ZIPPER SLIDER ASSEMBLY WITH A DIAPHRAGM FOR FLEXIBLE PACKAGES
FIELD OF THE INVENTION
This invention relates to a zipper slider assembly with a diaphragm for flexible packages.
BACKGROUND OF THE INVENTION
Existing packages having zipper assemblies suffer from problems such as not being able to retain aroma and freshness of food and other articles packaged inside them during transportation and storage. Hence, by the time the contents of the package reach the end user they are insipid. Furmeπriδre. said zipper slider assemblies do not provide any tamper-proof features for informing the end user whether the package has been opened ^previously or not.
US patents 5,435,864 and 5,425,825 disclose plastic bag having a reclosable plastic zipper and non-reclosable peel seal. In US patent 5,435,864, the peel seal is formed by co-extruding an adhesive onto a side strip adjacent to the interlocking zipper while, in US patent 5,425,825 the seal is formed by applying adhesive to the side strip. Further, the barrier provided by a peel seal is permeable and is not strong enough for preventing undesired aroma, microorganisms, and moisture from entering into packages containing food items, thereby making the packaged items vulnerable to fast deterioration.
US Patent Application no. 2002/0021499A1 discloses a flexible reclosable package having a reclosable zipper construction openable and closable by a slider device, and a primary tamper evident structure disposed over the zipper for indicating whether access has been gained to the interior of the package. The package also has a second tamper
evident structure consisting of a polymeric film or a peel seal, which is permeable. As a result, the structure has very limited barrier properties to prevent undesired aroma, microorganisms, and moisture from' the atmosphere from entering the package. At the same ti-me,.-the structure is not capable of retaining inside the package the desired aroma, microbe free air and gases like nitrogen that are filed in the package containing food items for keeping them fresh.
The further disadvantage of the above US patents 5,435,864 & 5,425,825 and US Patent Application no. 2002/0021499A1 using a polymeric film extruded together with the zipper profile for providing tamper evident structure is that it limits the choice of material in case a structure having special properties such as capable of being holographed or printed is required for the package. OBJECTS AND SUMMARY OF THE INVENTION
The object ,of this invention is to maintain the desired aroma and freshness of food and other articles packaged inside a flexible package during transportation and storage till the time they reach the end user.
Another object of this invention is to provide a tamper proof zipper slider assembly for a flexible package.
A further object of this invention is to provide a zipper slider assembly with diaphragm that is more convenient for the user to tear open to access the contents of the package and at the same time possesses strong barrier properties.
To achieve the said objectives, this invention provides a slider zipper assembly with a diaphragm for flexible packages comprising: - zipper profile consisting of male element and a female element, said profile having flaps on single side,
- said male element having at least a pair of notches, which are coupled to corresponding notches on female elements, a slider to close said zipper profile characterized in that a diaphragm of at least one metalized laminated film is-sealed between said flaps to seal and-make the package tamper proof and act as a barrier.
The metalized laminated film is holographed, printed or plain. The metalized laminated film includes at least one layer of aluminum foil.
The sealing of the film to the flaps is carried out by ultrasonic or heat sealing device.
The zipper profile and slider are made of plastic. The flexible package is a pouch. The flexible package is a stand up pouch with a base. One wall of the said pouch is sealed on three sides and open towards the zipper assembly.
The said wall is sealed to one of the flaps of the zipper assembly after filling the pouch with desired material.
The flap has plurality of horizontal lines for the purpose of selective heat transfer and enabling one side sealing on zipper assembly, thereby preventinlg the zipper from sealing from inside after the pouch is filled with desired material.
The diaphragm has a score line effected using means for scribing for making it easier and more convenient for the user to tear open and access the contents of the package. The means for scribing include lasers and water jet technology.
Brief Description of the Accompanying Drawings
The invention will now be described with reference to the accompanying drawings.
Figure 1 shows a slider zipper assembly with a diaphragm / laminate provided on the flaps of said profile, according to this invention.
Figure 2 shows the package with a slider zipper assembly according to this invention.
Figure 3 shows the second embodiment of the flexible package.
Figure 4 shows the cross-sectional view of the second embodiment of the flexible package.
Figure 5 shows an embodiment of the flexible package wherein the diaphragm is made easier to tear open by effecting a score line. Detailed description of the accompanying drawings
Referring to the drawings, Figure 1 shows the slider zipper assembly consisting of male member 1.1 having interlocking element 1.2 and flap 1.3. A female member 1.4 having interlocking element 1.5, a flap 1.6 and rectangular shaped protrusion 1.7 extending from said flap 1.6. A slider 1.8 is shown in the figure for closing and opening the zipper profile. A diaphragm 1.9 is sealed between flaps 1.3,1.6 by ultrasonic or heat sealing device.
