The present invention relates to a process for the manufacture of an easy open device for “Flow Pack” or similar packages with longitudinal seams and transversal closures, an opening device obtained through said process, and the package using it.[0001]
More specifically, it relates to a process for placing a detaching or easy open strip in packages with longitudinal seams and transversal closures [in] which, because of their current manufacturing characteristics, said opening is made by tearing, with the risk of spillage of the packaged product and subsequent destruction of the package. It could be said that package manufacturing techniques are divided into packages with and without longitudinal seams and transversal closures. The first are the so-called “Flow Pack” packages and the second are the so-called “portfolio” and/or wrapper packages.[0002]
Portfolio-type packages are produced by the movement in the machine direction of the already-printed packaging film, said printing generally being readable in the direction perpendicular to the film's movement. The product to be packaged arrives at the film perpendicularly to its movement, supported by disks on both ends. At the same time, a detaching or easy open strip is incorporated longitudinally into said film by an applicator head. The detaching strip comes on a spool. While continuously unwinding, it is fixed with adhesive to the internal face of the packaging film in an area near one end of the product to be packaged. Said strip is not longer than the width of the package, generally not exceeding 15 cm, and one of its ends is exposed by lateral incisions to allow for manual detachment so the packaged product can be accessed.[0003]
These types of machines have cylinders that adjust the area where said detachable strip will be placed, but their degree of precision is relative, so there is generally displacement which affects the proper operation of said strip. Also, during the process of constructing the package, the free end for tearing said strip may not match up with the circumference it should describe. Consequently, when it does not close over itself, the tear is not clean. In some cases, said strip is not even where it should be. As indicated, once the package is constructed with its detachment strip incorporated, one frangible end is left free to open it. This free end, not attached to the rest of the package, is made with at least one cut in one side of the strip. If there are two cuts to both sides, they may not be symmetrical because of synchronization problems, which makes a neat opening even more difficult to achieve. If this occurs, more force must be applied than that required for opening, which distorts it and entails high risk for the product and package integrity.[0004]
This type of package uses heat activated adhesive to seal the ends, because of which the product to be consumed can also be damaged, due to the pressure of the disks and the temperature applied, as in the case of packets of crackers, in which the first and last are generally damaged.[0005]
The undesired effects that may accompany the wrapping or portfolio technique, plus their hermetic closure, motivated the appearance and the increasingly frequent use of “FlowPack” type packages which, because of their transversal packaging characteristic, could not, until now, have an easy open device. There are two types of Flow Pack packages, those generated horizontally and those generated vertically, also called sacks.[0006]
In horizontal packaging, the product is positioned on the printed film which will make up the package in [a] direction parallel to the readable printing, because of which it must enter parallel to the machine direction, which means perpendicular with respect to the aforementioned packages that are produced longitudinally (or “portfolio”). The film closes over itself on one face of the package, producing a longitudinal fold or seam which is heat sealed. The same occurs on the ends. Due to the manufacturing characteristics of this type of package, the application of a detaching strip which is continuous and in the machine direction, as in the case of longitudinally-manufactured packages, involves several difficulties, such as:[0007]
It would use a longer strip, with the consequent higher cost[0008]
It would interfere with the heat seal areas, making [the sealing] difficult, acting as a potential contamination factor.[0009]
It would expose the entire packaged product without the ability to be re-closed, with the consequent product deterioration.[0010]
In the case of vertical or sack type “Flow Pack” packages (filled gravimetrically or volumetrically), the process is different because it is not continuous. Its intermittent nature is due to the fact that one end of the package must be sealed and the longitudinal seam must be generated so that, when gravity causes the product to fall, it is confined in the package. Subsequently, the other end (where the product enters) is sealed, thus generating the base for the next package. The inclusion of a detaching strip has also not been used because of the problems previously set forth with respect to the conventional processes for inserting said strips.[0011]
Therefore, and in keeping with what has been set forth, at this time, there are no known processes for including detaching (also known as “easy open”) strips in packages with longitudinal seams and transversal closures, commonly known as “Flow Pack.”[0012]
Based on what has been set forth, the need to develop a process for the manufacture of an easy opening for these types of packages is clear, since at the current time they are opened only by tearing one of the ends or through the longitudinal seam (which can be located anywhere on the package). In the majority of cases, this causes spillage of the product because of the force needed to break the heat seal and, in some cases, destruction of the package.[0013]
Another as yet unresolved problem is reclosing the packages after opening. Generally, once the packages are opened, they are closed with a rubber band, a clasp, a clip, or any other prehensile implement. It is well known that in food products with a high fat content, rapid oxidation occurs, producing the so-called “sogginess” (and possible sticking in the package), destroying crispness and freshness. In the case of Flow Pack packages, this difficulty increases because, as in the majority of cases, the package is in very poor condition after being manually opened and it is very difficult to reconstruct it to close it by any of the means mentioned. So there is a need to open these packages in a non-traumatic manner and then close them so they keep the packaged products fresh.[0014]
Another difficulty arises in the case of promotions or economy packs of any kind that include more of a product at the same time. In the case of wanting to package, for example, three packets of crackers for a promotion, double packaging is necessary. First, each product individually, and then grouping them in a single package, either with a wrapping film of sealed polyethylene or in a closed box. This is so because the difficulties mentioned with respect to the destruction of the packages with longitudinal seams are aggravated even more in this case, since, if there were no individual packages inside the collective package, many products would be exposed, and, in the event of its destruction by tearing, significant spillage would result. Also, the cost of this double packaging is so high that, in the majority of cases, promotions do not achieve their expectations or objectives.[0015]
Therefore, the purpose of using the present invention is to provide a process for inserting a detaching or “easy open” strip in Flow Pack or similar packages with longitudinal seams and transversal closures, manufactured horizontally or vertically.[0016]
Another purpose is that said detaching strip be easy to detach.[0017]
Still another purpose is that the opening procedure not endanger the integrity of the package.[0018]
Yet another purpose is that the process for including a detaching strip not increase costs.[0019]
A further purpose is to provide an easy closure for packages with longitudinal seams and transversal closures.[0020]