Migration Testing Conditions That Do Not Match Your Filling Line
Matching migration simulant and thermal parameters to exact filling line mechanics prevents compliance invalidation during customs and market audit checks.
Chemical Transfer Dynamics
Mass Transport
Transport rate phenomena describe the physical movement of low molecular weight compounds through fibrous substrates and coating layers. In paperboard packaging, chemical transfer dynamics govern how printing ink components or adhesive residues migrate across paper fibers into food contact interfaces. Storage conditions change these transfer rates.
Partition Boundary
Equilibrium concentration ratios dictate the thermodynamic distribution of migrants between substrate layers and contact media. Chemical transfer dynamics depend heavily on the solubility of migrating substances within the polymer coating or food simulant. Direct contact with fatty media creates a driving force that pulls hydrophobic substances out of recycled fiber layers.
Non-polar compounds exhibit high partition coefficients when exposed to lipophilic food matrices. Dry foods accept gas-phase transport rather than direct liquid absorption. Storage duration increases total transfer until thermodynamic equilibrium occurs across all packaging interfaces.
Rate Control
Functional barrier coatings alter transport rates by increasing the activation energy required for molecular penetration. Cross-linked polymer networks limit chemical transfer dynamics by forcing foulants into tortuous paths through dense crystalline regions. Pinholes created during converting operations disrupt this protective network and lower breakthrough time.
Measuring diffusion coefficients allows converters to specify minimum polymer coat weights for target shelf lives.