Mar 17 2004
Dow Corning has introduced two new polymeric silicone foam-control additives designed especially to address the process foaming problems that plague waterborne inks and coatings.
Dow Corning® 71 Additive is formulated for use in overprint varnishes, waterborne parquet lacquers and flexographic inks. Dow Corning® 74 Additive is suited for use in a variety of waterborne coatings, especially in wood coatings and automotive basecoats.
These new antifoams are balanced to deliver effective foam control on one hand and a low tendency to cause surface defects, such as craters and fisheyes, on the other. Because they do not contain hydrophobic particles, they are not prone to separation problems that can lead to surface blemishes.
Dow Corning 71 and 74 Additives are 100% active, so they are effective at lower use levels; and their self-emulsifying properties make them easier to incorporate into aqueous or polar coatings. Plus, they have highly stable polymers that enable them to be added under high shear. This facilitates addition during the pigment grind step. They can also be added during the let-down stage or post-added for even greater processing flexibility.
Environmental concerns over the levels of volatile organic compounds released into the atmosphere are pressuring formulators to produce waterborne alternatives for almost all classes of solvent-based coatings. As the use of waterborne coatings continues to grow, so do demands for faster production times and application speeds, which intensify the generation of foam.