US2412031A - Carton for sealing by immersion - Google Patents

Description

Dec. 3, 1946. s. BERGSTEIN 2,412,031

' CARTON FOR SEALING BY IMMERSION I F iled June 5, 1944 Samuel Bsnsga s the like.

growth in recent years in the use of dlpping proc- Patented Dec. 3, 1946 CARTON FOR SEALING BY IMMERSiON Samuel Bergstein,

Robert Morris Bergstein and Bergstein, trustees Cincinnati. Ohio, assignor to Frank David Application June 5, 1944, Serial No. 538,764

7 Claims. (01. 229-37) My invention relates to cartons designed to be proofed or sealed by immersing them in proofing agents. Such cartons are used for the packaging of milk, dairy products, frozen foods, and There has been a marked commercial esses for paperboard containers in the packaging industry, employing a variety of fluid sealing mediums including molten paraflin wax, wax and rubber mixtures, and. other sealing and proofing substances, to all of which my present invention pertains. The cartons are provided on one end at least with closure flaps, which are folded over and adhesively secured. In some instances, the carton is provided with similar flaps at both ends and is filled and closed; after which the entire carton is dipped in a bath of the proofing and sealing substance. In other instances, as in milk bottles, the carton is erected, closed at one end as described, and then passed through a bath of the proofing and sealing substance. Afterward, it is filled, and then closed at the top by suitable closure means.

Both types of procedure and both types of carton present essentially the same problem. each, at one or both ends, there is a closure formed by adhesively secured flaps lying in faceto-face relationship, with certain of the flaps presenting free or cut surfaces along'opposite side edges of the closure. It is at these places that the greatest weakness in such packages is encountered. A slight imperfection in the coating elsewhere, as on a wall surface, or rupture or abrasion of the sealing medium on a wall surface due to handling and shipping, does not necessarily weaken or rapidly destroy the effectiveness of the package itself. But the slightest imperfection or rupture of the coating along the free edges of the flaps at the end of a container starts leakage and loss of efiectiveness almost immediately.

The principal object of my invention is the provision of means for overcoming this weakness and providing along the edges of the closure not only a tight and dependable seal, but a seal oi such strength and resistance as to minimize damage in handling and shipping. It is my object to accomplish this in a simple. and inexpensive manner.

These and other objects of my invention, which will be set forth hereinafter or will be apparent to one skilled in the art upon reading these speciflcations, I accomplish by that certain construction and arrangement of parts, of which I shall now describe an exemplary embodiment. Re!- erence is made to the accompanying drawing wherein:

Figure 1 is a partial plan view of a paperboard blank for a carton embodying my invention.

' Figure 2 is a partial perspective view showing a stage in the formation of an end closure.

Figure 3' is a partial perspective view showing a later stage thereof. F

Figure 4 is a partial sectional view taken across the carton end closure after immersion in the sealing snbstance.

I have'discovered that by providing a seal-end carton blank wherein the edges of an underlying sealing flap are recessed, I provide a structure which, when sealed, is characterized by a crevice along opposite edges of the closure, whereby when such a, carton is dipped or immersed in the sealing medium, an excess or surplus oi the medium is retained in the crevice.

When a so-called seal-end" carton is closed and adhesively secured, an intermediate flap lies above a pair of shorter'flaps and is covered by an outer flap. The intermediate .;'and outer flaps present cut edges at opposite sldesfof the closure, which are coterminous.

taining the flaps in their closed positions is not relied upon to effect a seal. When the carton is dipped, there may be formed a very thin skin or coating, overlying the cut edges of the board and the bent edges of the underlying flaps, which will make the structure initially liquid tight. The slightest rupture of this thin skin, however, destroys the sealed character of the container. There is little or no penetration of the sealing medium between the layers oi. board at the side edges of the closure, and such penetration as there is cannot usually be relied upon.

However, if the edges of the intermediate flap are cut away 'or recessed, there is presented, be-

tween the outer flap and the inner flaps, a recess having a width at least as great as the thickness of a layer of board. The sealing medium collects in this recess directly bridging the gap between the outer flap and the inner flap, uniting them together in sealed relationship. The thickness of the sealing medium/in this recess is sufllcient to give the seal strength and resistance to handling and scufllng so that the abrasions normally expected duringuse cannot destroy the seal. The seal has none of the characteristics of a thin skin, but rather possesses the characteristics of a solid plug.

