Moisture-impermeable Package

Abstract

Moisture-impermeable packages include a container having a bottom wall, upstanding side walls cooperating with the bottom wall for defining a compartment to retain product, and an upper wall defining an opening in communication with the compartment. A lid member movable between a closed position overlying the opening, and an open position exposing the opening. Channels integrally formed with the container circumscribe the opening, and each channel has an open end defined by spaced, projecting ledge members. A substantially air-impervious, thin, flexible plastic web secured to the container overlies the opening in communication with the compartment to provide a primary moisture-impervious seal, and overlies the open end of the channel. The lid member includes inwardly directed ribs cooperating with the plastic web between the spaced projecting ledge members when the lid is in its closed position for engaging and flexing the plastic web to provide a secondary moisture-impervious seal about the opening after the primary seal is broken. Additional embodiments also form a part of this invention.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to moisture-impermeable packages, and more specifically to moisture-impermeable packages for retaining pre-moistened fibrous webs therein, and for permitting easy removal of said fibrous webs therefrom.

2. Description of the Prior Art

Pre-moistened wipers are extremely popular for cleansing many portions of the human body. For example, such wipers have provided the means for cleansing parts of the human body under conditions where water, towels and the like are not available. One specific use for pre-moistened wipers is for cleansing excreta from the human anus, and usually after toilet paper has been used in the normal manner. In such an application, the wiper normally is not a substitute for toilet paper, but provides the final cleansing operation after the bulk of the excreta has been removed in the usual manner. Pre-moistened wipers have many other applications. For example, they can be used to cleanse parts of the body other than the anus, such as under the arms, face and/or neck.

A wet wiper packaging system normally is prepared for dispensing by removing an overwrap material, or other primary seal. After the primary seal has been removed the packaging system still must be capable of retaining the wet-wipers at an acceptable moisture level during the period of time required to use all of the wet-wipers, i.e. 30-60 days.

One wet-wiper packaging system presently on the market is sold under the trademark WET ONES by Lehn & Fink Products Division of Sterling Drug, Inc. The moisture-impermeable package of this system employs a container having a main body member and a removable closure member. The closure member is provided with cross-slits through which wet wipers can be removed. A cap forms a part of the closure member, and must be snapped into sealing relationship with a peripheral rib which circumscribes the cross-slits. In the event the user of this system fails to snap the cap tightly closed, the wet wipers may dry out prior to use. In addition, this packaging system is sold with an aluminum foil sheet covering an open end of the main body member of the container. To use this system a person must remove the closure member, break the aluminum seal and feed a lead end of a continuous roll of wet wipers through the cross-slits. These preparatory operations are somewhat cumbersome.

Other moisture-impermeable packages have been designed for products such as pills, tablets and the like. A common moisture-impervious seal employed in these packages includes a resilient packaging material, such as rubber, disposed within channels extending about the periphery of a lid member. This resilient packaging material cooperates with upper marginal ends of a main body member of the package to provide an air-tight seal when the lid member is snapped into a closed position. Such sealing arrangements are shown in U.S. Pat. Nos. 2,117,151; 2,117,228; 2,321,946 and 3,294,222.

Packages employing a resilient packing material within a channel, as disclosed in the above patents, are believed to provide a satisfactory air-tight seal; however, such packages normally require the use of a friction locking arrangement between the lid and main body member to assure that the upper marginal ends of the main body member are maintained in compressed, air-tight sealing relationship with the packing material disposed within the channels of the lid. It normally is more difficult to open with one hand packages that employ such a friction locking arrangement than it is to open packages which do not employ such a locking arrangement.

Resilient packing materials employed within the peripheral channels of a lid member must be manufactured within close thickness tolerances. If a portion of the packing material extends beyond the marginal ends of the channels, the lid may have to be compressed with significant force to properly close the lid. This is an undesirable feature.

