A portion of the disclosure of this patent document contains material which is subject to copyright protection. This patent document may show and/or describe matter which is or may become trade dress of the owner. The copyright and trade dress owner has no objection to the facsimile reproduction by anyone of the patent disclosure as it appears in the Patent and Trademark Office patent files or records, but otherwise reserves all copyright and trade dress rights whatsoever.
This disclosure relates to a system and a method for storing, shipping, preserving and ripening produce. More particularly, the present invention is concerned with a packaging system for encasing and controlling ripening of produce and fruits, etc.
Respiring biological materials, e.g. fruits and vegetables, consume oxygen O2 and produce carbon dioxide CO2 at rates which depend upon the stage of their development, the atmosphere surrounding them and the temperature. In certain produce packaging, the objective is to produce a desired atmosphere around respiring materials by placing them in a sealed container whose permeability to O2 and CO2 is correlated with (i) the partial pressures of O2 and CO2 in the air outside the package, and (ii) the temperature, to produce a desired atmosphere within the container. The following US patents and patent publications pertain to packaging systems in this area: U.S. Pat. Nos. 4,886,372, 7,601,374, 7,329,452 and US20050266129.
Despite numerous attempts to control the ripening of produce prior to being displayed on the shelves in the market, there remains a need for a more sensitive and accurate packaging system, especially for controlling the ripening of produce such as avocados.
According to exemplary embodiments, a produce tray system is provided. The produce tray system includes a molded produce tray of solid continuous construction without vents having a general bowl-shape with a floor and upstanding walls rising to an upper lip. The floor and upstanding walls surround an inner cavity and have contours which form multiple compartments for cradling separate pieces of produce within the inner cavity. A flexible film attached across the upper lip, the film being configured to permit passage of water vapor and having an aperture formed therein. Finally, a breathable membrane is adhered across the aperture, the membrane having a structure which lower the rate of CO2 transmission relative to O2 transmission for higher temperatures.
An alternative produce tray system has a molded produce tray of solid continuous construction without vents defining a general bowl-shape with a floor and upstanding walls rising to an upper lip, the floor and upstanding walls surrounding an inner cavity. A flexible film attaches across the upper lip, the film being configured to permit passage of water vapor and having an aperture formed therein. A breathable membrane formed in the shape of a patch and sized to occlude the aperture is adhered across the aperture on an underside of the film within the inner cavity. The membrane has a breathable structural base layer and a polymer layer adhered thereto having pores and configured to lower the rate of CO2 transmission relative to O2 transmission for higher temperatures.
Other features and characteristics of the present invention, as well as the methods of operation, functions of related elements of structure and the combination of parts, and economies of manufacture, will become more apparent upon consideration of the following description and the appended claims with reference to the accompanying drawings, all of which form a part of this specification, wherein like reference numerals designate corresponding parts in the various figures.
The present application provides an improved produce tray system for storing produce during shipping and for display purposes. The produce tray system includes a lower relatively rigid produce tray covered with a flexible film and breathable membrane. The term “relatively rigid” refers to the solid nature of the produce tray relative to the flexible film. That is, the produce tray is preferably a molded polymer with sufficient rigidity to maintain its shape so that it may be stacked or nested with identical produce trays prior to assembly, and holds its shape when filled with produce. It should be understood that while the produce tray is formed so as to produce desirable airflow between stacked assembled tray systems, there are a number of particular shapes to produce such airflow, and the illustrated embodiment is merely exemplary.
The produce tray 30 has a general bowl shape with a floor 40 and a plurality of upstanding walls 42. An upper lip 44 defines a top edge of the produce tray 30 surrounding a relatively large upper opening leading to an inner cavity 46. The illustrated produce tray 30 is sized and shaped to contain a plurality, specifically four, avocados, and thus is shaped accordingly. However, it should be understood those of skill in the art that the size and shape of the produce tray could be modified for other fruits and vegetables.
In the exemplary embodiment, the produce tray 30 defines four regions within the inner cavity 46 within which four avocados can be separated. More particularly, and as seen best in the perspective of
The central protrusion 60 extends upward from the lower surface 48 of the floor 40 to a height of between about ¼ to ½ of a total height of the tray 30, while the rails 64 do not extend upward as far as the central protrusion 60, and preferably only between 5-10% of the total height. This can also be seen in the sectional views of
Still with reference to
A horizontal step 80 is formed around the entirety of the upstanding walls 42 at a location a short distance above the lower corner edge 70. More particularly, the step 80 is formed by a small outward jog in the walls 42 from lower to upper. As best seen in
With reference back to
With reference to
As seen in
The film 32 is desirably intended to transmit water vapor throughout the packaging and shipping process so as to avoid build-up of moisture within the inner cavity 46, which naturally retards mold growth. An exemplary film of this sort is an extruded monolayer polymer biaxially-orientated polyester film. Such a film may be obtained from DuPont under the tradename Mylar HXO2AP, which has an amorphous polyester heat seal layer with antifog on one side combined with a crystalline co-polymer that possesses an intrinsically higher rate of water vapor transmission compared to standard PET films of the same thickness. An exemplary thickness is 100 gauge (1 mil, 0.001 inch). The water vapor transmission rate is around 8 g/100 in2/24 hr. The end result is an optimal water vapor transmission rate when in storage and during shipping.
