The founders of Optimer Inc have sold a controlling interest in the performance fibre maker to private equity firm Sterling Capital Partners for an undisclosed sum.

The JW Moore family says the deal will infuse the Wilmington, Delaware-based fibre firm with extra funding to boost sales of its research, development and consulting services, as well as protect its patents and trademarks.

Optimer is best known for its Optimer Performance Fibers (OPF) division which markets Dri-release with FreshGuard, a patented moisture release and odour blocking textile technology.

Dri-release technology, licensed worldwide, is used primarily in performance activewear by over 100 brands such as Adidas, Polo Ralph Lauren and Hanes.

"We first became acquainted with Sterling in 2006 while working with them to develop a fire retardant version of Dri-release for one of their divisions," says Dr John W Moore, CEO and spokesperson for the Moore family, founders of Optimer Inc.

"We chose the company to join us because of their unparalleled success in helping grow companies like ours."

Sterling Capital Partners is a middle-market private equity fund with over USD$3bn under management and offices in Chicago and Baltimore.