Packaging as it Relates to Core Storage and Preservation What follows is an attempt to synthesize current information from a wide variety of sources into a useful guide to methods of core storage and preservation. It must be stressed that the focus of the packaging industry is twofold. The first is the relatively short term preservation of, mostly, food and medical products. The second is packaging for protection and display purposes. Clearly, neither of these industries address the specific needs and requirements of IODP, so we must be creative and eclectic in our selection of the most suitable products for our application. Moreover, we must be actively involved in the research, testing and development of new products and methods by partnership/involvement with other institutions, so that IODP can be at the forefront of this technology as befits our ethos. Section 1 - Vacuum Packaging Vacuum packing (or vacuum sealing) is a form of packaging that involves the removal of air (and sometimes its replacement) from a pouch or plastic container. Vacuum packaging provides several benefits: protection against dehydration; barrier against air or moisture; tamper evident protection; compressed packaging for fragmented cores; protection from dust and moisture. Types of Vacuum Sealing Equipment Non Chamber Vacuum Sealers These units vacuum and seal the pouches externally. Some units also come equipped with special external nozzles to allow for the vacuum packaging using plastic containers. Non Chamber Vacuum sealers are meant for low volumes, and are suitable for vacuum sealing products that have little or no moisture. However some units do have special collectors for products that have excess moisture. Not recommended for vacuum sealing liquids, or powdered products. Chamber Vacuum Sealers Chamber Vacuum Sealers are designed for sealing higher volumes of products than their non chamber counterparts. The vacuum pouches are placed within a box-like chamber, the desired amount of air is pulled from the machine, and the pouch is then sealed. Some chamber vacuum sealers have the option of gas flush kits. Chamber vacuum sealers are an economical solution for high volume vacuum applications because the vacuum pouches are more economical than the micro layered pouches used in non chamber sealers. Additionally, chamber vacuum sealers can seal a wider variety of vacuum pouches and bags. Units must include an oil-based vacuum pump. This type of equipment is commonly used in the food packaging industry to pack meats, fish, and dried products. Required Maintenance Chamber Vacuum Sealers require routine maintenance. The vacuum pumps are oil-based, so the vacuum oil needs to be changed regularly. Additionally, since these units use an impulse mechanism to heat seal the pouches, Teflon tape and seal wires also need periodic replacement. Vacuum Sealer options MAP, Modified Atmosphere Packaging MAP is a packaging method in which an altered atmosphere inside a package is used to retard chemical deterioration of the product, and the growth of unwanted microorganisms. Vacuum packaging itself (i.e. the removal of air) is a form of MAP. However, the most familiar usage of the term describes the creation of an artificial atmosphere of mixed gases inside a package. Such a method is usually used in conjunction with a non-barrier type film, in order to let the food product respire naturally. An Inert Gas Kit or Gas Flush Kit, is required for vacuum sealers to allow the user to modify the atmosphere within their vacuum pouches. Inert gas is injected into the package allowing the package to obtain a ‘pillow effect’ or a packaging of the product without the tight rigidity that may destroy or compromise the product. Seal Bar Options Most Chamber Vacuum Sealers come with a seal bar consisting of one 4mm seal wire and a trimmer wire. However, other seal configurations may be available including: Double seal: one bar with two 4mm seal wires; Wide seal: One bar with 6mm bar. Vacuum Pouches Also known as food vacuum pouches or barrier pouches, provide a barrier against atmosphere and moisture. Vacuum Pouches for Non-Chamber Machines These pouches are designed specifically for machines that perform an external vacuum. The micro layered vacuum bags are made from food grade plastic material. Each pouch consists of 3 layers of construction: Two smooth outer layers of 3mil polyamide (nylon)-polyethylene barrier material and one polyethylene mesh layer of material in the middle of the pouch. The mesh middle layer is the most important component of the pouch. It allows the air inside the pouch to be directly vacuumed out of the pouch. Vacuum Pouches for Chamber Machines These pouches consist of two smooth layers of 3mil polyamide (nylon)-polyethylene barrier material. 