Solvent based inks in different colors and patterns are applied to paper, plastic, film and foil substrates. Finished products include all sorts of wrapping paper, wall covering, candy wrappers, flexible food packages, shrink labels, high quality magazines and many, many more. These industries employ ovens or dryers to remove the solvents from the finished product.
The key hazard is an explosion from the buildup of solvent vapors in the oven or dryer atmosphere. This buildup could occur by a malfunction in the production process such as: a sudden or improper amount of coating, a change in ventilation controls or excessive speed. In any of these cases, the concentration of flammable vapor has an opportunity to rise above safe levels, creating a potentially explosive mixture of vapor in air.
The design specification for safe operation of a solvent oven or dryer is outlined in safety and fire codes. The codes limit the maximum solvent concentration allowable to 25% of the LFL under worst case operation. However if a flammable vapor analyzer is installed as a safety control the maximum allowable concentration is 50% LFL. Our PrevEx analyzers are the only analyzers that meet all the requirements of the NFPA standards. In addition, the analyzers improve the efficiency of the process and significantly lower process energy requirements.
Examples of solvent-based printing applications include:
- Pressure sensitive labels
- Shrink labels
- Heatset web offset printing
- Flexible packaging
- Wall coverings
- Gravure printing
- Flexographic printing
- Decorated paper