DECORATION AND OTHER COMPONENTS If the packaging is printed directly, the printing inks must at least be EuPIA-compliant and non-bleeding in order to prevent potential contamination. Minimal printing with light or glazing colours is advantageous. If labels are used, they should be made of the same base material as the packaging (e.g. HDPE,LDPE, MDPE,LLDPE). If the decoration is made of a material other than PE, a maximum of 50% of the packaging surface should be covered so as not to hinder the correct sorting of the base material8. The batch coding and the indication of the best-before date should best be carried out in the form of an embossing or laser marking. Wet-strength paper labels are preferable to conventional paper labels as they do not release fibres that contaminate the recyclate. Labels made of PP can be used if necessary, provided that a maximum of 50% of the packaging surface is covered8. The batch coding and indication of the best-before date can, if necessary, also be done by minimal direct printing with other coding systems (e.g. ink-jet), provided that foodgrade inks are used.
Labels made of materials other than PE, PP or paper should be avoided. Large-scale decorations (> 50% of the packaging surface) made of a material other than PE can impair the sorting of the packaging8. Adhesive materials containing metal or aluminium (with a layer thickness of > 5 µm) can lead to unwanted sorting into the metal fraction. Bleeding inks should be avoided.
CLOSURE SYSTEM Closures are ideally made of the same base material as the film (e.g. HDPE, LDPE, LLDPE, MDPE). If sealing foils are used, they must be easy to remove without leaving any residue. Flexible closures made of PE and PP plastic laminates are compatible with the PE fraction in small quantities9. PP closures can lead to contamination in larger quantities9. Closures made of other materials such as PET, PET-G, PS and PLA should be avoided, as these can lead to secondary contamination of the PE fraction. Metals, thermosets, EPS and PVC as well as seals and silicones that cannot be completely removed are considered interfering substances. Sealing foils that are not completely removable and contain an aluminium component (layer thickness > 5 µm) can impair the sorting.
DESIGN RECOMMENDATIONS FOR PACKAGING TYPES
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