The present disclosure relates generally to containers for products, and more particularly to containers formed at least in part by a flexible membrane material, and wherein the membrane defines an opening feature for creating an opening through the membrane to gain access to the contents of the container.
Various types of such containers have been developed or proposed over the years, having a variety of opening features. Some such containers employ additional separately formed components such as labels or tabs affixed to the membrane to allow the consumer to grasp and pull the tab in order to sever the membrane along a preformed line of weakness. The use of such separate components complicates the process of manufacturing the containers, as the components have to be procured, inventoried, fed into the manufacturing process, properly registered with the membranes to which they are attached, etc.
It is also known to provide a membrane with an integral tab that projects beyond an edge of the membrane, or beyond an edge of a removable portion of the membrane, to facilitate grasping and pulling the membrane or removable portion thereof. Such projecting tabs can cause problems in automated handling of packages because they can get stuck on equipment and cause jams in the manufacturing line. In other cases, such a projecting integral tab is folded back onto the membrane so as not to project beyond the edge of the membrane, but to keep the tab from unfolding it is frequently necessary to tack the tab down with a spot of adhesive or by other means. The tab folding and tacking operations further complicate the manufacturing process.
The present disclosure relates to a membrane for a container, in which the membrane has an integral opening feature in the form of a removable portion that is at least partially removable from the remainder of the membrane. The membrane comprises a laminate of at least first and second layers adhesively laminated together. The removable portion is formed by substantially coincident first and second score lines, the first score line being formed in the first layer but not breaching the second layer, and the second score line being formed in the second layer but not breaching the first layer. In one embodiment there is a third layer disposed between the first and second layers, and the third layer is not breached by either score line. The third layer can comprise an easily severable material such as aluminum foil or the like, which also serves as a barrier to the passage of moisture and gases through the membrane. The first and second layers can comprise polymer film materials and/or paper, or the like.
In the removable portion of the membrane, an adhesive-free region is provided within which the first layer is not adhered to the underlying layer(s). The adhesive-free region occupies less than the entire area of the removable portion. An integral tab is defined in the first layer within the adhesive-free region, the tab being formed by a cut line in the first layer. The tab is located entirely inside the bounds of the first and second score lines, and thus the tab does not project beyond any edge of the membrane. The tab can be lifted and pulled in order to sever the membrane along the score lines so as to at least partially remove the removable portion of the membrane and thereby gain access to the interior of the container through the resulting opening formed in the membrane. A coating of a release material can be disposed between a lower surface of the tab and an upper surface of the underlying layer to prevent the tab from sticking thereto, although in many cases no release material may be required.
In one embodiment, the score lines form a closed loop such that the removable portion is completely removable from the rest of the membrane.
In some embodiments, the membrane comprises a lid that is attached to a separately formed container to close an opening in the container.
Having thus described the disclosure in general terms, reference will now be made to the accompanying drawings, which are not necessarily drawn to scale, and wherein:
The present invention now will be described more fully hereinafter with reference to the accompanying drawings in which some but not all embodiments of the inventions are shown. Indeed, these inventions may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will satisfy applicable legal requirements. Like numbers refer to like elements throughout.
A first embodiment of the invention is illustrated in
The membrane 20 comprises a flexible laminate of at least two layers that are adhesively joined together. The layers are coextensive with each other, i.e., they have the same surface area and their respective edges are aligned such no edge of any layer extends beyond a corresponding edge of the other layer(s). The layers can comprise various materials such as polymer film, metal foil, paper, or combinations thereof. Suitable examples of polymer films that can be employed include but are not limited to polyethylene, polypropylene, polyamide, polyester, and the like. The film can be oriented if desired. Metallized film (i.e., film having a vapor-deposited layer of non-oxidized metal such as aluminum) can be employed. Film coated with a ceramic layer such as silicon oxide or aluminum oxide can be used.
The membrane 20 includes a removable portion 22 that can be at least partially removed from the remainder of the membrane in order to form an opening through the membrane into the interior of the container. The removable portion 22 is provided by scoring the layers of the membrane to create a line of weakness along which the membrane can be severed.
