Fraunhofer Institute for Electron BeamThe use of low-energy, non-thermal electron beam processes results in biohybrid textiles with specifically adjusted surface properties. The finalized project HuminTex shows how bio-based materials can be further developed into functional mask components using natural substances with antiviral properties, called humic substances, and transferred to industrial production.
Sustainability is becoming increasingly important in both medical technology and personal protective equipment. In addition to the protective function, the focus is shifting to material origin, environmental compatibility, and end-of-life concepts. Particularly, disposable products such as respiratory masks require new approaches that combine functionality with resource-saving materials and processes. Within this context, the HuminTex joint project addresses the development of antiviral, bio-based protective textiles for medical applications.
In this project, Fraunhofer FEP's approach was based on low-energy, non-thermal electron beam technology for the selective modification of textile surfaces. The two-stage electron beam-assisted grafting enables precise, substrate-specific surface functionalization and coating of textile substrates with low thermal stability. At the same time, process-induced heat stress can be avoided entirely, eliminating the need for additional chemicals, such as surfactants, that are typically used in standard textile finishing.
This allows tailored functional property profiles to be created while maintaining the structural integrity of the textiles. One focus was on the stable electron beam-induced immobilization of naturally occurring humic substances on biodegradable nonwovens made of polylactide (PLA). The covalent bonding of the functional humic acid molecules was confirmed spectroscopically. Additional investigations confirmed the high resistance of the coating to process- and usage-related stresses. The introduction of a bio-based chitosan layer as an adhesion promoter further improved both the bonding of the humic substances and the long-term stability of the functional layer. The selected humic substances were shown to be effective against viruses using plaque assays with specially established bacteriophage models.
The results showed remarkable reduction in viral activity both in the pure natural substances and in the PLA textiles functionalized with humic substances. Overall, these data confirm that surfaces containing humic substances have the potential to effectively inactivate viral particles.
The final functional PLA nonwoven fabrics were successfully integrated as an intermediate layer in the standard design of FFP2 respirators. In collaboration with project partner STFI e. V. and industry partners Zschimmer & Schwarz GmbH and Sentias GmbH, the serial production of biodegradable FFP2 respirator masks was realized. Thus, the research work at Fraunhofer FEP demonstrates the high application potential of low-energy,
non-thermal electron beam processes for the precise and selective surface engineering of textile substrates. This enables the development of application-specific and resource-efficient protective textiles for future medical technology applications.
The HuminTex joint project (funding code 16PS104004) was financed by the Innovative Protective Equipment funding program of the German Federal Ministry for Economic Affairs and Energy.
