Marabu’s UV LED curable printing inks shines in the world of glass decoration
17 December 2022: To make full use of the strengths of UV LED curing, inks must be formulated to match its attributes. Marabu GmbH & Co. KG, a leading global manufacturer of liquid coatings and screen, digital as well as pad printing inks with headquarters in Germany, has made a name for itself in this field. In association with glass manufacturers, Marabu fine-tunes ink formulations in line with specific use cases. These collaborative activities led to Ultra Glass LEDGL. This UV LED-curable screen-printing ink combines excellent initial adhesion with superb opacity, sheen and reactivity. The product line includes brilliant, glossy colours and high-opacity tones for dark substrates.
The Marabu portfolio comprises premium-quality ink ranges, in particular for glass substrates. At Glasstec 2022, Marabu had showcased its energy-saving LED-curable screen printing inks with a small carbon footprint and a new digital varnish for customisable haptic effects. The company also presented inks for screen printing, digital printing and pad printing for the glass industry.
Marabu specialises in organic UV-curable glass printing inks, which are an effective and energy efficient alternative to ceramic glass printing inks. The potential energy savings can amount to 65 percent. Additional savings in energy and CO2 emissions are possible with the Ultra Glass LEDGL UVLED-curable ink system. Unlike ordinary UV lamps, UV-LED lamps require no warm-up time. This permits high printing speeds and cost savings because there is no need to switch to standby mode during machine stoppages or job changes. UV-LED lamps are slightly more expensive but have a much longer service life and consume significant less energy for curing than UV lamps. The lamps contain no mercury and ozone extraction, which is standard with UV curing, is unnecessary. These factors make UV-LED curing is an economically interesting alternative. Sustainability is another advantage. Printed glass can be recycled after use.
According to Marabu experts, UV LED technology offers a variety of benefits, especially for glass substrates. According to Marabu officials, printing-system engineers and ink manufacturers are increasingly making use of this pioneering technology. UV LED curing eliminates the need for a warm-up period, saving time.
One of the advantages is the greater printing speed, and therefore higher throughput, as there is no need for a standby mode when the printer is paused or when switching print jobs. Moreover, the UV LED lights have a far longer service life than conventional UV tube lights. The greatest benefit is, however, the wavelength of the light. LED units operate in the UV A band, so no ozone is emitted. An air extraction system for the production area is therefore not required. Together, these factors lead to markedly lower electricity consumption and significantly reduced costs. As a result, there is rapid payback of the initial capital outlay. Overall, LED technology leads to more sustainable business operations and is an attractive alternative to conventional UV-curable printing.
Pascal Iffland, Key Account Manager for Packaging, Marabu, explains “UV LED-curable inks, such as Marabu’s Ultra Glass LEDGL line, contain photoinitiators. These absorb light in the UV A band, and ensure complete curing at the speed required for the corresponding print jobs.”
Ultra Glass LEDGL is a two-component system that requires the admixture of an adhesion promoter (bonding agent) for effective use. It also permits flexibility with regard to the chosen printing method, as LEDGL is a dual-cure screen ink. The company is soon to launch a bronze binder for special metallic colours. Furthermore, Marabu is cooperating with an engineering partner to test a primer suitable for UV LED curing. This would allow the subsequent decoration of glass substrates with hot-stamp foil. Equipment capable of this production method is already established in the marketplace.
The Marabu official says that glass containers for personal care items must avoid contaminating their contents in any way. For the decoration of cylindrical containers, such as drinking glasses, the priority is dishwasher safeness. UV LED screen printing complies with both requirements, and offers further strengths. Inks printed directly onto glass items, such as bottles for beverages, have greater colour fastness and brilliance, communicating enhanced quality and achieving competitive advantage over conventional labels.
Marabu’s UV-curable Ultra Glass UVGL ink system is for highly effective screen printing on glass. UVGL-RH/-RL relief varnishes can achieve haptic effects that are otherwise possible only with costly moulds and profitable only when manufactured in very large quantities. Pre-printed motifs applied by screen printing on container glass or flat glass are overprinted congruently with a thick layer of varnish and cured under UV light. Combinations of the two varnishes can achieve a wide variety of effects.
Moreover, Marabu offers a broad range of inks and ink combinations for printing on glass: screen printing, digital printing and pad printing. Its comprehensive product portfolio includes the solvent-based screen printing ink Mara Glass MGL and the pad printing ink Tampa Glass TPGL. Solvent-based printing inks are ideal for multicolour glass decoration.
The single-component baking ink Mara Tech MGO for glass and metal can be used for screen printing or pad printing and is ideal for first- and second-surface applications on container glass and flat glass.
For printing on glass front panels (glass touch) and operator control panels, Marabu offers the UVcurable Ultra Glass UVG3C ink system and two solvent-based screen printing inks: Mara Glass MGL and Mara Glass MGLA. Applications include automotive display cover glass and high-quality operator control panels on kitchen appliances and similar equipment.
Ultra Jet DUV-C is made for direct digital printing on glass, for example custom decoration of drink bottles and cosmetic container in filling lines.