Tear-open package

United States Patent

Π1] 3,570,751

[72] Inventor Robert J. Trewella Reading, Pa.

[21] Appl. No. 838,881

[22] Filed July 3,1969

[45] Patented Mar. 16,1971

[73] Assignee Wyomissing Corporation

Reading, Pa.

[54] TEAR-OPEN PACKAGE

Claims, 16 Drawing Figs.

[52] U.S. Cl....................................................... 229/66,

229/51,229/85

[51] Int. CI.........................................................B65d 17/20,

B65d 65/26

[50] Field of Search............................................ 229/66,51 (is), 85,87,40; 53/14; 93/(ITS)

[56] References Cited

UNITED STATES PATENTS

2,270,547 1/1942 Nichols........................ 229/66X

3,249,288 5/1966 Repko.......................... 229/66

3,349,993 10/1967 Ells etal....................... 229/66

3,456,867 7/1969 Repko.......................... 229/66

Primary Examiner—David M. Bockener

Attorney—Howson and Howson

ABSTRACT: A package formed by a sheet of flexible packaging material having a tear-open seam extending across a face or along an edge thereof. The tear-open seam is characterized by a flap formed by an edge of the package sheet and a tearable insert strip which secures the flap to the adjacent sheet edges.

The method of making the package includes the steps of applying spaced transverse stripes of adhesive to a continuous flat web of packaging material, depositing articles to be packaged on the web between the applied adhesive stripes, folding the package web so that the edges thereof are disposed in overlying relation, introducing an adhesive coated insert web between the overlying web edges, sealing the transverse adhesive stripes, and cutting the web along the sealed adhesive stripes.

<img file="US3570751A_D0001.tif" />

PATENTED MARI 61971 3,570,751

SHEET 1 OF 3

<img file="US3570751A_D0002.tif" />

ATTYS.

PATENTED MAR 1 61971

3,570,751

SHEET 2 OF 3

<img file="US3570751A_D0003.tif" />

PATENTED MAR 161971

3,570,751

SHEET 3 OF 3

<img file="US3570751A_D0004.tif" />

<img file="US3570751A_D0005.tif" />

INVENTOR:

ROBERT J. TREWELLA

BY

ATTYS.

3,570,751

TEAR-OPEN PACKAGE

The present invention relates generally to packages formed of flexible packaging material and relates specifically to a novel tear-open package and a method of making said package. 5

The invention includes a tear-open seam construction which is particularly adapted for use with flat paper packages such as the type employed for the packing of bandages and the like. A novel method of making such a package incorporating the present tear-open seam is included in the present inven- 10 tion.

Packages of the general type described incorporating tearopen flaps have previously been used. However, in the conventional package, the tear-open flap is adhesively secured. The opening of such a package is, as a result, somewhat unpre- 15 dictable due to the vagaries of the adhesive bond. The amount of force required to tear open the adhesive-bonded seam is not uniform over the length of the seam and ripping of the flap may consequently occur.

In the present tear-open package, the tear is effected along 20 a narrow, relatively low-strength area, such as a fold or score line, of an insert strip of tearable material and thus can be accomplished with a uniform force without danger of tearing the flap. The package comprises a tear-open seam which extends across a face or along an edge of the package and includes a 25 flap formed by an edge of the package sheet and a tearable insert strip which secures the flap to the adjacent sheet edge. The insert strip is adhesively secured to each of the adjacent sheet edges preferably with a score or fold line therebetween along which the insert strip will predictably part upon applica- 30 tion of force to the overlying flap. The adhesively secured insert strip portions serve to reinforce the adjacent sheet edges and accordingly prevent tearing of these edges.

The present method of making the described package from a continuous web of packaging material includes in brief the 35 steps of applying spaced transverse stripes of adhesive to a continuous flat web of packaging material, depositing articles to be packaged on the web between the applied adhesive stripes, folding the package web so that the edges thereof are disposed in overlying relation, introducing an adhesive-coated 40 insert web between the overlying web edges, sealing the transverse adhesive stripes, and cutting the web along the sealed adhesive stripes to separate the filled packages.

It is accordingly a first object of the present invention to provide a package of flexible packaging material having a 45 tear-open seam which may be easily opened along its entire length by application of a moderate and uniform opening force.

Another object of the present invention is to provide a package as describe wherein the tear line is accurately 50 established and wherein the regions adjacent thereto are reinforced to prevent inadvertent tearing thereof.

A further object of the invention is to provide a package as described which may with its contents be readily sterilized, and which will not jeopardize the sterility of the contents dur- 55 ing opening of the package and removal of the contents.

