Process engineers at leading automotive supplier Valeo Inc. were having a hard time checking the durability and performance of the rectangular gaskets the company makes for radiators. Sensors they used kept giving inaccurate readings. As an experiment, they tried Pressurex sensor film from Sensor Products LLC for stress-distribution analysis.
The film consists of thin, clear Mylar sheets treated to turn color in response to pressing. A color-coded chart supplied with the film is used to interpret the pressure related to each color. The film can be inserted between mating objects, such as a gasket and radiator, or placed under an object, such as a tire tread, to generate a pressure-distribution image. The film detects pressures from 2 to 43,2000 psi (0.14 to 3,037 kg/cm2), and can be customized to work despite the presence of oil, water or other liquids.
The quality assurance staff at Valeo cut Pressurex into strips to fit between the gasket and radiator and got results in seconds. It let them spot areas with inconsistent pressure and correct them. The sensor film is now used in several Valeo plants during design, development, and production of auto parts.