ViscosityViscosity is a measure of the thickness or flow of a liquid; the higher the viscosity, the thicker the liquid. Viscosity affects feed rate, film thickness, drying time, and the quality of the finished product. Maintaining the optimum level specified by Nicoat is critical to successful coating. Any change from this specified viscosity will change the coating's running characteristics and finished quality. With lower viscosity (thinner coating), rollers lay down less coating, which can make the finished film too thin. With higher viscosity (thicker coating), rollers lay down more coating, which in addition to increasing cost, can create a host of problems from orange peel to build-up at the edge of the sheet to blocking. Sometimes you may need to adjust the coating viscosity to meet the requirements of a particular job. Do this by diluting the coating with water or by changing its temperature. Colder temperatures thicken coatings, and warmer temperatures thin them. |
