This invention relates to a system, apparatus, and method for sealing a cover onto a container.
Systems for precision filling and sealing of single and multicompartment food containers are used for packaging food products, including refrigerated and frozen foods. One common type of sealing system is a platen sealing system. Platen sealing systems include variable speed machines that seal film or paperboard to containers. Platen sealers typically compress the film-tray mating surfaces between two opposing surfaces of the sealer. Commonly, one of the surfaces is the flat surface of a metal platen, and the opposing surface is a resilient rubber seal on which rests at least a portion of the container being sealed. Platen sealing systems have been developed that seal containers at speeds of up to 20-300 containers per minute.
One type of platen sealing system involves a heat sealing machine, in which a heated platen presses a seal film onto a container and seals the film onto the container at specific locations (e.g., the periphery of the container). Heat sealing systems use a combination of heat, force, and time to provide optimum seals. A common system for heat sealing includes a tray receiving die and a heated platen sealer. The tray receiving die typically includes a resilient rubber seal on which the periphery of the container rests. Commonly, the seal is glued or physically formed onto the die by rubber to metal bonding.
Over time, the seal on a tray receiving die tends to deform or crack and needs replacing. Replacement of glued or rubber to metal bonded seals can be disruptive to manufacturing. Often, replacement requires disassembly of the sealing system and specialized removal and reattachment of a new seal, which can only be done by the manufacturer of the sealing system at a distant location. The process is thus time consuming and expensive, and can disrupt manufacturing for several days. New systems are needed that possess a replaceable seal that can be easily changed by on-site service mechanics at low cost and with only momentary interruption of manufacturing.
The present invention is directed to overcoming limitations in the art and providing a system, seal, and method which achieve needed improvements in the cost and efficiency of replacing worn-out resilient seals on sealing systems.
One aspect of the present invention relates to a system for sealing a cover onto a container. This system includes a die comprising a surface into which is formed a container receiving cavity and a groove. The system also includes a seal comprising a groove insert member comprising a body and a neck formed at one end of the body and a contact member comprising a first end and side walls extending to a second end, where the contact member is connected to the neck at the first end, the first end being wider than the neck to form two opposing edges that extend laterally from the neck, where the groove insert member is removably seated in the groove so that the two opposing edges rest on the surface to seal the groove.
Another aspect of the present invention relates to a seal comprising a groove insert member comprising a body and a neck formed at one end of the body, the neck having a width less than that of the body; a contact member having a first end connected to the neck, the first end being wider than the neck to form two opposing edges that extend laterally from the neck; where the contact member comprises side walls extending convergently from the first end to a second end to form a tip at the second end, the tip having a width less than that of the body of the groove insert member; and where the stamp member has a length greater than that of the groove insert member.
A further aspect of the present invention relates to a method of sealing a cover onto a container. This method involves providing the system according to the present invention; seating a container in the container receiving cavity; providing a cover for the container; and pressing together the cover and at least a portion of the container between the second end of the contact member and a sealing platen under conditions effective to seal the cover to the container.
The present invention improves the cost and efficiency by which a worn-out seal in a platen sealing system can be replaced. In addition, the system and seal of the present invention provide improvements in the seal structure to prevent bacterial growth and contamination, thus providing a system that is cleaner and prevents bacterial contamination of the food products being manufactured.
The present invention relates to a system, apparatus, and method for sealing a cover onto a container. A first aspect of the present invention relates to a system for sealing a cover onto a container.
Die 10 may be formed of any durable material, and will most commonly be constructed from metal, e.g., aluminum or steel. In one embodiment, surface 12 of die 10 is substantially planar.
Seals 20(1) and 20(2) are seated in a groove formed in die 10 around the edges of container receiving cavity 14(1) and 14(2), respectively.
Die 10 is shown separate of any seal in the perspective view of
In the particular embodiment illustrated in
Groove 16(1) is shown in the cross section view of
As can be seen in
As mentioned supra, the system of the present invention includes a die and a seal. The details of one embodiment of the seal of the present invention are illustrated in
The seal of the present invention is, according to one embodiment, constructed of a resilient and durable rubber material. In one embodiment, the seal is bendable, so as to be formed into a necessary shape (e.g., rectangular) matching the outline of a container. In another embodiment, the seal is constructed of a polymeric material or, e.g., the rubber NBR 85A or other rubber material with properties similar to that of NBR 85A, although other materials having other properties may also be used.
Groove insert member 30 has body 34 which, in the particular embodiment illustrated in
In one embodiment, the body of the groove insert member is a continuously smooth surface. In other words, the body is formed without any rib formations or other features that, e.g., prevent the surface of the body from fitting entirely into the cavity defining the groove. It may be advantageous for the body of the groove insert member to fill the entirety of the cavity defining the groove to prevent the formation of cavities that, e.g., serve as places of bacterial growth.
Contact member 32 has first end 38 and side walls 44 extending to second end 40. Contact member 32 is connected to neck 36 at first end 38. As illustrated, first end 38 is wider than neck 36 so as to form two opposing edges 46(1) and 46(2) that extend laterally from neck 36. In one embodiment, opposing edges 46(1) and 46(2) extend laterally from neck 36 in a single plane.
In the particular embodiment of seal 20 shown in
In the system of the present invention, the groove insert member of the seal is removably seated in the groove so that the two opposing edges rest on the surface of the die to seal the groove. In one embodiment, the seal is forcefully inserted into the groove so that the groove insert member fits snuggly with the cavity defining the groove. When replacement of the seal is needed due to deterioration or cracking of the seal, the seal may be pried loose of the groove and replaced with a new seal. Thus, replacement of the seal does not require specialized knowledge and skills.
As illustrated in
A further aspect of the present invention relates to a method of sealing a cover onto a container. This method involves providing the system according to the present invention; seating a container in the container receiving cavity; providing a cover for the container; and pressing together the cover and at least a portion of the container between the second end of the contact member and a sealing platen under conditions effective to seal the cover to the container.
In carrying out the method of the present invention, it may be necessary to apply heat during said processing to create a seal between the container and the cover for the container.
Although the invention has been described in detail for the purpose of illustration, it is understood that such detail is solely for that purpose, and variations can be made therein by those skilled in the art without departing from the spirit and scope of the invention which is defined by the following claims.