PPG Industries' has added three window manufacturers as licensees of its proprietary technology for producing energy-efficient "warm-edge" insulating glass units. Licensed to use the company's Intercept glass unit technology are MGM Industries, Hendersonville, Tenn.; Jannock Vinyl Group, Pittsburgh, Pa.; and Marshall Vinyl Windows, Corona, Calif.

According to Bradley P. Boone, PPG manager of Intercept technology and licensing, the patented technology enables residential window manufacturers to produce a high-quality, warm-edge insulating unit at very efficient rates. Intercept technology accounts for more than 40% of insulating glass unit production in North America, Boone said.

PPG has licensed more than 70 window and insulating glass unit manufacturers in six countries to use its Intercept insulating glass unit technology, which was introduced in 1992.