News IST METZ / Narrow Web

On the safe side with Cold-UV

For the X-label GmbH Company in Gebesee the term security plays a particular role in many aspects. For the printing company which produces self-adhesive labels in a modern company building in the vicinity of Erfurt, production reliability is as important as maintenance of industrial health and safety standards. The following article shows the reasons why Managing Director Jan Oberbeck and Production Manager Martin Kaufmann hold technical safety requirements in high regard. Since Jan Oberbeck and Tim Fiedler as well as the Schleipen & Erkens AG as shareholders of the X-label company took over the helm, things are improving for the Thuringian printing company (see information box: „expansive years take the place of a difficult time after the German Reunification“). In 1997 the company moved away from the town of Erfurt towards the community of Gebesee (see photograph 1) situated north of Erfurt. In the spacious company grounds with modern and well organised premises approximately 50 staff are employed. The sales and administration centre of the X-label-group in Solingen has ambitious plans for the future, which is proven by the extension under construction which aims to expand the production and stock capacities at the location of Gebesee. Since there are two printing companies within the X-label-group which produce rotary labels, the structure of both sites is concentrated on certain market segments.

Jan Oberbeck explains that the main emphasis in Gebesee lies in the segment „packaging label“, i.e. decorative labels for cosmetics, cleaning, chemicals as well as the whole range „Premium Food“ (see photograph 2). The EK-Print GmbH in Lübbecke however is concentrated on the sector „VIP Label“ (Variable Information Printing), i.e. labels for marking and labelling, for commerce and logistics, weigh systems, etc. as well as label specialities under the term „Select Label“, where they often use special network systems. For the production of these materials, the X-label-group has a coating machine with a working width of 1 mtr at their disposal at their daughter company SEP selbstklebende Papiere (self-adhesive papers) in Lübbecke. High Technology for sophisticated labels According to the strategic orientation at X-label, the choice of the technology plays an important role in order to achieve the envisaged quality level in producing label-products in demanding sectors. Since the pre-press stage has an important influence on the quality, also difficult reproduction works as well as the production of all print forms (with the exception of the sieves for the rotary screen printing) are carried out in the own pre-press department of the company.

As regards the printing technique, Dipl.-Ing. Martin Kaufmann, production manager at X-label, attributes the best chances to the offset printing method, if required in combination with screen printing, and to UV-flexo printing. Another possible variation for the future could be the combination of offset printing and gravure printing. Actually the fleet of machines in Gebesee contains a well-equipped Nilpeter M-3300 for the combination of offset printing and screen printing, a digital printing system Nilpeter DL-3300 working with the Xeikon-technology and four flexo printing machines in the widths between 220 and 410 mm. At the beginning of X-label, the main emphasis was the classical flexo printing. Due to Jan Oberbeck, it was especially through the installation of the offset rotation that the company could transform itself into a supplier of high tech quality products. The platform technology allows the integration of screen printing at the desired station within the machine. X-label makes use of this possibility in a successful manner in order to realise actual trends in the design sector, e.g. 3D-effects. The UV-Flexo programme economically rounded Additionally to the existing offer in the high-quality sector, which is covered very well by he Nilpeter M-3300 for a large, up to a very large circulation, they are searching for an alternative in Gebesee, which comes nearly up to the quality requirements and also is able to execute middle and small order volumes economically. For fulfilling this task, the ten colour press Arsoma EM 280 has been acquired. According to Jan Oberbeck, the results that can be achieved this way with UV-Flexo- printing can easily be compared in quality to offset labels printed at X-label. However, for this statement it has to be taken into account that in Gebesee they use the waterless offset printing, which is well-known for their special possibilities regarding the quality. Thus X-label is working in the offset-printing with screenings from 80 L/cm onwards as standard. Compared with the conventional offset-printing, the results of the Arsoma EM 280 are absolutely equal, in the estimation of Martin Kaufmann. The decision to buy a 10-colour press is based on the order structure.

As we know from the experiences with the offset-presses up to know, the available 8 printing units are often not sufficient to execute all requirements like 4- or 6- colour illustrations with extensive screen printing, interdeck laminating, back-side printing, silicon application, glue application, etc inline. This is the reason for buying the new Arsoma EM 280 in a constellation with 10 units. From today’s point of view this decision was absolutely right, as on this press per order an average of 7 inking units are occupied – similarly to the Nilpeter M-3300. As the 10-colour press convinced the persons responsible at X-label regarding printing quality as well as economy, in Gebesee they intend installing another press equipped with the same constellation with a web width of 500 mm during the year 2001. UV-System with a reassuring capacity reserve Additionally the UV-Flexo-printing X-label gives opportunity to go into new market sectors. Jan Oberbeck mentioned as an example mono-materials like sleeve-labels or packaging-foil. For this using methods a UV-system will be required for working safely with temperature-sensitive substrates. For that X-label decided to obtain the UV-radiators of IST Metz GmbH in Nürtingen. After each of the 10 printing units a radiator of the MBS-series (each with a 200 W/cm lamp) is installed.

