High Performance

Increasing the yield in melt spinning of recycled fibers polymer

Saal B
Donnerstag, 12.09.2024, 16:45 - 17:10 Uhr

Key message (max. 3 sentences) To achieve sustainability goals, more fibers made from recycled polymers have to be used. Up to now, the quality of the fiber, the uptime time of the melt spinning machinery and the processability of the fiber in further process steps have been obstacles. All these challenges can be overcome by polymer melt filters made from metal fibers.

Abstract (max. 10 sentences): The recycling of textiles from all sectors, whether clothing, home textiles or technical textiles, is an essential part of enabling a holistic circular economy. PET is the most widely used material for all textiles worldwide, which makes the recycling of this polymer particularly relevant. However, if the recycled PET pellets are to be spun back into filament yarn, various challenges arise. These are the low quality of the filament, the processability of the filament in further process steps and the reduction in the operating time of the melt spinning plant. All three difficulties can be significantly influenced by one component of the melt spinning system: The polymer filter in the spin pack. The filter properties can be optimized by optimizing the diameter of the metal fibres used in the filter, the fibre placement and the filter structure. For this purpose, the metal fibers are sintered, resulting in up to 20 connection points per fiber. This leads to a mechanically stable and twisted pore structure. The novel filter shows a 10x higher dirt holding capacity at the same pressure drop in comparison to conventional filter media while maintaining a stable pressure inside the spinning package. Such filters were successfully developed at Bekaert and tested at the ITA from RWTH Aachen University.


1. Stefan Vandendijk, Bekaert NV, setfan.vandendijk@beakert.com

2. Leonie Beek, Institut für Textiltechnik der RWTH Aachen, leonie.beek@ita.rwth-aachen.de