Equipment and duct liner insulation and method

Resilient, polymeric fiber liner insulation, comprising:

• a resilient insulation blanket core of polymeric fibers;
• the blanket core having a length an a width;
• the blanket core having first and second major surfaces defined by the length and width of the blanket;
• the blanket core having a thickness of about 0.5 inches or greater;
• the blanket core having a density between 1 pcf and 3 pcf;
• the polymeric bars being between 60% and 90% by weight standard polymeric staple fibers and/or flame retardant polymeric staple fibers and between 10% and 40% by weight lofting and bonding polymeric fibers;
• the polymeric fibers having an average denier between 3 and 15;
• the polymeric fibers having an average length between 0.5 and 4.0 inches;
• the polymeric fibers including thermoplastic polymeric staple fibers that, at and adjacent the first major surface of the blanket core, have been melted and consolidated to form a surface layer on the first major surface of the blanket core that is coextensive and integral with the first major surface of the blanket core;
• the surface layer being less permeable than the second major surface of the blanket core;
• the the surface layer having a porosity between 200 and 1000 Mks Rayls that provides the polymeric fiber liner insulation with a higher noise reduction coefficient than an identical polymeric fiber insulation with a higher noise reduction coefficient than an identical polymeric fiber insulation blanket without the surface layer and that enhances the sound absorption properties of the inner insulation while maintaining a smooth surface to minimize locations where dust, dirt particles, bacteria and mold can collect;
• and
• the polymeric fiber liner insulation having a flame spread/smoke developed index of ≦25/50.