Optimization and Manufacturing of Opacified Fibrous Insulation

HeetShield Inc. will optimize a thermal insulation for 1100oC to 1700oC using a physics-based model, demonstrate its fabrication in a pilot production facility, and validate its performance at elevated temperatures using a test method developed at NASA.  In this temperature range, most of the heat is transferred by radiation, and the peak wavelength of radiation at these temperatures can be determined and modeled using a model that predicts radiative heat transfer from first principles.  This model can be used to determine the heat transfer through samples made of different materials.  For launch and re-entry vehicles, high temperature materials are needed.  Silicon carbide is one example among various high temperature materials whose properties are known to be good at blocking radiative heat transfer.  Flexible, fibrous insulations, made of silicon carbide, will be modeled, and optimized for fiber diameter and density.  The optimized fibers will be produced using  electrospinning processes developed at Virginia Tech University (VT).  Compared to other methods of producing fibers, electrospinning has the advantage of being able to produce continuous, bead-free, sub-micron fibers.  Additionally, electrospinning is known to be a scalable, repeatable process that is being accepted into production environments.  Fibers from VT will be used in bench scale tests to demonstrate insulation manufacturing process compatibility.  Pilot scale manufacturability will be demonstrated using a pilot production plant recently developed to produce high-performance thermal insulations in small quantities with little waste.   Thermal insulation samples will be evaluated using Thermal Insulation Characterization (ThermIC) methodology, which uses a pulse of heat from an open flame through the test specimen to determine thermal properties, like thermal conductivity and specific heat, as a function of temperature.  These steps of modeling, manufacturing and validation will lay the groundwork for manufacturing scale-up of an optimized Opacified Fibrous Insulation (OFI) in Phase II.