A low settled density loose fill heat insulation for building structures is formed by the addition to cellulose insulation of staple fibers selected from the group polypropylene, acetate, polyethylene, polyester, acrylic and vinyl. The staple fibers extend the cellulose insulation....http://www.google.es/patents/US4468336?utm_source=gb-gplus-sharePatente US4468336 - Low density loose fill insulation
