What is heat deflection temperature in plastics?
HDT stands for Heat Deflection Temperature or Heat Distortion Temperature. The heat deflection temperature is a measure of polymer’s resistance to distortion under a given load at elevated temperature. In other words, it is the temperature at which a given polymer test bar will be bended of 0.25 mm under a given load.
What is heat deflection temperature test?
Heat deflection temperature is defined as the temperature at which a standard test bar deflects a specified distance under a load. It distinguishes between materials that are able to sustain light loads at high temperatures and those that lose rigidity over a narrow temperature range.
What is the heat deflection temperature of polypropylene?
What are the properties of Polypropylene?
| Property | Value |
|---|---|
| Melt Temperature | 130°C (266°F) |
| Typical Injection Mold Temperature | 32 – 66 °C (90 – 150 °F) *** |
| Heat Deflection Temperature (HDT) | 100 °C (212 °F) at 0.46 MPa (66 PSI) ** |
| Tensile Strength | 32 MPa (4700 PSI) *** |
What is ASTM D648?
ASTM D648 determines the temperature at which an arbitrary deformation occurs when specimens are subjected to an arbitrary set of testing conditions. ASTM D648 applies to molded and sheet materials available in thicknesses of 3 mm (0.125 in) or greater which are rigid or semirigid at normal temperature.
Why is heat deflection temperature useful?
The heat distortion temperature (HDT) – also known as the deflection temperature under load (DTUL) or heat deflection temperature – is an important property of polymers. It gives an indication at what temperature materials start to “soften” when exposed to a fixed load at elevated temperatures.
How does temperature affect polymerization?
The temperature affects both the rate of free radical formation and the thermody- namic properties of the polymerization system. It is also shown that higher levels of initiator at a particular temperature actually produced larger particles.
What is temperature of deflection under load?
The deflection temperature is a measure of a polymer’s ability to bear a given load at elevated temperatures. The deflection temperature is also known as the ‘deflection temperature under load’ (DTUL), ‘heat deflection temperature’, or ‘heat distortion temperature’ (HDT).
Is polypropylene safe for hot food?
It’s FDA-approved for food contact, so you’ll find polypropylene in food containers like those that hold yogurt, cream cheese, and butter products. Because it has a high heat tolerance, it’s also often used in packaging of food that can be heated in a microwave.
What are the factors which affect the HDT?
However, the HDT test is a short-term test and other factors such as the time of exposure to elevated temperatures, the rate of temperature increase, and part geometry all affect the overall performance of the material under heat.
What is the purpose of heat deflection temperature?
How is heat deflection defined in ASTM D648?
Heat Deflection Temperature (HDT) ISO 75 and ASTM D648 Another measurand is the heat deflection temperature (HDT) at which a prismatic specimen is subjected to bending and warmed to a defined temperature increase. Once the heat deflection temperature is reached, the specimen has achieved a deflection defined by the standard.
Which is ASTM D648, ISO 75 or DTUL?
Heat Deflection Temperature ASTM D648, ISO 75 Intertek provides Deflection Temperature Under Load (DTUL or HDT) ASTM D648, ISO 75 data for polymer datasheets and material specifications.
What is heat deflection temperature under load ( DTUL )?
Intertek provides Deflection Temperature Under Load (DTUL or HDT) ASTM D648, ISO 75 data for polymer datasheets and material specifications. Heat deflection temperature is defined as the temperature at which a standard test bar deflects a specified distance under a load.
What is the heat deflection temperature of plastics?
Deflection Temperature Testing of Plastics. The deflection temperature is also known as the ‘deflection temperature under load’ (DTUL), ‘heat deflection temperature’, or ‘heat distortion temperature’ (HDT). The two common loads used are 0.46 MPa (66 psi) and 1.8 MPa (264 psi), although tests performed at higher loads such as 5.0 MPa (725 psi)…