High-performance sewing threads based on a fine-titer PEEK yarn

The objective of this research is the development of a polyether-ether-ketone (PEEK) yarn and its further processing into a sewing thread. The melt spun fine-titer PEEK yarn with a titer of 50 dtex and 18 single filaments (50f18) has a strength of 72.3 cN/tex (939.9 MPa) and a Young’s Modulus of 8.4 N/tex (10.9 GPa). Thus, the mechanical properties significantly exceed the state of technology. The PEEK yarn is further processed into two different sewing threads (50x2 and 50x3) with 2 twists per cm in z-direction. Using both types of thread for knitting, embroidery, and sewing is evidence of textile processing. The mechanical properties of the high-performance sewing threads are comparable to commercial sewing threads made of engineering polymers like polyethylene terephthalate (PET). The developed PEEK sewing threads can be used for non-crimped fabrics in high-performance composites.