Collected packaging waste has to be sorted into different material streams to make it suitable for recycling. The accuracy of these sorting systems and therefore the purity of the sorted material streams has a major impact on the available recycling opportunities and the final value of the recyclate.
The manner in which packaging waste materials are sorted can differ between member states. While one country might have a fully automated sorting infrastructure another might be more dependent on manual sorting. Below a description of the best available and most commonly used techniques per packaging waste flow are described.
Sorting techniques of different packaging materials
Small metal packaging materials are mostly made from tin and aluminium. Large barrels are made from packaging steel or stainless steel. Metals can be divided into ferrous and non-ferrous metals. Packaging steel and tin are classified as ferrous metals. These packaging materials are generally magnetic and can therefore be separated from a waste stream using a magnet.
Aluminium is a non-ferrous metal. Aluminium packaging materials are non-magnetic, but they can be charged using an electric field (eddy current), which makes it possible to separate them from a waste stream using a special technique. However, this is not possible for composite materials that contain a thin layer of aluminium or vapour-deposited aluminium, because the power generated by the eddy current is too small to effectively separate the aluminium from the waste stream.
Any contaminants are eliminated from the collected material, which is then used for the production of new glass packaging materials. If glass is separated by colour, clear glass can be used to make new clear glass, but coloured glass cannot be used for the production of clear glass. The most common colours used in glass are clear, green, and brown.
Collected plastics are sorted by type of material. If necessary, metal and beverage cartons are first taken out of the collected waste stream. Because of the many variants that exist, plastics are harder to separate and recycle than for example glass, paper, and metal. During the sorting process, very small components are removed first. Next, rigid materials are separated from large films.
Rigid packaging materials
Rigid packaging materials are sorted by type of plastic: PP (trays and containers), HDPE (bottles and flasks), and PET (mainly bottles, but also trays). These sorted packaging materials are compressed into large bales and sent to a recycler.
Flexible packaging materials
Large flexible packaging materials end up with the films. This material mainly consists of PE and PP.
Mixed stream of rigid and flexible packaging materials.
All other rigid and flexible plastics, which are recognised as plastic but are not PE, PP, or large film, are sorted in what is known as the “mixed stream.” The more monomaterials the mix contains, the more it pays to sort these materials. If the mix contains a large amount of small (smaller than an A4 page) flexible packaging materials made from monomaterials, it can be worthwhile for a recycler to sort the stream first. These packaging materials can be reused in a different manner.
Paper and cardboard
Many countries have an efficient collection system in place for paper, and the material is easy to recycle. However, the number of possible cycles is limited to circa four to seven, because the quality of the fibres deteriorates during each recycling process. The use of protective layers and coatings affects the paper’s recyclability.
Beverage cartons cannot be collected and recycled alongside paper and cardboard. This is because such cartons contain a layer of plastic and are contaminated with organic material. In more and more countries, beverage cartons are collected and sorted separately to ensure they can be recycled as well. The beverage cartons are processed in a different factory than other paper and cardboard materials. Currently, only the fibres are recovered.
After collection, the types of paper and cardboard are sorted by quality, from Kraft paper to newspaper. Paper and cardboard producers purchase the material based on its quality and process it to make new paper and cardboard. The smallest fibres fall through the sieves used during the recycling process and are processed to make for example toilet paper. To preserve the paper cycle, a certain quantity of new fibres is always needed. This balance is achieved because cardboard packaging materials, which must withstand heavy loads, require longer – and therefore new – paper fibres. Solid cardboard and some types of folding cardboard can be made from shorter fibres.
Wooden packaging materials can be reused or recycled, so that the material can be used for new products or packaging materials. Wooden pallets are recycled and turned into e.g. chipboard, MDF or wood chips. Wood fibres can also be used for the production of paper and cardboard.
Situation in various countries
The waste stage
The use of packaging materials is subject of European legislation. On 20 December 1994, the European Parliament and the Council of the European Union introduced the Directive 94/62/EG (hereinafter: Directive) for packaging materials and packaging waste. This Directive was subsequently revised on 22 May 2018. The goal of this Directive is to limit the use of packaging materials and stimulate recycling, reuse and other useful applications for packaging waste.
All EU Member States are required to implement the Directive in their own national legislation. Every Member State has its own way of doing so. Packforward started to give an overview of the way the different Member States implemented the Directive, but the overview is not completed yet. You can find more information for the Netherlands, information about other countries will follow soon.
Despite the efforts made with regard to collecting, sorting and recycling packaging waste, new raw materials will have to flow into the packaging chain in order to safeguard the quality of the material and compensate for the loss of material in the chain. For a growing number of the new raw materials, steps are being taken towards a circular economy, e.g. by making use of biobased materials.