Grille Supplier Turns to New Coating to Meet Demanding Color Needs

Creative Millwork, an Ohio-based supplier of standard and custom window and door grille products to window and door manufacturers and distributors, serves more than 60 customers, providing up to 10 standard grille colors for each, as well as custom colors. Working with a variety of substrates, including pine, extruded cellular PVC, extruded aluminum and CNC-profiled aluminum, the company estimates that its current color palate includes more than 400 colors that must be kept on hand to meet customer needs.

 
 The company's finishes must closely match those of its customers' sash and frames.

Creative Millwork’s finishing line, which includes two paint booths and gravity-fed paint guns, must coat the grille bars to perfectly match the color and gloss levels of each customer’s exterior window sash and frames within 1.0 Delta-E, the smallest color difference that can be seen by the human eye. The finishing work must also meet exacting standards for adhesion and color retention on vinyl and aluminum materials and meet AAMA exterior grade performance standards.

When the company started in 1987, all of its products were wood, and lead times were three to five weeks. Because Creative Millwork worked with carpenters and painters who were finishing homes, most of the business involved supplying interior grilles. In those early days, vinyl-based product sales were low, and aluminum product was considered high-end.

Today, those materials are in demand and Creative initially used a water-based polyurethane coating, but adhesion to PVC and primed aluminum was not as robust as desired. As a result, the supplier sought a coating that could be used simply and effectively on aluminum and vinyl substrates.
“Our goal was to find a coating that would enhance our adhesion quality as well as provide color-matching for the wide variety of colors we are asked to deliver, plus have the ability to perform on our existing coating equipment,” says Mark Estock, Creative Millwork president.

A polyurethane enamel coating from Sherwin-Williams–Polane UVR–met the adhesion and color matching qualifications. It offered additional benefits as well. “Color matching and adhesion were great from day one, but the added benefit of lower dry/cure times allowed us to complete the remaining machining processes several days sooner, which meant quicker shipments to our customers,” Estock reports.

 
 Shades of white may dominate the business, but customers demand darker colors too.

As time passed and the market evolved, demand has increased for interior and exterior vinyl products; which makes up the majority of Creative Millwork’s business today. Vinyl also adds the challenge of heat sensitivity, providing the potential for warping at 140⁰F (approximately twice the coefficient of thermal expansion as that of aluminum).

As a result, Creative Millwork tested Polane SR, a solar reflective coating variation of the Sherwin Williams product, and found it to work extremely well on PVC, significantly reducing any design concerns of solar heat gain and any corresponding thermal expansion. While darker colors are usually special order items—the overwhelming majority of business remains shades of white, followed by tan and, to a lesser extent, clay—the company settled on solar reflective option as its standard finish, thus reducing inventory costs.