The environmental and health problems caused by the inks Containing volatile organic compounds (VOCs) call for new solutions in printing chemistry and technology. One of the approaches may be hot melt. It refers to ink, which is solid at ambient temperature and liquid at the time of printing. Such inks contain no VOCs to be trapped in the ink film or to produce VOCs.
In 1990s, the European Technical Committee for Printing Inks of CEPE (European Technical Committee for printing inks and Artists Color Manufacturers Industry) published a guideline paper on health and safety. Since then energy curing products have gained significant growth both in coatings and printing techniques. The major energy curing processes are used: UV and EB (Ultra violet lamps and Electron Beam). Energy curing technology is important in the production of all types of printing applications where fast drying, durability and high gloss finish make them sustainable for immediate use, e.g. carton printing –Food and pharmaceutical packaging, labels plastic substitutes and metal decoration.
Another development area of immense interests Development of water based UV systems. Water is ideally suited to reduce the viscosity of ink systems. However, the main problem with water UV system is that it is inevitable to remove water completely before UV curing. Water based flex inks are being used in Naplan printing inks [NPI]. NPIs were initially formulated using petroleum-based materials. However, they left an offensive odor on printed substrates. Some printers used glycol (water washable inks) to over come the drawbacks .The ultimate solution was the use of water based flex inks, which apart from being odor freehand several other advantages. Rising petrochemical crisis and environmental concerns draw attention to vegetable oil based inks.
Although vegetable oils have been used in inks for many years, the first soy bean oil based ink were developed in 1985 and were marketed in 1987.Soy inks now make up at least one third of the colored newspaper ink. Soy ink contains less VOC, less alcohol and can be washed up without solvent. Their disadvantages include their high cost compared to conventional link as well as their disposal. For the present, UV and EB cured ink technology continues to develop. Efforts are being directed towards the use of water-based inks. Key uses presently remain in the development of vegetable oil containing inks using UV and EB cure technologies in the world of printing inks. We are destines to expertise many industry innovations in this field in the next few years with almost unlimited possibilities
Source “Polymer Science - Coatings and Adhesives and Technology of Printing Inks”