Still another object of the invention is to provide a package as described which is adapted for manufacture from continuous webs of packaging material.

A still further object of the invention is to provide a method 60 of making the described package in a rapid, economical and Uniform manner.

Additional objects and advantages of the invention will be more readily apparent from the following detailed description of embodiments thereof when taken together with the accom- 65 panying drawings in which:

FIG. 1 is a perspective view showing a package formed in accordance with the present invention with one end edge unsealed to reveal the configuration of the tear-open seam;

FIG. 2 is a perspective schematic view illustrating the 70 present method of forming the package shown in FIG. 1;

FIGS. 3—6 are sectional views taken respectively along lines 3-3, 4-4, 5-5 and 6-6 of FIG. 2 showing the successive steps of folding the package web and insert web to form the desired sectional package configuration; 75

FIG. 7 is a plan view of the present package illustrating the manner in which the package is opened;

FIG. 8 is a sectional view taken along line 8-8 of FIG. 7;

FIG. 9 is a plan view of a modified form of the package, showing the package in the partially opened condition;

FIG. 10 is a sectional view taken along line 10-10 of FIG. 9;

FIG. 11 is an enlarged view of the circled area of FIG. 10;

FIG. 12 is a plan view of a further modified form of the invention also shown in the partially opened condition;

FIG. 13 is a sectional view taken along line 13-13 of FIG. 12;

FIG. 14 is a sectional view showing still another modified form of the present package;

FIG. 15 is a schematic elevational view further illustrating the novel method of making the preferred form of the invention; and

FIG. 16 is a schematic plan view showing a modified method of forming the present package.

Referring to the drawings, a package 20 illustrating a preferred form of the invention is shown in FIGS. 7 and 8 and also, with one end unsealed, in FIG. 1. The package is formed of a rectangular sheet 22 of flexible packaging material having side edges 24 and 26 and end edges 28 and 30. The sheet 22 is folded along parallel fold lines 32 and 33 parallel to and spaced from the side edges 24 and 26 to form a flattened tube, the side edge 26 overlapping the side edge 24. The fold lines and sheet edges thus define a package back panel 34, outer front panel 35, and inner front panel 36. The end edges 28 and 30 are respectively sealed by adhesive layers 38 and 40 which preferably form peel-open bonds; thereby effectively sealing the package except for the overlapped side edge region. It is in this region that the novel tear-open seam construction is employed.

In the preferred embodiment, the tear-open seam includes an insert strip 42 of tearable material which extends the full length of the overlapped side edges. The strip 42 is longitudinally folded into a U-shape along a medial fold line 43 and the oppositely facing panels 44 and 45 thereof are adhesively bonded to the adjacent surfaces of the overlapped sheet side edges. The folded edge 43 of the insert strip is directed inwardly so that the outer edge 26 of the package sheet forms a flap 46 in conjunction with the strip panel 44 which may be conveniently grasped to open the package.

FIGS. 7 and 8 illustrate the manner in which the tear-open seam is opened. The package is gripped adjacent the fold line 32 with one hand and by the flap 46 with the other hand. Upon movement of the hands apart with a moderate uniform force, the insert strip will tear cleanly along its fold line 43. The insert strip will tear at its fold line along the entire length of the seam since in view of the adhesive attachment of the adjacent strip panels to the sheet edges, this is the weakest point of the insert strip.

After the insert strip has been completely severed, the entire outer front panel 35 may be fully opened by peeling open the associated portions of the end seams 38 and 40 to expose the package contents. By positioning the insert strip 42 in outwardly spaced relation from the sheet edge 24, an inwardly extending flap 48 formed by the sheet edge will, after opening of the tear-open seam, prevent contact of the packaged article with the insert strip during removal of the article from the package. It is thus possible to remove sterile articles from the package without contamination.

A novel method of making the above-described package is illustrated in FIGS. 2—6 and in FIG. 15. In this method, the package sheet 22 and the insert strip 42 are supplied in continuously moving web form and the package is filled and formed in a continuous operation. Referring to FIG. IS, the package web 22 is advanced by feed rolls 50 into an adhesive applicator 52, in which a heat-sensitive adhesive is applied in spaced transverse stripes 54 to the upper surface of the web. The web then passes beneath the feeder 56 which sequentially deposits articles 58 to be packaged on the web surface between the adhesive stripe 54. The package web bearing the articles to be packaged is then passed through the formers 60,

3,570,751 and 64, the former 60 forming the fold 32 in the web. Between the formers 60 and 62, the insert strip web 42 is introduced from above, passing beneath the roll 66 spaced above the package web. The web 42 is precoated with a liquid adhesive on the surface facing away from the roll 66. The former 62 forms the fold 43 in the insert web 42 and combines the two webs, while the former 64 forms the fold 33 in the package web and completes the formation of the package tube. The manner in which these folds are formed is schematically shown in FIG. 2, the formers being omitted to more clearly show the formation of the several folds. Upon emerging from the formers, the combined webs have the sectional tubular configuration shown in FIG. 6.

