A good way to achieve solid fixing agents that are very dull is to envelop the amorphous additives, before their introduction into the polyblend of the binders, with a lubricating additive that enables their acceptance into the polymer film with a greater mechanical compatibility in the dry system. If not carefully selected, the surfactants that stay inside the dried film can compromise the fastness of the finishing in wet conditions. When changing from solvent to water-based finishing, it should also be considered that a high application of solids made with a rollercoater allows you to achieve a quick drying of the film with the same dryers and the same time, whereas a spray application needs to be more diluted with water and needs a lot more thermal energy to dry out. This major need for energy increases by 3-4 times compared to solvent topcoats, so it is wise to take this into consideration. The specific physical properties of water and those of organic solvents differ considerably and have to be taken in consideration when water is used as a diluent.
Water molecules have a high dipole moment and are joined together by means of a hydrogen bonding.
This means that water has a high latent heat, which results in a longer evaporation time or the need for a much larger supply of thermal energy to remove the water from the applied product. The high dipole moment is also responsible for the higher surface tension of the water-borne systems. The poor wetting properties of water dilutable systems may result in a lack of flow-out and poor adhesion. Fortunately, some chemical products once dissolved possess a greater power in changing the surface tension of their solvents, even if used in limited quantities. The drying is natural, but made easier by the heat supply.