Subproject A2: Multi-axially reinforced knitted fabrics with a high number of layers for thermoplastic composites

Supervision
Prof. Dr.-Ing. habil. Dipl.-Wirt. Ing. Chokri Cherif
TU Dresden
Institute of Textile Machinery and High Performance Material Technology 
01062 Dresden
Germany
Phone: 0351 / 463-39303
Fax: 0351 / 463-39301


Prof. Dr.-Ing. habil. Sybille Krzywinski
TU Dresden
Institute of Textile Machinery and High Performance Material Technology
01062 Dresden
Germany
Phone: +49 351 463-39312
Fax: +49 351 463-39301



Abstract
Textile-reinforced thermoplastics of hybrid yarn are of great interest as the new group of materials for numerous applications in function integrated lightweight constructions of multi-material design. The further development of the flat-knitting technology to a unique fundamental technology and a significant contribution to an automatic manufacturing of handling and stress-related multi-axially reinforced textile preforms from hybrid yarn for the reproducible subsequent treatment to flat and specially curved thermoplastic composites can be achieved by the research work of SP A2 integrated into the development process of lightweight structures in multi-material design.

Two aims are pursued in the subproject A2. The first aim serves the consistent expansion of the basic findings compiled in the base period for the development of multi-layered knitted fabrics with higher number of layers in reproducible quality as well as the integration of sensor networks. The second aim is the development of a chain of processes from the component geometry of knitted fabric contours assisted and determined over computer into pattern programs to 2D/3D-shaped and biaxially reinforced MLG. The following summarized operating points are worked on in subproject A2 during the combination phase:

• The modelling, experimental development, manufacturing and testing of knitted fabrics from hybrid (GF/PP) yarns having a higher number of layers and reproducible properties
• The development of required knitted fabrics of hybrid yarns for compliant structures and composites with integrated sensor systems
• The development of a chain of processes of the component geometry of knitted fabric contours and reinforcement yarn layers assisted and determined over computer as well as their transfer to programs for a flatbed knitting machine in order to manufacture the 2D/3D-shaped, biaxially reinforced knitted fabrics made of hybrid yarns
• The testing of the production technology for 2D/3D-shaped knitted fabrics from hybrid yarns and the realization of selected exemplary complex geometries to a demonstrator component.

The reproducible design and securing of the stress-related reinforcement structure stand thereby in the centre of the work.

The aim of the demonstrator phase is the provision of a continuous concept for the automatic manufacturing of complex and multi-axially reinforced textile preforms from hybrid yarn in reproducible quality for the subsequent treatment to flat or specially curved and dish-shaped thermoplastic composites with a high number of layers and integration of function. This concept is to be tested consistently on the basis of complex 3D preforms for real demonstrator components of the SFB and provides a substantial basis for the development of technology demonstrators in function-integrating multi-material design.