It is not, however, preferred'to recess or cut back the edges of the intermediate flap throughout the entire length of these edges. This would The adhesive used in re- Referring to Figure 1,.I have shown a flat, out and creased paperboard carton blank comprising main body panels -I, 2, 3 and l and a glue flap 5 articulated together by longitudinal score lines in the usual fashion. Closureflaps are articulated by a common score line .to the ends of the body walls. A pair of closure flaps. 6 and 1, are short flaps, articulated to opposite walls I and 3. An intermediate flap 8 is articulated to the body wall 2, while an outer flap 9 is articulated to the body wall 4. The flap 9 is of full dimensions to -extend entirely across the end of the carton. The flap 8 is similarly dimensioned in general;

but its side edges are recessed, as shown at l and ll, not, however, for the full length of these side edges. Adjacent the articulation of flap 8 to wall 2 there are full width portions 12 and I3 of minor extent, and similar full width portions l4 and i occur adjacent the outer end of the flap.

The blank shown in Figure 1 is not complete and has been shown with one closure only. The

other end of thebody may be provided with an -flap between the extreme ends thereof, leaving these extreme ends of full width.

exactly similar closure, where the carton is to be filledand closed and then dipped bodily in the sealing bath. Where the carton is to be closed on one end only and then dipped, the other end may be provided with any desired type of closure appropriate to the uses to which the carton is to be put. The size and cross-sectional shape of the carton form no limitation upon my invention nor does the number of enclosing body walls possessed by the carton, since it will be clear to one skilled in the art upon reading these specifications how the teachings hereof may be applied to cartons of other polygonal cross-section.

The paperboard blank of Figure 1 is tubed in the ordinary way on the ordinary carton tubing devices by being bent on a pair of intermediate score lines, glue or other suitable adhesive being applied to the meeting surfaces of wall I and glue flap 5, and these being adhered together, as will be readily understood. The glue flap 5 may be adhered either inside or outside the wall I. The blank may initially be made of proofed board if desired; but this is not necessary for most purposes in view of the immersion treatment to which it will be subjected. The tubed blank is shipped'in the flap or collapsed form to the purpressure on both sides of the closure to insure A proper setting of the adhesive, and aconformity ofthe flaps which is as complete as possible.

The carton, having been closed on one end as described, may then be bodily immersed in a bath of proofing and sealing substance. Or, if the carton is of a type having the illustrated closure at each end, it may then be inverted-filled with the desired contents, and similarly closed-'and 'adl0 hesively secured on the opposite. end, after which .it will bedipped in a bath of proofing substance. While I have mentioned dipping, itwill be understood that this is the normal procedure; but that other modes of applying the p'rooflng and sealing substance may be employed without departing 1 from the spirit of my invention, such for example,

as painting, spraying, or otherwise applying the coating agent or, in the instance of cartons made of proofed boards, immersion of theends thereof as distinguished from complete submergence in a bath. v Y.

Figure 4 is a semi-diagrammatic cross-sectiona1 view of the carton showing the closureand the] effect of dipping it into a bath ofproofing substance, or otherwise applying th substance as described. The flaps 6 and I lie in a single plane surmounted by the intermediate flap 8 and the outerflap 9, all of these flaps lying parallel and in face-to-face relationship; but it will be seen that the edges of the intermediate flap 8 are spaced inwardly of the correspondingedges' of the overlying flap 9 and the upper ends of the body walls of the carton, leaving recesses. The

chaser.

The user squares up the tubular body of the blank and effects a closure. The firststage of this closure is illustrated in Figure 2 where the short flaps 6 and I have first been folded in.- Glue orother adhesive may be applied to flaps 6 and 1 if desired, and preferably will be so applied.

A next stage is shown in Figure 3 where the in termediate flap 8 has been folded over upon and preferably adhered to the short flaps 6 and 1.