The diaphragm 1.9 is a metalized laminate film for providing strong barrier properties that does not allow undesired aroma, moisture and the like in the atmosphere to enter inside the package through it thereby, protecting the packed contents from deterioration. At the same time, aroma of the, packed articles, microorganism free air, and packaging gases like nitrogen are retained by the diaphragm 1.9 inside the package. Therefore, the diaphragm 1.9 helps in maintaining the
desired aroma and freshness of the food article even during transportation and'storage. In addition, when the slider zipper assembly with diaphragm 1.9 is applied to flexible packages, it makes the package tamper proof. The said flexible packages can. beuse for. carrying pharmaceuticals, stationary, tea leaves, coffee powder and other miscellaneous articles also.
The constituent films of the laminate can be chosen to provide desired properties as desired in different kind of packages, e.g. the diaphragm 1.9 can be holographed for identifying the manufacturer and authenticating a genuine product where necessary.
The zipper assembly and slider are made of plastic. In Figure 2,; a slider assembly with a package 2.1, diaphragm 2.2, a slider 2.3 and zipper assembly 2.4 is shown. The slider 2.3 and zipper assembly 2.4 are made of plastic. Figure 3 shows another embodiment of the present invention wherein the flexible package is a standup pouch 3.2 according to the present invention having a slider 3.3, zipper assembly 3.4 and a diaphragm 3.5. The bottom 3.1 of the pouch 3.2 is such that the pouch stands upright after it is filled with contents. One of the walls of said pouch 3.2 is sealed with zipper assembly 3.4.
However, the other wall 3.6 of the pouch is left unsealed for allowing the contents to be filled inside the pouch 3.2. After the pouch has been filled, the other wall 3.6 also is sealed to one of the flaps 4.2 of the zipper assembly. The said flap 4.2 has plurality of horizontal lines 4.1 for the purpose of selective heat transfer and enabling one side sealing on zipper assembly, thereby preventing the zipper from sealing from inside after the pouch is filled.
The diaphragm 3.5 is a metalized laminate film for providing strong barrier properties that does not allow undesired aroma, moisture and the like in the atmosphere to enter inside the pouch through it thereby, protecting the packed contents from deterioration. At the same time, aroma of the packed articles, microorganism free air, and packaging gases like nitrogen are retained by the diaphragm 3.5 inside the pouch. Therefore, the diaphragm 3.5 helps in maintaining the desired
' I; aroma and freshness of the food article even during transportation and storage. In addition, the slider zipper assembly with diaphragm 3-5 makes the pouch tamper proof. The said pouches can be used for carrying pharmaceuticals, stationary, tea leaves, coffee powder and other miscellaneous articles also.
The constituent films of the laminate can be chosen to provide desired properties as desired in different kind of packages, e.g. the diaphragm 3.5 can be holographed for identifying the manufacturer and authenticating a genuine product where necessary.
Figure 4 shows the cross sectional view of the zipper assembly wherein the male" element 4.3 and the female element 4.4 of the zipper assembly are shown along with the diaphragm 4.5. The flap 4.2 has plurality of horizontal lines 4.1 for the purpose of selective heat transfer for one side sealing of the wall.
Although the diaphragm described above has strong barrier properties and also provides a tamper evident feature, it is difficult for the end user to tear open the diaphragm to access the contents of the flexible package. One of the conventional approaches used to overcome the aforementioned drawback involves perforating the diaphragm for making it easier to tear open. However, such a perforation compromises
the barrier property of the diaphragm and hence, of the flexible package. Therefore, it is not fit in cases where the barrier is an essential requirement for storing the contents in the flexible package.
Thus in another embodiment of the present invention as shown in Figure 5 the diaphragm can be made easier to tear open by effecting a score line on it. In the figure, the exploded view of the diaphragm 5.5 shows the score line effected by means for scribing which include laser for cutting the diaphragm without compromising its strong barrier properties.
The laminate shown in this embodiment comprises three layers: the outer two layers being polymeric and the center layer being a metalized polymeric for providing the strong barrier property. The score line in this case is applied partially such that the depth of the score line is limited only up to metalized structure of the laminate, leaving metalized layer intact and thereby maintaining the strong barrier of the laminate. With such a score line cut in place, user can more easily open the bag by tearing along the score line on the diaphragm.
The laminate may also comprise an aluniinum foil in between two layers of polymeric films or even a combination of a metalized layer and an aluminum foil may also be used to provide an even stronger barrier. In such an embodiment also the score line is such that the depth of cut is limited only up to the aluminum foil or a combination of the metalized layer and aluminum foil of the laminate as the case may be and thereby mamtaining the strong barrier of the laminate.
It may be observed that the laminates used in the above embodiments have been described using only three layers for the ease of illustration and is in no way a limitation of the present invention. A man skilled in the art will appreciate that number of layers and their
composition in a laminate may vary as per the requirements of different flexible packages.