When specifying cover coatings for such applications as perfect-bound book covers, which option do you choose for the least harmful effect on the environment? With UV coating, lamination, aqueous coating, and varnish as the choices, which is best?
First of all, varnish, like ink, usually has a petroleum base (varnish is basically the vehicle of an ink mixture without the pigment), and during the drying process, the petroleum enters the atmosphere as toxic VOCs (volatile organic compounds). If your printer can use soy-based products for your project, of course, such a varnish would be far less harmful to the environment. (That is, it would be less toxic to humans and wildlife, it would cause less air pollution, and it would be less prone to contaminate the soil and groundwater.)
Laminates, such as the liquid, lay-flat, or film laminates used to coat the covers of perfect-bound books, are essentially plastics applied to the paper stock.
In general, this would be problematic, due to the petroleum base of most plastics. However, less harmful options are becoming available, such as laminates made from soy polymers, which are manufactured from soybean proteins. (Keep in mind, however, that although soy polymers are biodegradable, they do require land and water for growing the crops from which they are made. In addition, carbon dioxide, which contributes to global warming, is released during their manufacture. Soy polymers are also expensive. So while they are better for the environment than petroleum based materials, they are not without their problems.)
UV coatings are prized for their deep and lustrous sheen Newer UV materials are not classified by the EPA as hazardous substances. Workers’ exposure to these materials therefore does not pose the health risks of some other technologies. Also, new UV technologies are not carcinogenic. Happily, UV coatings can now be included in the “mixed waste” category of recycled stock.
UV coatings also have the following benefits:
1. They don’t release VOCs into the atmosphere, as solvent-based coatings do.
2. Because they don’t require the application of heat for the drying process and are cured through the application of UV light, less energy is used in their application.
3. They are less flammable than solvent-based materials.
Water-based coatings, on the other hand, called aqueous coatings, can be a good option but are also energy-hungry. They come in gloss, satin, and matte finishes, providing variety in paper surface coating. Unfortunately, they are not as shiny or deep as their UV counterparts, so there is significant sacrifice in choosing this option. They also require the application of energy-intensive heat to cure which adds to their Carbon footprint.
Spot the difference
After processing of Gloss UV coating or Lamination it is generally difficult to find which process is done as both will look very similar. If, however, you try to tear the substrate you’ll quickly identify that on a laminated product, the plastic stretches and refuses to break as the paper tears away.
For a non-destructive test, try folding the UV coating or Laminated sheet and press thoroughly with fingers at folded area. You’ll find Cracks in the folded area if it is UV coated or a Smooth Surface if it is Laminated.
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