What To Look Out For

The primary environmental threats posed by screen printing result from the chemicals and processes used in screen cleaning and reclamation and the practice of flushing wastewater down the drain without proper filtration. Here are a few indicators to consider when you are in the market for safer supplies:

VOC Content

The EPA defines VOC's as organic compounds that participate in atmospheric photochemical reactions. In less scientific terms, VOC's are chemicals that evaporate and contribute to air pollution. Traditionally, screen cleaning and reclamation products have contained high levels of VOC's. The solvent methyl ethyl ketone (MEK), for instance, is 100% volatile. The major problem with VOC's is that when they react with nitrous oxide, an automobile emmission, they create smog. So, generally speaking, the lower a product's VOC content, the lower the threat of air pollution it represents.

Vapor Pressure

A solvent's vapor pressure is its rate of evaporation at room temperature on a mercury guage. So, the lower the vapor pressure a product has, the slower it evaporates. As a result, fewer VOC's are released into the air, translating into less air pollution.

Hazardous Chemicals

A product is considered hazardous if it is ignitable, corrosive, reactive, or toxic. Color matching, screen cleaning, and screen reclamation commonly create hazardous waste. Hazardous chemicals, if disposed of inappropriately, are major-league contributors to ground and water pollution.

Safety Solvents

Safety solvents earned their name simply by being safer than the products they were designed to replace, such as lacquer thinner. So it's important to note that these products are safe only in a relative sense, and a vast range of products could fall into this category. Lacquer thinner, for example, could be considered a safety solvent compared to gasoline. So labeling a product a "safety solvent" can get pretty tricky, but if reducing the environmental threat posed by your shop is the goal, then safety solvents are a good place to start.

Most chemical companies now offer specifically designed cleaning and reclamation chemicals in lower-VOC, lower-vapor pressure, and lower-hazard alternatives. When used in conjunction, these products not only streamline the screen cleaning and reclamation process, they also reduce the environmental impact your shop poses.

Platen Adhesives

Because they are used in much smaller quantities and aren't as hazardous as solvents, platen adhesives don't pose as significant a threat as screen cleaning and reclamation products. They do, however, offer an easy way to cut down VOC emissions and waste. The standard platen adhesive in the industry today is solvent-based and, as a result, presents VOC emissions problems. Several companies have developed VOC-free, water-based adhesives that are either spread or pumped onto the platen.