Patent Grant
11434061
The present invention provides for a film for use on a modified atmosphere packaging container. More specifically, the film controls transfer of gas and water vapour between the interior of the container and the environment outside the container.
Fruit, vegetables and cut-flowers are highly perishable agricultural commodities. Decay and growth of microorganisms including bacteria and fungi can lead to rapid quality deterioration and spoilage after harvest of agricultural commodities, as well as for other raw and processed food materials.
Maintenance of conditions optimal to the perishable goods within a package during shipment would prolong the lifetime of the goods for shipment. Environmental properties important to maintaining the quality of the perishable goods include oxygen (O2) and carbon dioxide (CO2) levels. As well, buildup of moisture in the vicinity of the perishable goods can lead to growth of microorganisms such as bacteria, fungus, and yeast. Sub-optimal conditions can lead to decay and spoilage of perishable goods.
The invention provides for a system for mitigating spoilage of perishable materials. The system comprises a container defining a compartment for storage of perishable materials, the container further defining an opening for providing communication between the compartment and an outside environment. The system further comprises a film that cooperates with the container to seal the opening of the container and control flow of gas and water vapor transfer between the compartment and outside environment.
In an aspect of the invention, the film has a water vapor transfer rate between 170 and 470 g m2/day at 38° C. and 100% relative humidity.
In an aspect of the invention, the film has a water vapor transfer rate exceeding 200 g m2/day at 38° C. and 100% relative humidity.
In a preferred embodiment, the film has a water vapor transfer rate between 171 and 202 g m2/day at 38° C. and 100% relative humidity.
In an aspect, the film is permeable to water vapor to maintain a relative humidity between 85% and 100%.
In an aspect, the film has an O2 transfer rate of 20-1245 cm3/m2/day atm at 25° C. and 0% relative humidity.
In an aspect, the film is formed to have a O2 transfer rate of 20-36 cm3/m2/day atm at 25° C. and 0% relative humidity.
In an aspect, the film is formed to have a CO2 permeability of 60-100 cm3/m2/day atm at 25° C. and 0% relative humidity.
In an aspect, the film has a thickness of 500-10,000 μm.
In an aspect, the film has a thickness of over 2,000 μm.
In an aspect, the film is a label and further comprises ink.
In an aspect, properties of the ink cooperate with the film to allow desired moisture and gas transfer properties to be maintained.
In an aspect, the ink is hydrophilic and non-metallic.
In an aspect, the container is formed from a rigid material formed to maintain shape when carrying perishable materials.
In an aspect, the container is comprised of a base defining the compartment for holding perishable materials, the base further defining an opening providing communication between the compartment and outside environment. The container further comprises a lid which cooperates with base forming a seal over the opening defined by the base, the lid defining a second opening. The film cooperates with the surface of the lid to seal the second opening and control gas flow and water vapor transfer between the compartment defined by the base and the lid, and the outside environment.
In an aspect, the lid comprises a recessed surface, wherein the second opening is positioned within the recessed surface, whereby the second opening is sealed upon application of the film.
In an aspect, the second opening is a perforated surface.
In an aspect, the recessed surface and the film define a second compartment formed to fit a spoilage inhibiting agent for mitigating spoilage of perishable items.
In an aspect, the film is comprised of the material Capran 2500.
In an aspect, the container is comprised of corrugated linerboard consisting of 40 gsm kraft/35 gsmPP/170 gsm kraft.
In an aspect, the lid is comprised of plastic. The plastic the lid is comprised of may be polyethylene terephthalate.
In a preferred embodiment of the system, the CO2 and O2 transmission rates of the sealed container are a maximum of 1000 cm3/container/day and 1200 cm3/container/day, respectively.
In another aspect, film is a flexible film.
A detailed description of the preferred embodiments are provided herein below by way of example only and with reference to the following drawings, in which:
In the drawings, preferred embodiments of the invention are illustrated by way of example. It is to be expressly understood that the description and drawings are only for the purpose of illustration and as an aid to understanding, and are not intended as a definition of the limits of the invention.
It is appreciated that the many embodiments of the present invention can be utilized in a wide variety of applications and industries. The present invention can be utilized with the transportation, treatment, and storage of a plethora of items. Items include but are not limited to produce, cheeses, flowers, poultry, and other meats and seafoods, nuts, dehydrated foods, mail, parcels, medical tools and equipment, etc.
