For Eco-Friendly Paint, Use Solvents, Not Water

Ford says that it can cut the energy and carbon associated with paint by phasing out water for industrial chemicals. What?

High-solid, solvent-based paint. It's the new green.

In a counterintuitive twist, Ford Motor Company has found that it is more ecologically friendly to swap water-based paints for paints made with industrial chemicals. Ford has tested out its relatively new painting process on a pilot line for Econoline vans in Ohio and now is rolling it out to plants in India, Romania, Mexico and China.

The difference is a relative lack of activity required on Ford's part. Water has to be sucked out of water-based paints and primers before the next coat can go on. That is accomplished through a flashing process "which is essentially a bake," said Tim Weingartz, manager of paint materials and strategies. 

The painting booths for water-based paints are also somewhat large, which means more air conditioning and handling. A paint booth might require 250,000 to 500,000 cubic feet of air removed every minute. 

"The biggest CO2 contributor is the booth where we apply the paint," Weingartz said. "The second is the oven."

Solvent-based paints have a much higher solvent quality and one coat can be applied while the preceding coat is still wet. In all, the process allows the company to eliminate one baking step and throttle the air handlers.

"Everyone is still looking at water-borne paint as more environmentally correct, but if you go through the lifecycle analysis it doesn't add up," he said.

Paint is one of those areas that will likely receive considerable attention in the coming years as companies try to lower their carbon footprints for profit and publicity. It's omnipresent, it's heavily fossil-fuel dependent, and a lot of the processes and assumptions are decades old. One of the more interesting small companies in the market is Bio-Reaction Industries, which has a system that gets rid of volatile organic compounds in the air in industrial plants with bacteria, soil and water. Various clients employ the technology to clean the air in booths with 150,000 cubic feet per minute plus air handling requirements. Typically, paint shops or lumber processors get rid of VOCs by incinerating them in natural gas-fired ovens.

Sony, meanwhile, has employed a paint strategy for its "green" cell phones that involves shipping the pigments only and adding the liquid carrier (water, actually) at the factory. This cuts down fuel consumed in transportation.

Ford notes that the company is not reverting back to the solvent-based painting techniques that water-based paints eliminated. That older process is ecologically the worst of all alternatives. Instead, its process is new and emits the least of the three in carbon dioxide.

It's cheaper too. Ford can save approximately $5 to $11 per car, he said, or about $25 million per plant a year.

Ford is also working on a "liquid wood" made from wood and polymers. The substance could ultimately be used in car interiors or to position components like batteries.


Learn how to differentiate your company through greener product lines at Greening the Supply Chain on September 17 in Boston.