Method And Construction For Package

Abstract

A container and a closure means are formed as a unitary structure constructed of pliable or bindable sheet material. The closure means comprises a pair of flaps lightly biased to closed position, and disposed so that an attempt to remove the container contents before opening the closure means will result in generating forces which assist the biasing means in maintaining the flaps closed. These flaps are also positioned so that upon manual manipulation, without the aid of a tool, the flaps are deformed and become separated to open the closure means and permit the contents of the container to be poured or squeezed out.

Description

This invention relates to packages in general, and more particularly relates to packages having closure means that are formed simultaneously with formation of the container in a form-fill-seal process.

Plastic film is particularly useful for constructing fluid tight sanitary low-cost packages. Such packages are found particularly useful for holding food seasonings in liquid form or suspended in liquid. In order to produce such packages at low cost, one typical prior art construction is a so-called pillow-pack that is produced on a form-fill-seal machine. The entire contents of form-fill-seal packages must be used at the time the package is first opened since the closure means is destroyed upon opening thereof.

Because the closure of a form-fill-seal package of the prior art is destroyed upon initial opening thereof, such packages must be made in small sizes so that the contents thereof will not be wasted. Even so, a substantial portion of the contents is usually wasted in that the quantity in each package must be sufficient to satisfy a generous one-shot demand.

Accordingly, a primary object of the instant invention is to provide a novel package with a reusable closure.

Another object is to provide a package of this type in which the closure is always biased toward closed position and may be intentionally opened through manual operation thereof.

Still another object is to provide a package of this type in which the closure closes more tightly when an attempt is made to empty the package contents before manually opening the closure.

Yet another object is to provide a package of this type in which the closure is applied prior to filling of the package.

A further object is to provide a package of this type in which the container portion and the closure elements are constructed of pliable sheet materials.

A still further object is to provide a novel package that is hermetically sealed and is provided with reusable closure means.

These objects as well as other objects of this invention will become readily apparent after reading the following description of the accompanying drawings in which:

FIG. 1 is a perspective of a form-fill-seal package constructed in accordance with the teachings of the instant invention.

FIG. 2 is a perspective illustrating the elements for constructing the package of FIG. 1 at an early stage in the production cycle.

FIG. 3 is a side elevation of the elements of FIG. 2 at a later stage in the production cycle.

FIG. 4 is a cross-section taken through line 4--4 of FIG. 3, looking in the direction of arrows 4--4.

FIG. 5 is a perspective showing the elements for producing a modified version of the embodiment of FIG. 1, such elements being shown in an intermediate stage of production.

FIG. 6 is a cross-section, taken through line 6--6 of FIG. 1, looking in the direction of arrows 6--6 with the foam biasing elements for the flaps of the closure means removed for illustrating a modified closure means.

FIGS. 7 and 8 are enlarged plan views of the container neck region, showing a further modified version of the closure means. In FIG. 7, the closure means is in closed position, while in FIG. 8 it is in open position.

FIG. 9 is an end view of the elements for producing a hermetically sealed form-fill-seal package in accordance with the teachings of the instant invention.

FIG. 10 is a side elevation similar to FIG. 3, showing the elements of FIG. 9 as a hermetically sealed unit.

FIG. 11 is an edge view of a further modified embodiment especially useful for powder and granular material. FIG. 12 is a front elevation of the package of FIG. 11.

Now referring to the Figures, and more particularly to the embodiment illustrated in FIGS. 1-4. Form-fill-seal package 15 of FIG. 1 is constructed of heat sealable relatively wide plastic strip 16, typically sheet vinyl in roll form or pre-cut to length, and relatively narrow strips 17, 18 of open cell foam plastic. The outer edges of strip 16 are inwardly folded and, as will hereinafter be seen, constitute closure flaps 21, 22, which, in the final product, extend down to line 19 in FIG. 1. Strip 16 is also folded longitudinally in half to form side walls 23, 24 for the container portion of package 15.

Sheet 16, folded substantially flat at the three fold lines 25, 26, 27, and having foam strip 17 interposed between flap 21 and wall 23, and having foam strip 18 interposed between flap 22 and wall 24, is heat sealed, or welded, along lines 28, 29, to provide generally rectangular body portion and narrow elongated neck 32 joined to body portion by tapered portion 33. A plurality of packages 15 may be formed simultaneously, as illustrated in FIG. 3, at which time appropriate perforations are provided for separation of packages 15 from one another and removal of excess plastic film material at regions 34. Foam strips 17, 18 are positioned at tapered portion 33.

