Meaning
Thermal analysis standards specify procedures for measuring transition temperatures and enthalpy changes in polymeric materials. Testing under ISO 11357 differential scanning calorimetry provides controlled heating and cooling cycles to determine glass transition temperature, melting point, and degree of crystallinity in thermoplastic resins. Molders rely on these thermal measurements to establish barrel temperature profiles and predict part shrinkage during cooling.
Datasheet thermal values derived under static laboratory heating rates differ significantly from the rapid cooling environments found in injection molds. Unintended thermal history, resin cross-contamination, and degradation show clearly on the resulting thermograms.
Thermal Transition
Crystalline structure development during resin cooling determines final mechanical strength and dimensional stability. Utilizing ISO 11357 differential scanning calorimetry allows quality control laboratories to verify that incoming lot-to-lot polymer shipments match established thermal benchmarks. Shifted melting peaks or secondary crystallization events reveal the presence of recycled additives or thermal history from prior processing steps.
Enthalpy Measurement
Heat of fusion calculations quantify the percentage of crystalline phase present within a molded part. Comparing raw resin enthalpy against molded part enthalpy indicates whether mold cooling rates were fast enough to freeze amorphous structures or slow enough to allow high crystallinity.
Sample Preparation
Specimen mass and thermal contact accuracy directly influence test results. Consistent sample preparation prevents baseline drift during high-temperature test runs.
