
Accurate Dorwin
Accurate Dorwin created the world’s first fiberglass window in 1983 and has manufactured and installed these ultra-energy efficient windows ever since. Because of their highest ER ratings and lowest U-values, Accurate Dorwin fiberglass windows are the top choice of green building professionals. Enjoy the energy savings and beauty of fiberglass—the fastest growing window frame of choice in North America.
It’s a strong statement, and we stand behind it: Accurate Dorwin fiberglass window systems, featuring technologically advanced pultruded fiberglass lineals, are superior to PVC, aluminum, or metal-clad wood window frame materials. In 1983, Accurate Dorwin developed a new and unique window system that utilized a pultruded fiberglass frame, insulating foam, and high-performance insulated glass. Today we refer to it as the Fiberglass Advantage.
The manufacturing process for fiberglass windows is different from traditional application. Accurate Dorwin windows are created using a pultrusion process. Glass fibers are coated in a thermoset resin and pulled through a hot die the shape of the frame or sash profile. They are pulled through the die rather than pushed or extruded through the die, hence the term pultrusion.