Patent Application
20120324836
The invention relates to an inner seal for a container and more particularly to a pull-tab for the inner seal to permit a proper seal while allowing for easy removal of the inner seal to the container.
A heat sealable inner seal is often used in sealing a container for products such as anti-freeze, peanut butter, mayonnaise, liquid detergent, etc. Such an inner seal prevents leakage and is also popular for providing an indication of whether there has been tampering with the contents of a container.
Presently, a heat sealable inner seal generally includes a multi layer composite structure with an upper layer of metallic foil which is attached to a lower layer of adhesive material which bonds the heat seal material. The inner seal also can include an upper backing layer. Generally, the inner seals are inserted into caps and shipped to a packager of containers. The packager places the caps onto filled containers, with the coating of heat sealable material being in contact with the land area of the neck of the containers. The containers then pass through a conduction heating system which conducts heat into the foil, under an induction heater which generates heat within the metallic foil causing the temperature of the foil to increase. The high temperature of the foil melts the attached heat sealable adhesive layer, causing the inner seal to bond to the container.
In a hot fill process and after the product is filled in the container, the liner, when placed on the container, may have an edge curl up, thus will not seal properly. The bonding between the heat sealable layer and container may be weak or may not occur and prevent the inner seal from performing its sealing function. As a result, the predominant closures for hot-fill have been metal or closures with imbedded liners. Therefore, it is desirable to maintain the liner in contact with the mouth of the container and to heat the foil to a temperature within a desired temperature range to ensure proper bonding of the inner seal to the container.
In hot-fill food packaging, with bottles, the use of liners is increasing. The process generally involves filling product into the bottle or other container, placing the liner on the mouth of the bottle or other containers, and heat sealing through induction or conduction. The subject invention involves immediately cooling the liner while holding it against the bottle mouth sealing the surface. The cooling may be accomplished by sprayed water or other application of water, a refrigerated plate or simply blowing refrigerated air at the liner. The liner may be secured against the mouth of the bottle by the refrigerated plate. A conveyor may also be used to apply pressure to the liner while it is on the mouth of the bottle.
The present invention will be more readily apparent from the following detailed description of the invention and the appended claims, when taken in conjunction with the accompanying drawings in which:
While the present invention is susceptible of embodiment in various forms, there is shown in the drawings and will hereinafter be described a presently preferred embodiment with the understanding that the present disclosure is to be considered an exemplification of the invention and is not intended to limit the invention to the specific embodiment illustrated.
Referring now to the figures and particularly to
The cap 12 has a top wall portion 30 and a depending skirt portion 32 depending from the top wall portion 30. The inner surface 34 of the top wall portion 30 is adapted to coact with the sealing surface 22 of the container 16 to form a seal therebetween. When the package 10 is assembled, the liner 14 comprises a circular disc and resides between the top wall portion 30 of the cap 12 and the sealing surface 22 of the container 16, spanning the opening or mouth 36 of the container 16.
The liner 14 has a central portion 40 that is positioned over and in use, sealed to the sealing surface 22 of the container 16. As shown in
In one embodiment, as illustrated in
Attention is now directed to
The containers may be cooled by spraying the bottles with a refrigerant or other fluid, such as water, to cool the containers while pressure is being applied to the liner. This is shown in
Thus, the liner is cooled after the hot-fill process. Further, the second conveyor assembly 77 biases the second surface 90 thereof toward the first surface 76 against the containers 15 on the first conveyor to provide a substantially constant pressure between sealing surface 22 and liner 40 as the two travel on the conveyor as a unit.
As each container/liner combination 15 passes between the opposing first and second conveyor assemblies 76 and 77, respectively, they cooperate to squeeze liner 40 against container mouth or sealing surface 22 at a constant pressure during passage through the pathway. A constant pressure is thus applied between the container mouth sealing surface 22 and the liner 40 which squeezes and maintains pressure during the cooling process of the liner 40, to thereby keep the liner in a sealed condition after the fusing of the liner in the induction process.
While the container/liner assembly travels along first conveyor assembly, a blast of refrigerated media such as air or liquid from refrigeration blower 93 may be directed to the liner surface as graphically depicted in
It will be understood that the foregoing description is of preferred exemplary embodiments of the invention and that the invention is not limited to the specific forms shown or described herein. Various modifications may be made in the design, arrangement, and type of elements disclosed herein, as well as the steps of making and using the invention without departing from the scope of the invention as expressed in the appended claims.
