What Does Flowcoating Mean?
Flowcoating is an automated method of applying industrial liquid coatings. It involves directing numerous individual streams of coating over one or multiple parts that move horizontally on a conveyor. Flowcoating can be used to cover multi-dimensional surfaces of a variety of shapes.
Flowcoating results in a scratch-resistant, long-lasting finish, with higher gloss and distinctness of image than with conventional spray techniques. Advantages of flowcoating over other coating methods include:
- Transfer efficiency
Flowcoating is suited to large or oddly shaped parts that are difficult or impossible to dip coat. The advantages and limitations of the dipping process generally also apply to flowcoating.
Corrosionpedia Explains Flowcoating
Flowcoating is an automatic process, which has been adapted for applying weatherable, optically-clear, abrasion-resistant coatings for thermoplastics used on automotive exteriors and many other parts.
Flowcoating consists of controlled gravity flow of a coating over the substrate. Excess coating is collected, filtered, and combined with a fresh coating and make-up solvent, and then re-used. This results in less solid waste and lower material usage.
Flowcoating is a variation and extension of pre-coating, in that a panel is not only pre-coated, but the finish is coated as well. This technique can be used on any flat, horizontal surface, such as flowcoating an entire plywood panel to be used to form frame gussets and floors, or using the procedure to cover flat surfaces, such as a transom, centerboard, rudder, sole, etc. The main reason to use the flowcoating procedure is to achieve a smooth surface of high thickness in one operation, as opposed to applying several coats.
Flowcoating overcomes some of the limitations of dip coating. The volume of coating required in the system is lower than with dipping; parts will not float off the conveyor and extremely large, complex products, too large to dip, can be painted. Flowcoating can be done with parts on a conveyor that takes them through the enclosure, or manually, in exhausted booths.
Flowcoating, like dip coating, has problems with the wedge effect and solvent reflux. The process requires careful control of evaporation to obtain uniform coatings. When using waterborne paints, bubbling and foaming control is required. In both the dipping and flowcoating methods, hanging of the product is important to its final appearance.
While the process is surprisingly simple, flexible and easy to maintain, there are considerations in part design, coating and equipment selection which must be addressed to determine whether flowcoating is the optimal process for a given application. For several manufacturers of automotive headlamp lenses and exterior trim components, flowcoating has been the process of choice.