Polyolefin Low Molecular Weight Extraction and Migration Testing
Polyolefin migration compliance requires batch-specific testing for low molecular weight hydrocarbons using accredited simulants, exact temperatures, and GC-MS.
HT-GC-FID
Meaning
Gas chromatography performed at elevated oven temperatures and paired with a flame ionization detector allows for the analysis of high boiling point compounds. While standard methods stop at lower limits, ht-gc-fid extends the range to include long chain hydrocarbons found in heavy waxes and resins. This configuration enables the detection of molecules that would otherwise remain on the column or degrade under standard conditions.
Thermal Capability
Sustaining temperatures up to 450 degrees Celsius prevents the condensation of heavy fractions within the analytical path. Because ht-gc-fid uses specialized columns and metal ferrules, it maintains a stable baseline even during extreme heat ramps. This thermal stability is required to accurately quantify the tail end of molecular weight distributions.
Wax Quantification
Polyethylene and polypropylene waxes require this specific setup to resolve individual carbon chain lengths. Measuring the concentration of each oligomer via ht-gc-fid provides a fingerprint of the lubricant package in a raw material. Such data is used to predict the flow behavior of the resin during the injection moulding cycle.
Analytical Range
Separation of molecules with carbon numbers exceeding C100 is possible with this method. Unlike liquid chromatography, ht-gc-fid offers high resolution for saturated hydrocarbons without the need for complex mobile phases. The result is a precise measurement of the non-volatile residue that affects the surface finish of moulded parts.
Reliable detection of these high mass species prevents the accidental inclusion of additives that could cause mould fouling or part failure during long production runs.