Detailaufnahme von Keramikfasern
Anspinnen keramischer Fasern zur Faserherstellung
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Fiber Manufacturing and Processing

Functional fiber materials and their applications

The Fraunhofer ISC develops materials and optimizes processes for fiber production and processing. Functional fiber materials are used in various applications in a wide range of sectors, including regenerative medicine, the glass and textile industry and lightweight ceramic construction.

Depending on your filds of ​​application, we will advise you on the right fiber material and its optimal production process. Among other things, we offer you materials that are biodegradable, electrically conductive or temperature-stable.

 

The development of ceramic fibers and fiber coatings is the main research focus of the ISC location, the Fraunhofer Center for High Temperature Materials and Design HTL in Bayreuth.

 

 

Current Priorities

  • Reinforcing fibers: Mechanical properties, temperature stability, textile fiber processing, pre-preg manufacturing
  • Hollow fibers: Porous, dense, thick and thin continuous fibers
  • Bioresorbable fibers and fiber fleece materials (Silica gel fiber fleeces and TiPLA-fiber)


Base materials

  • Oxidic reinforcing fibers of alumina, mullite, zirconium oxide or yttrium-aluminum garnet
  • Non-oxide reinforcing fibers of silicon carbide (SiC) or SiBN3C
  • Fiber coatings consist of silicon carbide, silicon nitride, boron nitride, zirconium oxide or spinel
  • Preceramic polymers / Hybrid polymers / Glass

Our processes

The Fraunhofer ISC has a wide range of methods and equipment for fiber production and processing:
 

  • Melt spinning (solid sol-gel precursors and preceramic polymers)
  • Dry spinning (preceramic polymer solutions and liquid sol-gel precursors)
  • Wet spinning
  • Electrospinning
  • Fiber Coating
  • Heat treatment (sintering, pyrolysis)
  • Drawing of specialty glass

Our services

  • Application-related material and process selection
  • Material adjustment or development
  • Development and synthesis of coatings
  • Coating of fibers and textile structures
  • Process adaptation and optimization
  • Sampling
  • Small series/pilot production
  • Analytics accompanying development and production
  • Upscaling from laboratory to pilot plant scale
  • Fiber characterization according to DIN EN standards

Focus "Ceramic fibers" at the Fraunhofer HTL

Spinning process for ceramic fibers

Ceramic fibers spinning process
© Fraunhofer ISC

All spinning processes are carried out as continuous spinning processes of rovings with 1 - 1000 filaments. Monofilament spinning lines for hollow fibers and two-component fibers for thick continuous fibers with diameters > 100 µm are also available. All spinning processes can be carried out in air or under inert gas. The conditions in the spinning shaft, such as atmosphere, temperature and gas flow, can be adapted to the specific requirements of the spinning mass. The spinning process is followed by pyrolysis and sintering of the spun fibers, which results in the transformation to ceramic fibers (1800 °C in air and 2000 °C under inert conditions).

 

 

Coating of ceramic fibers

Ceramic fibres coatings
© Fraunhofer HTL

Besides the ceramic fiber itself, fiber coatings are also developed at the HTL. The task of the coating is to enable damage-tolerant behavior of ceramic composites and to protect the ceramic fiber from corrosion. A comparatively inexpensive wet chemical process is used to apply the fibre coating. Process speeds of up to 1000 m/h are currently achieved. The HTL develops novel coating precursors for its customers and optimizes existing coating systems.