Image Number 2 for United States Patent #4311751.
A moldable sound control composite is disclosed combining in itself when molded damping, barrier performance, and structural strength for use within a predetermined environment temperature range. As such, the moldable composite is not applied to other structures to damp their sound generation, but forms by itself a complete structural member having not only desirable sound reducing properties but desirable strength properties as well. The composite comprises a blend of a primary non-viscoelastic organic polymeric resinous material intended to impart structural strength to the composite, a secondary viscoelastic organic polymeric resinous material to provide damping performance, and filler material adapted to densify the composite and impart barrier performance. Optionally, at least one of the primary and secondary resinous materials may be thermosetting. By virtue of the blend of all of these ingredients, the molded composite has a glass transitional temperature range generally corresponding to the predetermined environmental temperature range for which the composite is designed for use and a maximum loss factor, n, falling within that range.