Research on Aerogel Thermal Insulation Coating to Ensure Personal Safety
Traditionally, the main method of thermal insulation has been the use of hollow ceramic microspheres, which have improved thermal insulation due to their hollow construction. Recently, formulators have begun to use aerogel particles as a major additive in thermal insulation coatings. Aerogel, a highly porous solid material known for its excellent thermal and thermal insulation properties, is made from amorphous silica as the base structure. The thermal conductivity of the porous structural material is about 0.012 W / m · K (0.007 Btu-ft / [h-ft2 ° F]), the thermal conductivity of the ceramic microspheres is 0.05~0.2 W / m · K 0.116 Btu-ft / [h-ft2 ° F]. Unlike the degradation of the properties of a hollow sphere, the aerogel particles can be comminuted without losing their thermal insulation properties.
In an industrial environment, a contact time of 5 seconds may cause pain when the temperature is between 44C (111T) -48_C (11BT). One burn at 58C (137'F) and a second degree burn at 61C (141T) or higher.
Thermal insulation paint evaluation
The skin contact temperature Tc at the time of 5-minute contact with the coating material of 4 types of commercially available thermal insulating materials, such as a ceramic and an aerogel, was evaluated using the temperature sensor, and the acrylic paint was used as a reference. Figure 2 shows the performance of a 40 mil thick coating with substrate temperatures of 160X: and 200X:.
Aerogel Insulation Coating A shows superior performance at both substrate temperatures. Aerogel Insulation Coating A reduces the skin contact temperature of the 160C substrate by more than 14X: compared to the ceramic coating, and 200X: the skin contact temperature of the substrate by more than 18X:.
When it comes to personal protection, exposure to a skin contact temperature of less than 3X: (5T) for 5 seconds means no burns and no difference in OSHA-recorded injuries (see below), which means that with a ceramic coating Compared to the aerogel insulation coating can provide greater security space.
Personal protection at the factory workplace is more than just preventing burns. The ASTM standard states that the first burn that begins to occur is the upper limit of hot surface exposure to an injury event. However, an accidental exposure of an employee to such a surface may be like a discomfort experienced and will leave the surface reflexively. This reflex response can cause a variety of safety problems, especially when working in workplaces that are close to or crowded with each other. Only a few millimeters thick of an aerogel insulation coating can prevent this from happening, not only keeping the skin contact temperature below the threshold of irreversible skin lesions but also near or below the threshold of pain.
Less coating means increased economic efficiency
Unlike typical coatings, thicker coatings are used for ballast coatings using thermal barrier coatings of ceramic beads and aerogel particles. Ceramic microsphere functional coatings can be applied at thicknesses of 15 to 20 mils (0.37 to 0.5 mm) and aerogel functional coatings can be applied at thicknesses of up to 60 mils (1.5 mm) or larger.
In contrast, single-channel aerogel coating provide better protection from burns at service temperatures up to 200 ° C (392 ° F).