A preferred assembly method includes first printing multiple product labels in series on a long strip of the flexible film 32 which is wound onto a spool. After printing, the film 32 is un-wound and the apertures 100 are die-cut punched. The breathable membrane patches 34 are then placed over the apertures 100, and the film is re-wound onto a roll. The roll of film 32 with the attached membrane 34 is sent to a packing plant where it is mounted on a top sealing machine. Subsequently, 4-pack trays (with 4 ripe avocados inside) are run through the top sealing machine and the film 32 sealed to the PET plastic tray 30. Desirably, these steps are all automated.
The intent of the currently disclosed package is not to quickly ripen the avocados in the package, but instead slow down the ripening of the avocados, especially at higher temperatures. The package enables ripe or almost ripe avocados to be packed into a sealed package, and the membrane 34 then controls the O2 and CO2 inside the package depending on temperature. With ripe avocados inside the sealed package having the membrane 34, and stored at 40° F., the O2 level is around 10% and the CO2 level is around 4%. The cooler temperature helps to slow respiration of the avocado thus slowing the ripening (due to cooling). At elevated temperatures the fruit will begin to respire more and ripen faster. However, the membrane 34 adjusts to the higher temperatures, and as result, the atmosphere inside the sealed packed changes to 8% CO2 and 4% O2, even though the pores 102 open up. When this occurs, the avocados receive less O2 and slow down their respiration, and thus their ripening. Normally, when the retailer places the ripe avocados on the store shelf at 68° F. the avocados would tend to ripen faster at the hotter temperatures. The present package 20 slows this ripening down when the ripe avocados are sitting on the store shelf. This will mean less waste, and longer shelf life of the avocados for the consumer.
The preferred packaging atmosphere is a relatively high CO2 content and a relatively low O2 content. In order to obtain such a packaging atmosphere in the modified atmosphere package, it is desirable to make use of a membrane 34 which has a relatively low COTR/OTR ratio (often referred to herein as the R ratio, where COTR is the CO2 transmission rate and OTR is the O2 transmission rate). At higher temperatures, i.e. >68° F., the membrane structure adjusts to decrease the COTR/OTR—which means that the atmosphere inside the container is higher in CO2 than O2. Higher CO2 puts the fruit to “sleep,” slows respiration and slows ripening. Decreasing the O2 helps to retard respiration of the fruit and slows the ripening process. The goal with the present package is to pack ripe or almost ripe fruit, and then control and slow further ripening of the fruit, thereby extending the shelf life of ripe fruit. That is, an increase in the CO2 inside the package as the fruit respires acts as a negative feedback and slows the respiration of the fruit.
Unless otherwise indicated or the context suggests otherwise, as used herein, “a” or “an” means “at least one” or “one or more.”
Furthermore, unless otherwise stated, any specific dimensions mentioned in this description are merely representative of an exemplary implementation of a device embodying aspects of the invention and are not intended to be limiting.
While the present invention has been described and shown in considerable detail with reference to certain illustrative embodiments, including various combinations and sub-combinations of features, those skilled in the art will readily appreciate other embodiments and variations and modifications thereof as encompassed within the scope of the present invention. Moreover, the descriptions of such embodiments, combinations, and sub-combinations is not intended to convey that the invention requires features or combinations of features other than those expressly recited in the claims. Accordingly, the present invention is deemed to include all modifications and variations encompassed within the spirit and scope of the following appended claims.
This patent is a continuation of application Ser. No. 16/425,784 filed May 29, 2019, the disclosure of which is expressly incorporated herein by reference.
Number | Name | Date | Kind |
---|---|---|---|
3716180 | Bemiss | Feb 1973 | A |
4886372 | Greengrass et al. | Dec 1989 | A |
6667067 | Noel et al. | Dec 2003 | B1 |
7329452 | Clarke et al. | Feb 2008 | B2 |
7601374 | Clarke | Oct 2009 | B2 |
7621412 | Raniwala | Nov 2009 | B2 |
20050266129 | Mir | Dec 2005 | A1 |
20080166458 | Weber | Jul 2008 | A1 |
20120187122 | Glasow | Jul 2012 | A1 |
20170107048 | Adam | Apr 2017 | A1 |
20170305633 | Pickard | Oct 2017 | A1 |
20180141738 | Armano | May 2018 | A1 |
Number | Date | Country | |
---|---|---|---|
20210371183 A1 | Dec 2021 | US |
Number | Date | Country | |
---|---|---|---|
Parent | 16425784 | May 2019 | US |
Child | 17403625 | US |