Dynamic Mechanical Analysis (DMA)
ARDL’s capabilities for Dynamic Mechanical Analysis (DMA) and Dynamic Thermal Mechanical Analysis (DTMA) include coefficient of linear thermal expansion, forced vibration and glass transition temperature testing.
Coefficient of Linear Thermal Expansion
As a polymer material is heated or cooled, its molecules become more or less excited and so its length changes in proportion to its original length. Our Chemical Services and Engineering Services laboratories test for this using specifications for coefficient of linear thermal expansion (CLTE) by use of a vitreous silica dilatometer. Changes in moisture content, curing, loss of plasticizer or solvents, release of stresses, phase changes and other factors can also occur when the material is exposed to elevated temperatures and the test is designed to exclude these variables in its measurement to provide truest thermal expansion.
ARDL’s testing capabilities allow us to measure the forced vibration of materials through dynamic mechanical analysis. Forced vibration is vibration caused by one object being forced to vibrate when another connected object is vibrated. Using specific test methodologies and fixturing, we are able to measure the response of materials when forced into vibration.
Glass Transition Temperature Testing
The introduction of heat, cooling or compression can have an effect on the properties of materials. When these environments cause the material to change from exhibiting solid-like properties to a liquid-like phase, the material is said to have passed through its glass transition temperature (Tg). ARDL measures glass transition using Dynamic Mechanical Analyzer (DMA) and Dynamic Thermal Mechanical Analyzer (DTMA) equipment in addition to Differential Scanning Calorimetry (DSC) methods. According to ASTM, Dynamic Mechanical Analyzers monitor changes in the viscoelastic properties of a material as a function of temperature and frequency, providing a means to quantify these changes. In ideal cases, the temperature of the onset of the decrease in storage modulus marks the glass transition. Our DTMA equipment provides for analysis using frequency and temperature sweeps. ARDL can also test using three-point bend, Metravib and other DMA equipment.
Dynamic Mechanical Analysis (DMA) - Dynamic Testing of Vulcanized Rubber - Vibratory Method
Standard Guide for Dynamic Testing of Vulcanized Rubber and Rubber-Like Materials Using Vibratory MethodsASTM D 5992
Dynamic Mechanical Analysis (DMA) - Forced Vibration
Standard Practice for Rubber Properties in Forced VibrationASTM D 2231
Dynamic Mechanical Analysis (DMA) - Glass Transition, Tg - Dynamic Mechanical Analysis Method
Standard Test Method for Assignment of the Glass Transition Temperature By Dynamic Mechanical AnalysisASTM E 1640
Dynamic Mechanical Analysis (DMA) - Plastics
Standard Practice for Plastics: Dynamic Mechanical Properties: Determination and Report of ProceduresASTM D 4065
Dynamic Mechanical Analysis (DMA) - Plastics Properties
Standard Terminology for Plastics: Dynamic Mechanical PropertiesASTM D 4092
Metravib - DMA Testing - Compression
Standard Guide for Dynamic Testing of Vulcanized Rubber and Rubber-Like Materials Using Vibratory MethodsASTM D 5992 - Compression
Metravib - DMA Testing - Dual Lap Shear
Standard Guide for Dynamic Testing of Vulcanized Rubber and Rubber-Like Materials Using Vibratory MethodsASTM D 5992 - Dual Lap Shear