Container

March 29, 1966

A, J. WHITE

CONTAINER

3,242,829

Filed Nov. 7, 1963

<img file="US3242829A_D0001.tif" />

3,242,829

Patented Mar. 29, 1966

United States Patent Office

3,242,829 CONTAINER

Arthur John White, Woodbury, N.Y., assignor to American Can Company, New York, N.Y., a corporation of New Jersey

Filed Nov. 7,1963, Ser. No. 322,228

Claim. (Cl. 93—94)

This invention relates to lap seam fibre container bodies and has particular reference to a body provided with a continuous inside and outside impermeable barrier and having the raw side edges of the body concealed in the interior of its lap side seam.

Numerous attempts have been made to provide a satisfactory leakproof composite container which includes a convolutely wound fibre body having its opposite ends closed by suitable metal end members. One form of such a fibre body is produced from a relatively long thin body blank which is convolutely wound upon itself several times to form a multi-ply body. Another form of fibre body is made from a shorter, single length blank having its opposite longitudinal edge portions overlapped and glued together to form a side seam. While in both cases, both the inner and outer surfaces of the blank have been provided with prelaminated barrier layers, in the heretofore known body constructions one or both of the raw uncovered edges of the body stock along the inner and/or the outer longitudinal side edges of the body blank have remained exposed after the formation of the body, and it has been necessary to coat these edges with a sealing material to prevent wickage of interior or exterior moisture, grease, etc. into the body stock. The application of this sealing material has required separate and extra operations in the body making process, and has thus added to the cost of the container.

It is the purpose of this invention to provide a container body wherein complete raw edge protection may be obtained without the necessity of such additional sealing operations. To accomplish this, the container body is formed from a single blank of fibre stock which is provided on one side with a prelaminated barrier material such as aluminum foil or plastic film, which is impervious to liquids, greases, etc. The blank is made substantially twice the length of a normal lap seam container blank, and is folded transversely back upon itself in such manner that its opposite, raw edges are disposed in juxtaposition near one edge of the resultant, single length blank. This is done by folding the double length blank along two lines of fold which are spaced unequal distances from the opposite edges of the blank. The folded, single length blank then is bent into tubular body shape with its edges overlapped to form a lap side seam in such manner that the juxtaposed raw edges are buried in the interior of the lap seam. As a result, the tubular body has both its inside and outside surfaces completely covered by the barrier material. The circumferential end edges of the body, which remain raw, are subsequently buried in the end seams of the finished container, with the result that the finished container is 'completely impervious to wickage.

An object of the invention, therefore, is the provision of a fibre container body having a continuous inner and an outer layer of impervious material which is completely resistant to the penetration of liquids, both internal and external, into the underlying fibre body stock.

Another object is the provision of such a body wherein the raw longitudinal body edges are buried in the lap seam to protect them from internal and external wickage.

Numerous other objects and advantages of the invention will be apparent as it is better understood from the following description, which, taken in connection with the accompanying drawings, discloses a preferred embodiment thereof.

Referring to the drawings:

FIGURE 1 is a perspective view of a composite container embodying the principles of the present invention;

FIG. 2 is a fragmentary sectional view drawn to an enlarged scale through the lap side seam of the container shown in FIG. 1, the view being taken substantially along the line 2—2 in FIG. 1;

FIG. 3 is a perspective view showing a laminated fibre body blank used for producing the container shown in FIG. 1;

FIG. 4 is a view showing the body blank of FIG. 3, after being folded back upon itself in such manner that the raw edges of the blank are disposed in juxtaposition near one of the folded edges; and

FIG. 5 is an enlarged sectional view on an enlarged scale taken through one of the end seams of the container, the view being taken substantially along the line 5—5 in FIG. 1.

As a preferred or exemplary embodiment of the instant invention, FIGURE 1 illustrates a composite container 11 comprising a tubular body 13 having its opposite longitudinal edge portions overlapped and secured together in a lap type side seam 15. The opposite ends of the body are closed by top and bottom metal end members 17 which are secured to the body in crimped end seams 18.

