What challenges do packaging suppliers currently have to face in order to advance the topic of sustainability?

The current linear principle of “dismantle - produce - consume - throw away” is no longer up to date. A rethink is needed here: Packaging waste is not waste, but a valuable source of raw materials for the production of new packaging. This is why we at Ströbel are intensively addressing the issue of value creation and are constantly working on new packaging solutions.

What specific packaging trend is Ströbel pursuing?

When it comes to recyclable packaging, consumers are often semi-aware or unaware, i.e. they tend to choose food packaging with a high paper content. At first glance, these look environmentally friendly and feel very high-quality to the touch. An additional layer of aluminum or plastic ensures aroma protection. However, this so-called composite packaging cannot be recycled and therefore ends up in the incinerator.

We at Ströbel therefore rely on...

What is plastic - and what does it contain?

The colloquial plastic is also called synthetic material - both substances are the same. Plastic is primarily obtained from the fossil raw materials oil and gas. They consist of so-called polymers. In short, polymers are high-molecular chemical compounds (macromolecules) made up of repeated units.
Plastic is an amazing material. We use it for life-saving medical devices, to make clothes, toys and cosmetics, or to build aeroplanes and electric cars. We wrap food in it to protect it from spoiling, or machinery from corrosion. It is stable, waterproof and durable. But whenever plastic ends up in the environment, a problem arises. Unfortunately, a large proportion of plastic waste still ends up in ovens for thermal utilisation or in the environment. The only way to change this is through a change in consumer behaviour (avoiding unnecessary packaging), sensitivity in disposal and a plastic design that allows for subsequent recycling.

What is recycling and how does it work?

Much of the waste we produce every day can be recycled. Separated waste is processed through recycling and turned into new products. It is important to sort waste correctly. New raw materials are then created through various processes. These are reintroduced into the manufacturing process, into a cycle. For example, less new plastic has to be produced for recycled plastic. This conserves resources.
A lot of packaging has a green dot, which is collected in a yellow bin and then recycled. Others, however, do not have a green dot, even though they are made from the same material. Why is that? The green dot merely indicates that there is someone who takes care of the recycling and not that the material itself can be recycled. Unfortunately, there are no standardised regulations for waste separation and disposal in households in Germany. This is usually regulated by the local authority.
Currently, plastics are mainly recycled using mechanical processes. For this purpose, plastic waste is sorted by type of plastic, washed, melted down and processed into so-called recyclates.

How can we significantly increase the recycling rate of packaging?

Plastics are generally easy to recycle, but unfortunately not 100 per cent. Appropriate facilities, capacities and infrastructures must therefore be further expanded. It would be desirable to organise a round table on this topic involving all stakeholders, from product manufacturers, the packaging industry, sorting and recycling companies to political representatives.

Recycling facts

The idea of recycling is not new. Even in ancient times, people collected, melted down and reworked metal and glass to produce new products. These ‘mechanical recycling processes’ are implemented on a large industrial scale in Germany.
Today, the global recycling rate is only 14 per cent. To increase this, the EU has agreed on the ‘Green Deal’: by 2030, all packaging placed on the market in the EU should be reusable or recyclable.

Important facts about mechanical plastic recycling

1. collection / disposal:

Packaging that is disposed of in the yellow bin or yellow bag is usually made of plastic, aluminium, tinplate or composite materials. As they sometimes consist of different materials, for example the yoghurt pot made of plastic and the yoghurt pot lid made of aluminium, these components must be disposed of separately in the yellow bin or yellow bag. The reason: different packaging materials that are disposed of together in the yellow bin or yellow bag cannot be separated from each other mechanically in the sorting plant. In addition, the packaging should be completely empty or spoon-clean - additional rinsing is not necessary.
Incidentally, of the around 2.5 million tonnes of materials collected annually in Germany via the yellow bins and yellow bags, around 30% is residual waste that has not been disposed of correctly. In some areas, the incorrect disposal rate is as high as 60%. This so-called mis-throwing makes it difficult or even prevents the recycling of valuable raw materials.