The invention provides for a system for mitigating spoilage of perishable materials, the system comprising a container defining a compartment for storage of perishable materials, the container further defining an opening for providing communication between the compartment and an outside environment. The system further comprises a film that cooperates with the container to seal the opening of the container and control gas flow and water vapor transfer between the compartment and the outside environment.
The outside environment is the area outside of the system. The outside environment may be the atmosphere within shipping containers, warehouses, distribution centres, or any other location the system may be placed. For example, it is not uncommon for perishable materials such as produce to be packed into the system in an agricultural field, shipped over long distances, and stored for periods of time at storage locations. All of these locations may comprise the outside environment at one time or another.
The permeability of material is typically defined as the water vapor transfer rate, moisture vapor transmission rate, or water vapor transmission rate. For greater certainty, water vapor transfer rate, moisture vapor transmission rate, and water vapor transmission rate have the same meaning. These are defined as the measure of the movement of water vapor through a material. The conditions under which the measurement is made affects the measurement. These conditions include temperature and humidity, which should be measured, controlled, and recorded with the result, when defining the water vapor transfer rate of a material.
In an embodiment, the film has a permeability to water vapor exceeding about 200 g/m2/day at 38° C. and 100% relative humidity. Preferably, the permeability of the film provides for a relative humidity within the system of 85-90%.
In an embodiment, the water vapor transfer rate of the film is 170-470 g/m2/day at 38° C. and 100% relative humidity.
In an embodiment, the water vapor transfer rate of the film is 171-202 g/m2/day at 37.8° C. and 100% relative humidity.
In an embodiment, the film maintains an atmosphere within the system of 1-20% O2 and 0.5-20% CO2, and a relative humidity of 85-100% at −0.5 to 15° C.
In an embodiment of the invention, the film is a plastic material having a thickness of 500 to 10,000 μm. Preferably the film material has a thickness of 2,000 μm or greater.
Increasing thickness of the film is inversely proportional to the transfer rate of water vapour through the film. It is preferable that the film has a sufficient thickness to be handled and applied to the container using automated machinery, yet thin enough to maintain optimal water vapour transfer rates. It is also desirable to maintain optimal CO2 and O2 transfer rates in order to mitigate spoilage of perishable goods.
An embodiment of the film is formed from a material having a CO2 transfer rate of approximately 50-100 cm3/m2/day at 0% relative humidity and 38° C.
In an embodiment, the film is formed to have an O2 transfer rate of 20-36 cm3/m2/day at 0% relative humidity and 25° C. In another embodiment, the film is formed to have an O2 transfer rate of 20-1245 cm3/m2/day at 25° C. and 0% relative humidity.
In an embodiment, the film is formed to have an O2 transfer rate of 2500-7500 cm3/m2/day at 15° C. and 90% relative humidity.
The CO2 and O2 transmission rates of the sealed container should be a maximum of 1000 cm3/container/day and 1200 cm3/container/day, respectively, at a relative humidity of 85-100% at −0.5 to 15° C.
An embodiment of the film comprises a polyamide. The polyamide may comprise nylon-6 or nylon-66 or copolyamides such as nylon-6/66 or nylon-6/12. For example, the material may be manufactured from a polymeric material that comprises a blend of nylon-6 and nylon-66, nylon-6/66, or nylon 6/12 with other polymeric and/or non-polymeric components.
In an embodiment, the raw material the film is comprised of may be manipulated to tailor its permeability to water vapor, to either increase or decrease the water vapor permeability of the film. For example, blends of nylon-6 or nylon 6/66 with other raw materials may be processed to provide a film with a lower water vapor permeability or a higher water vapor permeability than a film processed with nylon-6 alone.
Alternatively, the film material may be manipulated by steam treatment or other processes to increase its water vapor permeability.
