Packaging Tech: Rolling along
The choices in packaging options for protein products are nearly endless. For those with a lot of products to pack, rollstock chamber packaging may be a good choice.
Another name for rollstock chambers is thermoform fill seal (TFFS), says Huston Keith, the principal and founder of Marietta, Ga.-based Keymark Associates. Thermoform-fill-seal is the primary means of high-volume packaging of sliced processed meats, as well as certain smaller fresh-meat cuts, prepared foods, etc. Chamber machines are used for larger cuts (hams, primals) and in-store packages that are manually processed.
The whole process began with the invention of vacuum chamber machines several decades ago. The meat is placed in already made, usually into a barrier or pouch. The pouch is then put in the chamber, evacuated, gas-flushed if needed and sealed. The machines are effective in packaging meat to extend shelf-life, but are labor intensive and require pre-made pouches. Models have been developed with conveyors which decrease labor and increase productivity. However, most of these machines are now used mostly for the packaging of large cuts of meat where less labor is required per pound of product, or for small plants or retail shops where production is low.
The processThe TFFS machine was developed a few decades ago for high-volume packaging of sliced processed meats in smaller retail sizes, says Keith.
The process requires two rolls of film of about the same width, called the forming film, and lid or non-forming film. The forming roll enters a thermoformer, where it is heated and drawn via vacuum and plugs if needed. Leaving the thermoformer, the meat is placed in cavities manually or automatically. The loaded cavities enter the vacuum chamber in tandem with the lid film resting on the top of the cavities. The chamber closes, is evacuated, gas-flushed if needed and sealed. The sealed packages exit the chamber and are cut apart with knives, scissor wheels or steel rule dies.
Rollstock does tend to lend itself more toward uniform products and are better used in displaying on shelves, according to Kevin J. Caputo, vice president of sales and marketing at Carando Foods, a deli and specialty meats processor in Springfield, Mass and division of Farmland Foods. Regular thermoseal packages work better for products that don’t have a uniform shape.
“Our facility uses both thermoseal and rollstock machines,” he says. “We need to inspect rollstock packs more closely for ‘channel leakers’ (packs not completely sealed). Our food-safety confidence level is high, however.”
The rollstock packages also sometimes leave excess packaging on the product due to the fact it can’t be shaped exactly like the product. They are also much more expensive than a chamber machine, and are often customized to a specific package. Thus the package needs high volume to pay off the investment.
There are some perks to using the packaging option. The TFFS machine saves substantially on labor costs, produces at much higher rates, uses less-costly packaging materials and usually produces a more attractive package that conforms neatly to the product than many other options, says Keith.
Making a choiceKeith says that when purchasing a TFFS machine, processors should first look at whether the reduced cost of labor and materials will pay back the higher investment.
“Since there is a wide range of machine sizes and many are available used, it may not be difficult to justify obtaining one, even for small processors,” he says.
Next, the processor should determine whether the machine can meet the packaging requirements of the product, such as low enough levels of residual oxygen, package size, gas-flushing if required and consistent, hermetic seals.
“Our advice to others would be mainly to try to make certain that the final chamber size selected is appropriate, as additional tooling dies can add up quickly, thus raising overall project costs,” says Caputo.
According to Keith, TFFS machines are widely used throughout the meat industry, producing most of the processed meat packages for the retail market, as well as many other packages.