Meaning
Analytical method used to establish the zero point or reference level in chromatograms of extracted plastic samples. Correct baseline integration ensures the accurate measurement of peak areas for volatile and semi-volatile substances during quality control runs. If this step is performed poorly, false readings for monomer or additive concentrations will lead to incorrect rejection or approval of batches.
Analytical Boundary
Detection thresholds and noise levels in chromatography depend heavily on this calculation. Standard runs utilize baseline integration to separate overlapping peaks of polymer additives from the underlying signal drift. Run times must be held constant to prevent shifting baseline slopes.
Operational Influence
Melt temperature and dwell times during the extrusion phase alter the release of volatile components that appear in the analysis. Accurate baseline integration prevents the mischaracterization of polymer degradation products as residual solvents. This analysis is critical for food-contact polymer approvals.
Defect Correlation
Overestimating the concentration of residual species often results from incorrect reference lines in the chromatogram. This error forces moulders to run parts through extra degassing cycles, which increases cycle times and wastes energy. Poorly executed measurements can mask actual resin degradation problems, resulting in brittle molded parts that fail under mechanical stress because of unnoticed chain scission during the previous processing cycles.
