The best packaging is no packaging at all - a nice theory in itself.

However, this is not feasible for many products, as they require packaging due to their nature. This is not least due to the way consumption functions in our society today. Now approaches can be discussed which lead to a sustainable rethinking in the consumer society, such as unpackaged food or reusable packaging.  

Our mission at rezemo is not to take away from the people in the here and now everything that makes up our consumption today, instead we want to use our technology:

  1. Strengthen the readiness for regional and fresh produce without forcing consumers to make significant changes in their consumption; by
  2. offer an ecologically superior solution for existing one-way packaging.

That's why we, at rezemo GmbH, have been working in our Stuttgart-based start-up for more than three years with Coffee capsules.

Close-up of a pile of the rezemo wooden coffee capsules

What the packaging market offers or: "A little materials science"

In Germany alone, over 3 billion coffee capsules are sold every year. Worldwide, industry estimates put the figure at around 59 billion capsules (AMI Consulting, 2018). Based on their material composition, the capsules can be divided into the following three categories: aluminium, plastic and partially biodegradable composites.

Aluminium is a high-tech material that offers many advantages, such as good processability and very low permeability, as well as a wide range of possible applications (House of Switzerland, 2018). Aluminium available on the market can be divided into two categories. The first is so-called primary aluminium - this is extracted from the aluminium ore "bauxite" in the Brazilian rainforest, for example. Aluminium is finally produced from the bauxite in a multi-stage process involving the addition of various process chemicals and a high energy input, as well as the generation of waste materials (keyword: red sludge).

There is also so-called secondary aluminium - this is recovered from waste by recycling within the framework of the circular economy, e.g. through the dual system established in Germany. In theory, the metal aluminium can be recycled an infinite number of times. According to manufacturers, only primary aluminium has so far been used to produce coffee capsules from aluminium (Welt, 2017).  

Other suppliers rely on petrochemical plastics for their capsules. The main material used is so-called polypropylene. This standard plastic has been well researched, is widely and cheaply available and can be easily processed, e.g. by injection moulding. Mainly because of its poor barrier properties (e.g. against the penetration of oxygen molecules), the finished capsules are either provided with a further outer packaging (e.g. nitrogen-filled tubular bags, made of high-performance plastics or with an aluminium coating) or high-performance plastics are added to the polypropylene, either as a layered composite or as an outer coating, to achieve a corresponding barrier.

Pure polypropylene can be recycled within the scope of the circular economy - although the Recycling rates in practice are relatively low and with plastics, in contrast to metals or glass, only down-cycling - i.e. recycling in a lower-value application - is possible. However, since it is usually not pure plastics but the composites just described that are used for capsule production, and since the capsules are filled with coffee grounds after use and usually sealed with aluminium foil, no recycling of this type of capsule can take place in practice.

With the debate about packaging waste growing louder, capsule types have also been emerging for some years that are advertised on the market as being particularly ecological. The most frequently mentioned property is compostability or biodegradability. Various concepts exist here, in which a standard petrochemical plastic is usually substituted proportionally by bio-based plastics, such as PLA. Since pure bio-based plastics have comparatively poor mechanical and chemical properties, it has so far been indispensable to add substantial proportions of petrochemical plastics and high-performance additives in order to guarantee the function in connection with the technically demanding environment of coffee capsule preparation (key words: high pressure of up to 19bar; hot water with up to 100°C; food contact). Recycling of these capsules is impossible due to their material mix. It should also be mentioned here that the applicable standards for Composting (e.g. DIN EN 13432) are very broadly defined and packaging certified according to them is generally not suitable for disposal in the BIO bin.

Close-up of a pile of the rezemo wooden coffee capsules

Our solution: The rezemo wooden coffee capsule

Based on the vision of completely replacing petrochemical plastics and aluminium as the starting material for coffee capsules, we at rezemo approached the question of materials from a different perspective. Starting with the natural material wood, we added the bio-based plastic PLA to the wood fibres until the resulting material had the necessary properties for processing and subsequent use as a coffee capsule.

In the material we use, the advantages of wood as a fibre are combined with the advantages of PLA, thus compensating the technical disadvantages of the two raw materials, each considered separately. This basic material consists or is based entirely on renewable raw materials. This is unique in the field of coffee capsules and patented by us.

We already start with the raw materials starting point. These are renewable derived from the cycle of nature. The Wood we obtain as a remnant from the wood processing industry from the Swabian Alb. This means that no extra trees have to be felled. Moreover, the wood chips can be processed directly without having to be chemically altered or prepared. Since the wood fibres are a residual product - alternatively they would be pressed directly into heating pellets and then used as fuel - we create an additional value-added stage for them. Furthermore, the regional raw material wood results in short transport routes to our production in Baden-Württemberg.

This means that both the raw materials we use and the final disposal are more ecological than all solutions available on the market to date. We are thus addressing two points in the life cycle of the disposable "coffee capsule" packaging.

Through our constant development work, we can further increase the proportion of wood fibres in our material over time. We also assume that we will be able to further reduce the layer thickness of the capsules from currently 0.4 mm at the thinnest point - thus further reducing the amount of material used.

Since we regularly receive enquiries about our technology from other industries and other products, we are planning to use our technology to make other products, which are not recyclable and are made of petrochemical plastics, more ecological.

Finally, we want to market our capsule and the associated technology beyond Germany in the future. Especially in areas where the waste management industry is not as well organized as in Germany and where much more extensive use is made of landfills for waste disposal than in Germany, we want to contribute to noticeable ecological improvements with our solution.

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