Preferably, an embodiment of the composition of the film material includes a polyamide such as nylon-6 or nylon-66, commercially available from Allied Signal as Capron® 3090FN, or copolyamides such as nylon-6/66, commercially available from Allied Signal as Capron® CA95YP, or nylon-6/12, commercially available from EMS as Grilon® CR8. The material may be manufactured from blends containing nylon-6, nylon-66, nylon-6/66, or nylon-6/12 with other polymeric and/or non-polymeric components. For such polyamides alone, oxygen (O2) permeability is about 0.4-1.5 cm3 mm/m2 day atm and carbon dioxide (CO2) permeability is about 1.8-3.0 cm3 mm/m2 day atm when measured at 23-25° C. and 0% relative humidity.
An embodiment of the film additionally comprises a blend of polyamides with other homopolymer polyamides. By blending a given polyamide with a second polyamide having a higher percentage of amide groups than the original polyamide, the water vapor permeability of the blend will usually be higher than that of the original polyamide. By blending a given polyamide with a second polyamide having a lower percentage of amide groups than the original polyamide, the water vapor permeability of the blend will usually be lower than that of the original polyamide. For example, nylon-6 may be blended with nylon-11 or nylon-12 to produce films having reduced water vapor permeability relative to that of nylon-6 alone and are characterized by minimal moisture condensation on the film surface when used in cooperation with a container to package produce.
An embodiment of the film comprises a blend of polyamides with copolymers containing amide groups. For example, blends of nylon-6/66 copolymer with nylon-6, in an amount ranging from 5-100% nylon-6/66 give increased water vapor permeability and gloss relative to nylon-6 alone. As a further example, the plastic packaging material may comprise nylon-6 blended with nylon-6I/6T, commercially available from Du Pont as SELAR® PA 3426, to produce films of 20 and 30 micron thickness. Ratios may be between 80-99% nylon-6 and 1-20% nylon-6I/6T. The resulting films have reduced water vapor permeability relative to nylon-6 alone and retain the ability to minimize condensation.
Another embodiment of the film material may comprise polyamides or other hydrogen bonding polymers blended with polyether-block-amides, such as Pebax® MX1205, commercially available from Elf Atochem, to increase water vapor permeability of the material relative to the polymers without polyether-block-amides.
Embodiments of the film can include varied thickness, water vapor transfer rate, gas transfer rate of CO2 and/or O2, and size and area covered by the film. For example, increased water vapor transmission can be achieved with films having a larger area.
Properties of the film are such that the water vapor transmission rate increases with temperature. This leads to removal of more moisture produced by produce or other perishable goods at higher temperatures.
In an embodiment, the film is comprised of CAPRAN® 2500, MDPE/PE, 75 EVHS1, 40 EV, 30 EVHS1, or 25EV material. Preferably, the film is comprised of CAPRAN® 2500.
CAPRAN® 2500 is a 1.0 mil (25 micron) biaxially oriented nylon 6 film. Properties of CAPRAN® 2500 are elaborated on in Table 2.
As shown in
The label is functional in that it provides graphic and identifying information, while allowing water vapor to transmit.
Messaging provided on the label can be customized through application of ink in various designs which may include words, logos, brands, colors and pictures.
In an embodiment, the label further serves to seal in antimicrobial vapors held within the container in order to maintain antimicrobial activity within the compartment of the system. The purpose of maintaining antimicrobial activity within the compartment of the system is to mitigate growth of pathogens and microbials and thus mitigate spoilage of perishable goods such as produce within the system.
As shown in
As shown in
The lid 20 may further comprise a recessed surface 28 relative to a raised surface 26 of the rest of the lid 20, the second opening 22 defined by the recessed surface 28. The film 24 may be applied to the portion of the lid 20 raised relative to the recessed area to cover and seal the space 32 defined by the recessed surface 28 and walls 32 between the raised surface 26 and recessed surface 28. The walls 32 connecting the raised surface 26 and recessed surface 28 may be substantially perpendicular or they may be slanted relative to the surfaces 26 and 28.
As shown in
As shown in
In an embodiment, the second opening 22 defined by the lid is 3″ by 4″ and the film 24 is sized as a 5″×4″.
