Woven composite reinforcements usually have very specific and high performances. However, the weaving process may be aggressive and damage warp tows, due to the flexion and friction sensitivity of the used materials, for example, carbon and glass. This is a crucial point as damages, which consist of filament breakages, material loss or bonding errors, tend to cause a loss of mechanical properties and/or a bad visual aspect. Stages from tensioning to reed were quite widely studied and optimised. Nevertheless, recently since density is high the impact of yarn-to-yarn and yarn to heddle wires friction at the shedding step have been clearly established. The weaving devices used are a loom specifically adapted to interlock weaving and a UNIVAL 100 Jacquard shedding system. A UNIVAL Jacquard from Stäubli, which is a motorised technology, enables any shed geometry and individual yarn motion thanks to special parameters. Such yarn movements, which are hardly reproducible with standard shedding devices, may help towards a better understanding of yarn interactions and wear mechanisms inside the shed. To understand the damage phenomenon and to reduce it, a methodology would consist in counting damage events which occur on yarns and hamper a correct shedding according to time. Several yarn interactions were set up in order to understand the effect of shedding parameter configuration on yarn damage generation. The results clearly show the several damage evolutions in time are different according to shedding configurations and that some configurations can help to reduce warp yarn damages for high-density multilayer weaving. In addition, an algorithm for weave pattern reading and processing has also been set up to manage automatically shed geometry and tow density in the shed.
Decrette et al. (Sun,) studied this question.