Braille Comes to Pharmaceutical Cartons

Image courtesy Global Vision Inc.

Requiring just name and strength in Braille, the new requirement sounds pretty minimal, right? After all, adding a few dots might not even affect existing carton layouts. There are challenges, however: determining Braille dot height and verifying that height.

Embossing is traditionally used to apply Braille dots to cartons, and screen printing is often used to add it to labels. These methods, however, cannot create on cartons the rounded dots typically expected on signage and other media.

Ideal heights have been suggested for these methods, but there are no mandated minimums. Targets under discussion include a mean dot height of 0.1 to 0.2 mm with a standard deviation of 0.025 mm for embossing and a mean dot height of 0.16 to 0.2 mm with a standard deviation of 0.01 mm for screen printing.

“Blind and visually impaired people – and their interest groups – strive for a Braille dot height as high as possible. When embossing folding cartons, though, this naturally results in cracking up the carton board surface and damaging the print,” reports Dieter Mößner of carton producer Carl Edelmann GmbH/Germany. “Legibility of text and graphics could be compromised. So there is a conflict between obtaining a high Braille dot height for a limited number of blind and partially sighted people and preserving visual appearance and text readability for the overall majority of sighted consumers of medicines.” Mößner is chairman of the working group NA 115-01-03 AA “Braille on packaging” at the German Standards Institute DIN (www.din.de), which published in 2006 the adopted German draft standard DIN 55561 “Braille on packaging.” He is also Convenor of CEN/TC 261/SC 5/WG 12, “Marking: Braille on Packaging for Medicinal Products.”

“Various readability tests made by blind and visually impaired people have shown that Braille dot heights from 0.10 mm and higher could be read by blind people,” Mößner notes.

Height verification is another issue. “In the absence of an agreed Braille dot height figure and method for verification, many folding carton producers inspect the Braille dot height visually,” explains Mößner. “This has worked for many years now.” Instead of measuring a value, visual inspection assumes that a minimum height will be achieved with the validated or controlled embossing process, so inspectors simply determine to what general degree the carton board surface cracks up: no visible cracking; starting to crack up; or cracked up substantially. “This method is very easy to handle and very cost-effective: it needs no batch-wise-measurement, no retaining of samples, no measuring devices. It needs only experience and documentation,” says Mößner.

Pharmaceutical companies may seek an automated system, however, that can measure height accuracy. “Height is the main criteria for quality,” says David Perlis, chief operating officer, of Global Vision (Montreal, Quebec, Canada).

Automatic vision systems can be very efficient quality systems, says Mößner.

A provider of automatic proofreading systems for the pharmaceutical industry, Global Vision initially pursued an optical solution. To figure out a cost-effective means of height verification, Global Vision began working with an independent lab to compare vision inspection with contact inspection. Testing found the two to be comparable.

To offer a practical solution, Global Vision decided to develop a system that would use sensors to mimic the way a human would read Braille, says Perlis. The firm sought the advice of a large pharmaceutical company along the way. “We tried optical methods, but in the end we turned to a mechanical one.” The company’s white paper states that “although both laser and optical methods may provide a reasonable solution, their acquisition costs are higher than those for contact devices.” Also, “the light-refracting properties of the material being measured can influence results and their sensitivity may render them unsuitable for use in a factory environment.”

Whatever inspection method a pharmaceutical firm chooses, Mößner says that “the control procedures shall be agreed upon between a folding carton producer and its customer. But it has to be remembered that each measuring device will cost time, money, and labor. One has to remember that different methods of height measurement will produce different results.”

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