Antidumping Duty Lines That Move a Polymer off the Shortlist
Antidumping duties reorder polymer shortlists when cash deposits, scope rulings, and customs reclassifications destroy the landed cost advantage of imported resin.
ISO 11357 DSC Thermal Analysis
Meaning
Analytical laboratory protocols characterize the thermal transitions of thermoplastic resins by measuring heat flow during controlled heating and cooling cycles. Executing ISO 11357 DSC Thermal Analysis generates a thermogram that shows the melting, crystallization, and glass transition temperatures of a resin sample. This analysis is used to verify the consistency of incoming resin lots and detect contamination from other polymers.
Test Execution
A tiny specimen weighing between five and twenty milligrams is sealed inside an aluminum pan and placed into the sensor chamber alongside an empty reference pan. The system heats both pans at a constant rate, such as ten degrees Celsius per minute, while recording the differential power required to keep their temperatures identical. This temperature ramp is followed by a controlled cooling phase and a second heating phase to erase the thermal history of the material.
Thermal Transition
Deviations in the heating curve reveal structural changes within the polymer, such as the glass transition where the amorphous region shifts from a brittle to a rubbery state. Crystalline polymers display a sharp endothermic peak during the melting phase, which shows the temperature where the crystal structure collapses. A shift in these transition temperatures can indicate the presence of recycled material or copolymer variations.
Cooling Effect
The crystallization peak during the cooling phase shows how quickly the polymer forms its crystal structure as it solidifies. Slow crystallization requires longer cooling times in the mold, which increases the cycle time and raises production costs. Processors use the crystallization temperature to determine the optimal mold temperature that achieves the desired part properties.