Textiles can be used for heating, cooling and lighting. They can measure the heart rate, as well as monitor soil erosion on slopes, and can even be launched into space for use as space reflectors – as long as they are electrically conductive.
The electrical conductivity of warp-knitted textiles is the subject of extensive development work at KARL MAYER. In this project, entitled “textile-circuit”, multibar raschel machines are used with and without a jacquard facility to incorporate conductive yarns directly into the textile during manufacture. The first results are now available and show what can be achieved, including the use of textiles for remote control. The original control tool and its production principles were both successfully shown at the IDTechEx Show in Santa Clara and at the Aachen-Dresden-Denkendorf International Textile Conference, both of which were held in November 2018.
The pattern provides electrical conductivity
Electrically conductive structures with a virtually unlimited range of designs can be produced on multibar raschel machines. This is possible, thanks to multibar patterning using KARL MAYER’s innovative string bar system, with which the yarns can be positioned individually and as required onto a ground – following the principles of tailored fibre placement. The ground can be produced with a wide variety of different designs, and jacquard patterns can also be worked, depending on the type of machine.
As well as offering extensive design freedom, warp knitting also delivers maximum efficiency when producing electrically conductive textiles. Furthermore, the typical performance features of textiles, such as softness, flexibility, elasticity and breathability, are fully retained.
Production without any problems
At the functional heart of these innovative E-warp-knitted textiles are filaments containing metal, such as ELITEX®. In the experience of Sophia Krinner, a textile Product Developer at KARL MAYER, “silver-plated polyamide can be processed very easily on multibar raschel machines.” Her aim in the next few stages is to optimise the sequences on the machine to suit mass production. This textile engineer studied the processing of functional yarns in her master’s degree. As well as ELITEX®, she also achieved good results with the warp knitting of other fine, insulating metal filaments and metallised yarns, e.g. Shieldex® and Agsis™.
Of course, the flexibility and diameter of the conductive yarns must generally be harmonised to suit the machine gauge and the characteristics of the base fabric.