More particularly, with reference to
In order to facilitate grasping the removable portion 22 to sever it from the rest of the membrane, the membrane includes an integral tab 30 formed in the first layer 24. The tab is formed by a cut line 32 that extends entirely through the thickness of the first layer. The cut line 32 can have various shapes, a generally U-shaped cut line being shown in
In order to allow the tab 30 to be lifted from the layer underlying it, the membrane 20 includes an adhesive-free region 40 that is within the bounds of the score lines L1,2. The adhesive layer 28 is absent in the adhesive-free region, and thus the layers 24, 26 are not affixed to each other in this region. In the embodiment illustrated in
If desired or needed, a coating of a release material can be applied to the underside of the tab 30 or to the surface of the layer directly underlying the tab to prevent the tab from sticking to the underlying surface.
The membrane 20 in the embodiment of
To open the container shown in
A second embodiment of the invention is depicted in
In one embodiment, the first layer 124 can comprise a polyester film such as polyethylene terephthalate. The second layer 126 can comprise an oriented polypropylene (OPP) film. The OPP film is heat-sealable to a compatible heat seal material disposed on the container. Other heat-sealable films can also be used instead of OPP.
The first layer 124 and second layer 126 include respective first and second score lines L1 and L2 as in the previous embodiment for defining a removable portion 122 of the membrane. The first score line extends through the first layer 124 but does not breach the third layer 129. The second score line likewise extends through the second layer 126 but does not breach the third layer 129. A tab 130 is defined in the first layer 124 by a cut line 132. An adhesive-free region 140 is defined within the removable portion 122, in which the first layer 124 is not adhered to the third layer 129, and the tab 130 is located in the adhesive-free region.
The membrane 120 operates in a manner similar to the membrane 20 previously described. Pulling on the tab 130 causes the membrane to sever along the score lines. Although the foil layer 129 is not scored, the foil will easily sever when the plastic layers 124, 126 begin to sever. However, prior to being severed, the foil layer provides a good barrier against moisture and gases.
The membranes 20, 120 can be manufactured using a continuous web process in which continuous webs of the various layers are advanced through a series of stations at which various operations are performed on the webs and the webs are laminated together. For example, a manufacturing process for making the laminate 120 is depicted in
Either concurrently or non-concurrently with the formation of the laminate 170, a continuous web of the first layer 124 is advanced from a supply roll thereof to a tab-forming station at which a cutting mechanism 180 forms the cut lines defining the tabs in the first layer. The tab cut lines are formed in the laminate at fixed distance intervals along the length of the web such that a series of interconnected membrane lids can be formed from the continuous web. In the illustrated embodiment, the cutting mechanism 180 comprises a laser, but other cutting mechanisms can be used instead. Next, the first layer is advanced to an adhesive applicator 190 that pattern-applies the adhesive 125 onto the first layer such that adhesive-free regions are left. The adhesive-free regions are in registration with the tab cut lines such that the tabs are located in the adhesive-free regions. The adhesive applicator 190 can comprise any suitable device capable of pattern-applying the adhesive, such as a gravure roll or the like. The first layer with the adhesive thereon is then advanced to a lamination station 200 where the first layer is laminated with the laminate 170 comprising the second and third layers 126, 129.
Finally, the resulting laminate is advanced to a second scoring station 210 at which the second score lines are formed in the second layer 126 in registration with the tab cut lines and adhesive-free areas, and a first scoring station 220 at which the first score lines are formed in the first layer 124 in registration with the second score lines. The scoring stations 210, 220 are illustrated as comprising lasers, but other scoring mechanisms can be used instead. The scoring stations 210, 220 are shown as being separated by a distance in the web travel direction, but alternatively they can be located at the same place along the travel direction.
The order of operations shown in
Many modifications and other embodiments of the inventions set forth herein will come to mind to one skilled in the art to which these inventions pertain having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is to be understood that the inventions are not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.