For some applications it is desirable to employ a primary moisture-impervious seal disposed in overlying relationship with an opening into a main body member of a package, and also a secondary seal disposed about the periphery of the opening. Such packages are displayed for sale with the primary seal intact. To remove produce disposed within such a package, the primary seal is broken to permit access into the main body member. The secondary seal disposed about the periphery of the opening functions to retain the package in a moisture-impervious condition after the primary seal has been broken. When a resilient packing material is disposed within channels to provide the secondary seal, a separate moisture impervious member must be employed to cover the opening into the main body member to form the primary seal. A package having a separate moisture-impervious member to effect the primary seal is more complicated to manufacture, and therefore more costly, than a package wherein both the primary and secondary seals are formed by the same moisture-impervious member.

Packages employing a resilient packing material within channels to aid in effecting a moisture-impervious seal are somewhat expensive to manufacture. In some applications, such as in retaining pre-moistened wet wipers, the package is intended to be disposed of after the contents therein are completely used. For such non-reusable applications, the product must be priced relatively low. High manufacturing cost may necessitate a sales price to provide a reasonable return which makes the product unattractive to prospective purchasers.

SUMMARY OF THE INVENTION

A moisture-impermeable package of this invention includes a container having a bottom wall, upstanding side walls cooperating with the bottom wall to define a compartment for retaining product, and an upper wall defining an opening in communication with the compartment. A lid member is movable between a closed position overlying the opening which is in communication with the compartment, and an open position exposing said opening. Preferably, the lid member is pivotally secured to the container. Channels are associated with the container and circumscribe the opening, and each channel has an open end defined by spaced upstanding ledge members. A substantially air-impervious, thin, flexible plastic web is disposed over the open end of the channels for providing a flexible closure for said channels. Inwardly directed ribs are associated with the lid for engaging and flexing the plastic web intermediate the upstanding ledges when the lid is in a closed position to provide a substantially moisture-impervious seal around the opening.

The plastic web employed in this invention is less expensive than the resilient packaging material employed in the prior art packages. Furthermore, the manufacturing operation of securing an impervious, flexible plastic web over the open end of a channel is believed to be more easily accomplished, and less costly than directly adhering a resilient packing material within a channel.

In the closed position of the lid, the weight of the lid will cause the ribs associated therewith to engage, and flex the plastic web intermediate the upstanding ledges to assure that a substantially moisture-impervious seal is obtained. Since the weight of the lid is sufficient, by itself, to create this flexing action, a frictional locking arrangement between the lid and the container normally is not required, and therefore the attended disadvantages of a frictional locking arrangement, as described earlier in this application, are eliminated. However, if desired, a frictional locking arrangement can be employed in the packaging systems of this invention.

In the preferred embodiment of this invention, the plastic web also is disposed over the opening which is in communication with the compartment to provide a primary seal disposed over said opening. The plastic web is adhered to both upstanding ledge members, preferably by a heat sealing operation which provides weakened regions in the plastic web adjacent the periphery of the opening which is in communication with the compartment. A portion of the plastic sheet overlying the opening can be opened, or removed, by breaking the web along these weakened regions without removing portions of the plastic web disposed over the channels. In this manner, the inwardly directed ribs associated with the lid will cooperate with the plastic web disposed over the open end of the channels to flex the plastic web to effect a moisture-impervious secondary seal after the primary seal is broken. In this construction the primary and secondary seals are formed with the same plastic web. This arrangement is less expensive than an arrangement requiring the use of separate impervious covering materials to effect the primary and secondary seals.

When a primary seal is not desired, or when it is desired to form a primary seal with a material different from the material employed to form a secondary seal, the channel defined by the upstanding ledge members can be associated with the lid, rather than the container. In such an arrangement, the upstanding ribs will be associated with the container and will be disposed about the periphery of the opening which is in communication with the compartment of said container.