Finally, the outer flap 9 will be folded over upon the intermediate flap 8 with the interposition of adhesive between their meeting surfaces. The closure may be effected in any way desired; and

there are machines'available for the purpose formation of the external coating iii of proofing substance results in the introduction of the substance into the recesses, as shown in Figure 4 at H and i8. It willbe noted that the recesses are large enough so that capillarity or the lack of it is not controlling as to whether or'not they are filled. Hence, as distinguished from the forma:

tion of a comparatively thin skinof sealing s stance over superposed and coterminous out edges, of the board at the opposite sides of the closure, with uncertain penetration of the sealing substance between the board layers,'in my carton a heavy deposit of sealing substance at I1 and! fills a definite recess in the structure anddirectly joins the outer flap 9 with the ends of the body I walls and immediately adjacent portions of the short flaps 6 and 1.. These masses of sealing substance are quite strong; and the bond, and: consequently the seal, is not liable to destruction under ordinary handling strains.

Yet, the formation of my seal is a matter of] negligible expense. It requires only a slight mod: ification of the ordinary die by which the carton blanks are cut and scored and a very slight addi- 1 tional quantity of sealing substance in' th recesses, as at H and I8. The physical operations of closure and immersion are not altered as such, v i

and may be performed either by hand or on standard and available equipment.

Modifications maybe made in my invention without departing from the spirit of it. Having thus described my invention in an exemplary em bodiment, what I claim as new and desire to secure by Letters'Patent is:

1. A carton blank having enclosingbody walls I in articulation and end closure flaps articulated to said body walls, said end closure flaps adapted to be folded in sequence to form a plural layered-j closure in which the flaps lie in Iace-to-fac'e en gagement and adhesive union, one of said flaps, being an outer flap dimensioned to covertlie enif; v tire end cross-section of said body; another of said closure flaps being an intermediate flap sim-' ilarly dimensioned to cover the entire end crosssection of said carton body, excepting that edge portions thereof where exposed in the closure are slightly recessed so as to extend inwardly of the corresponding edges of the outer flap to form recesses in said closure adapted to be filled with sealing substance.

2. The structure claimed in claim 1, wherein the recessed edges of said intermediate. flap have at the ends one or more of said edge portions of substantially full dimension so as to be coterminous with adjacent portions of the outer flap at corners of the closed carton body.

3. A blank for a paperboard carton scalable by immersion or the like, said blank comprising a body portion having four walls and a glue flap in articulation and an end closure comprising closing flaps, an opposite pair of said flaps being short enough in length to lie in the same plane across an end of the carton formed from said blank, another flap, adapted to overlie said first mentioned flaps, being dimensioned to cover the entire cross section of the end of said carton excepting that its' side edges are slightly recessed, and a fourth flap adapted to overlie the last mentioned flap and dimensioned to cover the entire cross section of the end of said carton.

4. The structure claimed in claim 3, wherein the recessing of the edges of the third mentioned flap is confined to intermediate portions thereof, end portions of said edges being of full width.

5. The structure. claimed in claim 3, wherein the recessing of the edges of the third mentioned flap is confined to intermediate portions thereof, end portions of said edges being of full width, said carton body having at its opposite end a similar series of closure flaps.

6. A sealed carton comprising enclosing body walls in articulation and an end closure comprising flaps articulated to said body walls and adhered in face-to-face engagement, intermediate and outer ones of said flaps dimensioned to cover the end of said carton, said intermediate flap having edge portions thereof recessed inwardly of corresponding edges of the outer flap, and a coating of sealing substance on said carton covering at least opposite edge portions of said closure and enteringsaid recesses whereby to seal edge portions of said outer flap directly to inner flaps past the recessed edges of said intermediate flap.

7. A sealed carton comprising enclosing body walls in articulation and an end closure comprising flaps articulated to said body walls and adhered in face-to-face engagement, intermediate and outer ones of said flaps dimensioned to cover the end or said carton, said intermediate flap having edge portions thereof recessed inwardly of corresponding edges of the Outer flap, and a coating of sealing substance on said carton covering at least opposite edge portions of said closure and entering said recesses whereby to seal edge por-i tions of said outer flap directly to inner flaps past the recessed edges of said intermediate flap, the said recessed edges of said intermediate flap hav- 7 ing portions at their corners of full width.

SAMUEL BERGSTE'IN.

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