Patent Application
20090161995
1. Technical Field
The present invention relates to an easy to open package, designed in a plate-mat bag configuration, and a method for making same. When the package of the present invention is opened it forms a plate which the consumer can set on a surface and consume the packaged contents. Several features of one end of the package provide for easy opening of the package by a consumer.
2. Description of Related Art
Snack foods and other items are often packaged in bags formed from thin, flexible packaging films. These thin films are formed primarily of plastics, such as polypropylene and polyethylene, but can also contain metalized films, foil, paper, or oriented films. These packaging films can have numerous layers directed to achieving specific needs, but are generally formed at least in part by extrusion of a plastic layer, co-extrusion of multiple layers simultaneously, extrusion coating of another material (such as paper), and the lamination of two layers together via either extrusion lamination or adhesive lamination. In the discussions below, both extrusion lamination and adhesive lamination processes are discussed in more detail, but it is noted that any designated layer that is fed into these two processes can already be a multi-layer film formed by any of the above processes.
An exemplary film 100 for packaging of food products is seen in
Once the material is formed and cut into desired widths, it can be loaded into a vertical form, fill, and seal machine to be used in packaging the many products that are packaged using this method.
The form, fill, and seal machines are quite expensive, in the range of $250,000 each, but pay for themselves easily when compared to the cost of pre-formed bags and the machinery to fill them. However, in order to maximize the productivity of the form, fill, and seal machines, it is common for the product delivery tube 218 and former 216 to be made as a unit that is easily interchangeable, so that different size packages can be made by the same machine. The length of the transverse seal can also be changed, by exchanging the sealing jaws 226, or in some cases, merely by exchanging their facings (the portion of the sealing jaws which actually makes contact with the packaging film). By changing these elements, as well as the width of film roll feeding into the machine and the programming of the machine, one form, fill, and seal machine can handle a number of different products in different size packages, limited primarily by the width of film the machine will handle, the maximum length of bag the machine is designed to handle, and the available former/delivery tube assemblies.
Although there is no one perfect package for all uses, there are a number of desirable features that manufacturers strive for in packages made on a vertical form, fill, and seal machine. One such feature is the ability to easily open the package. Consumers now must grip and open the package, usually with a thumb and one or several fingers on both hands. The thumb and fingers must pinch and tear with sufficient force to break the seal. This can become more difficult as a consumer gets older. For example, some consumers have arthritis or have lost strength in their hands. Grasping the sides of a flexible bag and opening it as previously described may be a difficult task for them. Therefore, it is desirable to have a bag that is easier to open by hand than is available from the prior art. There have been some attempts at this to include an easy open package containing, for example a tear notch and perforations that allow for easier opening. However, even these traditional pillow containers have a downside in that when opened the package falls on its side and consequently must be balanced to keep product from spilling. Thus, it is desirable to have a package that does not need to be balanced for fear of spillage. New stand-up packages have been developed that ease the balancing problem such as the package disclosed by commonly owned U.S. Pat. No. 6,722,106 to Bartel et al. However, these vertical stand-up packages still only offer a small cross-sectional area from which product can be retrieved. Many consumers prefer the ease of eating snacks from a plate or a bowl that offers a relatively large surface area for product retrieval rather than a package wherein a consumer's hand must be inserted into the package to retrieve a food product. Thus, it is also desirable to have a package that offers maximum surface area from which product can be retrieved. Consequently, it is desirable to have an easy to open package that upon opening functions as a “plate-mat” which holds food product. The word “plate-mat” comes from combining plate and placemat, and means a container that is generally horizontal when opened such that it can be eaten from like a plate. A feature of the container can also be used as a placemat once the container is open. Finally, because of the speed and productivity achieved on a vertical form, fill, and seal machine, it is desirable that any such package alteration be capable of being produced on such a machine.
A flexible easy to open package that also serves as a plate for storing and eating food and method for making same is provided. The package comprises two seals: a lower seal and an upper peelable seal. The upper seal has geometry so that as the seal is pulled downward, the force gets distributed downward and outward. There is a portion of unsealed film above the upper seal which forms a tab. This allows a consumer to easily grip the tab and pull downward, breaking the upper seal and opening the package. The inner layer of the package has score lines. Consequently, as the consumer breaks the upper seal, the package continues to tear along the direction of the score lines. Once opened, the package resembles a plate. Further, the torn top portion of the package can be used as a place-mat upon which cups or drinks or other items may be placed.
