In recent years, plastic's use in food packaging has far outpaced that of its can, paperboard carton and glass counterparts. Last year, The Freedonia Group (www.freedoniagroup.com), an industrial market research firm in Cleveland, reported that plastic pouches and bags made up 39 percent of the $17.7 billion food-container market, while rigid plastic containers comprised 15 percent. In contrast, only 23 percent of food packaging was made of paperboard, 18 percent of metal and 5 percent of glass. Among the advantages plastic packaging can offer are enhanced barrier properties, resealability, flexibility, a lighter weight and high-impact graphics, among others.
However, in today's present environment of unstable fuel costs, the advantages of plastic packaging come at a cost. Derived from petroleum, or natural gas, plastic resins have increased tremendously in price in 2005, and there seems to be no relief in sight.
It is because of this volatile economic atmosphere that San Bernardino, CA-based Farmdale Creamery, Inc. equipped itself earlier this year to reduce the amount of polyethylene used in its sour cream packaging, by moving some of its product packed in rigid plastic containers into plastic pouches. "With the price of oil increasing, resin is now more expensive, and this affects the cost of plastic containers and bags," relates Norman Shotts, Farmdale's systems engineer and grandson of the company's founders. "But there's so much more resin in a plastic container. To offset that, we are using bags to save some money."
Last May, Farmdale installed a new vertical form/fill/seal machine for filling sour cream bags. Vital to the line is a new, in-line, thermal-transfer overprinter (TTO) from ID Technology (www.idtechnology.com) that applies essential product information, including a batch number and an expiration date for the perishable product, onto the pouch.
In addition, to enhance the consumer's experience with its sour cream containers, Farmdale began the installation in August of several continuous ink-jet printers, also from ID Technology, that move product coding from the bottom of the bucket to the side, while increasing legibility.
Family-owned Farmdale has been in business since 1979, supplying sour cream, buttermilk and cheese to an assortment of end users. In its 90,000-sq-ft facility, the dairy packs cheddar, jack and low-fat cheeses in 44-lb blocks under its Taco Lada and Lada Jack brand names for wholesalers and distributors. Buttermilk—in sizes anywhere from "a half-pint size all the way up to a truckload tanker," says Shotts—is copacked for retail, bakeries and other large food manufacturers.
Farmdale's staple product, however, is sour cream, which it produces in a traditional, gelatin-based version, as well as in Russian, Hispanic and kosher varieties, in package sizes from 1/2-pt containers up to 32-lb bags and buckets. Farmdale offers its own brand of sour cream "in most sizes," says Shotts, as well as copacked product prepared according to private-label customers' recipes. The larger-volume packs are targeted at bakeries, restaurants, dressing manufacturers and others.
Farmdale uses four packaging lines to fill its range of sour-cream products. One handles pails; one packs 5-lb buckets; one fills smaller, retail sizes, such as 1/2- and 1-pt containers; and the newest line fills plastic pouches in sizes from 16 to 32 lb. The pouching line, running since last spring, comprises a Cryovac(R) Onpack Model 2100 vertical form/fill/seal machine from the Cryovac Div. of Sealed Air (www.cryovac.com), equipped with ID Technology's intermittent TTO.
The automated, vf/f/s machine creates pillow-style pouches in volumes from 1.5 to 5 gal; Farmdale uses it for 16-, 25- and 32-lb bags of sour cream. The pouch film is a polypropylene construction from Cryovac.
Per Cryovac's recommendation, Farmdale installed ID Technology's TTO in-line on the vf/f/s machine in order to cleanly and clearly add an expiration date, a batch number and Julian date information to its sour cream pouches. As Shotts relates, there were several requirements that the printing equipment had to meet before being considered for the dairy packaging application.
"The main requirement was that the ink have good adhesion to the bag, which is why we chose thermal transfer—it's more permanent. The ink is very difficult to rub or scratch off, whereas ink-jet printing would not work in this application," Shotts explains.
During thermal-transfer printing, a printhead containing resistive elements in a linear array heats ink- or resin-coated ribbons. In this process, the printhead is in direct contact with the uncoated side of the ribbon, while the ink-coated side is in direct contact with the printing surface. When the ink is heated, it melts and adheres to the printing surface.
The ID Technology intermittent overprinter is offered in 2- or 5-in.-wide versions that can create text and bar codes at 300 dpi. Farmdale chose the 2-in. version with a black wax/resin ribbon, which enables the overprinter to produce a message that is 2 in. wide by 2 in. long with excellent scratch- and rub-resistance. Shotts says that the dairy selected the 2-in. model in order to save on ribbon costs, but nonetheless, he says that the resulting codes are "very readable." He adds: "It's very clear, more of a solid font than a dot matrix. The type is not very large, but it works very well for our needs."
