Migration of functional design of flexible packaging
Migration is refers to the packaging materials from the material transfer, migration including residual monomer, catalyst, solvent, antioxidant and other additives in polymer, the migration of some material without toxicity, but will cause changes in the performance of packaging materials, impact packaging protection performance, there is also a part of the migration have toxicity or smell, such as vinyl chloride, acrylonitrile monomer, some plasticizers, etc. In the experiment of determining the migration of plastic packaging materials, the simulated solvent is often used for measurement.
Simulated solvents prescribed for four food categories
Fats and fatty foods | alcohol | Other classes with pH>5 | Other classes with pH<5 | |
Japan | n-heptane | 20% ethanol | water | 4% vinegar |
The United States | Water, n-heptane | 8% and 5% alcohols | water | water |
Germany | Peanut oil, coconut oil, synthetic triglycerides | 10% ethanol | water | 3% acetic acid |
Britain | Olive oil, 2% fatty acids | 5% ethanol | 5%Na2CO3 | 5% acetic acid |
Italy | Sunflower oil, water, or 3% acetic acid | Concentration of ethanol (15% +) | water | 3% acetic acid |
The French | Sunflower oil, water or 3% acetic acid and other similar foods | 10% or 15% ethanol | water | 3% acetic acid |
In the Netherlands, | Triglycerides, olive oil, peanut oil and their mixtures | Concentration of ethanol (10% +) | water | Concentrated acetic acid above 3% |
As a matter of fact, the composition of most foods is complex, and the above simulated solvents can only represent the relatively real situation encountered when various foods are used as extraction media. When simulated solvents are used, foods are classified so that a tradeoff coefficient is determined for the food and the amount of migration obtained with the simulated solvent is closer to that of the real state. For example, the grease of fermented yoghurt experiment, experiment should be separately using water-soluble and fatty two simulated solvent, the results obtained with fatty solvent (M) used to divided by a weighing coefficient, namely M / 3, among them, 3 is the weighing coefficient, the reason is that given the fatty simulation compared with yogurt has the stronger ability of extraction solvent.