2. sorting:

Different material layers & Colouring with carbon black-based inks
Some packaging consists of different layers of material. The layers cannot be separated in the sorting plant. However, they cannot be recycled when mixed. This packaging is incinerated in residual waste (thermal utilisation).
Black packaging often contains a high proportion of soot to represent the colour. This causes problems for the infrared scanner in the sorting plant. In this case, the packaging is also sorted out and thermally utilised. Ströbel, together with the recycling service provider Interseroh+, therefore recommends using dark colours that do not contain any carbon black.

Endless recycling - is that possible?

Unfortunately not! Plastics such as polythene cannot be recycled without a loss of quality because the original building blocks can no longer be separated from each other. The molecular chains inevitably become shorter during the recycling process. As a result, the properties of the plastic deteriorate, for example it becomes softer and less stable, so that it can only be used for less demanding purposes. This is known as ‘downcycling’; the material is not used in a cycle, but in a kind of downward spiral that eventually ends in incineration. The use of recycled raw materials (‘recyclates’) for new products is of course still more resource-efficient than new production.

Exemplary cycle:

PET bottles in the deposit system. The popular bottles can be reprocessed up to ten times into new PET bottles. The reason for this is that this is already a closed cycle.

Chemical recycling - in its infancy

Chemical recycling is being discussed as an alternative or supplement to the mechanical recycling of plastic waste. Here there is the possibility of separating out harmful substances and recycling waste that is difficult to recycle or heavily contaminated. Chemical recycling techniques have not yet been established.
Based on current data, it must be assumed that mechanical recycling is generally more favourable from an ecological and economic perspective.
Chemical recycling is therefore still in its infancy. It will take some time and research before a definitive assessment can be made.

What are bio-based plastics? Are they better than conventional plastics and can they also be recycled better?

Bio-based plastics are usually made from biomass, e.g. from maize or sugar cane. Sounds good at first, but on closer inspection there are a few catches: in Germany, bio-based plastics usually end up in residual waste and have to be recycled for energy. The sorting plants for the yellow bag/yellow bin are not designed for sorting these plastics.
We know from comparative life cycle assessments that the environmental impact does not improve significantly if the raw materials are bio-based instead of fossil-based. The effects shift: the ecological footprint for bio-based plastics is expressed in a higher land requirement. This is due to the agricultural production of the raw materials. There may be competition for land with food production and there may be less compensation and forest areas. In addition, monocultures are created and the soil is sometimes heavily over-fertilised.

Are bio-based plastic bags allowed in the organic waste bin?

Probably not. However, it depends on the product in question and would have to be analysed on a case-by-case basis. Bio-based plastics are not always biodegradable. Plastic bags that are resistant to biodegradation do not decompose during composting or fermentation and must be sorted out. This involves a great deal of effort for plant operators.
The analysis by a European research team also shows that just like conventional plastic products, bioplastics also contain harmful substances that can be released during biodegradation.

What are biodegradable plastics?

Biodegradable plastics usually consist of thermoplastic starch, cellulose, degradable polyesters and polylactide (PLA). Some degradable polyesters are sometimes also made from petroleum. This means that not all biodegradable plastics are also bio-based.

Where should packaging made from biodegradable plastics be disposed of?

Many consumers think they can dispose of biodegradable packaging in the compost behind the house. But this is not true. According to current knowledge, these materials take several months to degrade, depending on the environmental conditions. During this time, waste poses a risk to people and the environment.
Packaging must be disposed of in the yellow bin/yellow bag. This also applies to packaging made from biodegradable plastics. Therefore, the use of biodegradable packaging does not offer any significant advantages in comparison. It should also be borne in mind that biodegradable plastics are easily colonised by degrading microorganisms. Under certain circumstances, these can also contaminate the product or the food - and nobody really wants that.

At Ströbel, we have developed an alternative to non-recyclable composite packaging. Our Ströbel MONO-Line consists of a fully recyclable PE mono-material (including zipper and valve) and can therefore be easily disposed of in the recycling bin after use. When recycled, regenerated material is obtained from it, which is reused in the plastic cycle.

To this end, we have had our MONO-Line tested by Interseroh+ for its recyclability. We are very proud that the material passed with honours and can now bear the ‘Made for Recycling’ seal! Our customers can also print this directly on their packaging - to show the end consumer that the environment is important to them.