Up to this maximum temperature, a material is able to support a load for some appreciable time. The tests for the heat deflection temperature hdt and the vicat softening temperature vst form part of the fundamental characterization methods for plastics. Nylon 66 gf30 has more than double the strength and stiffness of unreinforced nylons and a heat deflection temperature which approaches its melting point. This property of a given plastic material is applied in many aspects of product design, engineering, and manufacture of products using thermoplastic components. When presenting hdt data, note the stress level used in the test. The deflection temperature is the temperature at which a test bar, loaded to the specified bending stress, deflects by 0. If that is still confusing here is a youtube video demonstrating a heat deflection test. Run at least two samples and report the average temperature when the 0.
The heat deflection temperature or heat distortion temperature hdt, hdtul, or dtul is the temperature at which a polymer or plastic sample deforms under a specified load. Additionally, the machines are ready to be linked to tinius olsens horizon software so that the pc can configure the controller, collect the test data. Digital plastic heat deflection temperature tester, packaging. Polycarbonate has a glass transition temperature of about 147 c 297 f, so it softens gradually above this point and flows above about 155 c 311 f. Heat deflection temperature can be defined as the temperature at which a standard test sample deforms bends under a predefined load. Common thermal tests like coefficient of thermal expansion astm e 831, astm d 696, astm e 1545, iso 159 heat deflection temperature hdt and deflection temperature under load dtul astm d648, iso 75, melting point and glass transition temperature by differential scanning calorimetry dsc astm d3417, astm d 3418, iso 157, iso 3146 method c vicat softening point astm d1525. The hdt of a given material is defined as the temperature at which a standard test bar deflects a specific distance under load and is often used to determine shortterm. Heat distortion temperature testing of plastics hdt is a standard test astm d648 and iso 75 used to assess the temperature at which a polymer, plastic or plastic composite specimen deforms under a given flexural load fiber stress. Heat deflection temperature is defined as the temperature at which a standard test bar deflects a. It is one of the two basic methods for assigning a value to the.
The heat deflection temperature or heat distortion temperature hdt, hdtul. However, many manufacturers will evaluate a materials heat resistance by exposing a finished part to meximum use temperature under gravity load rather than the high loadings associated with the heat deflection test. Zwicks new product line offers test devices to measure these properties with compter controlled functions. May 22, 20 heat deflection temperature vicat softening point. Ccsi features this high quality heat deflection temperature tester hdt conforming to the requirements of astm d648 and other methods for determining the temperature at which an arbitrary deformation under a flexural load occurs on molded and sheet materials that. The distortion temperature is that temperature at which a test specimen of defined geometry deforms to a level of strain under applied stress of 0. Standard test method for deflection temperature of plastics. Psm polymer service gmbh merseburg heat distortion. The heat distortion temperature is determined by the following test procedure. But the test duration in this case is barely over 1 hr. Heat deflection temperature akron rubber development.
It distinguishes between materials that are able to sustain light loads at high temperatures and those that lose rigidity over a narrow temperature range. Dynamic mechanical analysis dma provides a rich and detailed picture of polymer performance, and it can be challenging to understand all the things that we can and should know about our materials. Deflection temp and vicat testers the models 603 hdtm and 303 hdtm are the latest generation of tinius olsens digitally controlled automatic deflection temperaturevicat test equipment, with an automated testing sequence that proceeds according to user. Instead there is a gradual softening as the temperature increases. Astm d1525 standard test method for vicat softening temperature of plastics. Determination of vicat softening temperature vst of thermoplastics as per iso 306 and astm d1525. Standard test method for distortion temperature in three. Heat deflection temperature and vicat tester deflection temperature under load tester 303 hdtm the model 303 hdtm is the smaller of the two models of dtul vicat test equipment and is capable of testing up to three different specimens simultaneously, using an automated testing sequence that proceeds according to user defined control and. Hdt deflection temperature and vicat testers from tinius olsen. Thermal tests performed at plastics technology laboratories, inc.