After passage through the formers, the combined webs are presented to the heat seal station 70 wherein the transverse adhesive stripes 54 are sealed. From the heat seal station, the webs pass beneath the rotary knives 72 located between draw rolls 74 which cut the webs into the individual sealed packages 20 by severing the webs along lines passing medially trough the adhesive stripes 54. By use of the described method, the present tear-open package can be rapidly and efficiently manufactured.

A modified method of making the present package is schematically shown in FIG. 16. In the modified method, the package is not filled during manufacture and the step of feeding the articles onto the package web is accordingly omitted. The method is otherwise identical to that described above with two additional steps. The first is the provision of a longitudinal heat-sealable adhesive stripe 76 on the package web adjacent the fold line 33. The second is the longitudinal slitting of the package web along the adhesive stripe 76 at the slitting station 77 shown between the heat seal station 70 and the cutoff station 72. The slitting station 77 may alternately be located before the heat seal station. The package 78 resulting from this method is a bag-shaped enclosure having an open end 79 which may be heat sealed in a conventional manner after filing the package. The package incorporates the same tear-open seam described above in connection with the preferred package embodiment.

A modified form of the present package is illustrated in FIGS. 9—11 and is similar to that illustrated in FIGS. 1, 7 and 8 except that the insert strip 42' is not folded. Instead, the front panel 35' is doubled back at fold line 35α to form a flap portion 3Sb underlying the adhesively bonded insert strip panel 44'. The edge of panel 36' extends in offset fashion beneath a portion of the doubled back panel 35' as flap 48'. The strip 42' is preferably scored along a score line 42α as shown in FIG. 11 to insure a tearing of the seam along this line when the package is opened as shown in FIG. 9. The score line although desirable is not essential since the insert web will be weakest along this line due to the reinforcing effect of the adhesive bonds with the package edges over the remainder of its area.

In the additional modified embodiment shown in FIGS. 12 and 13, the package 80 is formed of a package sheet 81 folded in half along fold line 82 which defines one side edge of the package. The opposite side edge is formed by the tear away seam which includes a U-shaped insert strip 84 adhesively bonded between the overlying edges 85 and 86 of the sheet 81, the folded edge 84α of the insert strip being inwardly directed. By grasping the sheet edges 85 and 86, the seam may be tom open uniformly along the fold 84α of the insert strip as illustrated in FIG. 12. As in the case of the previously described embodiments, the adhesively bonded insert strip reinforces the package sheet edges and prevents inadvertent tearing of the edges.

FIG. 14 still another embodiment of the present package is illustrated in section. This embodiment is identical with that of FIGS. 1, 7 and 8 except that the insert strip 42 is not folded. Instead, a longitudinal media! score line 42b is provided on one side of the strip. The strip is, as in the preferred form, adhesively bonded to the opposed package edge surfaces, but the adhesive is applied to opposite faces of the strip. Opening of the package is effected in the manner shown in FIGS. 7 and

8, the tearing of the insert strip taking place along the score line 42b.

From the foregoing description of embodiments of the invention, it can be understood that the insert strip tear occurs along a narrow region of the strip which is not adhesively bonded to a package edge, which region may include a fold line or score line. The unsecured region is relatively weak compared to the adjacent adhesively bonded portions, particularly if folded or scored, and the strip will thus tear evenly along this narrow region.

The materials from which the package sheet and insert strip can be formed encompass a wide variety of flexible packaging materials such as paper, foils, films and the like. The insert strip is preferably of a weaker material than the packaging sheet although it could be of the same material if it may be readily tom.

The adhesives utilized in forming the package similarly may be of any suitable type and need not be limited to the liquid and heat-sealable adhesives described.

The shape, size and type of package with which the present tear-open seam is employed may of course be varied from that of the illustrated embodiments. Two or more tear-open seams of the type described could be employed in the same package panel to permit the complete removal of the panel to provide access to the package contents. Similarly, although the tearopen seam of the illustrated embodiments is a straight line seam, the seam could have a curved configuration or could continue around several edges of the tear-open panel.

Manifestly, changes in details of construction can be effected by those skilled in the art without departing from the spirit and scope of the invention as defined in and limited solely by the appended claims.