Lignin-reinforced PLA: innovative bioplastic from KraussMaffei and Synergy Horizon

Image: Granulate of lignin-reinforced PLA, behind it an object made from the material; Copyright: KraussMaffei

Lignin-reinforced PLA: 30 % lignin for improved properties. Natural antioxidants, higher strength, controlled degradability. Copyright: KraussMaffei

02.02.2024

KraussMaffei and Synergy Horizon have jointly developed a new type of bio-based reinforced thermoplastic that prioritises functionality and sustainability.

Bio-based plastics innovation: lignin as a key component

KraussMaffei and Synergy Horizon, a member of the Cyprus-based Synergy Horizon Group, have developed a 100% bio-based reinforced thermoplastic known as lignin-reinforced PLA. "With our compounding expertise and our project partner's unique knowledge of lignin processing, we have succeeded in incorporating up to 30% lignin into the PLA matrix and producing a compound with natural antioxidant capacity/activity, improved mechanical properties and controlled biodegradability," explains Lars Darnedde from Process Engineering Development and Project Manager at KraussMaffei Extrusion.

Exhibitors & products around raw materials & auxiliaries

Lignin: from by-product to innovative filler

Synergy Horizon specialises in the refinement of lignin through hydrolysis. "However, processing hydrolysis lignin is no easy task," says Alexander Gonchar, Head of Research and Development at Synergy Horizon. The company converts lignin into valuable products for a wide range of applications.

Synergy Horizon has now developed a new process for the production of free-flowing lignin powder, which can be dosed into the extruder as a filler.

Process optimisation and increased mechanical performance

Image: ZE BluePower 28 laboratory extruder; Copyright: KraussMaffei

Up to 30% lignin incorporated into PLA matrix with the ZE Blue Power 28 laboratory extruder. Special screw configuration and innovative technologies enable precise processing at a low temperature. Copyright: KraussMaffei

The successful processing of lignin into the PLA matrix was confirmed by KraussMaffei in Laatzen. "We customised the screw configuration with highly sensitive mixing elements specifically for the lignin," says Lars Darnedde, which led to an increase in the bending and tensile modulus of around 30%.

Additional benefits and applications

Antioxidant capacity: Lignin helps to prevent the oxidation of food in packaging, thus ensuring quality and safety.
Odour neutrality: Unlike other types of lignin, the biocompound is odourless, ideal for food packaging.
Biodegradability: PLA biocompounds containing lignin show improved biodegradability with a degradation rate of over 90% in 99 days.

This innovation marks a significant step towards sustainable plastics production. The integration of lignin into the PLA matrix not only offers ecological advantages, but also improves the mechanical properties of the material, which opens up new application possibilities.