ACTEGA – Advances in glass decoration
An essential packaging material, glass is valued for its transparency and aesthetic appearance, but has always presented a challenge when it comes to decoration. Whilst labels and sleeves are printed using traditional processes, direct printing with screen or UV inkjet processes has opened up a wide range of new opportunities for brands, in particular at the premium end of the market. More recently, resin application processes using inkjet printheads have enabled the addition of clear or coloured 3D effects, such as O-I Expressions, developed jointly by O-I and Krones.
ACTEGA specialises in coatings, inks and adhesives for packaging. With Signite, the company offers a new technology that resembles self-adhesive labels with a no-label appearance, but with a number of differentiating factors, notably the absence of a liner, the application methods and the thickness of the materials used. “It is based on the same principle as decals, using a transfer film to apply the print to the products”, explains Anthony Carignano, who leads strategic marketing and B2B development activities for ACTEGA’s printing technologies incubator in Rhode Island, USA.
How does it work? A photopolymer clear topcoat, also referred to as the L3 layer, is applied first to the carrier film. The L3 layer fulfils two functions at once: as face stock and as a protective overcoat for the four-colour printing that follows, using a traditional flexo or inkjet press, or hybrid machines combining the two. High opacity white layers and special effects such as metallics and fluorescent pigments, as well as other finishes, can then be printed onto or embedded in the decoration. “It is, in fact, a label, but it looks like a direct print”, states Carignano. “The decoration is highly scratch-resistant, but can be easily removed with hot water in an industrial bottle washing system at a temperature above 80°C and a pH value of more than 12, if the bottle needs to be washed for re-use within a bottle deposit scheme, for instance.”
In terms of cost-savings, the ACTEGA technology can reduce waste by more than 50% compared to a self-adhesive label of similar size by eliminating the liner and die-cut matrix and reducing the thickness of the decoration to a third of a standard label. Specifically, a Signite decoration has a thickness of 25 µm: 5-10 µm for the ink layer, 5-10 µm for the adhesive, and the rest for the L3 layer. Testing is currently in progress to equip Mark-Andy printing presses with Signite, while other developments aiming to improve the process in terms of costs, the environment and marketing are also under way.
The first project concerns the transfer film. Currently, BOPP (Biaxially Oriented Polypropylene) film is being used, ensuring the correct surface tension and register to achieve a good quality print result. However, it should shortly be replaced with more easily recyclable PET (Polyethylene Terephthalate) film and, further down the line, with SCK (Super Calendered Kraft) paper.
The second project is about application speeds, which are limited to 40 750ml cylindrical bottles per minute at best. The aim is to achieve 100 bottles per minute in order to meet the demands of an industry used to higher production rates. After two years in development, the process is now commercially available in North America, with Europe to follow in 2023. It is already in beta use by several customers in North America.
ACTEGA is targeting the wines and spirits market, specifically craft beverages, as well as drinks, cosmetics and glass objects for the home. The first applications are designed for rigid cylindrical containers. Future versions will focus on aluminium cans and asymmetrical containers, as well as thin-walled PET bottles that require inflating to transfer the decoration.