Changes in Ink Jet Technology
For inline, high-volume printing, ink jet printing continues to be cost-effective for most packaging operations.
by Clyde E. Witt, editor
In the past, there have been numerous reasons why ink jet printing saw only limited success if bar codes were to be printed directly onto cartons. The porosity and generally poor reflective quality of corrugated, motion caused by conveyors and the variable locations of cartons on the conveyor were a few of the challenges.
Now, based on standards established by the Uniform Code Council (UCC) for shipping containers, ink jet technology does a passable job on controlled substrates. There is still a problem printing the smaller codes, Code 128 for example, or the new two-dimensional codes.
The greatest advancements in ink jet printing are happening in the quality of the ink as well as improvements in print head technology.
To overcome the problem of reflection when printing bar codes, new glycol-based inks that print darker (thus more contrast) are being used. Also resin- and wax-based inks that provide better edge definition of the bar codes are being used.
Here is a sampling of ink jet and related labeling technologies:
• Weber Marking Systems’ LegiJet ML256 ink jet coder is said to produce crisp large- and small-character text, bar codes and graphics at 200 dpi on porous and non-porous substrates. Its twin printheads are capable of printing in heights ranging from .06" to 1.4" at speeds up to 200 feet per minute. The unit is fully programmable from a PC with bold characters, upper and lower case letters and variable time/date coding formats as standard print features.
• Diagraph Corporation’s new I.V./700 NP ink jet printer is designed for marking non-porous surfaces such as films, plastics, metals and coated corrugate. This single-jet printer combines quick set-up and ease of operation. It uses a patented integrated valve printhead technology for delivering consistent markings. Controlled through the keypad, each dot size can be fine-tuned for clarity, readability and maximum ink economy. This unit can print five-dot, seven-dot, seven-dot bold or multiple fonts in a single pass. The printhead is repositionable and independent of the controller. Print speed ranges from five to 250 feet per minute Another version of this unit is available for porous surfaces.
• Iconotech, manufacturer of digital case printing equipment, has introduced an inline bar code printer for corrugated shipping containers. The Icon-224 prints bar codes and human-readable text directly on filled cases at speeds up to 200 feet per minute. Designed specifically for bar code applications, the unit has a print area of 2" x 24" and provides label quality printing without the label. The machine uses high-resolution digital print film and pigmented ink to ensure perfect text and graphics. ADF