Motorized Jacquard technology for multilayer weaving damages study and reduction: Shed profile and close shed profile

Abstract

Materials used for composite reinforcements usually have high mechanical performances which are linked to a very sensitive and brittle behaviour to friction. The weaving process applied to delicate yarns, like glass, carbon and some other technical yarns, generate damages which tend to reduce the performances of the final composite. Shedding may be a major weaving stage for the generation of yarn damages. Based on a specific weaving pattern, it was observed that different shedding configurations could influence yarn damages at the shedding step. The specificity of the motorized Jacquard device is used to generate different movements and geometry configurations. A particular methodology needed to be set in order to confirm these observations and bring out a clear effect of shedding parameters on yarn damages. After damages have been identified and classified, some experiments will count the damage occurrences and evolutions in time according to shedding parameters. The aim of this research is first to show a clear effect of shedding on warp damaging thanks to the quantification of damages and then to set out an optimized configuration of shedding parameters which may reduce deterioration involved in high-density multilayer woven fabrics.

In-situ measurement of tension and contact forces for weaving process monitoring: Application to 3D interlock

“…The production speeds must be increased without degrading product quality while keeping an acceptable cost-efficiency. The damage that occurs is due to the high shedding speed and warp rubbing against loom parts, which produces more damage [29]. In order to increase the cost-efficiency, machine stops must be reduced to cut the losses of time.…”

“…Only a few studies have investigated process monitoring and the impact of tows damage on process execution. McHugh [36] and later Decrette et al [29,37] presented an optimisation strategy based on warp tow degradation events during a weaving process and proposed to reduce tow damage by adjusting the Jacquard UNIVAL 100 parameters. UNIVAL technology allows a precise control of yarn movement and shed geometry thanks to motorized heddles.…”

The matching relation analysis of yarn pre-tension in weaving 3D bi-directional angle-interlock fabrics

“…Fiber breakage and yarn wear can easily occur when the warp tension is too high due to repeated friction between the warp yarn and the heald frame in the 3D woven fabric weaving process. 30–31 And the warp tension increases significantly in the shedding movement. 32 Warp pre-tension is the basis of all changes in warp tension during weaving.…”

Heald frame motion trajectory based on minimum warp friction in the shedding process of three-dimensional woven fabrics

“…The breaking and wearing of warp yarn have become prominent problems in the fabrication process of three-dimensional (3D) woven fabrics, and are the most serious in the shedding stage. 1 The primary reason why some fibers in the warp yarn are broken lies with the unreasonable motion laws of the heald frame. The warp yarn suffers two kinds of damage in the shedding process, namely impact breaking and friction wearing.…”