Deconvolution Protocols for Melt Crystallization Peaks in Recyclate Blends
Deconvolution of DSC melt crystallization peaks isolates PE and PP fractions in recyclates to verify composition before compounding.
Heat Flow Thermogram
Meaning
Analytical curves generated by differential scanning calorimetry illustrate the energy absorbed or released by a polymer sample as a function of temperature. Laboratory technicians examine a heat flow thermogram to identify the melting point, glass transition temperature, and crystallization behavior of a plastic material. The vertical axis represents the heat flow rate in milliwatts, while the horizontal axis displays either time or temperature.
This graphical output establishes a clear fingerprint of the material’s thermal history and resin composition.
Thermal Transition
Endothermic and exothermic peaks appear on the plot as the temperature of the polymer sample changes. Analyzing a heat flow thermogram reveals the melting peak where the crystal structures break down. The temperature at which this peak occurs is a critical specification for setting extruder and nozzle heats.
Resin Characterization
Quality control departments use these thermal profiles to verify incoming material purity and grade consistency. An irregular heat flow thermogram can indicate contamination, resin blending, or degradation from previous heat history. The chart shows whether the material is a homopolymer or a blend by displaying single or multiple melting peaks.
Process Prediction
Moulders run these tests to determine the optimum mold temperature and required cooling time before part ejection. The crystallization behavior shown in the heat flow thermogram helps predict how quickly a polymer will solidify in the mold. Faster crystallization rates translate to shorter cycle times in production.