Patent Application
20090239432
1. Field of the Invention
The invention relates to a Gas Permeable Non-Woven Fabric based Film with high permeability towards oxygen and carbon dioxide, and is directed more particularly to such a packaging system as is suitable for extending the shelf life of fresh fruits and vegetables (both whole and fresh cut), and vase life of flowers.
2. Description of the Prior Art
Produce is a living tissue that derives energy primarily by exchanging gases with its surroundings through the process of respiration. Respiration involves the consumption of atmospheric oxygen, carbohydrates, and organic acids by the plant tissue, and the consequent production and release of metabolic energy, heat, carbon dioxide and water vapor.
The packaging systems provided in the art range from basic low density polyethylene bags to fairly sophisticated high oxygen transmission rate gas permeable membranes.
Some shortcomings of such packaging systems include the inability to establish ideal oxygen and carbon dioxide atmosphere levels inside the packaging simultaneously. Typically, since the permeation rate for such packages for oxygen and carbon dioxide is same, if the oxygen atmosphere inside the package is 5% the carbon dioxide atmosphere will be 21−5=16%. So in essence the sum of oxygen and carbon dioxide levels will be 21%. Therefore, atmospheres such as 2% Oxygen and 5% Carbon Dioxide cannot be achieved.
Further, many of the packaging systems in use control and/or inhibit the growth of ethylene levels inside the package containing produce. Ethylene is a ripening agent, which is produced naturally in fresh fruits and vegetables as they respire. However, controlling the ethylene levels does not guarantee shelf life or for that matter vase life extension, because the oxygen levels and carbon dioxide levels need to be controlled simultaneously. Reduced oxygen levels caused increased metabolic activity and hence reduction in shelf life, and increased carbon dioxide levels leads to tissue softening, and fungal and bacterial growth.
Still further, use of polyethylene bags do not have the adequate permeability needed for long term storage of produce and/or flowers. Issues such as development of anaerobic conditions when the oxygen levels go below 1% and development of high carbon dioxide levels permanently injure the produce; make the use of low density plastic bags incapable in shelf life extensions.
Accordingly, there remains room for improvement in many areas of shelf life and vase life extension technologies.
An objective of the invention is, therefore, to provide a packaging system with a high permeable polymer coated non-woven fabric, which in essence by naturally establishing modified atmospheres inside a package containing fresh produce/flower can effectively extends its shelf/vase life.
Produce is a living tissue that derives energy primarily by exchanging gases with its surroundings through the process of respiration. Respiration involves the consumption of atmospheric oxygen, carbohydrates, and organic acids by the plant tissue, and the consequent production and release of metabolic energy, heat, carbon dioxide and water vapor.
Thus the created atmosphere is able to extend shelf life, maintain high quality and preserve nutrients of fresh produce items by regulating the respiration of the targeted items. Gas Permeable Non-Woven Fabric based Film, which allows for Carbon Dioxide gas to move in and out of the packaging at a rate many times greater than that of Oxygen. By reducing the atmospheric levels of Oxygen and increasing the atmospheric levels of Carbon Dioxide within the packaging, the ripening of fresh produce and fresh cut flowers can be delayed, the produce's respiration and ethylene production rates can be reduced, the softening of the produce can be retarded, and various compositional changes associated with produce ripening can be slowed down.
The highly permeable non woven fabric based film is obtained by coating nonwoven fabric such as one with 50% polyester and 50% rayon, with a thin layer of polymer, the fabric based system gets its structural strength from the fabric and the permeability from the polymer. This discovery has enabled us to reduce the thickness of the polymer coating on the fabric, and yet maintain enough strength with the fabric, and therefore enhancing its Oxygen Permeation Rate to 110,000 cc/100 in2/day/atm, or even up to 611,111 cc/100 in2/day/atm, with carbon dioxide permeability of at least 350,000 cc/100 in2/day/atm, with a maximum permeability of 3,888,889 cc/100 in2/day/atm at 13° C.
With the above and other objects in view, as will hereinafter appear, a feature of the present invention is the provision of a packaging system including a polyethylene bag, with a hole cutout at the center of the bag, thereof adapted to receive a permeable film, including an adhesive patch for binding the film to the cutout part of the plastic bag, an elastic band for closing the mouth of the plastic bag.
Gas Permeable Non-Woven Fabric Based Film Fabrication Process
Process to design packages using the Gas Permeable Non-Woven Fabric based film. The respiration rates, ideal atmospheres, and ethylene sensitivities for various perishable items, including fresh fruits and vegetables and fresh cut flowers have been documented by University of California, Davis. The information available was utilized in designing these packages.
The produce bag with the Gas Permeable Non-Woven Fabric based Films will naturally attain the ideal atmospheres needed for bananas, and therefore will extend its shelf life. Testing results have successfully been able to extend the life of bananas to 20+ days.
The above and other features of the invention, including various novel details of construction and combinations of parts, will now be more particularly described with reference to the accompanying drawings and pointed out in the claims. It will be understood that the particular device embodying the invention is shown by way of illustration only and not as a limitation of the invention. The principles and features of this invention may be employed in various and numerous embodiments without departing from the scope of the invention.
Reference is made to the accompanying drawings in which is shown an illustrative embodiment of the invention, from which its novel features and advantages will be apparent.
In the drawings:
Referring to
Referring to
