European Food Contact Polymer Migration Limit Determination
European food contact compliance requires validating overall and specific migration limits using designated simulants, geometric ratios, and traceable dossiers.
Single Sided Cell
Meaning
Testing fixtures isolate a single surface of a polymer film or sheet to quantify unilateral chemical migration or gas transport into contact media. In food packaging compliance and barrier film testing, a single sided cell secures a flat plastic test specimen between a sealed chamber containing a food simulant and an external clamping plate. This mounting configuration ensures that test fluids contact exclusively the designated contact side of multilayer or coextruded barrier structures.
It governs directional permeation and specific migration measurements, stopping where total immersion testing of complete hollow containers is required.
Permeation Testing
Multi-layer packaging films feature specific functional layers designed for direct food contact while outer layers provide mechanical support or printing surfaces. Testing these asymmetrical structures in a single sided cell prevents non-contact outer layers from interacting with test simulants. Accurately measuring migration from the inner sealing layer isolates migrant release to reflect actual package exposure conditions.
Specimen Mounting
Clamping mechanisms compress circular elastomeric gaskets against the outer edge of the polymer specimen to prevent liquid leakage. Mechanical compression must be carefully balanced to prevent edge tearing or pinhole formation in thin barrier films.
Migration Analysis
Exposure chambers filled with liquid simulants remain in temperature-controlled environments for mandated contact periods. Following exposure, analysts extract and quantify migrated additives like slip agents or light stabilizers using gas chromatography mass spectrometry. Using single-sided testing avoids overestimating chemical migration caused by simultaneous extraction from non-contact outer film surfaces.