HOW TO: Do in Register Coating
The continued evolution of packaging requires converters to keep upgrading their conversion portfolio with additional features. Thus, not just printing and lamination but also the ability to complete the final product by adding coatings of various nature. Coatings are offered to converters to allow improving the mechanical, optical and functional characteristics of the final packaging.
Flexible packaging, in particular, and converted products in general, benefit from such upgrades, definitely differentiating the offer to converted materials buyers. The selection of functional coatings is large and covers an extended array of needs. Primers, release lacquers, barrier boosters, sealing solutions (cold seal; Hot Melt), embellishments in general. Some of these applications require in register coating to an existing print. In register coatings have been part of the conversion process for many years.
The need to follow the print repeat on a flexible substrate, dealing with the fluctuation of the print repeat triggered by the elastic nature of some of those substrates, generated serious troubles in the early days.
The reason: the rudimental level of motors control technology unable to deal with the printing repeat fluctuation. Consequently, the practical solution for decades has been to convert in register applications in line with the printing press; the last color of the press or a downstream station made for the solution. Of course the productivity was affected as the printing press was slowed down and the complexity of the productions line conspired for the downtime.
It was years ago, around the mid 80s, that converters started feeling those limits: repercussions on productivity, the need to reduce the scrap rate in one with the growing level of quality requested by the market being the obvious motivations. In the mid 80s I was working in an engineering department of a printing press company when our sales office sold an "in-register coater out of line". It was almost panic. It was even questioned if such out of line conversion was possible. The solution was, at the age, pure ingenuity: strain wave gear technology employed as an actuator, a technology developed for the aerospace industry.
For years we have been the supplier to the industry of such applications. I had the opportunity to witness how the out of line technology globally benefited customers for their needs. As part of our continuous improvement Nordmeccanica has developed its own proprietary solution, a technology intended expressly for in-register applications in a second pass optimizing efficiency and accuracy. Nordmeccanica package is based on an in-feed nip located just before the coating head. The entire system is managed through off the shelf hardware by Siemens and governed by a software developed in house that works straight inside the motor drive. The result is an unprecedented speed of calculation that benefits the system reaction to variables. The advantages are: accuracy; time to register; scrap re-duction; automation of the "back to register" state after a full automatic or manual splice. These days in register coating is a mature technology that, thanks to the innovation provided by Nordmeccanica, offers a dedicated package developed for the entire Combi product range, serving all runs sizes.
Nordmeccanica NA Ltd
Ph. +1 631 242 9898