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Finished rollers emerge from an oven after having been powder coated and cured. After curing, each part is subjected to manual inspection for quality assurance.
When it comes to out-of-the-box thinking, Greenfield Products–located 70 miles east of Cincinnati, Ohio–has the market cornered. "If there's a box, we've never been invited inside," said the company's vice president, Wesley Pence.
Founded in 1959 as a manufacturer of marine accessories and outdoor cookware, Greenfield's flagship service is the production of anchors for the recreational boating industry. Many of the anchors are coated in heavy, mar-resistant plastisol coating, approximately 50 mils thick. The thick rubber-like coating not only protects the anchors–which are exposed to a variety of climate conditions and being scraped along rough surfaces on a regular basis–but helps preserve the finish of the boat as well.
While Greenfield has maintained the largest share of the cast-anchor market in the U.S. and Canada, it became clear several years ago that seasonal product lines would not sustain the business on a year-round basis. As a result, the company began marketing plastisol coating services to other industries on a job-shop basis. Soon, Greenfield was applying PVC to tools and automotive parts in addition to its own products. As these projects materialized, the company has added specialized equipment to improve its capabilities.
Adding Powder to the Mix
When Greenfield began marketing its services on a job-shop basis, it explored opportunities to work with powder coatings. While conducting some early experiments, the company became involved in the development of a powder coating project for General Motors. This job–the application of powder coat to battery cells for electric cars–later evolved into a contract. With this new contract in hand, Greenfield installed a small, specialized powder system to perform the job.
"The GM project required an unconventional masking technique, and none of the off-the-shelf masking products were working out for us," said Mr. Pence. "At that time, we had very little experience with masking and, because we had limited resources, we weren't in a position to contract the masking design to an established supplier."
Development and production for the General Motors project posed a challenge. The work required elaborate masking techniques in order to meet extremely stringent specifications.
"Basically, because we were out of ideas, I enlisted the help of a buddy of mine who had worked with silicones while he was at art school in New York City. He developed a very inventive cap configuration and built us a mold so we could produce caps ourselves. I think his creativity had a lot to do with us winning the contract."
With the help of Greenfield's anchor staff, the company eventually conquered the masking challenges and became comfortable with powder coating.
Dual Coating for Durability
In 1999, Greenfield decided to expand its operations. The expansion began with construction of a new 21,000 sq ft facility and installation of a much larger powder system as well as an electrocoat line.
Greenfield's expanded capabilities and its reputation in the marine industry for quality coatings brought interest from other, unrelated, marine manufacturers. Since there was increasing demand for coatings on parts, which had traditionally been stainless or galvanized, manufacturers turned to Greenfield to assist with development of deck hardware, such as cleats and winch housings. The primary challenge posed by these marine projects was that the parts needed to be both durable and attractive.
"We had a really difficult combination of salt resistance and UV resistance," said Mr. Puckett. To assist with this challenge, Greenfield turned to Morton Powder Coatings, whose experience in formulating hybrid powders proved invaluable. "They developed a custom powder for us, which offered the abrasion and salt resistance of an epoxy with the UV stability of a polyester." The result was a very durable coating suitable for the difficult environment of saltwater boating.
For added long-term protection, Greenfield used electrocoat as a primer, before applying the powder. "Our customers have been very pleased with the performance of the dual-coating technique," said Mr. Pence.
Finding a Niche
In the highly competitive business of coatings, Greenfield has found its niche with difficult jobs. Its largest powder customer is a manufacturer of rollers for exercise equipment and conveyor systems. In order to meet the customer's tight specifications, Greenfield developed radical masking techniques that kept areas clear for post-assembly. However, they found difficulty maintaining thickness specs on long, round tubes.
What made the job even more unusual was that Greenfield wanted to utilize a PVC powder, something that is generally not applied with electrostatic spray equipment. "Everybody said ‘don't do it'," said David Puckett, Greenfield's director of operations. "It won't work. You'll never hold the tolerances."
The solution to these obstacles was the installation of a spinner system into the powder booth, allowing vertically hung parts to begin spinning uniformly as powder is sprayed. This solved the thickness problem and allowed Greenfield to maintain tolerances of +/- 0.003 inch on all surfaces of round parts.
A Little Help From Its Friends
Greenfield's management attributes the company's success to three key factors: a creative approach, a willingness to take on tough projects and lots of assistance from key suppliers. It is the latter that Mr. Puckett is most grateful for.
"Morton was instrumental in supplying us when we first started up the plant," he said. "They've given us a ton of technical support. You develop some relationships and these relationships are why we all do business together."
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