materials characterization

The materials characterizations group provides test data to measure the mechanical integrity of molded resin castings and composites as well as offering sophisticated thermal analysis and rheological testing.

The group performs many ASTM test procedures applied to analyses of plastics, composites, adhesives and coatings. The data are used to qualify materials for customer specifications, to help design materials for optimum end-use performance, or to evaluate the effects of exposure environments on mechanical integrity.

differential scanning calorimetry

Differential scanning calorimetry (DSC) measures the heat flow into and out of a material as a function of time or temperature. This technique can be used to characterize thermal transitions and chemical reactions. Modulated DSC is a single-test technique that allows the separation of reversing phenomena (Tg, melting, etc.) from non-reversing events (volatilization, curing, etc.). Problems or applications that could not be solved by DSC because of interfering events can now be clearly resolved and understood using modulated DSC.

dynamic mechanical analysis

Dynamic mechanical analysis (DMA) is a non-destructive mechanical test that measures the stiffness modulus (elastic nature) and energy damping (viscous nature) properties of materials as the materials are deformed under periodic strain or stress.

mechanical testing using a video extensometer

The use of a video extensometer avoids materials prematurely failing during mechanical testing due to induced stresses or micro-cracks caused by physical contact with the extensometers used to measure the strain (elongation). The measurement of the ultimate elongation and an accurate modulus for materials which exhibit a very high elongation prior to failure are particularly difficult.

As there is no physical contact between the sample and the extensometer, analyses can be directed to specific regions of the digitized stress-strain curve for detailed and accurate characterization of the material’s mechanical performance.

The technique is applicable to measurements in more hostile environments as the absence of physical contact also allows for the unit to be located outside of the sample environment. For example, strain measurements need not be corrected for the effects of temperature. This technique is well-suited for measurements of brittle castings, rubber, high-elongation (tough) polymers and composites.

rheological analysis

Rheological capabilities include both dynamic and constant shear. A wide range of transducers allows the rheological measurements of highly filled viscous pastes and polymer melts, as well as low-viscosity fluids and emulsions. Disposable plates allow the measurement of flow and cure for chemically reacting or cross-linking samples. This information is essential for processing design and end-use property determination.

thermogravimetric analysis

Thermogravimetric analysis measures weight changes with temperature and time, and provides information about composition analysis and thermal stability. A complete picture of the amount, rates and composition of volatiles and decomposition products can be ascertained by combining these results with chromatography and/or spectroscopy techniques. Modulated Thermogravimetric analysis and high resolution analysis provide enhanced separation of component thermal decomposition profiles and associated kinetics.

thermomechanical analysis

Thermomechanical analysis measures the expansion and contraction of materials as a function of temperature. This technique is applicable to coatings, thin films, plastics and composites.

mechanical testing

This area provides test data to characterize the mechanical integrity (stiffness, strength, elongation to failure, etc.) of molded resin castings and composites. The group performs many ASTM test procedures. Part of this laboratory is a well equipped sample preparation area, which includes diamond saws, sanders, surface grinders, and special support fixtures to accurately and precisely prepare the specimens for testing. The data are used to qualify materials for customer specifications, to help design materials for optimum end-use performance, or to evaluate the effects of exposure environments on mechanical integrity.

impact testing

This area measures the impact-resistance properties of composites, adhesives, and other materials as a function of speed and temperature. This testing includes pendulum type impact tests (e.g., Izod and Charpy), drop ball, drop dart, and instrumented puncture testing.   The sophisticated instrumented impact instrument quantifies crack initiation energy, crack propagation energy, as well as the total energy absorbed by the material during puncture at a controlled speed of testing.