Going With the Flow- High Resolution Ink Jet Coding
High-resolution inkjet coding systems using piezo-electric technology regularly print bar codes on corrugated cases. But these systems are notorious for being fussy about being kept primed with ink.
Not only must they be reprimed whenever they’re started up or refilled, the slightest bump or vibration can also interrupt the flow of gravity-fed liquid. With a separate bottle for each printhead, bottle changes can also eat away at uptime, especially when using multiple heads.
Arcadia Farms, Arden, NC, sidestepped these obstacles when it upgraded the Hi-Res coding system on one of its bottling lines for water, fruit drinks and fruit juices. The new coding system, installed in May ’96, relies on a new Centralized Ink Delivery System (CIDS) from Diagraph (St. Louis, MO). The system is connected to one of the supplier’s Model PEL high-resolution coders.
The theory behind centralized delivery is quite simple: instead of a separate, external ink reservoir for each printhead, one central supply feeds as many as four printheads. (Currently Arcadia has two printheads on its PEL system, one for each side of the case.) The supply tank pumps ink to a small, 3-oz reservoir that’s contained inside the printhead’s housing. The ink then flows to the printhead via gravity, which is all the pressure that piezo-electric printheads can withstand.
Typical piezo-electric-based printheads have an external reservoir with several inches of hose connecting it to the printhead. If either the printhead or the reservoir is bumped, moved or vibrated, it can disrupt the flow.
With the new system, the relationship of the reservoir to the printhead is permanently fixed inside one industrial housing, thereby ensuring that ink will have a permanent, working path from reservoir to printhead. The centralized pump keeps ink flowing to the reservoir, keeping the system primed, even when the unit is first turned on. “
It’s always primed,” confirms plant manager Jerry Ledford. “We turn it on in the morning, it heats up automatically, and it’s working within seconds.” Plus, only one supply needs to be monitored and changed. Changeover of the ink itself is easier, too. “You can change it on the fly while it’s coding,” says Ledford. “You don’t even have to stop the line.”
Ledford says a desire to start bar coding cases necessitated a switch to the PEL high-resolution coding system. The company’s previous valve-style printer couldn’t provide the print quality needed for bar codes.
Arcadia downsized from a 25- count case (5x5) to a 12-count to encourage consumers to purchase the case as a multipack. As a result, Arcadia is ink-jet printing a UPC-A bar code that allows the case to be scanned at the checkout counter. It’s also scanned in customers’ warehouses as a distribution code.
Ledford reports the strategy is working so far. “We thought it would be a big change, something new and different. It has become so, and we’ve actually grown because of it.” Arcadia itself doesn’t use the bar code internally. Another drawback of its former system, says Ledford, was messiness. Ink bottles on the new system have a needle that punctures a membrane as the bottle is screwed in. “So you don’t have ink dripping down all over the floor,” comments Ledford. The final benefit is that the cost of ink has dropped
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