The body 13 is made from a half-thickness blank 19 (FIG. 3) which as initially provided comprises a main layer 20 of paperboard, fiberboard or similar fibre stock, one surface of which is completely covered by a coextensive barrier layer 21 which is impervious to penetration by water, moisture, or any greasy or oily fluid or product which may come into contact with it. Examples of materials suitable for barrier 21 are aluminum or other metal foils which may or may not be laminated to a paper backing; coherent films of plastic such as mylar, nylon, etc.; and coatings of plastic materials such as polymerized vinyl resins which may be sprayed or rollercoated onto the fibre layer 20. When metal foils are used for the barrier 21, they may be secured to the fibre layer 20 by a suitable adhesive (not shown). When plastic films are used, they may be extruded directly onto the layer 20, heat sealed thereto, or adhered thereto by suitable adhesives. As seen in FIG. 3, the four edges 22, 23, 24, 25 of the layer 20 of the blank 19 are raw and thus susceptible to wicking.

The length of the blank 19, i.e. the distance between its side edges 22, 23, is somewhat in excess of twice the length of the circumference of the finished body, the excess being provided in order to provide material for incorporation in the side seam of the finished body. The blank 19 is provided with a pair of spaced fold or score lines 26, 27 which are cut or pressed onto the unprotected surface of the layer 20. These score lines 26, 27 are spaced at unequal distances from the opposite side edges 22, 23 of the blank and extend parallel thereto (see FIG. 3).

The score line 26 is spaced from its adjacent side edge 22 of the laminated blank 19 a distance which is somewhat less than the circumferential width of the lap side seam 15, while the score line 27 is located a distance from the score line 26 equal to half of the length of the blank 19. These score lines 26, 27 thus divide the laminated body blank 19 into a minor fold portion 29, an intermediate portion 31 and a major fold portion 33 (see FIG. 3).

The laminated blank 19 is reversely folded on itself along the fold lines 26, 27 to bring the unprotected surfaces of the major and minor fold portions 33, 29 into contact with the surface of the intermediate portion 31, these mutually facing surfaces being secured to each other

3,242,829 ³ by a suitable adhesive 35 which preferably is applied as an overall coating to the unprotected surface of the blank 19 prior to this folding operation (see FIG. 3). As a result of this folding operation, the blank 19 is converted into the full thickness blank 37 which is illustrated in 5 FIG. 4, the length of this blank being that of a normal single length blank necessary to form the lap seam body 13. In this full thickness blank 37, the side edges 22, 23 are contiguous to, and preferably in contact with, each other. It should be understood that, if desired, the score lines 26, 27 can be omitted, and the folds made in the unscored blank.

Following the formation of the folded, full thickness, single length body blank 37 (FIG. 4), it is bent into tubular form and its opposite marginal edge portions are 15 overlapped in the side seam 15 to thus form the body 13. The blank 37 preferably is bent so that the intermediate portion 31 is inwardly disposed while the minor and major fold portions 31, 33 are outwardly disposed. The overlapped opposite marginal edges of the body are 20 glued together by a suitable impervious adhesive 39 to form the side seam 15. When the barrier layer 21 is a plastic film, the adhesive 39 may be omitted and the seam bond made by heat sealing or by solvent fusing the mutually facing barrier layer surfaces together. 25

This lap seam 15 (see FIG. 2) comprises an underlap 44 and an overlap 46, the underlap 44 comprising the end of the folded body blank 37 in which the contiguous butted raw side edges 22, 23 are located. As a result, these raw edges 22, 23 are disposed in the interior of the 30 lap seam 15 and are thus shielded from contact with the contents of the container 11, as well as from external fluids, etc.

It will be obvious that the blank 37 may be bent in the reverse direction so that the raw edges 22, 23 are 35 disposed in the overlap 46, without losing the advantages of the instant invention.

The ends of the thus formed tubular body are subsequently closed by means of the end members 17 which are secured onto the peripheral marginal edges of the 10 body in the end seams 18 which may be of any suitable type, such as single clinched seams or double seams. As seen in FIGS. 1 and 5, these end members 17 are preferably formed with flat countersunk imperforate panels 50 which are surrounded by substantially U-shaped chan- 45 nels 52 which receive the circumferential body edges 24, 25 and are bent into gripping relationship with the body 13 therebelow. As a result, the raw peripheral edges 24, 25 of the body are buried in these end seams 18 and are thus protected from internal and external fluids. Thus 53 there is produced a container wherein only the end members 17 and the barrier layer 21 are exposed, both inter nally and externally, and which is thus completely impervious to penetration by both internal or external fluids. If desired, a suitable lining compound may be provided in the end seams 18 to more positively seal off the raw body edges 24, 25.

It is thought that the invention and many of its attendant advantages will be understood from the foregoing description and it will be apparent that various changes may be made in the form, construction, and arrangement of the parts without departing from the spirit and scope of the invention or sacrificing all of its material advantages, the form hereinbefore described being merely a preferred embodiment thereof.