Painting cars has negative effects on the environment, while also being a costly process. Researchers have been given over half a million dollars to discover better methods for this industry.
If paint its formulated incorrectly, instabilities can form pockmarks on cars. It requires a great deal of energy to apply paint to a car, accounting for 60% of the energy consumed by a single automotive plant, according to Gilchrist.
Manufacturers use robots to spray the paint, and that spraying takes place in rooms designed to contain and safely emit volatile organic compounds. When an application isn’t done correctly, the vehicle must be recoated and touched up, a process that can cost a single plant more than $10m (~€8.9m) per year.
“Consumers are extremely picky regarding the quality of the paint job on any car they purchase, new or old, and the 10- to 20-year appearance of a car depends on 10 to 20 critical minutes of application and drying,” says James Gilchrist, a professor of chemical and biomolecular engineering at Lehigh University’s PC Rossin College of Engineering and Applied Science.
In November 2019, Gilchrist and his collaborators obtained a grant for a project that will essentially help industry get it right the first time.
The National Science Foundation’s Fluid Dynamics program awarded Gilchrist, who is working with collaborators at Case Western Reserve University (CWRU) and PPG, more than half a million dollars in support of his Grant Opportunities for Academic Liaison with Industry (GOALI) proposal to better understand paint through kinematics and rheology.
GOALI proposals focus on shared interests of academic researchers and industrial partners, seeking to advance scientific and engineering knowledge that could lead to technological breakthroughs relevant to industry needs. PPG is one of the largest global coating companies, with more than 47,000 employees and operations in over 70 countries.
“We’re trying to understand the fundamental drying process, and how these paints chemically and physically evolve while they’re drying,” Gilchrist says.
Gilchrist joined the project through CWRU assistant professor Chris Wirth and Reza Rock, Ph.D., principal investigator for PPG. “PPG provided financial support to my lab for two and a half years leading up to the NSF GOALI project,” says Wirth.
He continued: “This early support from them was critical in showing our techniques were feasible in such complex systems and in helping this team identify the fundamental issues that needed to be solved for the full potential of our strategy to be realised.”
“We anticipate that this project will significantly advance our understanding of the complexities of coating application, drying, and curing behaviour, through development and implementation of new
Gilchrist’s team are using microrheology to study the effect on the system of adding different rheological modifiers, particles with a range of geometric and surface properties. By putting fluorescent probes in the paint and tracking with a microscope how they move, the researchers can determine if a formulation is causing the paint to act like a solid or a liquid as it’s drying.