Polypropylene Surface Lamination Crease Failure Mechanics in Folding Carton Converting
Polypropylene lamination crease failure is prevented by expanding female matrix channel width to one point seven times board caliper plus rule thickness.
Overall Migration Limits
Chemical Transfer
Total mass of non-volatile substances transferring from food contact packaging materials into food simulant liquids measures overall inertness under standardized exposure conditions. Statutory food safety frameworks establish overall migration limits to ensure packaging materials do not alter food composition or organoleptic properties. European Regulation EU 10/2011 sets a maximum total migration threshold of ten milligrams per square decimetre of packaging contact surface.
The limit applies to plastics, barrier coatings, and functional polymer layers, but excludes specific toxicological thresholds for individual substances.
Testing Protocol
Laboratory testing exposes packaging samples to food simulants, including ethanol solutions, acetic acid, and vegetable oil, at controlled temperatures for specified durations. Analysts evaporate the liquid simulant and weigh the dry residue to determine if overall migration limits have been exceeded. Coated paperboard packaging used for fatty or liquid foods requires functional barrier coatings to block low-molecular-weight compounds from migrating out of the fibrous substrate.
When packaging fails testing, converters must reformulate barrier latexes or increase coating coat weights to prevent chemical transfer.
Regulatory Ceiling
Overall migration testing measures total mass transfer without identifying individual chemical species. Specific migration limits govern toxic substances such as heavy metals, phthalates, and primary aromatic amines through targeted analytical techniques.