Industry Advancements in Exterior Durability of Coatings

By Cynthia Challener

Core paint and coatings manufac­turing processes have remained largely unchanged since the dawn of the industry. Ingredients are mixed into a liquid (organic solvent or water), a process that is often followed by milling to achieve the correct particle size for products comprising dispersions. Despite this, the paint and coatings industry is very dynamic. Business trends, market demands, governmental regulations, sci­entific innovations, and other forces are continually prompting changes that call on manufacturing equipment suppliers to provide new solutions.

One such change, the move from nor­mal steel to a primarily stainless steel construction for high-speed dissolvers (HSD), occurred over the last 70-80 years, according to Hans-Joachim Jacob, senior process engineer and customer application specialist at ystral gmbh maschinenbau + processtechnik. “HSDs are low-shear machines, but high-shear forces are often required for proper dispersion of paint ingredi­ents. These forces can be generated by increasing the viscosity, but the viscos­ity changes from the start to the end of a process, requiring careful control by the operator.

As a result, processes today are still heavily influenced by the specific operator, and a cyclical mix-quality check-adjust with additives and repeat system is used that can be time con­suming,” he observes. Jacob believes it is time for a change. “Instead of relying so heavily on additives to solve perfor­mance issues,” he says, “the industry should be doing more with technology, such as to prevent foaming.” Other changes, such as to formula­tions and batch sizes, have made it a challenge to produce new products in legacy assets, according to Stuart Rae, advanced manufacturing director at AkzoNobel. “There is need for greater agility to handle smaller batch sizes with the same levels of efficiency and cost, even for formulations that have lower levels of biocides, so they require higher levels of hygienic conditions.

The reduction in biocide use for consumer water-based products has, in particular, created challenges to ensuring product quality given existing raw material qual­ity, storage, and legacy plant designs. Smaller production orders, meanwhile, require the same cleaning times and incur higher residual losses, and thus process and product redesign are needed to enable sustainable manufacturing under current conditions,” he explains.