Keeping pace with the vf/f/s machine's top-rated speed of 20 packs/min (depending on film type, package size and product viscosity), the intermittent TTO can print at speeds from 10 to 120 ft/min. At Farmdale, the overprinter is positioned on the pouching machine so that it adds the printed information onto unformed film rollstock as it feeds into the vf/f/s system.
Another requirement for the overprinter was its durability for use in the damp, washdown environment of the dairy. "Since we're a dairy, we use a lot of water, so we needed equipment that was water-resistant," Shotts says. To address this need, ID Technology installed the TTO within the vf/f/s machine so that the unit is protected behind Plexiglas(R) doors. Farmdale also chose the upgraded Unicontroller control and input device, designed for harsh environments.
Used to create and adjust the messages printed with the TTO, the Unicontroller is an industrial, Windows-based PC with a built-in, 32-MB Flashcard and Ethernet port. Operators program the overprinter by way of a 5.7-in. LCD touchscreen with an intuitive menu. Each job requires the operator to select an expiration date—either 30 or 60 days, according to the customer's preference—and input a batch number. "After that, you push the enter button, and the overprinter starts running," Shotts says.
The main requirement was that the ink have good adhesion to the bag, which is why we chose thermal transfer—it's more permanent.
He adds that the final feature necessary for the overprinter was low maintenance, which so far, the intermittent TTO has delivered. "You have to clean the printhead with a swab and alcohol every time you change the ribbon," Shotts says. "We've only had to do it once so far. We have yet to have any other maintenance issues."
Although some of the larger-volume product previously packed in buckets has been moved into pouch packaging, Farmdale still offers its customers the option of using high-density polyethylene containers. "There are some advantages to the buckets versus the bags," explains Shotts. "They can be resealed, and, with the bags, you have to work a little harder to get all of the sour cream out of the package."
Farmdale has made an adjustment to its bucket packaging, however, to enhance its ease of use. In August, the dairy purchased six ink-jet printers, three of which are being used to print the expiration date, batch number and time onto the side of the sour-cream buckets; the balance are being used to apply codes to corrugated cases. Previously, Farmdale used wet-ink stamping machines to apply data onto the bottom of the buckets. Not only was the information inconvenient for the end user to access, but the stamping machines also produced inconsistent results. "We had to constantly monitor the printers," says Shotts, "and sometimes we would have to get rid of product when the codes were not legible."
Another problem was the time it took to change the printers over from one batch to the next—up to 15 minutes, Shotts says. This ate up a lot of time, considering the dairy typically runs up to 12 batches per day on its container lines.
Installed two at a time, beginning last August and ending in November, the new printers are Ci1000 noncontact, continuous ink-jet printers from Citronix (www.citronix.com), supplied by ID Technology. "We were looking for new small- and large-character coding systems and evaluated a few different brands," says Shotts. "From our review, the Citronix ciSeries products provided the best fit for our applications. Not being fans of ink-jet, we needed something that was easy for our staff to understand and operate."
The Citronix ciSeries technology allows Farmdale to meet both its small- and large-character coding requirements, eliminating the need for two different coding systems through the use of its PixelPlus feature. This feature provides a software selection of different drop sizes, throw distances and print heights.
"To our surprise," says Shotts, "we were able to mount the printhead quite a few inches away from the product. This eliminated the potential for corrugated debris or sour cream to clog the printhead, which is what we had experienced with our former coding systems. The ciSeries technology is a robust technique.
"The user interface provides us with a very simple message input method and allows for quick changeovers. Minimal training was required to operate the graphical user interface, it is so simple to navigate. Looking towards the future, we opted for the ci1000, which has a fully integrated Ethernet communications port that allows for remote access and delivery of system warnings to our networked computers."
The Citronix printers are capable of printing up to five lines of text, but Farmdale prints just one to keep consumables' costs low, says Shotts. The dairy uses methyl ethyl ketone (MEK)-based ink that adheres well to the slick, HDPE surface of the pails.
Like the TTO, the new ink-jet printers are low-maintenance, requiring only daily ink purging before line startup, and a change in the filters every six months.
Since installing the new TTO and its six new ink-jet printers, Shotts says that Farmdale is very pleased with the quality, reliability and ease of use of the equipment. However, he adds that it's too soon to calculate the financial savings. "In terms of the overprinter, we're still researching whether the economics have worked out the way we had anticipated they would when we replaced some containers with bags. We're at a point where the price of resin is still changing all the time, so the financial impact of this packaging change still needs to be evaluated. But there definitely is a savings in using the bags."
He adds that Farmdale has so far been able to run the ink-jet printers at the same cost as the previous, stamping method, but with a much greater level of legibility and reliability than formerly possible.