As shown in
In an embodiment of the system, the container is formed from corrugated flat stock that has low carbon dioxide and oxygen transmission rates (1700-2000 cm3/m2/d and 500-700 cm3/m2/d, respectively at a relative humidity of 85-100% at −0.5 to 15° C.) and is impervious to water vapor transmission. Preferably the oxygen transmission rate of the corrugated flat stock is 600 cm3/m2/d. To achieve the low rates of oxygen, carbon dioxide and water vapor transmission rates, a linerboard consisting of 40 gsm kraft/35 gsmPP/170 gsm kraft is corrugated on one or both sides of the fluting material. The carton design consists of raised corners with intermediate support provided by either the corrugate or the lid corner supports. In this embodiment, the system further comprises plastic lid of unique design that is form fitted to the box and sealed with a high barrier tape. The film is applied to the surface of the lid to seal the second opening.
An embodiment of the lid is comprised of a plastic material. The plastic material is preferably polyethylene terephthalate (PETE).
In an embodiment of the system, the label may be designed from the following materials:
A perceived advantage of the system is that mass production of containers, or in some embodiments container bases and lids, can be economically achieved. This is followed by application of customized films having properties optimized to control water vapor and gas transfer rate of the system to mitigate spoilage of perishable goods. When the film is a label, the design of ink on the label may be customized. Application of customized films and labels to mass produced containers, container bases and lids to form a system for mitigating spoilage of perishable goods provides for economic efficiencies in production.
Bell peppers were harvested and transported to a cooler within 4 hours of harvest. The peppers are cooled to 7° C. within 6 hours by pressure cooling. They are held in forced air cooling at 7° C. overnight (75-90% RH). Peppers are packed containers comprising a ½ Euro box (30 cm×40 cm×11 cm tall). The container was comprised of corrugated linerboard consisting of 40 gsm kraft/35 gsmPP/170 gsm kraft. The container has low oxygen and carbon dioxide transmission rates and are impervious to water vapor transmission. A polyethylene terephthalate lid having a 4″ by 3″ opening was form fitted to the box and sealed with a high barrier tape to the opening at the top of each container.
Films of 5″ by 4″ dimensions were adhered and sealed to the lid to cover the openings. Film adhered to the containers were selected from the a list of films consisting of FreshTec, Capran 2500, 75EVHS1, 40EV, 30EVHS1, 25EV. Each box is weighted and the weight was recorded on the box and in a record book.
The material properties of the 6 films tested are outlined in Table 2.
It should be further noted that the MDPE/PE film had an approximate CO2 transmission rate of 2,732 cm3/m2/day±101, and a CO2 to O2 transmission rate ratio of approximately 2.79 at 23° C. and 52% RH.
Each container and film combination holding peppers was stored at between 3 and 4° C., and observations on visible moisture and the state of the peppers were recorded over time.
Evaluations were performed on the peppers immediately upon removal from storage and after two days at 18° C. and 50% RH. Samples taken for evaluation of color maturity and firmness at harvest, day 0, day 14, day 21 and day 28+. Samples were evaluated for fruit condition, stem shrivel, fruit shrivel, moisture level, decay, flavor and texture based on a five point scale, as well as carbon dioxide levels and weight loss on a percentage basis.
Tests of each container label combination were performed in duplicate and results are shown in
The results are further illustrated in photographs of pepper storage over the lifetime of the experiment. These can be seen in
Peppers were packaged as described in example 1. Either Capran 2500 or MDPE/PE films were adhered to the lids covering the openings. Packaged peppers were stored at either room temperature or a lower temperature. Observations from the test are recorded in Table 4.
Cherries and peppers were packaged as described in Example 1. Only Capran 2500 film was adhered the lids to cover the openings in the lids. In some pepper packages, sachets containing oxidizing compounds (sodium chlorite, citric acid and an inert carrier) were placed in the containers to mitigate growth of microbes and spoilage of the peppers or cherries. Time-lapse observations are provided in Table 5.
Other variations and modifications of the invention are possible. All such modifications or variations are believed to be within the sphere and scope of the invention as defined by the claims appended hereto.
This application is a national phase entry under 35 U.S.C. § 371 of PCT/CA2015/050282 filed on Apr. 8, 2015, which claims priority to U.S. Provisional Patent Application No. 61/977,126 filed on Apr. 9, 2014, the entirety of each of which is incorporated by this reference.
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| PCT/CA2015/050282 | 4/8/2015 | WO |
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| WO2015/154182 | 10/15/2015 | WO | A |
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