Case-ready packaging is having a major influence on the marketing and distribution of beef, pork, poultry, and other types of meats. Several major U.S. and Canadian retailers stock case-ready meats in a significant portion of their meat cases. Springdale, Arkansas-headquartered Tyson Foods reports that sales of its case-ready beef increased 33.8 percent and sales of its case-ready pork increased 33.3 percent during its first quarter of fiscal 2004.

As with all new technology, case-ready packaging systems require special maintenance procedures. The film-cutting knives, the gaskets that seal the film to the tray, the gaskets around the chambers that create the vacuum, and the head area of the case-ready packaging machine tend to require the most maintenance, Dave Wieland, a technical specialist at Koch Equipment LLC, Kansas City, MO, says. "For the knives, normally it is a replacement issue," he explains, adding that blade sharpness usually isn't an issue for processors running only one type of tray. However, problems occur when there is constant changing of tray size that requires physical handling of the blade. "If you drop the blades on the concrete floor while you are replacing the tooling or even set them on a stainless steel table, you are likely to bend the cutting knives," Mike Kennedy, Koch Equipment's service manager, notes. A clear sign of a dull blade is failure to obtain a crisp, clean-cut film.

Daily maintenance of case-ready packaging lines begins with examination of the quality of the seals. "Any gaskets or seals that are getting a lot of use need to be checked daily for signs of degradation or damage," Wieland says. Operators must also examine the condition of the seal plate on a daily basis and remove melted film or other residue that would prevent proper sealing. In addition, the operator must inspect the film-cutting knives for bent blades or worn areas, and remove film that may have become lodged on the blades.

Wieland emphasizes that operators must check the vacuum setting, gas settings, and other parameters daily at the beginning of each shift. "The second shift may have changed the settings to optimize packaging the product they are running. Sometimes they change just one setting. But the settings need to be checked to ensure continuity from one shift to the other."

Another daily maintenance task is checking the vacuum chamber for residue. Film or food particles can be drawn into the filters or pump and cause damage. Also, at the beginning of the shift the operator should conduct an oxygen check on the product to verify that the gas sources are connected properly. "They need to be sure they have the right gas hooked up and they are pulling the correct vacuum and gas flush," Wieland says. Test trays should contain product. Some case-ready packaging systems require weight in the trays to inject the trays with gas. "Filled trays give a more accurate reading of vacuum and gas concentrations," Wieland explains.

He doesn't recommend a specific sample size for testing the integrity or quality of sealed case-ready packages. "Some processors monitor the packages on a time basis-one sample every four or five minutes or every hour-and others monitor on a count basis," he says. With some meat products, the atmosphere inside the package is critical to quality and shelf-life; sampling needs to be more frequent. Advanced case-ready systems automatically measure the gas in the chamber.

Removing the collected water from water separators prevents water from running through the system's air-supply lines. "While they are doing this, they need to check that the air pressure is correct on the regulator," Wieland adds. "Pressure has a lot to do with sealing." Case-ready packaging systems rely on air pressure for sealing. Operators should also check the condition of the vacuum oil.

On a weekly basis, operators need to check the springs in the head area and the springs involved in film and seal clamping. The springs need to possess sufficient tension to hold the film taut so it doesn't slip when being cut. Also, the Torr. value of the vacuum in the chamber-and possibly the pump itself-should be checked weekly. "Is the pump pulling what it is supposed to be pulling?" Wieland says operators should ask. A special gauge is used to measure the vacuum, usually measured in Torr. or millibars.

Wieland advises operators to check the condition of the pump oil at least weekly. If it is dark, it needs changing. If it is milky before the pump is started, there is water in the line that needs to be removed. "Also, check the level of oil," he adds. "Vacuum pumps are very sensitive to oil level. You get a better vacuum when the oil is at the proper level." Most vacuum pumps have a filter or screen that should be checked and cleaned weekly- "Some processors use a lot of dry, powdered herbs that can get sucked into the pump." All moving parts on the packaging line should be lubricated on a weekly basis.

Operators should also grease the bearings and check the level of oil in the gearboxes once a month at a minimum. Vacuum seals should also be checked for leaks. "It doesn't take much of a leak to create a problem," Wieland says. "If there is a leak, the machine won't pull as much oxygen out of the package as the operator wants." On an annual basis, the vacuum pump exhaust filters should be changed.

A high turnover rate among the maintenance staff in meat processing plants means more training. He prefers maintenance personnel to travel to Koch's facility for maintenance and operation training. "When they are here we have their undivided attention, and we have someone in our service department available at all times to answer questions," he says.

He also prefers that operators receive training before the packaging system is installed at the meat plant. "I have never received a warranty call from a customer who has received training before the equipment was installed," he notes. Kennedy says that his company's technicians will travel to a customer's facility to train the customer's maintenance staff.

Maintenance personnel need to be reminded to make repairs and follow maintenance procedures correctly. "Often they make a quick fix, and then when something else goes wrong they make another quick fix and pretty soon they have multiple issues," Wieland says. He adds that at one meat company he knows, each maintenance person is assigned to a particular machine. The maintenance person becomes very familiar with the operation of his machine, and the approach fosters a friendly competition among the maintenance staff to see who can keep their machines running smoothest.

During his career, Wieland has seen his share of unusual maintenance situations. At one meat plant, film on the case-ready packaging line was changed to a shrink film to eliminate excess film. To accomplish this, the center of the tray must be cooled to prevent the film on the center of the tray from shrinking and collapsing the tray. "Even though the system had cooling plates and was operating properly, the trays were still collapsing," he recalls. "We took the cooling heads apart and found that the water was so hard that calcium deposits completely plugged the water channels in the cooling plates. The cooling plates were just warm enough to shrink the film. It drove us crazy for a while. It was something we could never solve over the telephone."

Wieland adds that another common issue is film that is incompatible with certain case-ready trays. "A purchasing agent will buy film from a different vendor to save money and suddenly nothing works," Wieland explains. "The vendor tells the purchasing agent that it is the same film, but actually it is from a different manufacturer and it doesn't work with the trays the meat processor had been using."

Over-filling trays, or using trays too small for a product, is a problem. "If a customer uses a tray that is not the correct size, the product could fold over onto the seal area," Wieland explains. "Sometimes a new product is too high for the tray and it spills onto the seal area."