Bond The Layers Of The Retort Pouch example essay topic

The MRE (Meal - Ready to Eat) Retort Pouch and Component PackagingOUTLINEI. Abstract A. The Meal, Ready-to-Eat. Nutrition 1) Caloric value 2) Recommended Daily Allowance II. Introduction to the Retort PouchA. Make-up of the pouch 1) Tri-laminate MRE retort pouch 2) Manufacturing specification 3) Thermo-stability requirements. Laminate qualities 1) Three layers and object of design implementation.

Possible problems with military retort pouch use 1) Punctures, tears, holes 2) Outer carton use and integrity boost. Difference between retort pouch and non-retort pouchA. Adhesive use on seals. Types of food and retort pouch useC. Other packaging use in M REIV.

Retort Pouch Printing A. Required Markings. Soldier or inspector use of markings. Defects Likely to Occur A. Delamination. Inspection for defect pouches VI.

Design Improvement and Testing. Laboratory testing of pouch suitability B. Pouch component shelf-life 1) Freezing effects 2) Dry storage shelf-life 3) Refrigerated shelf-life VII. Summation A. Combat soldier acceptance. Field feedback The Meal, Ready-To-Eat (MRE) has been specially designed to sustain an individual soldier in heavy activity such as during actual military operations when normal food service facilities are not available. The MRE is a totally self-contained operational ration consisting of a full meal packed in a flexible meal bag. The full bag is lightweight and fits easily into the soldier's military field clothing pockets.

The contents of one MRE meal bag provide an average of 1250 kilocalories (13% protein, 36% fat, and 51% carbohydrates). It also provides 1/3 of the Military Recommended Daily Allowance of vitamins and minerals as determined by the Surgeon General of the United States. Most of the food components of the MRE are packaged in flexible packages. Some of the packages are the same or very similar to those used for previous types of operational ration components, but others are newer forms of packaging technology such as the vacuum packed tri-laminate, non-retort able pouch, and the tri-laminate, retort able pouch. Since almost all of the primary and secondary components of the MRE are packaged in tri-laminate pouches, these will be the primary presentation focus. The retort able pouch, often referred to as the flexible can, is what brought the MRE into production in 1980.

It is fabricated as a three-ply laminate consisting of, from inside to outside, a 0.003 to 0.004 inch thick poly olefin layer, a 0.00035 to 0.0007 inch thick aluminum foil layer, and a 0.0005 inch thick polyester layer. When fabricated in accordance with military specifications, it should be able to withstand thermal processing, or retort processing, and a wide temperature range sufficient enough to prevent package damage during transportation and storage. Food packaged in a conventional can must be cooked approximately twice as long as food contained in a retort pouch, as well. To sterilize the food contained in either form of packaging, it must be brought up to approximately 245^0 F and kept there for a specified period of time.

Retort packages have a thin profile and a high ratio of surface area to volume. Heat penetrates the food much more quickly when it only has to reach the inside of an approximately half-inch-thick mass, rather than a much larger mass in a round can. Coloring is also applied to either the exterior or interior surface of the polyester layer. While the pouch is considered a 'tough' package, it is not indestructible. The strength of the pouch and its resistance to damage comes from its tri-laminar structure.

Strength of the pouch has always been an issue for the Military, and it's difficult for some to understand that plastic can be as strong as steel, as metal cans are usually associated with strength. Each of the three lamina's has its own individual qualities that contribute to the success of the pouch. A single laminate layer is not capable of providing all the qualities required of a package that undergoes the rigors of military handling, storage, and distribution. The outer layer of polyester provides strength and resistance to tearing. The middle layer of aluminum foil laminate provides an almost absolute barrier to the transfer of gases, especially oxygen, and water vapor between the environment and the product in the pouch.

The inner layer of poly olefin provides an inert product contact surface and is a heat sealable material essential for attaining a hermetic seal. The tri-laminar structure is so reliant on the cooperation (synergism) of the three layers, that the failure of one or more layers, including delamination of one of the layers from another, causes the pouch to be unserviceable or questionable in its integrity. One of the primary problems with the pouch is that it is prone to puncture by sharp objects both from external sources such as grains of sand, gravel, and twigs, and from internal sources such as ice crystals of frozen product. To protect the pouch from external sources of damage, it is placed in a secondary package referred to as the carton. The retort pouch integrity is broadly protected as a result of the carton use.