In one embodiment of this invention, the container is comprised only of a body member, upper marginal ends of which define the opening in communication with the compartment. In an alternative embodiment, the container includes a body member and a separate closure member secured over the open end of said body member. The closure member is provided with the opening therein which is in communication with the compartment of the body member. In this alternative embodiment, the lid preferably is pivotally connected to the closure member.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an isometric view of a moisture-impermeable package according to this invention;

FIG. 2 is a sectional view along line 2--2 of FIG. 1, with the lid shown in a closed position;

FIGS. 3 and 4 are enlargements of the circled regions 3 and 4, respectively, shown in FIG. 2; and

FIG. 5 is an isometric view of a moisture-impermeable package according to a second embodiment of this invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE INVENTION

Referring to FIGS. 1-4, a moisture-impermeable package 10, according to a first preferred embodiment of this invention, includes a container 12, and a lid 14 pivotally secured thereto. The container 12 includes a bottom wall 16, and side walls 18 extending upwardly therefrom and cooperating with said bottom wall to define a compartment 19 for retaining product therein.

Referring to FIGS. 3 and 4, each side wall terminates in a channel 20 provided by a base 22, internal ledge member 24 and external ledge member 26. The upper walls 25 of the internal ledge members 24 define an opening into the compartment 19.

In the preferred embodiment of this invention, the package 10 is employed to retain pre-moistened wet wipers 28 therein, such as are disclosed in U.S. Pat. applications Ser. No. 263,145, filed June 15, 1972, and Ser. No. 237,859, filed Mar. 24, 1972, both of which are assigned to Scott Paper Company. The premoistened wipers can be folded in any conventional manner, and stacked upon each other. Preferably, the wipers are folded to provide gripping edges 30 on the side of each wiper closest to the upper end of the container 12.

A substantially impervious, thin, flexible plastic web 32 is disposed in overlying relationship with the opening into the container 12, and over the ledge members 24 and 26 of the peripheral channel. The plastic web 32 is adhered to the upper walls of the ledge members by any suitable means, such as by an adhesive, or a heat sealing operation.

Referring to FIGS. 3 and 4, a heat sealing operation is preferred since such an operation flattens the plastic web 32 in regions 33 secured to the internal ledge members 24, and regions 35 secured to the external ledge members 26. In this manner, weakened transition lines 36 are formed between each flattened region 33 of the web 32 and the unflattened regions of said web which overlie the opening in communication with compartment 19. The function of these weakened transition lines 36 will be described later.

Preferably, the lid 14 is mounted through identical floating hinges 38 to be pivotal between a closed position in which it overlies the opening into the container 12 (FIGS. 3 and 4), and an open position for exposing the opening (FIG. 1 and 4). Each floating hinge 38 includes a pivot pin 40 fixed against movement within a lug 42 which is integrally formed with the container 12. The pin 40 is received within an oval pinway 44 of an inwardly directed lug 45 integrally formed with the lid 14. The oval configuration of the pinway permits limited linear movement of the lid normal to its plane, as indicated by arrow 46 in FIG. 2.

Referring to FIGS. 1-4, inwardly directed ribs 48 are integrally formed with the lid, and are positioned so as to engage the plastic sheet 32 intermediate the internal ledge members 24 and external ledge members 26 when the lid is in its closed position. In this manner, the ribs will flex the impervious sheet material to establish a substantially moisture-impervious seal between the lid 14 and the container 12. The floating hinge arrangement, as described above, permits the lid to move in a downward direction when in a closed position to assure that a moisture-impervious seal is established.

The lid is provided with inwardly angled flanges 50 adjacent the opposed lower ends thereof for engaging the container 12 to provide a positive stop for the lid in its opened position (phantom representation in FIG. 4). If desired, this stop can be arranged differently to limit the pivotal movement of the lid to less than 90.degree. so that the lid will pivot to a closed position solely under the influence of its own weight, i.e. without requiring the positive closing of the lid. In this manner, a user of the package cannot inadvertently forget to close the lid.

The package 10, when displayed for sale, has the lid sealed in a closed position by the use of a suitable tape means, or other conventional retaining means. To use the product retained within the package 10, a user opens the lid and pushes against the plastic web 32 adjacent the weakened transition lines 36 in the region overlying the opening into the container to cause the web to tear along these weakened transition lines 36 to thereby break the primary seal. In this manner, the contents are exposed for easy dispensibility. The plastic web overlying the channels 20 remain adhered to the internal and external ledge members 24 and 26, respectively, and provide an effective secondary moisture-impervious seal in cooperation with the inwardly directed ribs 48 associated with the lid 14 after the portion of the plastic web overlying the opening into the container has been removed, or broken.

