Predicting Set off Migration in Stacked Packaging Board under Non Uniform Compression
Predicting set-off migration requires calculating local pressure peaks across board caliper variations to set safe pile heights and barrier coat weights.
EuPIA Guidelines
Chemical Restriction
Migration limits form the foundation for safety in food contact printing. The eupia guidelines identify specific substances excluded from ink formulations to mitigate risks of contamination in packaging applications. These protocols establish a rigorous framework for raw material selection based on toxicological data.
Compliance ensures that volatile components and heavy metals remain below detectable thresholds in finished paper or film surfaces. This regulation effectively governs the manufacturing of high speed rotogravure and flexographic inks intended for consumer goods.
Migration Logic
Exposure control relies on a positive list of approved compounds. Formulators apply the eupia guidelines to evaluate the safety of photoinitiators and monomers under defined storage conditions. Heat exposure during lamination or thermal sealing processes forces a review of molecular stability against these established thresholds.
The assessment distinguishes between functional barriers that prevent solute transfer and permeable substrates that allow interaction with contents. Packaging designers select materials according to the permeation rate of solvents when using specific ink series.
Safety Verification
Analytical testing confirms that total extractables remain within accepted variance. Quality control departments implement the eupia guidelines to validate batch consistency for each print run. Laboratory procedures involve solvent extraction followed by chromatography to measure residues on non food contact surfaces.
This verification provides a measurable assurance of safety for the converter and the brand owner. Regulatory bodies recognize these standards as a definitive benchmark for safe ink production in the packaging sector.