Heat deflection temperature is defined as the temperature at which a standard test bar deflects a specified distance under a load. Using the dma q800 for astm international d 648 deflection. Deflection temp and vicat testers the models 603 hdtm and 303 hdtm are the latest generation of tinius olsens digitally controlled automatic deflection temperature vicat test equipment, with an automated testing sequence that proceeds according to user defined control and configuration parameters. Dynamic mechanical analysis part 3 originally titled part 3. Hdt stands for heat deflection temperature or heat distorsion temperature.
The asian apparatus for heat deflection temperature tester consists of a specimen support, an immersion bath, a set of weights under deflection measuring device. The hdt test involves heating the test specimen at a constant rate of 2 o cmin until the required deflection is achieved. I made a presentation in that session devoted to the property of deflection temperature under load dtul, also known in the industry as the heat deflection temperature hdt. The heat deflection temperature test determines to which extent a sample can withstand specified test loads under high temperatures and it is suitable for a wide range of different samples including plastic and. This material property is important to compare different plastics, and to know the maximum stable operating temperature in loadbearing parts. The oven sag test is an alternate method which looks at. Reaching temperatures of up to 300c, the lightweight hv3000d is an ideal choice for any testing environment, displaying the temperature from each test station. The deflection on the gauge is the measure of deformation of the test specimen. Nylon 66 is a 30% glassfiberreinforced nylon 66 material whose important properties include high tensile and flexural strength, stiffness, excellent heat deflection temperature, and. Heat deflection temperature is used to determine shortterm heat resistance and is equivalent to the temperature at which a standard test bar deflects a specified. Heat deflection temperature is used to determine shortterm heat resistance and is equivalent to the temperature at which a standard test bar deflects a specified distance under a load.
The heat deflection temperature of amorphous materials is related to the glass transition temperature amorphous materials or melting temperature crystalline materials. The temperature at the specified deflection point is then recorded. This test is often seen with the designation astm d648. Heat deflection temperature to iso 75 hdt heat deflection temperature hdt iso 75 123 indicates the relative behavior of different types of material under load at elevated temperatures. This property of a given plastic material is applied in many aspects of product design, engineering and manufacture of products using thermoplastic components determination. However, the hdt test is a shortterm test and other factors such as the time of exposure to elevated temperatures, the rate of temperature. The deflection temperature is a measure of a polymers ability to bear a given load at elevated temperatures. Deflection temperature under load hdt astm d 648 iso 75. Nov 21, 2016 heat deflection test is three point bending test, it is thermal stress test to verify polymer plastic material. The test for hdt was developed in the early years of plastic testing and it is not difficult to see how it. Ccsi features this high quality heat deflection temperature test er hdt conforming to the requirements of astm d648 and other methods for determining the temperature at which an arbitrary deformation under a flexural load occurs on molded and sheet materials that are rigid, or semirigid, at a normal temperature. Heat deflection temperature astm d648, iso 75 intertek.
To do so, that temperature will be evaluated at which a defined deflection hdt or a defined indentation depth vicat is reached. The heat deflection temperature is a measure of polymers resistance to distortion under a given load at elevated temperature. The deflection of the sample is measured using either a dial indicator or lvdt. Heat deflection temperature akron rubber development laboratory. Common thermal tests like coefficient of thermal expansion astm e 831, astm d 696, astm e 1545, iso 159 heat deflection temperature hdt and deflection temperature under load dtul astm d648, iso 75, melting point and glass transition temperature by differential scanning calorimetry dsc astm d3417, astm d 3418, iso 157, iso 3146 method c vicat softening point astm d1525, iso 306.
The test is applicable over the range of temperature from ambient to 300 c. The specimen support consists of a two parallel metal supports having rounded edges fixed at a specified distance on an aluminum frame. Sep 19, 2017 the deflection of the sample is measured using either a dial indicator or lvdt. The heat distortion temperature is also known as the deflection temperature under load dtul or. Heat deflection test is three point bending test, it is thermal stress test to verify polymer plastic material. The tester is equipped with touch screen that guides users step by step. Each test frame can be configured with optional accessories for either vicat or deflection temperature testing, including 4 or 100 mm edgewise or 64 mm flatwise deflection temperature.
