of the container so as to preclude circulating air from acting upon the contents of the container, the container being so sealed as to prevent the contents from taking on the odor or taste of the ordinary commercial glue or adhesive used in the rapid processes-of closing the containers. To explain more fully, it is wellknown that the closing of containers is performed by machinery or mechanical means at a rapid rate, so that it is necessary to employ a thinbodied highly volatile commercial glue which sets very quickly, so that the flaps will be held closed almost instantly upon application of the glue or adhesive and the folding of the flaps upon one another. This type of glue or adhesive is invariously odorous, and the vapors that emanate therefrom are liberated both interiorly and exteriorly of the container. The vapors that enter the container while the glue or adhesive is setting or drying have the effect of tainting the contents of the container, or imparting the glue odor thereto. This is a condition that the present invention is designed to obviate.

In practicing the invention, there is applied to the inner face of the intermediate flap It, a liberal quantity of heavy-bodied substantially odorless. joint sealing or plugging substance, indicated by the character ll. This substance may or may notbe a glue or adhesive, but by' preference it is a heavy adhesive of low volatility. By way of example, such a substance may comprise a mixture of balata gum, one part, two parts odorless resin, and one part petrolatum, the proportions to be varied as required by climatic conditions and the like, for securing the result herein set forth. The thick-heavy-bodied substance will plug the cracks or joints which are formed along the marginal edges of the short flaps 8 and 9 after said flaps are turned inwardly at right angles to the side walls of the container.

As the entire inner face of flap I0 is covered with the heavy-bodied joint sealing substance, it must be evident that no air may pass into or from the container, except possibly along the score line l3 of the outer flap" H. The joint at said score line, however,' is effectively plugged and sealedby the application of a quantity of the heavy-bodied sealing substance upon the area of flap H'which is adjacent to the score line l3.

Said area and the coating thereon, are indicated by the reference character l8.

'Inasmuch as the heavy-bodied substantially odorless substance referred to is not highly volatile, it is necessarily of a very slow-setting or possibly non-drying character. Said substance,

therefore, is not generally suitable for instantly fixing the flaps 'in their closed positions, wherefore it is desirable to provide the outer margin of the inner face of flap ll with a ribbon IQ of .quick-setting commercial glue or adhesive. At

, or taste to the contents of the container.

The heavy-bodied slow-drying substance referred to herein may be varied as to its constituents, as no claim is made to,the particular substance employed. Such substance, however, should be slow-drying, substantially odorless, and as near tasteless as possible.

Besides furnishing an effective seal for the container, the thick or heavy-bodied substance, when in the form of an adhesive, is capable of slightly penetrating the material of a carton which is treated to render it impervious to air, and under such circumstances the thick heavy-bodied substance holds the flaps in position upon one another until the highly volatile adhesive has had an opportunity to strongly join the flap M to the flap It. When the carton material is of the impervious type, the thick heavy-bodied adhesive holds the flaps in place as effectively as does the thin highly volatile adhesive, and in such a carton, the ribbon l8 of thick heavy-bodied adhesive may be extended outwardly to the margin l5 of flap l4, or to the inner edge of the adhesive ribbon l9.

As will be understood, the outer faces of the flaps 8 and 9 could carry the thick heavy-bodied adhesive, or said adhesive may be applied to all of the flaps, but in the preferred embodiment the inner faces of the flaps I I] and I4 would carry the adhesive in the manner illustrated in Fig. 1.

In Fig. 2, the heavy line 20 indicates a continuous ribbon of the thick heavy-bodied odorless and tasteless adhesive, extending along the innermost margin of the tab l6, while the second heavy line 2| indicates a continuous narrow ribbon of thin-bodied highly volatile adhesive applied also to the tab I6, but outwardly of the ribbon or coating 20. By referring to Fig. 2, it will readily be evident that the thick heavy-bodied adhesive coating prevents entry of the vapors from coating or ribbon 2| from entering the container interior. From the foregoing it will be understood that the method employed herein comprises applying a heavy-bodied substantially odorless slow drying adhesive or other substance to the flaps and tabs of the carton at selected 10-. cationsto preclude the volatile constituents of a quick-setting adhesive applied at other locations,

from passing into the interior of the container.

The thick heavy-bodied substance performs the function of plugging cracks and crevices at the variousflaps and joints, while the highly volatile quick-setting adhesive performs the function primarily'of joining and securing the parts.

Due to the slow or substantially non-drying character of the thick heavy-bodied substance repeated handling and rough treatment of the filled cartons will not destroy the effectiveness of the seal, as said substance may but flex with the material of the container. ton or container of this invention, a coating of suitable lacquer or other elastic adhesive substance may be sprayed, brushed or otherwise applied to the various joints, in the manner disclosed in my copending application Serial No. 713,902,

which was filed on March 3, 1934. Such a coating would of course provide double assurance of a tight seal which would not ordinarily be necessary in the packaging of materials such as food products which reach the consumer within a relatively short period after packing.

