Ash determination in polyethylene

Význam tématu

Ash fillers such as silicon, magnesium and iron oxides are commonly added to polyethylene to modify properties including mechanical strength, thermal stability and cost efficiency. Accurate determination of ash content is essential for quality control and material certification across polymer production and processing.

Cíle a přehled studie / článku

This study aims to evaluate near-infrared spectroscopy (NIRS) as a rapid alternative to thermogravimetric analysis (TGA) for ash content determination in polyethylene granulates. A predictive model was developed and validated against the standard TGA method.

Použitá metodika a instrumentace

A set of 154 polyethylene samples with ash contents ranging from 0.07 wt% to 0.12 wt% was analyzed.

• NIR measurements were performed on a Metrohm DS2500 Solid Analyzer using a rotating DS2500 large sample cup to average particle size effects.
• Data acquisition and chemometric modeling were conducted with Vision Air 2.0 Complete software.

Hlavní výsledky a diskuse

• The Vis-NIR prediction model achieved a coefficient of determination (R²) of 0.77 compared to TGA reference values.
• Figures of merit include a standard error of calibration (SEC) of 0.0055 wt% and a standard error of cross-validation (SECV) of 0.066 wt%.
• NIRS analysis was completed in under one minute per sample, demonstrating significant time savings versus the approximately two hours required for TGA.

Přínosy a praktické využití metody

NIRS enables rapid, non-destructive and cost-effective ash content analysis suitable for routine quality control in both laboratory and production environments. Its robustness against dust, moisture and vibration supports inline and at-line applications.

Budoucí trendy a možnosti využití

Potential developments include expanding calibration models to broader concentration ranges and other polymer matrices, integrating automated inline monitoring, and leveraging advanced machine learning algorithms for improved predictive accuracy.

Závěr

This work confirms that near-infrared spectroscopy is a feasible and efficient alternative to TGA for ash determination in polyethylene granulates, offering rapid turnaround and environmental benefits by eliminating the need for nitrogen.

Reference

No external references were cited in the original application note.