Analytical Verification of Polymer Migration Compliance across Industrial Container Shipments
Verify migration compliance using finished container single-sided cell tests, worst-case simulant conditions, and batch-matched documentation.
Single Sided Cell Extraction
Meaning
Analytical extraction technique designed to evaluate chemical migration from a single functional surface of a plastic film or sheet structure into a test simulant. The method utilizes a sealed extraction cell that isolates the food-contact side of the polymer, preventing simulant contact with the outer non-contact surface or printed layers. Applying single sided cell extraction provides precise migration measurements for coextruded packaging where inner and outer layer resin formulations differ.
The method stops applying to homogenous monolayer materials or articles intended for complete immersion during testing.
Cell Mechanics
Specialized stainless steel extraction cells clamp flat film samples securely against a fluid chamber using Teflon gaskets. Simulant fills the chamber, contacting only the designated internal contact surface area under controlled thermal conditions. Securing a tight seal prevents fluid leakage and isolates the outer printed or barrier layers completely from extraction.
Test Protocol
Exposure conditions mimic intended shelf life and temperature profile, ranging from refrigerated storage to boiling hot-fill processing. After exposure, the extracted simulant undergoes chemical analysis to measure migrated substances per unit surface area. Subtracting blank simulant values isolates specific migration quantities attributed to the functional layer.
Application Scope
Multilayer food packaging films feature specialized inner sealants and outer print surfaces that must be evaluated independently. Double-sided immersion tests overestimate migration by exposing non-contact inks and adhesive layers to simulants. Single sided cell extraction yields accurate migration data required for regulatory compliance declarations.