Unlike the conventional approach of weaving the fibres of a composite into a perpendicular arrangement then cutting the fabric to the required shape, TFP arranges the fibres in bundles exactly where they are most needed for structural performance and stitches them into position on a compatible base layer. ZSK says this offers freedom of positioning, allowing fibres to be placed in the optimum directions to carry the loads, ensures that they do not move during processing, and cuts fibre wastage to only 3% instead of the usual 30-70% on a typical automotive component. ZSK’s machines are able use TFP to create 3D preforms which match the finished shape of a typical automotive part.
ZSK has improved the TFP method through a number of patented innovations that speed up the deposition of fibres, increase versatility and streamline the design process. Process improvements include:
- fast fibre laying, which reduces stitching time;
- a fibre supply unit which doubles the deposition rate and allows simultaneous deposition of different fibres;
- automatic switching between different materials;
- a pneumatic cutting system for automated cutting of wires and fibres; and
- advanced design code that ensures perfect repetition of results, even controlling zig-zag stitching automatically.
“The demand for lightweight materials, to improve CO2 emissions and product performance as vehicles become heavier and more complex, has never been greater but the cost of composite manufacture has remained unaffordable in all but the most specialist niche applications,” explains Melanie Hoerr, Manager for Technical Embroidery at the German textile engineering firm. “Our approach using TFP breaks through that barrier by eliminating most of the manual processing and waste of conventional composite manufacture, while increasing design freedom and improving quality control.”
TFP allows the composite preform to be produced with a mix of fibres, including optical or metallic materials to provide specific properties such as electrical continuity or impedance. Naked antenna wires and isolated feed wires have already been combined by this method to make up RFID components.
TFP can also incorporate polymers commingled with carbon fibre to be melted later during moulding to form the matrix, accelerating the production of complex parts and improving the resin-to-fibre distribution, especially in the extremities of the mould. Current difficulties with end-of-life recycling of composites could be largely overcome by choosing appropriate polymers for re-melting to simplify separation during end-of-life recycling.
ZSK can either provide expertise to help automotive suppliers develop prototypes and establish new TFP facilities, or recommend one of its network of specialist manufacturers to co-develop TFP parts. The company also provides ongoing manufacturing support, with both Cloud-based and off-line solutions for quality control and an Industry 4.0 solution (MY.ZSK) to connect sensors and evaluate data from the manufacturing process.
Industries: Automotive and Road Transportation