HEAT REFLECTIVE TAPES AND FOILS
DEFINITIONS AND TECHNICAL DATA RELATED TO PERFORMANCE
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Tapes and foils are passive thermal control systems; their purpose is to minimize heat transfer through the panel or surface they protect . Top level motorsport shares many technologies and materials with the aerospace industry; heat-reflective tapes are but one example. There is however more than a little confusion regarding the specifications and performance of tapes that are actually used in space applications.
Since there is no atmosphere in space, the heat transfer properties of materials used there are defined by an emittance number for radiated heat. The lower that number, the less heat pass-through or transfer they allow. Real gold is typically used as the heat-reflective mirror for the tapes used in space for 2 reasons: 1) the gold has a very low emittance number (0.02) 2) gold is completely inert; gamma rays will not pass through it. Thus, in space applications, you will see gold used on both interior surfaces (to keep heat inside a satellite or spacecraft) as well as exterior surfaces (to keep gamma rays out). Here on earth, heat is transferred through both conduction (heating the air around an object; this warmed air then transfers heat to the object. This is how ovens work) as well as radiance (actual radiated heat energy from the heat source). The emittance number for our AEROLITE tape is 0.03, so 97% of the radiated heat is reflected (not passed through), as compared to 98% reflection for real gold tape ( 0.02 emittance): This is an insignificant difference, especially since the conduction heat effect is the same for both materials (when used in the presence of air). This is the exact opposite of a space application for the same material, where 0.02 to 0.03 is a 50% performance differential when you are trying to keep interior heat from escaping from a 30+ year life satellite ( and where no air conduction heating is present). The other earthly consideration is cost: our aluminum-mirror tape is approximately 80% less expensive than the real gold material . Finally, it should also be noted that the “gold” heat reflective tape that is marketed to the racing and automotive high-performance industries is actually an aluminum mirror that is overlayed with a gold-colored film which is FOR APPEARANCE SAKE ONLY: it adds nothing to the actual performance of the tape. Please note the chart below. |
TECHNICAL SPECIFICATIONS Coast AEROLITE tape: 5 layers
Coast AEROLITE PLUS: 3 layers
Total thickness: less than 0.015” ; weight: 288g per square meter; 8.5oz per square yard. Aerolite Plus rolls = 20" wide x 30 ft. Coast EMBOSSED ALUMINUM FOIL: 2 layers
Competitor’s EMBOSSED “GOLD” TAPE: 4 layers
COMPARISON TESTING In order to get an apples-to-apples comparison between our tapes and the slightly-embossed “gold” material that is in nearly universal circulation in racing, the materials were tested as follows: tapes were applied to an aluminum panel (0.063” 3003H14). A calibrated source of constant heat (1000F) was fixed 2.38” from the protected panel. Heat was applied to the front (tape-protected) side and times to 180F (82.2C) and 220F (104.4C) were measured multiple times on the back side of the panel and averaged. Tests were run with room ambient temperatures of 80-85F in still air |
☠ Please note the following ☠
Several samples of the embossed "gold" tape were tested, and performance was very inconsistent. The material referenced in the above table was from the highest performing samples. The performance of the other samples we tested barely exceeded bare metal. We were unable to identify any visual difference between the "good" and the "bad" material. OUR RECOMMENDATION IS TO AVOID THIS MATERIAL UNLESS YOU VERIFY ITS PERFORMANCE WITH YOUR OWN TESTS. Additionally, there have been reports of the PSA used with this material igniting! All PSA used on Coast types is certified to pass FAA and government flammability requirements for aircraft and aerospace usage.
Several samples of the embossed "gold" tape were tested, and performance was very inconsistent. The material referenced in the above table was from the highest performing samples. The performance of the other samples we tested barely exceeded bare metal. We were unable to identify any visual difference between the "good" and the "bad" material. OUR RECOMMENDATION IS TO AVOID THIS MATERIAL UNLESS YOU VERIFY ITS PERFORMANCE WITH YOUR OWN TESTS. Additionally, there have been reports of the PSA used with this material igniting! All PSA used on Coast types is certified to pass FAA and government flammability requirements for aircraft and aerospace usage.