NewsInformation Center
What is TPP and HTP?
2017/10/23
Share:
ASTM D4108-87 Thermal Protective Performance (TPP) test measured the amount of thermal protection a fabric would give a wearer in the event of a flash fire. The TPP is defined as the energy required to cause the onset of second-degree burn when a person is wearing the fabric. The higher the TPP, the more protective the fabric. The passing criteria for NFPA 2112 – 2007 Edition was a minimum TPP of six calories in a spaced configuration, and a minimum TPP of three calories in the contact configuration.
TPP was first utilized in the 1980s as a method to evaluate the effectiveness of fire fighter turnout gear. When the ASTM F23 Committee on Protective Apparel reviewed this test method in the mid-2000’s, the Committee determined that TPP did a poor job of measuring the heat a fabric would block to prevent a burn – the protective part of TPP. As such, the Committee created HTP (Heat Transfer Performance) where part of the transition from Thermal Protective Performance (TPP) was to remove all references to protection.
ASTM F2700 is the Standard Test Method for Unsteady-State Heat Transfer Evaluation of Flame Resistant Materials for Clothing with Continuous Heating. This test method is intended for the determination of the heat transfer performance (HTP) value of a material, a combination of materials, or a comparison of different materials used in flame resistant clothing for workers exposed to combined convective and radiant thermal hazards.
This test method evaluates a material’s unsteady-state heat transfer properties when exposed to a continuous and constant heat source. In the test method, a swatch of fabric is positioned horizontally and exposed to a two cal/second flame. A sensor measures the amount of energy that passes through the fabric during the exposure. Once sufficient heat has passed through the fabric to cause 2nd degree burn, the flame exposure is terminated. The difference between the amount of energy the fabric is exposed to, and the amount of energy that passes through the fabric during the exposure, is essentially that fabric’s HTP.
TPP was first utilized in the 1980s as a method to evaluate the effectiveness of fire fighter turnout gear. When the ASTM F23 Committee on Protective Apparel reviewed this test method in the mid-2000’s, the Committee determined that TPP did a poor job of measuring the heat a fabric would block to prevent a burn – the protective part of TPP. As such, the Committee created HTP (Heat Transfer Performance) where part of the transition from Thermal Protective Performance (TPP) was to remove all references to protection.
ASTM F2700 is the Standard Test Method for Unsteady-State Heat Transfer Evaluation of Flame Resistant Materials for Clothing with Continuous Heating. This test method is intended for the determination of the heat transfer performance (HTP) value of a material, a combination of materials, or a comparison of different materials used in flame resistant clothing for workers exposed to combined convective and radiant thermal hazards.
This test method evaluates a material’s unsteady-state heat transfer properties when exposed to a continuous and constant heat source. In the test method, a swatch of fabric is positioned horizontally and exposed to a two cal/second flame. A sensor measures the amount of energy that passes through the fabric during the exposure. Once sufficient heat has passed through the fabric to cause 2nd degree burn, the flame exposure is terminated. The difference between the amount of energy the fabric is exposed to, and the amount of energy that passes through the fabric during the exposure, is essentially that fabric’s HTP.
Previous: Test Illustration of Thermal Protective Performance Tester
N e x t : Operating procedures of Glow Wire testing Apparatus
