Meaning
Mass transfer processes govern the progressive release of polymer additives from a plastic article into food or simulants during sequential exposures. In evaluating repeat use migration, laboratories measure whether additive release decreases over consecutive contact cycles as required for multi-use kitchenware. This characteristic determines whether a plastic container is safe for long-term culinary applications and complies with global food contact regulations.
Diffusion Process
Additives like plasticizers and slip agents move from the bulk polymer to the surface through molecular diffusion. In cases of repeat use migration, the rate of transfer should drop with each successive exposure as the surface region becomes depleted of the migrant. This depletion profile distinguishes reusable containers from single-use packaging.
Regulatory Threshold
Compliance testing involves exposing the material to food simulants three times under specified temperature conditions. If repeat use migration does not decrease by the third exposure, the material fails safety standards for reusable food-contact articles. This test ensures that consumers are not exposed to high additive levels over time.
Safety Evaluation
Evaluating compound release rates requires sensitive analytical tools like liquid chromatography. Monitoring repeat use migration ensures that long-term contact does not compromise food safety. This quality verification supports product certification.
