| abstract |
A fibrous insulation product with improved thermal resistance and method of making it are provided. A plurality of base fibers (e.g. glass) are formed into an insulation product, which may be bindered or unbonded. At least one infrared opacifying agent, such as soot, carbon black or graphite, is applied to the fibrous insulation product such that the base fibers are substantially uniformly coated with opacifying agent. The opacifying agent may be applied, for example, from a fluid suspension or by pulling the fiber through a sooty flame. When opacifying agent applied via a suspension and a binder is desired, it is preferable to avoid binder dispersions that can dislocate the opacifying agent. Alternative binder applications may include co-mingling of base fibers with binder fibers, or other physical or mechanical distributions. |