It is within the scope of this invention to either eliminate the primary seal disposed over the open end of the container 12 or to form a primary seal with a moisture-impervious member which is separate from the moisture-impervious web which forms a part of the secondary seal. In such instances, the channels 20 can be integrally formed with the lid 14, and the ribs 48 can be integrally formed with the container 12 to constitute the upper margin of said container.

The container 12 can be made from any suitable material which has sufficient strength and is air-impervious. For example, the container can be constructed as a laminate of polystyrene and polyethylene. The polystyrene is chosen for its strength and low cost, and is disposed as the outer layer of the container. The polyethylene is chosen for its excellent air-impervious characteristics.

Preferably, the web 32 is formed from a thin (e.g. 1-3 mils) plastic material, such as polyethylene. Other thin materials can be utilized provided that they are flexible, have a low moisture vapor transmission rate, and are compatible with the material of the container 12. If desired, the web 32 can be constructed as a laminate of polyethylene and saran. The saran has excellent air-impervious characteristics and is disposed as the outer layer of the web.

The weakened tear line 36 can be formed by other means than disclosed above. For example, perforations can be provided in the web 32 in the regions overlying the upper wall 25 of the internal ledge member 24. Also, it is possible to provide a removable tear strip, similar to that which is used in cigarette packs, in conjunction with the plastic web.

Referring to FIG. 5, a moisture-impervious package 10a, according to a second preferred embodiment of this invention is shown. In this embodiment, a container 12a includes a body member 50 and a closure member 52. The body member 50 defines a compartment 19a for retaining producing therein, and the closure member 52 has an upper wall 53 defining an opening in communication with said compartment. A lid 14a is pivotally secured to the closure member 52 through floating hinges 38a which are identical to the floating hinges 38 of the first preferred embodiment of this invention. In all other respects, the moisture-impervious package 10a is identical to the moisture-impervious package 10, and can include the same structural variances as described with respect to said moisture-impervious package 10.

Claims

Having described our invention, we claim:

1. A moisture-impermeable package comprising:

A. a container having a bottom wall, upstanding side walls cooperating with said bottom wall for defining a compartment to retain product, and an upper wall defining an opening in communication with said compartment;

B. a lid member movable between a closed position overlying said opening, and an open position exposing said opening;

C. channel means integral with said container and circumscribing said opening, said channel means having an open upper end defined by spaced upstanding ledge members;

D. a substantially air-impervious, thin, flexible plastic web disposed in a substantially flat condition over the open upper end of the channel means and the opening into the container compartment, said plastic web being adhered to the upstanding ledge members to provide a flexible, substantially air-impervious closure for both said channel and container compartment;

E. separation means associated with the plastic web for permitting the formation of an opening through the plastic web in a region overlying the opening into the container compartment without disrupting the air-impervious closure of the channel means; and

F. rib means projecting from the lid member in cooperative relationship with the plastic web and the lid member is in its closed position for engaging and flexing the plastic web intermediate the upstanding ledge members of said channel means to thereby provide a substantially moisture-impervious seal about the opening into the container compartment after the opening through the plastic web has been formed.

2. The package according to claim 1, wherein said lid member is pivotally mounted to said container.

3. The package according to claim 2, wherein said lid member has a substantially planar upper surface and is pivotally mounted about a pivot axis through a floating hinge means for permitting linear movement of said lid member normal to said planar surface.

4. The package according to claim 1, wherein said container includes a main body member and a top closure member, said main body member defining said compartment to retain product therein, said closure member including said upper wall for defining an opening in communication with said cmpartment, said lid member being pivotally mounted to said closure member.

5. The package according to claim 1, wherein the plastic web is a single, continuous member, and the separation means includes weakened regions therein.

6. The package according to claim 5, wherein said lid member has a substantially planar upper surface and is pivotally mounted about a pivot axis through a floating hinge means for permitting linear movement of said lid member normal to said planar surface.