Mar 06 2009
VOCs and Offset Printing
With all the buzz around going green across all industries, you may have heard the term VOC brought up more than once. VOC stands for Volatile Organic Compound and relates to an organic chemical compound that can vaporize and enter the atmosphere. So what does this have to do with printing? Well, this is one of the hot topics of why printing can be hard on the environment.
VOCs are found in all stages of the production process, from prepress to post-production clean-up. The main culprits of VOCs in offset printing fall into 3 categories:
1) Inks – Most inks used in offset printing are solvent-based and many of those solvents are VOCs. Those solvents are evaporated during the drying time and are emitted into the air.
2) Cleaning – All offset presses need to be cleaned of excess inks after a run. The chemicals used in these cleaners can be some of the worst offenders when it comes to VOCs.
3) Fountain Solution – Most printers use IPA (Isopropyl Alcohol) to control the physical properties of their fountain solutions, which is mostly water. This ensures that oil doesn’t stick to the non-image area of the blanket, but by using IPA, the fountain solution is the primary source of VOC emissions in offset printing.
Thankfully, there are developing resources and technologies available to printers to reduce the amount of VOCs released into the atmosphere.
• Soy or vegetable-based inks have much lower VOCs, but they are still present due to the pigments and resins added to make these inks suitable for printing. Still, these are much more environmentally-friendly options than the traditional petroleum-based inks used in offset printing.
• Citrus or vegetable-based cleaners are becoming more available as well to replace the high-VOC cleaning agents used after the print run is completed.
• Waterless printing eliminates the need for IPA fountain solution, which as I said earlier is the primary source of VOC emissions in the printing process.
As a print buyer, you should be aware however, that the above solutions are still limited to many markets. Not every printer has the resources to invest in these new technologies, so it may take some time and effort on your part to find the best solution to your printing needs.
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