- September 01, 2000, Richard M. Podhajny, PhD, Contributing Editor
What do flexography and lemonade have in common? Let's see. From humble beginnings 100 years ago as aniline printing, flexo is now the fastest-growing printing process. Today, it represents about 22% of the total printing volume in North America and two-thirds of all package printing.
While it is expected that flexo will continue to grow, limitations in consistency and predictability are delaying further penetration into conventional sectors, such as rotogravure and lithography. Corrugated, labels, flexible packaging, paper bags, and folding cartons are the growth market sectors, with much of this growth at the expense of letterpress, offset, and gravure.
Anilox Rolls Lead the Way
The quality of flexo continues to improve as finer anilox rolls are developed. Whereas the standard anilox was in the range of 360-440 line screen only a decade ago, today it is 800 and is expected to go even higher. As a result, thinner ink films are being applied, and the focus has been on stronger inks that will not dry on these finer anilox rolls.
Flexo is also pushing higher press speeds. This trend is difficult for water-based flexo systems, since it requires higher pigment loading and excellent transfer characteristics.
Advances in computer-to-plate technology are changing the flexo landscape significantly in regard to quality. Laser-engraved photopolymer plates combined with chamber doctor blades and ceramic anilox rolls have been major factors in the move toward flexo. And, the trend continues toward greater numbers of printing decks on central impression presses.
UV Growth Adds New Dimension
The use of ultraviolet inks in flexographic printing continues to grow at a phenomenal rate. UV now represents 25% of the flexo printing tag and label business sector.
Unlike other sectors of the printing industry that moved to UV simply as an alternative compliance strategy to reduce solvent emissions, UV has given narrow web flexo printers the ability to compete with lithography.
UV has had limited success in wide web printing, due mainly to the fact that wide web's primary application is food packaging, leading to concerns over UV raw material migration.
Recent European findings identifying traces of benzene from a cationic UV application have further increased these concerns, and several UV ink suppliers have left the cationic UV ink business. Cationic UV is well suited for wide web applications that require extraordinary resistance, such as outdoor fertilizer bags.
Water, Water Everywhere
Water-based ink dominates corrugated, paper bags, paper products, preprinted and post-printed multiwall bags, and milk carton applications. Growth, although slow, is seen in film printing and laminating sectors, as some printers turn to water-based technology when aging incinerators must be replaced or upgraded. Growth is expected in folding cartons, as well as in some current gravure applications.
Governmental pressure continues to force reductions in volatile organic emissions, and the Environmental Protection Agency is tightening limits on ozone emissions, which ultimately puts pressure on VOC emissions. Any such pressure will favor water-based flexo.
The rise of flexography is one of the most interesting stories in the recent history of the printing/converting industry. It is an outstanding example of how this industry, when pushed into new technology through cost considerations and/or regulations, not only finds ways to make that technology work but continues to improve on it. What started as a problem has ended up being a boon to the industry. Kind of like that old saying about turning lemons into lemonade.