Deaerators designed on an organo-modified silicone platform provide superior macro- and microfoam suppression capabilities.
In the early 1980s, the domestic ink and coatings industry began a major effort to provide products that would help coatings manufacturers lower VOC emissions. The industry used a number of approaches including, but not limited to, exempt solvents, increased solvent capture by the coatings formulators and water-based coatings.
Each approach had positive and negative considerations. Using solvents exempt from the EPA Method 24 calculations lowered VOC output but proved of little use due to limited solubility with certain resins. Use of solvent capture equipment was, and is a viable option but is constrained by the high capital and maintenance costs. Partially driven by innovations at that time, water-based systems presented the most economical means of compliance with evolving VOC and HAPS (hazardous air pollutants) regulations. However, the resins and emulsions used for these systems require surfactants (soaps) to make them compatible in an aqueous medium. Unfortunately, these additives, plus others used to enhance properties like pigment and substrate wetting, contribute to foam formation within inks and coatings.
Today, the need to lower emission levels even further – combined with multiple-purpose raw materials – creates an even greater likelihood of formulating clearcoats that foam. This paper investigates the use of organo-modified siloxane technology to control the proliferation of foam, while maintaining desired properties.2