Yarn Damage Conditions Due to Interactions During Interlock Weaving Process: In-situ and In-lab Experiments

For some severe applications, pieces are made in composite materials with woven fabrics reinforcements: interlock. High yarn density and specific weaving pattern can slow the production speed because of yarn damages. The purpose of this study is to identify conditions causing warp yarn damages during dense weaving in terms of weaving sequence, interlacing and yarn structure and morphology. Two approaches are followed in-situ on the weaving machine and in-lab on a tribometer designed for this study. An instrumented 3D interlock machine is used in order to measure yarn tension and contact force during weaving. A specific sequence with different kinds of yarn intercrossings is applied and the more aggressive cases in terms of yarn tension and contact force are identified. From the data acquired on the weaving machine, a specific tribometer reproducing the intercrossing between two yarns with different yarn tension and contact force has been developed. The results obtained from weaving and friction tests show the source of aggressive conditions: i) the Jacquard mechanics: higher tension and contact force are obtained while yarn has a raising movement in comparison to a lowering movement, ii) the intercrossing sequence: a single yarn in movement with its neighbours having an opposite movement, iii) yarn structure and morphology: a coarse yarn and/or with twist, because it is bulky however it also have a better cohesion, therefore a compromise has to be found, iv) normal load increases yarn damage, and decreases the coefficient of friction, however the effect of yarn tension is not determined.