The package is capable of being produced on a vertical, form, fill, and seal machine with only minor alterations. First, a film is obtained wherein the first layer, or product side, of a film web comprises score lines. The film is oriented so that it preferentially tears in the direction of the score lines. The resulting film is fed to a vertical, form, fill and seal machine. The package is then formed into a tube, sealed at the bottom, filled with product, and then sealed at the top with a peelable seal. The peelable seal is made peelable by adjusting such factors as time, temperature, pressure, as well as the geometry of the seal. Further, the peelable seal has a force distributing configuration which directs the force downward and outward along the package as the consumer opens the package.
The novel features believed characteristic of the invention are set forth in the appended claims. The invention itself, however, as well as a preferred mode of use, further objectives and advantages thereof, will be best understood by reference to the following detailed description of illustrative embodiments when read in conjunction with the accompanying drawings, wherein:
Several embodiments of Applicants' invention will now be described with reference to the drawings. Unless otherwise noted, like elements will be identified by identical numbers throughout all figures.
Upon pulling the tear tab 305, the consumer's force will first be directed upon the tip 308 of the upper seal 302. As will be discussed in more detail below, the upper seal 302 is a peelable seal which is typically easier to destroy. It can be seen that one benefit of the upper seal 302 is that the seal comes to a tip 308. As depicted, the upper seal 302 is a chevron seal. The use of a chevron seal is shown only as a preferred embodiment and should not be deemed limiting. Other possible examples include a semicircle or any other shape that exhibits a force distributing configuration. As used herein a force distributing configuration is a configuration that concentrates the force at a force concentrating area such as a narrow tip and then distributes the forces downward and outward. Other shapes that do not concentrate the initial force at a narrow tip can be used, but such shapes result in increased force being necessary to initiate the tear and open the package. The seal has a seal area of a defined width and length. In a preferred embodiment the seal has a tip 308, defined herein as a force concentrating area. In a preferred embodiment the seal area at the tip is narrower than the width of the seal along the rest of the seal. Such a configuration allows for even greater concentration of force resulting in easier tear initiation. A chevron seal is used as the upper seal 302 in part because of its defined tip 308, In a preferred embodiment the width of the tip 308 of the upper seal 302 is between about 1/32nd and about ¼th of an inch and is narrower than the width of the seal 302 along other portions of the seal 302. In a more preferred embodiment the width of the tip 308 of the upper seal 302 is between about 1/16th of an inch and about ⅛th of an inch. The downward force exerted by the consumer will be concentrated on the tip 308, resulting in less required force to destroy the seal 302 at the tip 308, thus initiating the opening of the seal 302. If the upper seal 302 did not come to a tip or was thicker, the force would be less concentrated and consequently more force would be required to destroy or open the seal.
When the seal is destroyed, the force exerted gets distributed downward and outward along the package in the same direction of the upper seal 302. As the forces distribute outward, they run across a plurality (three in the embodiment illustrated) of score lines 303a, 303b, 303c, 303d, 303e, 303f on either side of the package. As used herein score lines encompasses lines which have been partially scored into the material, completely slit through the material, or perforated. In the pictured embodiment there are three score lines 303a, 303b, 303c, 303d, 303e, 303f which run the entire length of the package on both sides, left and right, of the package. In one embodiment of the current invention, it is preferred that these score lines 303a, 303b, 303c, 303d, 303e, 303f on either side be separated by about 1/10th of an inch to about one inch. It is more preferable that the score lines be separated by about ⅛th to about ½ of an inch. It is most preferable that the score lines be separated by about ¼ of an inch. It is desirable, though not required, to form score lines 303a, 303b, 303c, 303d, 303e, 303f such that when the package is filled with product the outermost score lines 303c, 303f are close to the product edge. This results in a greater possible planar surface area of the plate when the package is opened. In one embodiment of the current invention it is preferred that the outermost score lines be located from about 1/16th of an inch to about four inches from the edge of the package.
As a consumer pulls down on the tear tab 305, the force will run down the upper seal and into one of these three score lines 303a, 303b, 303c, 303d, 303e, 303f. Having multiple, or in this case three score lines 303a, 303b, 303c, 303d, 303e, 303f on either side is helpful, though not required, as it provides some room for error; if the tear does not intersect the innermost slot, the tear will continue until it intersects the outermost slot and the tear will continue to run vertical with the length of the package. As noted above, the oriented polymer material has been specially treated so that the long polymeric molecules tend to align in a given direction, causing the material to preferentially tear in that direction. Thus, because the polymer material is oriented so as to align with the score lines lines 303a, 303b, 303c, 303d, 303e, 303f, the material preferentially tears in the same direction as the score lines 303a, 303b, 303c, 303d, 303e, 303f. If the material was oriented perpendicular to the score line the material would not tear along a straight path. The polymer material is treated to cause this alignment in the formation of the material before the film layers are selected for lamination.