Having described the article of the invention, and the method of manufacture thereof, I will now proceed with a description of one form of apparatus that may be used in applying the different coatings l8 and I 9 to the flaps and tabs such as I4 and I6 of the carton or container. The

Upon filling of the car-' apparatus as disclosed in Fig. 3, may comprise a pair of reservoirs 22 and 23, one of which contains a quantity of the coating substance 19, and the other of which contains the coating substance IS. A pair of glue wheels 24 and 25 are mounted in side by side relationship, the wheel 24 being adapted to lift the thick heavy-bodied substance from reservoir 22 and apply it to a flap or tab while the other wheel 25 applies the thin highly volatile substance thereto from the reservoir 23. As will be understood, wheel 24 will apply a ribbon of substance as indicated at iii of Fig. 1, whereas wheel 25 will apply a ribbon of substance such as is indicated at [9. The remaining flaps of the container, which require a coating of, but one adhesive substance, may be treated in the usual manner, that is by means of a single glue wheel or applicator.

The wheels referred to may be rotated by means of power applied to an end of shaft 26, or if desired, rotation of the wheels may be effected by the friction resulting from moving the flap of the carton over the peripheries of the wheels. In either case, the two different types of substance contained within the reservoirs 22 and 23 will be applied in ribbon or line formation upon the face of a flap or tab. To accommodate carton flaps or tabs of different dimensions there is preferably provided any suitable means, such as for example a set screw or the like 21 on the hub of each wheel, whereby the wheels may be adjusted along the shaft toward and from one another.

The wheels may be wider or narrower than those illustrated in Fig. 3, depending upon the size and character of flap 'or tab to be treated with substances from the reservoirs 22 and 23. It is to be understood that ribbons of substance may be applied to a tab such as is, as well as to a flap such as It, by the means illustrated in Fig. 3. The wheels 24 and '25 are preferably, though not, necessarily, mounted upon a common supporting shaft such as 26.

In instances where the contents of one reservoir may require heating to secure the best results, it is desirable to separate the reservoirs and I as they move through the glueing and folding machine. By means of arrangement, the contents of one reservoir ay beheated without affecting the contents of the other reservoir. The glue wheels may be power rotated or not, as desired. An electrical heater for reservoir 23 is indicated conventionally by the character 29.

What is claimed is:

1. A container constructed of a sheet ofmaterial formed to provide sides and a series of foldable closure flaps, at least two of which flaps are initially turnedinwardly and exposed to the interior of the container, leaving small cracks along certain margins of the turned flaps, an intermediate flap turned upon said initi turnedflaps and having applied thereto a non-drying substantially odorless adhesive of heavy body character for plugging, the cracks along said margins of the initially turned flaps, and an outer flap overlying the intermediate flap and secured thereto by means of a highly volatile quicksetting adhesive.

2Acontainerconstructedofasheetofmaterial formed to provide'sides and a series of foldable closure flaps, at least two of which flaps are initially turned inwardly and exposed to the interior of the container, leaving small cracks along certain margins of the turned flaps, an intermediate flap turned upon said initially turned flaps and having applied to one entire face thereof a generous coating of odorless substantially non-drying character for plugging the cracks along said margins of the initially turned flaps, and an'outer flap having a similar coating along its line of meeting with an adjacent container side and a coating of quick-setting adhesive between the flaps for maintaining said outer flap in position upon the intermediate flap.

3. A container constructed of a sheet of material formed to provide sides and a series of foldable closure flaps, at least two of which flaps are initially turned inwardly of the carton and exposed to the interior thereof, leaving small cracks along certain margins of the turned flaps, an intermediate flap turned upon said initially turned flaps and having applied to one face thereof a generous coating of substantially tasteless and odorless non-drying heavy-bodied adhesive substance for plugging the 'cracks along said margins of the'initially turned flaps, and an outer flap having a similar coating upon a; portion of the outer flap which abuts the intermediate flap near the hinge line of the outer flap, and a separate coating of highly volatile and odorous quick-setting adhesive joining a different portion of the outer flap to the intermediate flap.

4. A carton in the process of manufacture,

comprising a blank of sheet material having a body portion, closure flaps, and a connecting tab on the body portion for holding the body por- I I tion in tubular shape, said tab having applied thereto two ribbon-like coatings one of which coatings is a highly volatile quick-setting adhesive, and the other of which is a heavy-bodied substantially odorless non-drying joint-sealing substance, said coatings being located side by side lengthwise of\the tab. Y

5. The method of precluding ton, which method comprises applying a heavybodied substantially odorless non-drying adhesive m the flaps and tabs of the carton at locationswhere the volatile element of the 'quicksetting adhesive could pass to the carton in-v terior, and using a highly volatile quick-setting adhesive at other locations where the volatile non-drying crack-plugging substance to the flaps and tabs of the carton at locations where air may enter into the interior of the carton through cracks formed along the margins of the flaps and tabs, and using a highly volatile quick-setting adhesive on the flaps and tabs at locations where the crack-plugging substance blocks the entry of the volatile constituent of said adhesive into the carton interior.

ALBERT the contents of a h carton from taking on the taste and odor of the -quick-setting adhesive used for sealing the car-

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