3mil is the most common thickness for vacuum pouches in the industry and meets USDA standards for food packaging. These pouches do not have a layer of mesh, since the chamber vacuum machines will evacuate the air once the pouch is within the chamber. Other Types of Vacuum Pouches There are other special vacuum pouches including light barrier bags, boilable vacuum pouches, and bone guard pouches that are commercially available. Vacuum Containers These high barrier, and durable plastic containers are an excellent choice when the application requires a durable vacuum storage. Case Studies 1. Maplewood Meats; • slow speed of conventional vacuum packaging • problems with seals • introduces the process of thermoforming Maplewood originally utilized a vacuum chamber system to package its savory products. The system required that company personnel place portion-sized meats into a preformed pouch and then accurately place the pouch on the machine to be vacuum-sealed and trimmed. The process was time-consuming, and the system would sometimes produce leaky packages, necessitating that the production cycle be repeated. "If you combined the amount of time it took us to package our products the first time, and then add in the time for repackaging the faulty ones, the system was extremely time and labor intensive," says Van Hemelryk the CEO. Maplewood spends a great deal of time focusing on the quality of its products, and the company did not feel the original system was producing a package that did justice to the product inside. The company decided to partner with Multivac to formulate a new strategy that would heighten the efficiency of its operation as well as the quality and attractiveness of its packages. Upon assessing the company's needs and current operation, Multivac's food packaging team recommended using a compact, rollstock system. Rollstock Machines Thermoformed packs are produced on rollstock machines automatically by sealing the formable lower web to an upper web. Product is loaded manually or automatically into the pocket or transformed on the lower web before sealing to the upper web takes place. 1. Packaging material for the base web (thermoformable film) is unwound from the reel. 2. It is heated in the forming die and formed into pockets/trays. 3./4. The formed pockets are loaded manually or automatically 5. The top web of packaging material (lid film) covers the filled pockets/trays. 6 The air is evacuated from the sealing die and protective gas is added if required. Then the pack is sealed by the application of heat and pressure. 7. The web of packs is cut across the machine direction initially. 8. Production of the individual packs has been completed after the longitudinal cutting operation. Within days of the integration, Maplewood noticed a considerable difference in its packaging. Product is easily loaded into customized compartments that are formed from a bottom web of roll-fed, flexible film that is heated and stamped. Then the machine's top web securely seals each package in-line. With its new automated thermoforming technology, Maplewood has dramatically simplified its packaging process, boosted productivity and eliminated the problem with leakers. "We are now packaging the same amount of product in three hours that would normally have taken a full nine- to ten-hour cycle," remarks Roger Van Hemelryk. "Our production speed has increased by 200 percent." Plates, compartment sizes and films can be changed over in as little as ten minutes. Simplifying this process has also helped Maplewood move forward with its food-safety initiatives. By quickly placing product into the thermoformed sections, the amount of time the meat needs to be handled is minimized, and any opportunity for product to come into contact with machine components is eliminated. "I worry less about contamination because of the machine's engineering. The stainless-steel, washdown design really gives us peace of mind," says Roger Van Hemelryk. The new system has also afforded Maplewood greater operational flexibility. With the company's expansive product line, it often needs to package more than one type of meat over the course of a production day. The quick and easy changeover procedure on the rollstock system enables plant personnel to change the plates, compartment sizes and appropriate films in roughly 10 minutes. Depending on the day, this switching can occur multiple times, making the simplicity of the changeover feature essential to minimizing downtime. The integration was not only beneficial to Maplewood, but also to its customers. The speed and accuracy of the new rollstock machine allows the company to sell a more compact and convenient package. To outweigh the material costs and time it took with the previous process, the company used to portion its products in 1-lb assortments to reach its cost-per-unit target. "The new system efficiently utilizes the packaging material so we can offer our customers more convenient half-pound portions," notes Van Hemelryk. "Customers appreciate the added value of our smaller packages." 2. Food sell-by dates criticized; • Temporal limitations on Shelf Life (2 years on vacuum packed goods) • Long term sell-by dates on some packaged foods are not justified, research has suggested.