The MRE components that are packaged in retort pouches rely on heat processing and package integrity for their shelf stabilization and protection against pathogenic and non-pathogenic microbial growth. The main difference between the retort pouch and the non-retort pouch is the fact that the adhesive used to laminate or bond the layers of the retort pouch together are extremely heat resistant, while the adhesives used for the non-retort able pouches are much less heat resistant and much less costly. Examples of MRE food components packaged in non-retort able, tri-laminar pouches are the jellies, the cheese and peanut butter, and the freeze dehydrated fruits. Other components such as the beverage bases, candies, condiments, and the spoon are all packaged in flexible packages of various styles and types. The only component packed in a glass bottle is the hot pepper sauce. The bottle is a must if the soldier is to receive the hot sauce as part of the menu because flexible packages for this item are either not available or not practical.

The military continues to research for a flexible package for hot sauce that has sufficient elemental barrier properties to protect the item from the extremes of time and temperature abuse, which the MRE is routinely exposed to. One of the most important factors concerning the packaging of the MRE components is the information that is printed on the package itself. For example, most entree and vegetable pouches contain numerous required markings. They include the product name, date of pack into the pouch, the processor establishment numbers, lot numbers, the production shift numbers, retort identification numbers, retort cook numbers, and the hot-fill equipment identification numbers. Beginning with dates of pack in 1988 to present, every one of the components in a meal will be Julian Date coded in addition to the required federal markings. It is essential that soldiers be able to extract as much information from the component package as possible when a problem arises, either during an inspection or while the product is being consumed.

The MRE shipping container has required markings that are essential, but by themselves are not sufficient to track down the cause of a component problem. Defects that are likely to occur, or are the most often encountered defects in MRE component packaging, are tears, cuts, holes and an inadequate vacuum. Delamination is also a defect often encountered in laminated packages. Delamination is the separation of one laminate, or layer, from another. Its significance varies depending on the area of the pouch that is delaminate d (the body of the pouch or the seal area), and the extent of the delamination. Specific defects and inspection guidance for each type of component are distributed to the military by the processors.

To check for minute tears, cuts or holes in any package, inspectors insert a pocket flashlight inside the package while in a dark room. This aids in identifying the location of the defects. Due to the color and glossy finish characteristic of MRE retort and non-retort pouches, tiny tears, cuts, and holes are often impossible or extremely difficult to see with the naked eye. As well, at the point of manufacture, retort pouches are subjected to "Zy glo" dye testing to detect microscopic holes that are not easily discernible with the naked eye. MRE pouches have been tested and redesigned where necessary according to standards much stricter than for commercial food.

They must be able to stand up to abuse tests such as obstacle courses while being carried in soldiers' field clothing pockets; storage outdoors anywhere in the world; shipping under extremely rough circumstances (such as by truck over rocky terrain); 100% survival of parachute drops; 75% survival from free failure drops; severe repetitive vibration; 7,920 individual pouch drops from 20 inches; and individual pouches being subject to a pressure load of 200 pounds for three minutes. Freezing an MRE retort pouch does not destroy the food inside, but repeated freezing increases the chance that the stretching and stressing of the pouch will cause a break on a layer of the laminated pouch. These pouches are made to withstand 1,000 flexes, but repetitive freezing does increase the failure rate by a small fraction of a percent. Also, if MRE food is frozen, then thawed out, it must be used the same as if one had thawed commercial food from a home freezer. Like normal canned foods, MRE meals have a very long shelf life. However, the shelf life is dependent on the storage temperatures.

If stored at 100 degrees F, an MRE is only viable for a few months. If stored at room temperature, an MRE can last for three years. Refrigerating an MRE could extend its life for up to ten years. In summation, the MRE and the use of the retort pouch increased combat ration acceptability by soldiers and reduced package weight ten-fold, making the ration easier to carry by the soldier. It also proved to problems of rust, corrosion and de tinning (problems of the old C-rations cans). This gave the MRE a significant shelf life than was obtainable with previous military rations.

As well, it eliminated problems of upon commercially avail notable can sizes, making the ration easier to improve as feedback comes in from the field. Soldier feedback has proved to be invaluable, as this has led to an extensive ongoing program by the Natick Military Research Laboratory and by the Army Center for Excellence - Subsistence. From the earliest known "combat ration" issued to Genghis Khan's armies, to the further development of canned foods by Louis Apperson to feed Napoleon's armies, technology and the development of improved food preservation techniques has occurred largely on the battlefields of the world. What started as a suitable package for space flight meals and the MRE, the retort pouch is now common for packaging of commercial food products of today. The retort pouch has become an industry icon of convenience and has proven food safety in preservation.

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Flexible Package Integrity. National Food Processors Association, Washington, DC. web Release: New Study Says Food Manufacturers Offering US Consumers Retort Packaging to Meet Conveniency / Lifestyle Demands. Paper, Film, & Foil Converters Magazine. April 29, 2004.
PRIMEDIA Business Magazines & Media Inc. web Stanley. Is the Retort Pouch Really Ready to Replace the Can? Paper, Film, & Foil Converter Magazine. APR 2003.