Data obtained by this test method shall not be used to predict the behavior of plastic materials at elevated temperatures except in applications in which the factors of time, temperature, method of loading, and fiber stress are similar to those specified in this test method. The hdt, is a useful indicator of the temperature limit above which the material cannot be. Heat deflection temperature of plastics omnexus specialchem. The heat deflection temperature hdt is determined when the bar deflects 0. Testing procedure a test sample of 80x10x4 mm is introduced in the test apparatus. The heat deflection temperature of amorphous materials is related to the glass transition temperature amorphous materials. The deflection temperature is also known as the deflection temperature under load dtul, heat deflection temperature, or heat distortion temperature hdt. The value obtained for a specific polymer grade will depend on the base resin and on the presence of reinforcing agents. Since we have demonstrated the lack of detail regarding elevatedtemperature performance provided by the heatdeflection temperature hdt test in the first two parts of this series, one may wonder why it is that we continue to perform it and publish the results.
During npe2018 i gave a short presentation entitled never use hdt values again. The heat deflection temperature is the temperature at which a sample deflects by a standard amount when applying a specified test load. The heat distortion temperature is determined by the following test procedure outlined in astm d648. Heat deflection temperature tester at best price in india. The specimen is given a flexion stress at the center, and the temperature should increase by 2 degrees celsius per minute. Determination of heat deflection temperature hdt and vicat softening temperature vst iso 306, astm d 1525, iso 75, astm d648 thermoplastics do not exhibit an exact melting point that indicates the precise transition from the solid to the liquid state. The outer fiber stress used for testing is either 0. One of the astm test methods for plastic commonly seen on data sheets is a test for heat deflection temperature hdt. Standard test methods that employ this approach are astm d 648 and astm e2092 which simulate industry tests for the heat deflection temperature hdt, also known as the deflection temperature under load dtul. Following the astm d 648 which is equivalent to the iso 75 the hdt is the temperature at which a given polymer test bar will be bended of 0. Vicat softening point apparatus, heat deflection test.
The asian heat deflection temperature tester consists of a specimen support, an immersion bath, a set of weights under deflection measuring device. Tools must be held at high temperatures, generally above 80 c 176 f to make strainfree and stressfree products. The test specimen is loaded in threepoint bending in the edgewise direction. Determination of heat deflection temperature hdt as per iso 75, parts 1 to 3, and astm d648, method b, on thermoplastics, hard rubber and fiberreinforced and filled thermosets. Utest utcm0050 vikat test seti en 196 3 utest utcm0050 vicat test set duration. When the specimens center undergoes a deflection of 0. Heat deflection temperature test a stress is applied on a sample in a 3point bending mode while temperature is raised at uniform rate hdt value for the material under test 9.
In other words, it is the temperature at which a given polymer test bar will be bended of 0. In that paper i suggested that the industry needed a better way of reporting the temperaturedependent behavior of. Het testen of analyseren van textiel en kunststoffen van grondstof tot afgewerkt product door een onafhankelijke en geaccrediteerd laboratorium, resulteert. Feb 23, 2016 the temperature at the specified deflection point is then recorded. Professional heat deflection temperature tester precise.
It is true that because the hdt test utilizes a constant load, creep is a component of the test. It distinguishes between materials that are able to sustain light loads at high temperatures and those that lose their rigidity over a narrow temperature range. Vicat test is used to identify a temperature at which a needle of specified dimensions penetrates into plastic specimen a specified distance under a given load. The hdt, is a useful indicator of the temperature limit above which the material cannot be used for structural applications. The heat distortion temperature hdt, deflection temperature under load dtul or softening temperature usually denote the highest temperature to which a thermoplastic polymer may be used as a rigid material 1. Heat deflection temperature testing of plastics matweb. The asian heat deflection temperature test er consists of a specimen support, an immersion bath, a set of weights under deflection measuring device. Figure 6 shows an example of this test on a sample of polystyrene. Presto heat deformation hdtvsp tester is equipped with indenter which indents the sample under specific load and offers heat deformation and vicat softening temperature of plastic or polymer materials.
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