For the first time, a CMYK digital printing process for BFS products
Because they are lightweight, space-saving, cost-effective and easily portioned, Blow-Fill-Seal containers (BFS) are increasingly replacing glass containers for aseptic liquid pharmaceutical products. This applies to eye drops, inhalation preparations and vaccines in pen injectors.
However, until now it was a challenge to customize the BFS for different market variants. Applying printed labels to BFS products which are very often small-format, is relatively complex and has a major disadvantage with respect to product safety: the labels may peel off accidentally and the stability of glue formulations is difficult to guarantee. The embossing process, which is not color-capable anyway, can cause damage to the BFS, it is time consuming to set up and results in text with poor legibility that cannot be checked by a camera, leading to quality control issues. In order to avoid these challenges, mechanical pad printing using the tampon printing process is commonly used. This requires the use of solvent based inks and print plates, however.
"Since batch sizes become increasingly smaller, the set-up times due to artwork changes have more and more of an impact", says a Hapa expert who has been dealing with the challenges of BFS production for several years. "This sometimes results in a drastic decline in overall equipment effectiveness (OEE)." By contrast, a digital solution means artwork can be changed at the click of a button, color saturation and artwork remain consistent and mechanical adjustments are eliminated leading to a "digital uplift".
Years of research and development work
The solution is the result of a collaboration between Hapa and Graniten and is the world's first system that supports a CMYK digital printing process suitable for this application. Based on Drop on Demand Inkjet technology (DOD), this printing solution was first presented during the Blow-Fill-Seal International Operators Association AGM in 2019, since then many pharmaceutical manufacturers in Europe and Asia have been looking very closely at this new approach. DOD technology offers significant advantages and is the perfect replacement for commonly used technologies: labeling, embossing, solvent based inkjet and pad printing. "The decisive key to success was the use of specially formulated inks which have been developed by Hapa. Furthermore, the development of a repeatable process for product transport, surface treatment, printing and UV curing that assure that the liquid drug products meet the required quality and safety”, reports the Hapa expert. "BFS are generally made of HDLPE (High Density Linear Polyethylene), which has a low barrier function. Our process meets the migration and print quality requirements.”
For Hapa, which specializes in inline printing technology for pharmaceutical packaging, the breakthrough in the BFS project came after years of research and development work. “A great advantage was that Hapa develops and manufactures both the inks and the printing technology. This resulted in a very close interaction between ink development and application technology, which is probably unique in this form in the pharmaceutical sector", the expert emphasizes. As part of the continuous cooperation with a leading pharmaceutical manufacturer, long-term tests with high-precision analytical measuring technology were carried out. From the beginning of the project, the focus was on the practical implementation and quantifiable benefits of late-stage customization, optimized overall equipment effectiveness (OEE), reduced costs and compliance with the EU Packaging Directive.
Maximum data density on the smallest areas
High-precision printing of even the smallest codes and demanding characters, such as those found in Asian fonts, can be handled by Hapa’s redcube or redcube plus. "At the fastest BFS packaging line speeds, these printers can compress more data into small areas reliably and repeatedly and with a higher contrast than probably any other currently available inline technology”, the expert says.
"When compared with traditional analogue customization techniques, market specific artwork and color changes are effortless with this new digital solution", the Hapa expert sums up. “We’ve created a solution that allows for unprecedented flexibility and cost efficiency in the customization of BFS containers and at the same time optimizes product and process safety.”