Surface Functionalization of Web Substrates In-line With Metal and Metal Oxide Deposition

Metallized and clear metal oxide coatings used in applications such a food packaging, printing, decorative, biomedical, electronic and agricultural, often require certain surface functionality that alters the properties of the metallized surface. Useful functional properties include high surface energy for adhesion to printing inks and other materials, low surface energy for slippage and hydrophobic properties, corrosion resistance, abrasion resistance, barrier to moisture and oxygen, antibacterial and antifungal properties. Sigma has developed and patented several “dry” treatment, grafting and coating processes that can be implemented in a vacuum environment without the use of aqueous and organic solvents. These processes are economical, they require a fraction of the energy and real estate used by conventional grafting and coating technologies and they are environmentally friendly. A wide range of functional materials may be used many of which are FDA approved for food contact. The ability to do this at metallizing speeds and in in-line with the metallization process, adds value both to the equipment as well as the metallized product. For many applications, polymeric films, membranes, and various other web-based products, need to be functionalized without the application of a metallized layer. Such treatments and coatings often have higher value than metallizing, which transforms the metallizing machine to a versatile converting tool. Several examples of post metallization treatments, grafts and coatings are presented, as well as functional coatings on membranes, woven and non-woven materials processed in a roll-to-roll metallizer.