Package making – Methods – With contents treating
Reexamination Certificate
1998-11-06
2001-03-20
Smith, Scott A. (Department: 3721)
Package making
Methods
With contents treating
C053S510000
Reexamination Certificate
active
06202388
ABSTRACT:
FIELD OF THE INVENTION
The invention generally relates to a tray sealing apparatus used in sealing plastic film to product filled containers. More specifically the invention relates to an apparatus and method for exposing containers filled with product, including, for example, food product and any product that has an adverse reaction to air, to a controlled environment during the sealing operation.
BACKGROUND OF THE INVENTION
Various products including food product, and any other product that has an adverse reaction to air, are packaged in a controlled environment. Various attempts have been made to efficiently package these products in a modified atmosphere using vacuum and/or controlled environment.
Various food products, including bakery goods, meats, fruits, vegetables, etc. are packaged under atmospheric conditions. Many of these products are presented in supermarkets, for example, in cartons or cardboard containers with a plastic or cellophane wrap covering the product.
One problem with this type of packaging is that the goods have a minimum limited shelf life, which for many products are only several days to a week. With bakery goods, for example, mold may begin to grow after a few days under atmospheric conditions. Such products obviously cannot be sold or consumed and must be discarded.
Another problem arises with respect to many fruits and vegetables, which continue to ripen and continue their metabolic process under atmospheric conditions. For example, within a few days a banana can become overripe and undesirable to the consumer.
The space available for gassing and sealing operations is often limited at many facilities. In general, existing controlled environment sealing systems are often expensive, bulky, and require use of vacuum pumps, and, accordingly are impractical for use at many of these facilities.
In an effort to alleviate these problems, various attempts have been made to package food in a controlled environment by injecting controlled environment directly into filled containers. A high velocity flow is often necessary to penetrate into the food product. In general, these attempts have proved unsuccessful. With bakery goods, for example, the high velocity jets may pull in air and re-contaminate the product, thereby failing to reduce the oxygen to levels that would prevent the normal onset of mold.
Various techniques for removing air in food filling processes are known in the art. Such processes are used, for example, in the packaging of nuts, coffee, powdered milk, cheese puffs, infant formula and various other dry foods. Typically, dry food containers are exposed to a controlled environment gas flush and/or vacuum for a period of time, subsequent to filling but prior to sealing. The product may also be flushed with a controlled environment gas prior to filling, or may be flushed after the filling process. When the oxygen has been substantially removed from the food contents therein, the containers are sealed, with or without vacuum. Various techniques are also known for replacing the atmosphere of packaged meat products with a modified atmosphere of carbon dioxide, oxygen and nitrogen, and/or other gases or mixtures of gases to extend shelf life.
Many existing modified atmosphere tray sealing systems use an indexing conveyer to allow the tray and product to enter into a vacuum chamber and be exposed to reduced pressure, and then sealed within the vacuum chamber. In some applications, inert gas is used to back flush as the pressure is returned to atmospheric. The tray may then be permanently sealed with plastic film, which is heat sealed to the tray flange with a vertically reciprocating seal bar.
One drawback to these existing systems is that the vacuum chambers may be expensive to operate and take up additional space on the line. Other drawbacks in rapid vacuum applications include pulling product into the seal area causing leakers, as well as, the necessity that the lidstock or film must be extra wide to cover the entire chamber, increasing overall scrap. It would be desirable to have a controlled environment tray sealing system for use with a non-continuous or indexing conveyer system and vertically reciprocating tray sealers that would efficiently seal product within trays.
SUMMARY OF THE INVENTION
One aspect of the invention provides a controlled environment sealing apparatus comprising a reciprocating seal head positioned above a conveyer carrying product-filled trays, a film feeder to dispense film between the tray and the reciprocating seal head, and at least one seal head gassing assembly positioned in the seal head and oriented to direct a flow of controlled environment gas through a cut-out portion of the film into a product-filled tray positioned beneath the seal head. The seal head gassing assembly may preferably direct a high velocity controlled environment gas stream surrounded by a lower velocity controlled environment gas stream downward into the tray positioned below the seal head. A programmable controller may preferably be used to control the timing of the high velocity and low velocity gas flow through the seal head gassing assembly. Preferably, the seal head gassing assembly includes a housing including a low velocity gas inlet opening and a high velocity gas inlet opening. The housing may preferably include a body and a cap with the inlet openings formed in the cap. A flow guide member is preferably positioned in the body of the housing. The flow guide member preferably includes a low velocity flow opening to communicate with the low velocity gas inlet opening, and includes a high velocity flow opening to communicate with the high velocity gas inlet opening. The high velocity flow opening of the flow guide member is preferably slotted and communicates with a centrally located high velocity gas orifice, which extends through the flow guide member. A distribution member may preferably be positioned within the body of the housing and below the flow guide member. The distribution member may preferably include a spout and at least one opening formed therein and surrounding the spout. The spout preferably communicates with the high velocity gas flow and the distribution member opening communicates with the low velocity gas flow. Preferably, the distribution member includes a plurality of openings formed therein and surrounding the spout. A baffle may preferably be positioned between the flow guide member and the distribution member. A gassing element may preferably be positioned in a bottom portion of the housing body. A second gassing element may preferably be positioned in a bottom portion of the housing body. The second gassing element is preferably in contact with the first gassing element to allow a dual laminarized flow of controlled environment gas to exit from the housing body. Preferably the conveyer may be a shuttle plate including two tray openings.
A further aspect of the invention provides a method of operating a controlled environment sealing apparatus. A reciprocating seal head positioned above an intermittent conveyer carrying product-filled trays is provided. At least one seal head gassing assembly is positioned in the seal head. A film feeder to dispense film is also provided. A product-filled tray is conveyed to a position below the seal head. A gas stream is flowed through a cut-out portion of a film dispensed through a film feeder into the product-filled tray positioned beneath the seal head. Preferably, a high velocity stream of controlled environment gas is flowed through the seal head gassing assembly. A low velocity stream of controlled environment gas may also simultaneously be flowed through the seal head gassing assembly. Preferably, the high velocity stream is stopped prior to advancing film from the film feeder. The seal head is preferably next moved downward to seal the film against a flange portion of the tray. As the seal head is moved upward, a top portion of the film is contacted by a simultaneous flow of high velocity gas. A programmable controller may be used to program a timing sequence to synchron
Sanfilippo James J.
Sanfilippo John E.
Cardinal Law Group
Jescorp, Inc.
Paradiso John
Smith Scott A.
LandOfFree
Controlled environment sealing apparatus and method does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Controlled environment sealing apparatus and method, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Controlled environment sealing apparatus and method will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2470457