A New Dielectro-phoretic Coating Process for Depositing Thin and Uniform Coatings on Films and FibrousSurfaces

摘要

The deposition of very thin functional coatings on polymer films and fibrous substrates is a challenge when using low percent solids in aqueous or solvent based solutions and practically impossible when using 100% solids. The challenge becomes even greater when coating fibrous materials such as paper, foam, and woven and non woven membranes and textiles with viscous solutions. Sigma has developed a proprietary coating technology that allows surfaces to be uniformly coated with relatively viscous monomers and water and solvent based solutions where the water and solvent are minimized to save energy and minimize coating costs. The coating process is composed of three separate and independent steps. An atmospheric plasma treatment station is used to improve surface energy, a coating module in then used to apply the coating and aDielectrophoreticstation is used to spread the coating on the surface using an electro-hydrodynamic force. The latter system acts upon the liquid with a force that can be controlled by the application of an electromagnetic field on the coated surface.This process is so effective, that a viscous liquid deposited on one surface of a non woven material can be driven to coat the fibers within the bulk of the fabric structure, as well as the opposite surface.