Subproject A1: Online spinning of glass/polymer commingling hybrid yarns
Supervision
Dr. rer. nat. Harald Brünig
Leibniz Institute of Polymer Research Dresden
Hohe Str. 6
01069 Dresden
Germany
Phone: +49 351 4658-301
Fax: +49 351 4658-219
Prof. Dr.-Ing. habil. Edith Mäder
Leibniz Institute of Polymer Research Dresden
Hohe Str. 6
01069 Dresden
Germany
Phone: +49 351 4658-305
Fax: +49 351 4658-362
Abstract
Emphasis of the ongoing work is placed on the modification of the online-spun hybrid yarns in order to improve the composite properties by better control of technological issues (distribution homogeneity of the yarns, filament shape) and superior interfacial design (nanostructured interfaces). By processing of hybrid yarns with property profiles adapted to the needs of other subprojects, the basis of applications for hybrid yarns will be broadened as well as by the use on engineering plastics as new matrix materials.
With the presently available online-spinning technology for glass fibres (GF) and polypropylene (PP) filaments, hybrid yarns with improved properties regarding their mechanical properties, thermal shrinkage, and filament distribution homogeneity, compared to those ones manufactured by air-jet texturing, were spun. The improved characteristics were achieved by proper adjustment of the online-spinning process regarding the take-up velocities, sizing application and filament diameter ratios.
Further work is directed towards the extension of the fundamental knowledge of the online-spinning process in order to improve the distribution homogeneity of the yarns, realize different fibre-volume ratios and higher take-up velocities as well as to enhance the textile process ability. For the application of the hybrid yarns as loop thread (SP A2), sewing thread (SP B1) and in compliant structures (SP D2), it is intended to spin GF with diameters below 12 µm and develop suitable sizing formulations for the different fields of application, allowing for improved bending properties of the GF. Furthermore, additionally to the developed surface modification for the GF/PP composites, based on aminosilane adhesion promoters and maleic anhydride grafted, nanodispersed PP film former, the incorporation of nanoparticles into the sizing is foreseen. Preliminary studies of the application of sizing's containing carbon-nanotubes showed, that the concentration of the nanoparticles in the fibre/matrix interface resulted in "surface defect healing" of the GF and nucleation of the polymeric matrix, involving new fracture mechanisms which caused improved composite properties. Based on the positively affected composite performance, this approach will be followed to achieve new, multifunctional effects by nanostructured interfaces in GF/PP composites.
In order to broaden the area of application for the unique online-spinning equipment, engineering thermoplastics such as Polyamide, Polybutylenterephthalate and Polyphenylensulfide shall be used firstly in the online-spinning process to investigate both, their processing behaviour as well as their improved thermo-mechanical properties as composites. Results of the nanoparticles-sized GF/PP hybrid yarns and composites will be transferred to the new material combinations and the effect of nanostructured interfaces in the new matrices will be investigated.