Development of the next generation of newspaper printing inks is guided by the quest for improved quality, better economics and environmental compatibility. Environmental issues have been brought into sharp focus in recent years through a combination of governmental regulations and heightened public awareness. Those issues which directly affect the design and formulation of newspaper inks include reduction of air pollutants as specified in the Clean Air Act, the use of renewable resources and increased newspaper recycling.
Atmospheric ozone is a known health hazard. Ozone can be formed by the interaction of volatile organic compounds (VOCs), oxygen, oxides of nitrogen and ultraviolet light. Emissions of VOCs into the atmosphere result from the evaporation of solvents such as those commonly used in printing inks.
There are two principal solutions to the VOC problem. One of these solutions involves the replacement of petroleum oils with vegetable oils such as soybean oil. Testing has shown that soybean oil contains no VOC component.
Inks based on soybean oil can be formulated to run on existing offset and letterpress equipment and offer advantages in addition to VOC reduction. From an environmental standpoint, vegetable oils are renewable resources. Crops can be planted and harvested repeatedly. Newspaper inks containing vegetable oils also show improved lithographic performance and enhanced color reproduction and mileage.
The second approach to reducing the VOC content of newspaper inks requires changing to water-based inks that are printed flexographically. These inks contain virtually no organic …