According to Bernd Prattl, sales manager of IST Metz, numerous presses in St. Gallen has been equipped with units of the MBS-series. The MBS-system of the EM 280 works very efficiently because of the exact co-ordination of the individual components like UV-lamp, reflectors, chokes, etc. To guarantee the required production safety even on a high printing speed there is meanwhile a good capacity reserve for ink and varnish curing because of the IST-radiator equipment, Martin Kaufmann said. The costs for a high-quality UV-unit will pay for themselves within a short period because of the above mentioned capacity potential. An effective cooling for difficult substrates On choosing the UV-system it was very important to have an effective cooling system as more than 95% of materials used for printing on the EM 280 are foil-compounds. Due to the heat build-up of up to 10 UV-radiators without a suitable cooling there would arise a web temperature of approx. 60°C. This will lead to a stretched web and this will cause unavoidable register and cutter problems. So printing on heat-sensitive materials like foil will be made more difficult or impossible. Additionally to the air-cooling of housing and UV-lamp, the IST-system also disposes of a radiator module in a water-cooled cylinder with a closed cooling circulation (refer to photo 3).

Through a display the user is able to regulate the preliminary temperature of the cooling water. At X-label the system is so regulated that there will be a temperature of 18 – 20°C on the cooling cylinder. The practise shows that the web temperature on leaving the last radiator comes up to 20-25°C. Thus, problems will be avoided during work adhesive compound. Especially difficult are for example: special adhesives with a very high adhesive power for contact on non-polar surfaces. Here a extreme heat-up of the web will lead to making more difficult taking off the matrix or to punch problems. A suitable cooling allows a exact register punch and also make easier the exact fixing of the punch depth, as the contact compound will remain unchanged in it’s structure. Security for the staff Also a criterion of high priority is the safety equipment of the UV-unit. Sensitised by a serious accident that happened some time ago despite of correct handling at X-label while changing the UV-lamp of an other press, the management wanted to being able to exclude any safety risk as far as possible. Therefore the criterions has been fixed correspondingly precisely. Especially the interior and the building up of the unit as well as the linking up of cables and the quality of the electrical components were focus of attention. After thorough investigations the final decision was made during the Drupa 2000 in Düsseldorf. The UV-unit manufacturer IST Metz situated in Nürtingen, was the only supplier who was able to come up to all expectations of X-label. On comparing the units offered on the market Jan Oberbeck and Martin Kaufmann were especially surprised of the enormous range of diverse qualities of the electrical equipment. Due to a lack of specialised knowledge many printing companies have to rely on the opinion of the manufacturers regarding safety, which is often a underestimated risk. A proficient investigation could be helpful to separate the wheat from the chaff. For X-lable the knowledge received by this way makes easier the price comparison, as it becomes clearly recognisable where favourable investment-costs are bought through cutbacks in quality of components or unit construction. The same goes for example for reflectors, which have a substantial influence on the actual power of an UV-system. The range includes from simple aluminium sheets up to high developed reflector-systems, which dispose of special coatings and which are optimised corresponding to the light guidance demanded. Secure production in several views The explanation mentioned make clear that the word “security” has a decisive importance for the printing company X-label in several views. However the UV-unit have to come up to the requirements regarding the production safety in the view of the sales department. What kind of products are offered to the customer within an acceptable price limit depends essentially on the power of the UV-equipment of the press and the printing speed achieved by that.

However, for the management the safety of the members as well as to avoid the production- stops are to the fore. As all production locations of the X-label group are working in three shifts, the reliability of technique is enormous important. Criterions like life time of the UV-lamp receive a special value under this conditions. The good accessibility and easy handling of the UV-radiators are also another point of view regarding a safe production. For Martin Kaufmann a consequently used cassette technique is advantageous (refer photo 4). This will drop uncomfortable up-folding of components for having access on the lamps or reflectors. Additionally the UV-radiators of IST Metz are well compatible with the technique of compact presses. In his opinion the whole solution of the exhaust air line worth mentioning as the printing staff enjoy the very low noise level thanks to a comfortable concomitant of practical dimensioning of pipe diameters and fans.