Industrial Processes for Biopolymers in Bavaria

In its Life Science Newsletter the Cluster Biotechnologie of Bayern Innovativ – Gesellschaft für Innovation und Wissenstransfer mbH showed different examples of companies in Bavaria, which are getting into the growing market of technical polymers. The companies are involved at various stages of the “biopolymer value chain”. Examples reach from polymer generation (Biomer) to fibre (Teijin Monofilament) and film production (Huhtamaki) to processing technologies (Brückner Technology).

Plastics derived from bacteria and plants
Polyhydroxybutyrate (PHB) is produced by fermentation with selected soil bacteria and at the end of the fermentation process the PHB makes up to 80% of the bacterial dry mass. The biomass is collected, washed and subsequently the PHB is extracted using solvents and precipitated to a white powder in water. The powder obtained in the extraction process is finally transformed into pellets in an extruder. Biomer, based in Krailling, is using PHB and processes it to pellets that can be handled on plastics machines the same way as classic plastics produced from oil. PHB has advantage over conventional polymers, such as polypropylene, due to reduced cycle times, hence decreasing machine times and costs.

Comprehensive experience with the processing of biobased polymers is concentrated at Huhtamaki, a Finnish company with a subsidiary in Forchheim. One example is the processing of polylactic acid (PLA) derived e.g. from corn. Huhtamaki is one of the few companies able to blow PLA pellets into the desired shape and size for applications such as packaging and hygiene. The latest inventions allow Huhtamaki Forchheim to produce highly transparent PLA films with the mechanical properties of polyolefins like polypropylene and polyethylene. With its BioWare range, a product portfolio based on renewable raw materials, Huhtamaki is the first to manufacture and commercialise a complete range of compostable foodservice packaging.

Monofilaments made of biopolymers
Teijin Monofilament Germany GmbH develops monofilaments based on PLA. The usage of PLA monofilaments from renewable resources reduces the dependency on petrochemical resources for the generation of polymers. PLA material can be regarded as “CO₂-neutral” since the polymer is biodegradable and the degradation products were made in equal amounts out of CO₂ in the plants.

The commencing application of polymers from renewable resources and the fact that they are biodegradable is a step towards an ecological production process. Teijin is capable of manufacturing PLA monofilaments with round and moulded profiles. Different degradation rates can be achieved through the modification of PLA. Based on their degradability, PLA monofilaments can be combined with natural products, thereby offering new application opportunities for both, natural products and monofilaments.

PLA testing at Brückner`s technology centre

Development of machines for the precessing of biobased polymers
The application of biobased polymers also requires the adaptation and improvement of existing technologies as well as the development of novel technologies for their processing. Since PLA resin is sensitive to humidity, special raw material handling and extrusion technology is necessary.

Brückner Technology Holding GmbH, a specialist for film stretching based in Siegsdorf, has developed a storage and stretching concept taking these particular requirements for PLA into account: the line layouts include silos with humidity protection, resin dryers prior to extrusion as well as extrusion processes with no additional drying needed. Furthermore, Brückner offers a unique technology centre enabling comprehensive R&D on a variety of stretching methods and PLA testing for optimising the product quality.