Heat Deflection Temperature Tester & Vicat Softening Temperature Tester Manufacturer
HDT / VICAT Testing Machine is a dual-purpose tester used to determine the heat deflection temperature of plastics under load and VICAT softening temperature of thermoplastic materials. This plastics testing machine is designed to suit the high-speed development of the plastics industry and enhance the research and development of non-metallic materials.
HTD is the temperature at which the deflection of the test specimen under load reaches the standard deflection while the temperature is raised at a uniform rate. VST (VICAT) is the temperature at which a flat-ended needle penetrates the specimen to a depth of 1 mm under a specified load.
Test Principle of Heat Deflection Temperature
A test piece in specified size placed in a heating bath is subjected to three-point bending under a constant load in the flatwise or the edgewise position to generate one of the flexural stresses. The temperature is lifted at an even rate, and the temperature at which the deflection corresponding to the specified increase in flexural strain happens is measured.
Test Principle of VICAT Softening Temperature
A standard test piece is mounted into the machine and placed in the heating bath filled with liquid. Under a prescribed force normal to the test piece, a standard indenter penetrates 1 mm into the surface of a test piece while the temperature is heated at a given rate. The temperature in degrees Celsius at which the penetration is 1 mm is called the Vicat softening temperature (VST).