One of the restrictions for the digital printing of flexible substrates has been the feasibility of lamination. Recently, some suppliers developed laminating machines, adhesives and primers which they consider a solution. But have they really solved all the issues?
It’s here, and it’s real. With the advent of digital technology, full width, digital printing presses have finally arrived in a very real way. By now, almost everyone is aware of HP’s digital printing press offering, the Indigo 20000, designed and built to serve the flexible packaging market. In a recent press release, Alon Bar-Shany, Vice president and General Manager, HP Indigo Division discussed the seemless integration of printing and laminating for flexible packaging. “As we drive the digital revolution in flexible packaging, it’s important that our customers benefit from the full value of digital across the printing, converting and lamination processes,” said Bar-Shany, “With the Comexi Nexus L20000, converters will be able to increase speed to market to further maximise the benefits of digital printing with the HP Indigo 20000.” Read the full article in our eDossier “Laminating to digitally printed substrates”.
In a meeting with Roy Oomen, Category & Product Manager for Hewlett-Packard, we discovered that there are currently 19 Indigo 20000 installations, plus the one on the show floor destined for Target Labels & Packaging in Salt Lake City, USA. When you add the 100 or so installations of the Indigo 10000 (for labels) and 20 installations of the Indigo 30000 (for carton board), HP has an installed base of about 140 digital presses. Then add Fuji and Xeikon, who make a similar platform press for the packaging and label markets, digital printing is definitely here.
Despite the marketing power and initiative taken by HP, digital printing accounts for less than 1% of all printing worldwide . What we are seeing is the birth of a technology. So, the question isn’t that it’s here, or if it’s real, but rather, “How does the converter laminate digitally printed films?” In order to get more information, visit our shop to download the whole article for EUR 3,30.
Delving into this a bit further, what’s the concern with bonding to a digitally printed substrate? The chemistry used to print on an HP Indigo 20000 is really not new. In fact, according to Dr Dene Taylor, printing industry expert with SPF Inc. in New Hope, USA, liquid toner technology is a 20 year old technology based on the fact that pigments and dyes are surrounded by a polymer. The inks are diluted in an isoparaffin, an inert, non-conductive, odour free acyclic C14 alkane. The Indigo press was first introduced 20 years ago at drupa in 1994.
In conversations with HP they indicated that the pigments and dyes used in its Indigo ElectroInks are let down in mineral oil, which is a blend of various molecular weight alkanes in the range of C20 to C40 acyclic alkanes. 
Herein lies the confusion and also the concern for adhesion to a digitally printed substrate. Both C14 and higher molecular weight C20–40 alkanes are naturally oily and waxy. The higher molecular weight implied by HP is cause for concern in that the low temperatures used in the process will not vaporise the oils, and thus the residual oils on the backside of the inks may poison the adhesive when laminated to another impervious film. Learn more about the “Laminating to digitally printed substrates” – you can easily download it for EUR 3,30 in our shop.