When package 15 is being formed in the heat sealing dies (not shown), a hollow needle extends between closure flaps 21, 22 and below edge 19 thereof, into the interior 35 of body portion 31. It is through such needle that package 15 is filled with a gas, liquid paste, powder, granules, and the like. After the needle is withdrawn, foam strips 17, 18 maintain closure flaps 21, 22 in closed position to prevent the contents of package 15 from leaking out or being poured out. Package 15 may also be filled through a discontinuity (not shown) that may be formed in one of the seal lines 28, 29, with such discontinuity being closed by heat sealing after package 15 is filled.

During the filling of package 15 the contents thereof cause package 15 to bulge slightly as shown in FIG. 1. Mere squeezing of body portion 31 will only increase the forces driving closure flaps 21, 22 together, in that the content material moves into the regions between flaps 21, 22 and walls 23, 24, respectively. To open the closure for package 15, manual pressure is applied to neck or mouth region 32 in the opposed directions indicated by arrows A and B in FIG. 1. This causes the mid-regions of flaps 21, 22 to bulge outward in opposite directions, and in so doing form an opening through which the contents of package 15, or any portion thereof, may be removed. As soon as the pressure, as indicated by arrows A and B in FIG. 1, is removed from the neck region 32, the biasing means for flaps 21, 22 moves the closure into closed position, and prevents further emptying of package 15. To facilitate manual opening of closure flaps 21, 22, neck region 32 may be tapered to widen at the free upper end thereof. It is noted that for some applications mouth region 32 may be as wide as body portion 31.

It is noted that package 15 may be constructed without foam biasing strips 17, 18, in which case the closing biasing force for closure flaps 21, 22 is obtained by holding the package forming sheet sections taut while heat seals 28, 29 are formed (See FIG. 6).

As an indicator that package 15 has not been tampered with prior to initial usage thereof, during production of package 15, after it has been filled with a measured quantity of material, air under pressure is added. The first time closure means 21, 22 is opened, the escape of this pressurized air will give an unmistakable indication that package 15 has not been tampered with. If the initial opening of valve 21, 22 does not give a clear indication that pressurized gas is escaping, this is a positive indication that package 15 has been tampered with. As a further indicator that tampering has not taken place, wall 23 or 24 may be provided with a small section that protrudes when there is sufficient pressure within package 15, but when this pressure drops this small section recedes.

FIG. 5 illustrates a modified construction for a form-fill-seal package. In the construction of FIG. 5, the side walls are formed of individual sheet 41, 42, as are closure flaps 43, 44. Before foam strips 17, 18 are sealed in place and before walls 41, 42 are sealed together, flap forming strip 43 is heat sealed at 45 along the upper edge of wall forming strip 41. Similarly, flap forming strip 44 is sealed at 46 along the upper edge of wall forming strip 42. In the die means used to connect the elements of FIG. 5, a single generally U-shaped seal line is formed, with the arms of the U having shapes corresponding to seal lines 28, 29 and the web of the U being along the bottom edges 41a 42a of wall forming strips 41, 42, respectively. As an alternative, wall forming strips 41, 42 may be combined as a single member longitudinally folded. Also, strips 43, 44 may be formed integrally with the respective strips 41, 42.

When package 15 is being formed a combination die and vacuum mold may be used in which case the various layers are stressed in such a manner that even without film strips 17, 18 or any other separate biasing means, closure forming flaps are still biased to closed position. Vacuum forming permits use of a semi-rigid plastic to form the container portion, in which case the upper end of the body portion sides are formed with aligned inward protrusions to which the central regions of the respective closure flaps are connected. By appropriate manual manipulation (squeezing) of the container the protrusions separate, thereby opening the closure.

In the embodiment of FIGS. 7 and 8, the closures forming flap 51, 52 are constructed of semi-rigid film that is transversely scored at 53, 54, respectively, so that when pressure is applied in the directions indicated by arrows C and D in FIGS. 7 and 8, score lines 53, 54 provide weakened areas that encourage opening separation of valve elements 51, 52.

FIGS. 9 and 10 illustrate the construction of and method for producing a hermetically sealed form-fill-seal package 70. Such package 70 is constructed of relatively wide plastic strips 61, 62, having closure flap forming relatively narrow plastic strips 63, 64, respectively, heat sealed thereto at points spaced from the upper edges of strips 61, 62. Strips 61, 62 are brought together and heat sealed along a line forming a closed loop indicated by side sections 67, 68, bottom section 69 and top section 71. The latter section 71 is formed after the filling needle is withdrawn from between closure flaps 63, 64. As an alternative, section 71 may be formed at the same time as the other sections 67-69 are formed, but one of the latter group is initially formed with a discontinuity forming an opening for filling package 70.

