Eggs-cellent marking and coding

Egg cartons are not easy to print on, according to Pepe Gonzalez plant manager at the JS West egg plant in Hilmar, CA. “We were using mechanical printers, but we had problems with the dates not being legible,” says Gonzalez. Headquartered in Modesto, CA, JS West is a major egg producer for the CA market. It sells more than 100,000 dozen eggs/day to more than 20,000 customers.

“We pack eggs in both foam and pulp cartons, and we had problems with both of them,” says Gonzalez. “Foam cartons didn't absorb the ink so the ink wouldn't dry and would smear, while the pulp cartons would absorb the ink, but the printing was fuzzy.”

Carton coding is a requirement for egg producers. If eggs are packed under USDA's voluntary grading service, the cartons can bear a shield-shaped USDA grademark. According to the USDA, when the USDA grade shield is present on the carton, the carton must also be labeled with the date and location of where the eggs were packed.

The pack date (the day that the eggs were washed, graded and placed in the carton) is a three-digit code that represents the consecutive day of the year (the “Julian Date”) starting with January 1 as 001 and ending with December 31 as 365. When a “sell-by” date appears on a carton bearing the USDA grade shield, the code date may not exceed 45 days from the date of pack. Most state requirements are similar.

JS West prints the production date, line number and plant number on the edges of its cartons.

Smaller printers

“The operators had to keep adjusting the printers, which reduced the plant efficiency,” says Gonzalez. In early 2009, Gonzalez began to investigate replacing the existing printers.

“We looked at a number of different models, and decided to go with the Citronix ciSeries industrial ink-jet printers from ID Technology Inc. The other printers we looked at were bigger and bulky. The ID Technology models fit into our existing lines better, and they were also less expensive than the other units we looked at.”

The JS West plant has 10 egg-carton packaging lines that run one, one-and-a half and two-dozen packs, and they replaced the printers on all 10 lines. JS West also purchased an 11th Citronix unit for an overwrap application at another plant.

CiSeries ink-jet printers include a user-friendly, icon-based operating system and video-graphics display (VGA) with a full-size QWERTY keyboard for effortless operation. Operating settings are automatically adjusted depending on the environment to maintain optimum print quality.

“These daters are like night and day compared to the machines that we had before,” says Gonzalez. “For one thing, each one has its own computer, so they're automatic and easy to operate.

The systems at JS West feature single-board, electronics technology coupled with integrated smart printhead and ink system components that monitor critical operating functions.

“Most of our line operators have never used computers, but with these, the dates are set automatically,” says Gonzalez. “The operator just enters the vender or lot number, and the computer sets up all of the remaining information.”

Housed in rugged, stainless-steel, NEMA 4-rated enclosures, the ciSeries systems are well suited for operation in JS West's egg-packaging operations.

Quick-drying ink

A big factor at JS West was the use of quick-drying inks, which give a dependable and consistent marking on most surfaces and coatings. They have a fast evaporation and high solids content, so they offer excellent dot definition and readability. “The quick-drying inks don't smear on the foam cartons, and they also work well on the pulp cartons,” says Gonzalez.

“ID Technology was very helpful,” he continues. “They were here every day during the several weeks that we were looking at the system, and then they helped us install and start up the printers. They've been someone we could rely on, and we are very comfortable calling them when we have any questions or need assistance.”