Recycling-friendly design of folding cartons
15.10.2019 - Sustainability, Cartonboard Know-How
Sustainable packaging is characterised not only by the use of renewable or recycled materials, but also by design and printing that allows complete recycling of the materials used in existing material cycles. Generally, any paper-based package can be recycled effectively after use. There are, however, some components that complicate the recycling process. New guidelines support packaging designers with recyclable product design.
Packaging must be designed for sustainability from the beginning in order to satisfy the requirements of product safety and sales promotion as well as recyclability to the greatest possible extent. In order to reach the goals of the EU’s recycling economy and to provide guidance to retailers, consumer goods producers and designers, new recycling recommendations for paper-based packaging have been and are still being established:
While CEPI (Confederation of European Paper Industries) is working to conceive a European Guideline by the 4th quarter of 2019, CPI (Confederation of Paper Industries in UK) and WRAP (The Waste and Resources Action Programme) have already published their versions of future design recommendations (see table). At the same time, labelling systems on the packaging will provide orientation for consumers.
Excerpt from the guideline by CPI and WRAP:
No negative effects on the waste streams from recycling plant
Limited negative effects on the waste streams from recycling plant
Negative effects on the waste streams from recycling plant
|Plastic Films and Laminates|
Less than 5 % by weight
|Coatings and Additives|
UV inks and varnishes
Glassine without silicone
Greaseproof, wax/wax coated, silicone
|Foil Bloc Printing|
Under 30 % of external surface area
Over 30 % of external surface area
With repulp certification
Incompatible with paper making
Foiled glitter or plastic based glitter
No food marks
Visible impurities on the surface
Adhering food residues
All MMK cartonboard qualities, including barrier qualities like FOODBOARD™ or Freeze Grease, are 100 % recyclable in the paper cycle after production.
MM Karton fulfils the EN 13430 standard (European Standard for Requirements for Packaging recoverable by material recycling).
Recycling-friendly packaging saves resources during production, simplifies collection, re-use and recycling, and represents a valuable secondary resource in the materials cycle. Ecological aspects must therefore be included early on in the entire planning, development, and design process of packaging solutions. We will be happy to support your creative process toward more sustainable packaging.
Dr. Manfred Feichtinger, Head of MMK Technology WLC and representative of the cartonboard / folding carton industry in the CEPI working group “Recycling guidelines for paper-based packaging”, on …
UV printing inks
UV inks and coatings are integrated by means of UV-induced polymerisation. After hardening they form a solid, chemically and mechanically stable layer – comparable to plastic adhesive foil. The printing ink is therefore difficult to remove during deinking.
Plastic coatings like MetPet
Plastic coatings can cause a loss of recyclability. During the dissolving process, plastics can disintegrate into micro-plastics due to high shear forces. When micro-plastics have the same density as fibres (0.95 to 1.15 g/cm³), it cannot be separated by the sorting equipment during materials recycling.
Double-sided plastic coatings – regardless of thickness – should be avoided in any case, as they inhibit the careful separation of paper fibres with water and centrifugal force. When plastic is coated onto the top and reverse side, water cannot penetrate the spaces between fibres and therefore cannot separate them. Packaging with double-sided coatings are sorted out as rejects and must be disposed of.
Coatings and barriers
When coatings or barriers are used, it must be ensured that they can be easily separated from the fibres in water. Water-soluble coatings and additives are accordingly preferable. The applicable principle is: When barriers are applied directly online on the cartonboard machine, they can be dissolved without difficulty.
Packaging papers and cartonboard essentially consist of different wood fibres that are prepared and cleaned in appropriate processes before being re-used. Alternative fibre materials like for instance straw, grass or coconut fibres can inhibit the sorting processes because of their different fibre structures and should therefore be avoided whenever possible, unless it is ensured during their production that they will be suitable for commonly used recycling processes.
A general principle is that offline coatings with non-paper materials applied after conversion should be kept to a minimum, in order to affect the recycling process as little as possible.