1.1 This specification covers glass fiber unsupported needled felt (mechanically bonded) binder-free insulation for thermal insulation. This material is used as the thermal insulation component in the fabrication of insulation systems for u This specification covers glass fiber unsupported needled felt binder-free thermal insulations. This material is used as the thermal insulation component in the fabrication of insulation systems for use on machinery and equipment, such as steam turbine