by Jewlissa Frickey, assistant editor, Plastics Decorating
The manufacturing of consumer products such as foods or cosmetic packaging requires deliberate awareness of the strict safety standards set to ensure that human health is not put at risk by any of the ingredients. The printing ink used for the decoration and labeling of these products is no exception. Marabu set out to address this issue with its Ultra Pack UVFP, a low-migration, UV-curable printing ink.
Marabu GmbH & Co. KG is a global manufacturer of screen, digital and pad printing inks. The company is headquartered near Stuttgart in southern Germany – a region renowned for its technology and engineering.
“Low-migration ink means safer beverages and food products,” said Marabu Vice President of Sales Tim Tesmer. “That means no need to worry about monomers and other chemicals from the ink getting into your drinks.”
In order to satisfactorily meet the requirements of such a demanding process, Ultra Pack UVFP, by virtue of its low-migration formulation, minimizes the risk of transfer of contaminants from the outer decoration on the product packaging through the substrate and into the contents.
“I know our customers are excited about the safety aspects,” said Tesmer. “The low migration is truly a first in the industry – an industry that needs to meet more regulatory requirements every day.”
UVFP’s technology addresses concerns with plastic packaging by not allowing the photoinitiators and monomers to leach/transfer through from the product exterior to the contents inside. Not allowing the ink to migrate through permeable plastics, such as HDPE and LDPE, results in less chemical pollution into the printed containers.
“As individuals become more conscience of what is in their products from a chemical and safety standpoint, UVFP allows consumers to finally stop worrying,” said Tesmer.
The ink has been engineered for exterior surface printing onto food, cosmetics and beverage packaging made of either pretreated polyethylene (HDPE/MDPE/LDPE) or pretreated polypropylene (PP). By using a UV-curable ink, the solvent emissions from the product are zero. Tesmer noted having zero emissions also means there is no need to worry about attainment zones or solvent emissions. “UVFP is BPA free, and what is in the ink stays in the ink – it doesn’t migrate through your bottle to the drink inside,” he said.
Before printing onto PE and PP, the substrate surface must be pretreated by flame treatment or corona treatment to ensure the surface is free of contaminating residues such as grease, oil and finger sweat With these processes, surface tension will rise and a good adhesion from 44 mN/m is possible. Since all print substrates may differ in printability, even within an individual type, preliminary trials are essential to determine the suitability for the intended use.
Additional characteristics of UVFP include a high resistance to water, steam, various filing goods and chemicals. The ink also is suitable for tubes, with good adhesion and a flexible ink film. All ingredients used are in compliance with the EuPIA Suitability list of Photoinitiators for Low Migration UV Printing Inks and Varnishes, part 1A; correspond to the Nestlé Guidance Note on Packaging Inks; and correspond to Resolution AP (89)1 for pigments.
Ultra Pack UVFP is a fast-curing UV-curable ink for a printing speed of up to 3,600 bottles per hour. A UV-curing unit (medium-pressure mercury lamp or fusion) of 120 to 200 W/cm is necessary. The curing speed of the ink generally is dependent on the kind of UV-curing unit (reflector); the number, age and power of the UV lamps; the printed ink film thickness; the color shade; the substrate in use; and the printing speed. Adhesion of the ink usually is measured by a tape test after the printed bottles have cooled down to room temperature.
The ink is available in 13 basic shades and three opaque shades, including a silicone-free opaque white (171), which is used as pre-print for flexo overprints. All shades are intermixable (except 171). Mixing with other ink types or auxiliaries must be avoided to maintain the special characteristics of this ink.