To initially use the hermetically sealed package 70 of FIG. 10, upper part 74 of the neck is removed by cutting along line 72, or any other line essentially parallel thereto, located at a point above the seal lines joining closure flaps 63, 64, to body forming strips 61, 62. Thereafter, package 70 is used in the same manner as package 15. Tampering with the contents of package 70 will be indicated by damage to any portion of seal line section 71.

In the embodiment of FIG. 10, reference numbers 81, 82 indicate heat seal lines along which flaps 63, 64 are bonded to one another. These diverging heat seal lines 81, 82 provide relatively taut connections between the free edges of flaps 63, 64 and body forming members 61, 62 at heat seals 67, 68. The lower ends of heat seals 81, 82 are spaced at the free edges of flaps 63, 64 at region 83, where flaps 63, 64 may separate to form an opening to the neck region of package 70.

Package 90 of FIG. 12 is especially useful for powder and granular material being formed of web 91 shown in the edge view of FIG. 11. Web 91 is folded at three places to form confronting long panels 92, 93 and confronting short panels 94, 95 with inner panels 93, 94 confronting one another with their respective free edges 93a, 94a being spaced from fold line 96 connecting outer panels 92, 95.

Parallel heat seal lines 88, 89, extending perpendicular to and between fold lines 96, 97, extend through all four panels 92-95. Heat seal lines 86, 87, inboard of lines 88,89 and parallel thereto, connect inner panels 93 and 94. Seal lines 86a, 87a extending left and right from lines 86, 87, respectively, to seal lines 88, 89, respectively, connect inner panels 93, 94 at fold line 98.

The contents of package 90 are loaded and emptied through the portion of the space between inner panels 93, 94 bounded by seal lines 86, 87, and through the space between free edge 93a and fold line 96. Such contents will occupy the space between longer panels 92, 93 and cause bulging, which brings the lower flap forming portion of panel 93 into engagement with flap forming panel 94 to normally close package 90.

The construction of package 90 eliminates the necessity for the manufacturer to close the package after filling thereof. The customer may use package 90 in a conventional manner by cutting same at or near fold line 97 to provide an opening. Depending upon the dimensions thereof, package 90 is opened for reuse, inserting a finger or hand between inner panels 93, 94 and deflecting them in opposite directions.

Thus, it is seen that the instant invention provides a novel unitary package having reusable closure, thereby permitting the user to dispense less than the entire contents of the package without the danger that the remaining portion of the contents will accidentally pour out. The flap means with a flexible interface constituting the closure is connected to the outside of the package so that manual manipulation, without the aid of a tool, is effective to open the closure. It is noted that for some applications a single flap may provide an effective closure. While the foregoing invention has herebefore been described in connection with what would appear to be small size packages, the construction principles previously described are advantageous for larger packages, such as a quart container of milk or oil and a fifty-pound bag of granular fertilizer, and may be used for packages constructed of many types of pliable materials beside sheet plastic. Such materials include coated and uncoated papers, as well as laminates typically including plastic with metal and/or paper.

Although there has been described a preferred embodiment of this novel invention, many variations and modifications will now be apparent to those skilled in the art. Therefore, this invention is to be limited not by the specific disclosure herein but only by the appending claims.

Claims

The embodiments of the invention in which an exclusive privilege or property is claimed are defined as follows:

1. A unitary package structure including a container having opposed side edges and a mouth portion at one end of said side edges, said mouth portion having an opening through which contents of said container are emptied in selected amounts, and a reusable closure means for normally closing said opening, said closure means including flap means within said container operatively positioned so that an unintentional attempt to empty such contents from said container will normally direct such contents against the flap means to automatically operate said closure means to a closed position thereby confining such contents within said container; said closure means proportioned and operatively connected to said side edges so that through manual manipulation of said side edges said closure means is operable to an open position wherein a selected amount of such contents may be emptied through said opening; biasing means normally urging said closure means to said closed position; said biasing means and contents of said container providing reinforcing forces to maintain the closure means closed during attempts to empty said container when said closure means is in said closed position; said container being constructed of first and second opposed layers; said flap means including third and fourth opposed layers constituting first and second cooperating flaps respectively; each of said layers constructed of plastic sheet material; heat seals connecting together all of said layers in their operative positions with said third and fourth layers positioned between said first and second layers; said flaps including weakened regions so positioned that upon the application of oppositely directed forces at the heat sealed lateral edges of said flaps the flaps will separate at the central region thereof by bending along lines defined by said weakened regions.

2. A package structure as set forth in claim 1, in which; the closure means is operated to said open position solely by exerting converging forces at said side edges of said flap means.