This packaging gives the vegetables a three-dimensional look and uses “barometric adjustment†to extend the appearance of the product, thus extending their shelf life.
This tray pack can be used to pack single or multiple servings. The prototype was a tray pack of heated ready-to-eat deli products developed by Cryovac in 2003 using Simple Steps technology. Smithfield Packaging has also launched such packaging products, and at the time also received FPA and DuPont awards.
After about a year of development, the packaging for agricultural products was successfully developed. The pallets used are similar to the prior art, but a more suitable capping film is used. Similar to the previous packaging, packaging for agricultural products can bring convenience to hurried consumers. Easy-to-open trays can make vegetables ready in just three steps: placing the packaging in the microwave; heating for two minutes; opening Package ready for use. During the heating process, the film will protrude, then automatically exhaust, and finally relax, attached to the food.
The automatic venting feature eliminates the need to penetrate or peel off the film prior to heating. After the vegetables are cooked, they do not need to be opened with a knife and scissors. After it has cooled in the microwave, it can be removed from the inside. In this way, the vegetables are ready and can be eaten directly on the plate.
The package combines sealing technology with good breathable materials to achieve what the company calls "passive adjustment of packaging pressure." This eliminates the need for gas flushing to reduce respiration and transpiration rates, thereby extending the shelf life of foods.
Myra Foster, business development manager at Cryovac, said. “With passive pressure adjustment, the headspace of the product does not change as dramatically as through flushing. Instead, it depends on the breathing rate of the product, combined with the oxygen permeability of the material, to produce a certain change in the headspace atmospheric pressure. The actual shelf life of different products is not the same, but it is usually several days longer than using other types of fresh produce."
Foster added that this vacuum-fitting packaging is very practical for both professional chefs and housewives, and its special materials can produce a very high oxygen permeability. "It uses the right resin, and then they co-extruded, can effectively guarantee the tightness of the tray, and at the same time it can be converted into higher oxygen and carbon dioxide permeability." She said that the oxygen permeability of the material The range varies from 6000 to 7000 cubic centimeters per square millimeter/24/hour.
This rigid, microwave-heatable sealed tray is manufactured by Mullinix Packaging and is made from thermoformed polypropylene and ethylene-vinyl alcohol copolymer. The lid is a 3 mil multilayer polyolefin and comes with an easy Open multi-layer co-extruded sealant layer. When the tray is evacuated, this permeable co-extruded capping film (with its own polymeric sealant layer) minimizes the ice crystals formed in the tray and eliminates frost spots.
Foster explained that the trays can be vacuumed using Multivac's T200 bench top or T350 vacuum skin packers. She said: "We have made some improvements to these machines so that they can be applied to packaging. Since the products breathe or consume oxygen and produce carbon dioxide at the same time, the permeability of the film can provide enough atmospheric oxygen for the interior of the package to prolong Shelf life."
Cryovac successfully used this package for a variety of agricultural products, including Sun Valley products. Foster added: "This package can also be used to freeze vegetables because it can withstand freezing temperatures and microwave heating temperatures up to 212 degrees Fahrenheit.
Source: Packaging Expo