01/2007
UV TIME! launched at Radtech France Seminar

The seminar organised by Radtech France in January this year at the Paris Congress Centre Porte Maillot, took place alongside the Intergraphique 2007 exhibition. It was dedicated to covering the current position of UV curing technology and included speeches from the main players IN the European graphics chain. After the welcome given by Rodolphe Pailliez, chief editor of France’s Graphique magazine, many interesting presentations followed. The first speakers were Professors Xavier Allonas and Céline Crouxté-Barghorn from the department of general photochemistry at the University of Moulhouse, a centre very involved in UV development. These two presentations focused on the many uses of UV technology and on UV ink formulations.


Speeches from ink producers included Siegwerk and Sun Chemical who pointed out the importance of ink formulations to increase the efficiency of UV curing. Also included were presentations from UV equipment suppliers IST and Cytec. The programme was completed by sessions from press manufacturers; Olav Spielmann from Heidelberg, Etienne d’Hauwe from Drent-Goebel and Federico d’Annunzio, President of GIDUE S.p.A.


The seminar provided the occasion for GIDUE to introduce the new and revolutionary UV curing system UV TIME!™, produced in partnership with Air Liquide France. The GIDUE presentation was followed and completed by the presentation of Géraldine Rames-Langlade of Air Liquide on ‘The possibilities of UV curing under inerted nitrogen atmosphere’.


The presentation was centred on the Air Liquide Aldyne™ gas phase primer product and UV TIME!™. UV TimeTM is the ultimate UV curing oxygen-free, clean, environmentally friendly solution. Aldyne™ are offering in combination with GIDUE, presses providing a total package, fully compliant with food packaging standards, whilst maintaining high speeds and maximum adhesion on variable substrates.


Federico d’Annunzio introduced his presentation with an overview of the worldwide packaging market, where the growth rate in the flexible packaging sector is encouraging, especially when considering the food packaging market share. He continued that packaging per se could not be separated from the importance of the change in the perception of it (ie the packaging appeal is initially surpassing the interest in the content), the needs of repeated jobs, flexibility in materials used and of course cost-savings.


Keeping in mind, that to respond to the packaging industry needs in terms of high quality, environmental safety, reduced energy consumption and cost efficiency on short runs, UV flexography is for the President of GIDUE, the only available choice. Based as it is, on the principle of polymerization (curing), opposed to traditional ink evaporation, it provides immediate positive effects in terms of working environment quality, of safety for the company and for the workers, (as no solvents are involved) and in stability of the printing process (neither seasonal nor day/night modifications occur). Consistency during production, higher opacity (the ink is cured directly on the substrate) and lower dot gain are additional plus factors. UV flexo can print high quality process designs, solids, screen effects and varnish, whilst also offering excellent management of frequent ink changes. The same job can be repeated many times without any change in the printed result, irrespective of the operator. UV flexo inks do not evaporate, do not change density depending on environmental changes, do not need additives and do not dry on the plates, thus reducing the time for cleaning. Set-up times are extremely short, due to the fact that UV flexo inks print immediately with less waste. Last but not least, less training is needed for the operator (less experienced operators easily become competent using UV flexo inks, as the level of skills needed are significantly lower than those needed for the use of solvent and water-based inks).


UV flexo technology is particularly suitable for the food packaging industry (flexible packaging and folding carton), where low odour levels and the total elimination of Volatile Organic Compounds (VOC) are required. Both flexible packaging and carton industries are interested in the colour stability and predictability that only UV inks can provide, especially when spot colours and designs for major brands need to be reproduced identically worldwide. Only UV flexo technology can guarantee a narrow window of tolerance in changes of colour hue and density, withstanding different environmental temperature and humidity conditions.


UV TIME™ has been developed to answer the critical issues raised by the food packaging industry. The concept of its creation, is to provide an environmentally friendly and safe solution, compliant with the strictest EC regulations on food packaging (the Food Packaging compliance is certified!) whilst maintaining cost effectiveness.


The heart of the process, is the prevention of photo-initiators. These are responsible for ink polymerization and as such, create unwanted radical combinations with the oxygen particles carried by the web (when exposed to UV radiations). The main effects are the elimination of radicals responsible for odours and ink migration, as well as a decrease in the amount of expensive photo-initiators incorporated in UV inks formulations and the increase in curing speed rates (higher levels of photo-initiators adversely effects UV curing efficiency, restricting press speeds even when using the most powerful and efficient UV lamps).