Referring now to
Referring back to
As an example, to produce a five inch wide bag, the width of the composite film 704 will be about eleven inches. If three score lines are desired on either side of the bag, and each score line is separated by about one-quarter of an inch, then the distance 705 between middle score lines 303b, 303e will be about four inches. The distance 701 between the middle score line on the right 303e and the right side of the film composite will be about 3.75 inches. The distance 703 between the middle score line of the left 303b and the left side of the film composite will be about 3.25 inches. Thus, it is apparent that the distance 702 between middle score lines 303b, 303e is dependent upon the width of the composite film 704, the distance between score lines 705, and the number of score lines. Thus, if an eight inch bag is desired, with six score line separated by about one-quarter inch, the resulting composite film would have a distance of about seven inches between the left and right middle score lines. Accordingly, if the package was opened along the middle score line, the resulting plate would have an open area width of about seven inches. It should be noted that the dimensions and ratios stated above are for one preferred embodiment and are given only as an illustrative example. Many other dimensions and ratios may also be preferred and can be obtained without varying from the scope of this invention.
The composite film 500 is then fed to a traditional form, fill and seal machine, similar to that shown in
In operation, the upper sealer 802 and the bottom sealer 801 are separated by a distance defined by the length of unsealed film 805. This distance will vary from about half an inch for smaller bags to about four inches or more for larger bags. The bottom sealer 801 is located above the upper sealer 802 by a distance 803 defined by the separation from the tip of the upper sealer 808 to the bottom sealer 801. This distance 803 will vary with the size of the bag. Suitable distances include from about one-half an inch for smaller bags to about four inches or more for larger bags. In operation, while the bottom sealer 801 is forming a bottom seal 301 for a bag above the bottom sealer 801, upper sealer 802 is forming an upper seal 302 for a bag located below the bottom sealer 801. After the two seals are formed, a knife, or other means (not shown) cuts the film beneath the bottom sealer 801 to form two separate bags.
It should also be noted that the seal produced by the upper sealer 802 is typically different from the bottom seal 301 in that the upper seal 302 is peelable. It should be noted however, that in some embodiments it may be desirable that the bottom seal 301 also comprise a peelable seal. As used herein a “peelable seal” is a seal which can be broken along a specified direction of travel, and which is typically easy to open. In one embodiment the peelable seal requires less force to destroy than a destructive seal. A destructive seal is a seal that cannot be opened without tearing. In many embodiments the peelable seal is easily opened with two hands. It is possible to produce a peelable seal in many ways which are discussed below. In one embodiment, the geometry of the upper seal 302 is manipulated to produce a seal which is easier to open. For example, in one embodiment the peelable upper seal 302 comprises a line seal. A line seal is a very narrow seal. Because the line seal is narrow, it requires less force to destroy than a wider seal. Thus, the peelable upper seal 302 can comprises an easy to open line seal whereas the bottom seal 301 comprises a traditional permanent or destructive seal. In some embodiments, the upper seal 302 and bottom seal 301 comprise the same seal type, for example a permanent seal, but the upper seal 302 is narrow making it easy to open and thus peelable. In another embodiment the peelable upper seal 302 comprises resin in what is sometimes referred to as a peelable sealant by design. Typically, in such an embodiment resin is applied to the entire film of the package. Upon the application of heat and pressure a seal forms between the two films comprising layers. The strength of the resultant seal is adjusted by varying the amount of heat applied to the seal, the pressure applied to the seal, the length of time the heat and pressure are applied to the seal, as well as the geometry of the seal. Thus, two seals of varying strength may be made by varying the temperature and pressure applied to a given seal. Likewise, as discussed above, one seal can be weaker and thus easier to open than a second seal if it is thinner than the second seal. In other embodiments the resin may be applied selectively to the area being sealed resulting in a peelable seal. In yet another embodiment the peelable upper seal 302 comprises a cold seal, for example, glue. Thus, there are many methods which produce a peelable seal. Any of these methods may be used to produce upper seal 302. In many embodiments of the current invention the upper seal 302 requires less force to destroy than the bottom seal 301. The reason the upper seal 302 needs to be peelable is that in the operation of this bag a consumer grabs the tear tab and pulls downward. As the consumer pulls downward, the force of the tab being pulled downward along the length of the package will be sufficient to separate the front and back layers of the package so that the seal is destroyed and the package is opened. Consequently, the upper seal 302 needs to be peelable to allow for this operation. If the seal was not peelable, then the package will just rip apart instead of following the path of the seal. Further, if the seal was not peelable then more force is typically required to destroy it. It should now be noted that while
In summary, the invention allows the production of a flexible film having an easily opened package that when opened operates as a plate. Many other variations are possible without straying from the intent of this inventive disclosure and will be obvious to one of ordinary skill in the art.
