Waterborne coatings possess some good properties such as hardness, flexibility, stain resistance, and corrosion resistance. Physical properties and performance depend on which type of resins and techniques are used in the coating process.
Emulsions-colloidal dispersions are a paint with a high molecular weight and dry fast through the coalescence of the resin particles. Resin clusters in emulsions tend to be larger and an emulsifier is used to keep them in suspension. This process can be helpful when using high-molecular-weight polymers that will impart improved properties like resistance to chemicals, and enhanced color. The increased permeability allows the coating to ventilate, reducing the chances for blistering or peeling.
Water-soluble coatings have individual molecules of water-soluble resins that completely dissolve in water. These resins are produced through reactions like poly-condensation or polymerization in an organic medium. Waterborne paints are only made up 30% to 40% solid content. Although sensitive to water these paints have a high gloss, good corrosion protection, and an excellent pigment.
Water-dispersible paints have tiny clusters of insoluble resin that are suspended in water by consistent mechanical agitation. A small percentage of the paint is organic solvents which act as coalescing agents that simultaneously dry and evaporate. Colloidal dispersions are mainly used for coating porous materials.
Waterborne coatings have a primary ingredient of one or more solvents. Solvents aid in dissolving the paint materials to form a sprayable liquid mixture. Once applied to a substrate, the curing process is required. The baking process depends on the type of water coating involved as some need to be heated to form a strong molecular bond and others just need the water to evaporate. The high curing process needs temperatures near 400 degrees Fahrenheit for approximately ten minutes. The low curing paints needs far less heat, and could also be completed through a dehumidification process. The evaporation rate is dependent upon the vapor pressure difference between the coating's water and the air being circulated over the surface part.