UV TIME™ is a true breakthrough. Unlike similar solutions which pump out oxygen substituting it with nitrogen, using a nitrogen "blade" to break the boundary layer of air transported by the web. This creates a very thin bed of inerted atmosphere very close to the substrate, which in turn allows the target oxygen presence to eliminate odours and ink migration (less than 30 ppm) with only minimal consumption of nitrogen, which is also recycled in the system.


In order to better understand the economic factors involved, the reduction in costs of the UV inks for inerted atmosphere (due to reduced use of photo-initiators, up to 10 times less) is equivalent to the cost increase due to nitrogen consumption.


Previously, the investment in inerting technology using nitrogen was too high, due to the effective consumption of costly nitrogen. The practical and economic disadvantages greatly outweighed the theoretical improvements achieved with the so-called Inert UV Curing. UV TIME™, simply substitutes the cost of the photo-initiators with the cost of nitrogen. Now UV flexo technology is set to make a further technological leap in the graphic industry, by fulfilling the strict norms of the entire packaging industry, including the food industry with less than 10 parts per billion ink migration, (0 to 1 Robinson odour test).


A further consequence of the technology is the possibility of applying heavier layers of ink for higher opacity effects (no longer is curing a limiting factor), so increasing the graphic scope of the flexography printing process. At the same time, each specific advantage of UV flexo technology is totally preserved; environmentally friendly, high printing quality, consistency and reliability of performance, high speeds, less skilled and less costly operators, ease of operations, no overnight washing-down and much more. Increased “scratch” resistance and better adhesion on non-absorbing substrates are other benefits.


UV TIME™ is offered to the market coupled to the latest GIDUE UV flexo press Athena™ (available widths: from 530 to 730mm), which, with its heavy duty and gearless configuration, is especially designed for the global packaging industry – with wide ranging benefits.


Athena™ is able to print and convert from thin film to heavy laminated board, in fact, practically any web substrate used by the packaging industry. This fully Intelligent mid-web press, has been created and designed to implement the advantages of in-line presses with an open structure – for multiple choices of web path, with a full range of accessories – flexo/gravure printing and ‘Intelligence’ which controls web temperature, register, tension, print pressure, UV and drying adjustments.


In order to avoid resonance effects and to allow correct direction of the forces which create vibrations redirecting them to a controlled area, eliminating disturbance of the printing quality, the print unit of Athena™ has been designed on a completely new triangular configuration, opposed to a 180° in-line. common to presses currently available in the market. This completely new approach is the result of a Finite Elements computer simulation, which has proven to be very successful. The dot gains value measured on the printing unit are the best available in the mid and wide web market. They are identical to those of narrow web presses, even with double the web width and with double printing speeds.


The press is PC controlled and is able to be Internet connected for remote service. The completely "digital" control on the machine supports the operator with fully automatic adjustments during set up operations (pre-register, automatic register, automatic pressure adjustment, automatic substrate calliper control, automatic tension control) and avoids unnecessary repeated operations. This means greatly reduced waste, as all the parameters of the optimal adjustments are digitally reproduced and only limited set up time is needed. Furthermore on new jobs, the possibility of errors, damaged plates or substrate is greatly reduced, if not eliminated, by the Intelligent Calliper feature. This automatically positions the plate cylinder and the anilox roller to achieve the correct pressure adjustment, relative to the plate thickness and to the substrate calliper, within a tolerance of less than 5 thousands of a mm!


The operator can concentrate on productivity as quality and set-up are taken care of by the Athena "Intelligence" (Servo Driven PC Integrated Control). A new term should be used: digital ergonomics. The control "depth" and the flexibility of servo controls on each operation make the retrofit of further software and hardware integrations easy and sustainable, both economically and practically.


Special care has been given to the development of the ‘Intelligent’ register control. It has been entirely developed by GIDUE and it is the only register control in the market, which incorporates a unique self-learning feature. The operator is no longer required to set he register control parameters based on the substrate instability to tension and temperature variables.


A specially developed algorithm allows the Intelligent Register Control to "sense" the different characteristics of the substrate, based on the different operating conditions (ramp up, ramp down, steady state etc.). The Intelligent Register Control "learns" the needs of the substrate and becomes more or less responsive, based on the different correction requirements. The accuracy of the control over the different operating conditions and the limited waste is unprecedented in any in-line press currently available.


The addition of UV TIME™ to the Intelligence-controlled mid-web press Athena™ takes UV flexography far beyond any expectation, really creating a new trend which takes UV curing to the highest performance limits and as such, represents the first, most complete answer to the needs of brand owners in the packaging industry.

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