The surface specialist Continental together with its industrial partners Janoschka Germany and H.C. Moog successfully conducted the first beta tests of the new elastomer-coated cylinder embossing technology at the end of 2021.
With regard to the ever-increasing aspects in sustainability, decorative embossing is made for a time when new production technologies are developed to reduce the use of inks and varnishes and the energy expenditure required for drying and hardening. Against this background, H.C. Moog, a manufacturer of sheetfed gravure printing machines decided to develop a new product in the anniversary year 2020 (70th anniversary). This new development is a rotary embossing system for the production of folding boxes and labels.
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Cooperation for an alternative technology
To prove the compatibility of elastomer – coated embossing cylinders the project partners of Janoschka Germany, H.C. Moog & Continental came together and conducted tests to confirm that steel, copper and aluminum embossing cylinders could be replaced by a special elastomer compound developed from Continental. Continental´s Dynasurf concept envisages replacing galvanic processes and metallic surfaces in view of increasingly stringent environmental regulations. Dynasurf´s elastomer group is manufactured without solvents and without the use of SVHC´s (Substances of Very High Concern) listed in the EU. “Production waste such as chips and burn-off (ashes) can easily be disposed of with household waste,” explains Dominik Michalek, Program & Sales Management Print at Continental.
The imaging of the elastomer – coated surfaces
The embossing forms were processed using the direct laser engraving process at the Janoschka production site in Kippenheim (southern Germany). In summary, the field report from the Janoschka experts is very promising.
There were clearly environmentally friendly advantages in the area of machining or processing the elastomer surface. This is mainly due to the burning behavior of the rubber, as the resulting loss of material is much less than e.g., with steel or copper. In addition, the elimination of the surface treatment and the electroplating process is much more resource-efficient and thus improves the sustainability balance of the embossing form. “After direct engraving, the elastomer embossing cylinder only has to be cleaned with water,” explains Dirk Jauch, Project Manager Print, and Matthias Heidt, Team Leader Embossing at Janoschka Germany.
On top the impression cylinder equipped with Black Pearl printing blanket, below the direct laser processed embossing roller from Janoschka (Source: Continental)
„We are very satisfied with the results. The processed cylinders have a very homogeny engraving and an outstanding clean embossed image and fully comply with the desired sustainability aspects. Our processes are closely coordinated and the continuous exchange between the operators of the system and the machine has made a significant contribution to this excellent result. The new empirical values can hardly be underestimated in order to advance the development and to bring the elastomer-coated cylinder to production maturity for the manufacturing of embossing cylinders,” says Daniela Heidt, Sales Manager Embossing at Janoschka Germany.
Embossing tests at the H.C. Moog competence center
During the embossing tests at the competence center of H.C. Moog, the impression cylinder was equipped with the glass bead blanket “Conti-Air Black Pearl” (also known under the product name “Super-Press”), which Continental has been producing in Northeim (Lower Saxony) for more than 50 years. “This product is not only used for hot and cold embossing of foils, but also for high-quality embossing production in the area of sheetfed gravure printing,” says Michael Simm, Head of Product Area Specialty & Security Printing in Northeim. He is the responsible contact at Continental for this special Material which is also used in the banknote and security printing industries. The glass bead blanket is used as counter pressure against the embossing cylinders. Material thickness is available from 0,65mm and 1,85mm for these applications.
A „Glass Bead Miracle”
Black Pearl´s unique surface consists of glass beads embedded in a rubber matrix and approximately 40% are visible. The matrix contains about 7000 of these glass beads per square centimeter.
Embossed aluminized cardboard with a thickness of 0,34mm (Source: Continental)
Many years of experience and the continuous process improvement of the individual production steps guarantee the consistent quality of the glass bead printing blanket. In addition, the high durability in the printing process makes this material an additional element for outstanding embossing results.
A concept for current and future embossing requirements
„In order to ensure the longevity of the elastomer in the embossing area, the next steps are further embossing tests with a wide variety of embossing technologies” says Dominik Michalek. „We are very confident that we will be able to offer a product here in the near future that will meet the current as well as the future standards and technologies in the embossing industry and therefore taking another step towards sustainability”.
