In the fight against climate change, species extinction and environmental pollution, natural, renewable raw materials are increasingly in demand in industry. These sustainable raw materials, which can be grown in large quantities, include seaweed. Unlike land plants, no pesticides are needed for their cultivation. This is a benefit for biodiversity. Today, seaweed is mainly used as food and to obtain gelling and thickening agents – agar, alginate and carrageenan. Due to the large ocean area, of about 70% of the earth’s surface, there is still much potential to expand cultivation.
Carraphane, developed at Brabender, is produced from seaweed without waste, using minimal resources. It thus minimizes the ecological footprint of packaging. It has the potential to make an important contribution to a sustainable packaging industry.
Interpack
At Interpack, we will demonstrate the production of films from Carraphane from May 4 to May 10, 2023 at the booth of the VDMA Fachverband Nahrungsmittelmaschinen und Verpackungsmaschinen e.V. – Hall 4, C54.
In addition, the TU Dresden, Chair of Processing Machinery/Processing Technology will present a feasibility study on forming films from Carraphane into cups. The forming process can be followed live at a demonstrator.
Circular economy
Sustainability is characterized by the fact that the value chain is a closed loop. There are no side streams that cannot be circulated. The seaweed, which serves as the starting material, is grown in aquacultures and then processed by extrusion. The films produced in this way contain all the nutrients that are also obtained in the source plant. Since the films are water-soluble and consist of natural marine algae biomass, they are biodegraded quickly. In the process, all the ingredients are returned to nature, serving as a source of nutrients for new marine algae, for example, thus completing the cycle. In applications where the water solubility is not exploited, the remaining films can still be easily integrated into the cycle by composting or as fertilizer.
Seaweed – a sustainable raw material
Seaweed is grown in aquacultures. The grown seaweed can be harvested after just a few weeks and is available as a raw material after a short time. During their growth phase, they enrich the seawater with oxygen and improve the water quality. But seaweed cultivation offers even greater potential for the regions.
For example, biodiversity in many suitable seaweed growing areas is threatened by overfishing, as fishing is one of the most important industries for the regions and the only source of income for many families. The industrial cultivation and processing of seaweed in these regions creates new sources of income that serve as an alternative to traditional fishing and contribute to the protection of biodiversity.
Film extrusion
The processing of the seaweed material, e.g. into films with a defined geometry, is based on extrusion. In this process, the material is formed under pressure and shaped into the desired form with the aid of a die. Extrusion is an established and proven process in many industries, which can be scaled very well.
The process developed at Brabender is characterized by the fact that the entire seaweed material is used. Therefore, no polymer extractions are required, which would be associated with very high costs, large resource consumption and associated high greenhouse gas emissions. Compared to conventional plastics and bioplastics made from other renewable raw materials, Carraphane thus has a smaller environmental footprint.
One film – many possibilities
In addition to the water solubility, which enables an optimal lifecycle, the high tensile strength and the diverse processing options of the films speak for the use of Carraphane as a packaging material.
For example, they can be injection molded and thermoformed into the desired shape and then sealed to protect the contents of the package from external influences. This means that more complex packaging shapes can also be made from Carraphane.
Forming of Carraphane – a project of the TU Dresden
The Professorship for Processing Machines/Processing Technology at TU Dresden has developed a pneumatically and electromechanically driven laboratory machine for forming by deep drawing. The technology enables the production of 3D packaging geometries from various ecological materials such as Carraphane films or fiber materials from agricultural residues. In the forming process, a punch moves into a corresponding negative mold and forms the flat blank into the desired 3D molded part. With the aid of this machine, the principal suitability of Carraphane for such forming processes was successfully demonstrated in initial feasibility studies. These results must be further developed into marketable qualities in future research projects by continuously deepening our understanding of the material and improving the process parameters