GEOMETRICAL MODELING OF WOVEN FABRICS WEAVABILITY-LIMIT NEW RELATIONSHIPS Mohamed Dalal 1 , Jean-Yves Drean 2 , Jean-François Osselin 2 1 REMTEX research laboratory /Ecole Supérieure des Industries du Textile et de l’habillement - ESITH Route d’Eljadida, Km 8 - BP. 7731 Oulfa, Casablanca Morocco; dalalmohamed@gmail.com – dalalmohamed@hotmail.com dalal@esith.ac.ma 2 LPMT research laboratory / Université de Haute Alsace (UHA), – Laboratoire de Physique et Mécanique Textiles (LPMT) EA 4365, 68093 Mulhouse, France; jean-yves.drean@uha.fr - jean-francois.osselin@uha.fr 1. Introduction During last many years, many works have conducted a considerable amount of research regarding the weavability limit, the maximum number of warps and picks per unit length that can be woven with a given yarn and weave. The driving force behind such research effort is: frst, to avoid attempting to weave impossible constructions and thus eliminating unnecessary costly trials, and second, to reduce yarn breakage during weaving and wear of weaving-machine parts. For only simple woven fabrics, the early work focused on conducting experiments that led to empirical relationships [1-8] that correlated the maximum number of threads per unit length with yam size and weave. Also, more recent research has followed the same theoretical approaches [9-24] to broaden the applications of the weavability-limit relationships. More recent and current research efforts have been directed toward establishing a standard or reference fabric against which fabrics can be compared. The reference fabric is normally that of maximum construction. The proposed comparison is usually expressed in terms of the ratio of a construction parameter of a given fabric to the corresponding value for the standard fabric. The ratio is termed frmness or tightness. The incentive behind such research is the thought that the physical, mechanical, and aesthetic properties of a fabric can be related to its degree of tightness. Designers would thus have scientifc rules to construct fabrics with predetermined end-use performance. It was found that a wide variety of properties of woven fabrics depend on the degree of tightness [25-38]. Since most of the research on weavability limit and tightness has been published when natural fbers were still dominant, the derived and proposed relationships are limited to fabrics from wool or cotton fber. This issue of Textile Progress reviews the soundest research work on the weavability limit, proposed tightness parameters, and the relationship between fabric properties and tightness. But all the relationship weavability limit and tightness published until nowadays are used only for simple woven fabrics and neither for complex woven fabrics nor for all material. And also does not give us true information about weavability limit and tightness. Therefore, the objective of this new research is to establish a correct standard or reference fabric against which fabrics can be objectively Abstract: The weavability limit and tightness for 2D and 3D woven fabrics is an important factor and depends on many geometric parameters. Based on a comprehensive review of the literature on textile fabric construction and property, and related research on fabric geometry, a study of the weavability limit and tightness relationships of 2D and 3D woven fabrics was undertaken. Experiments were conducted on a representative number of polyester and cotton woven fabrics which have been woven in our workshop, using three machines endowed with different insertion systems (rapier, projectiles and air jet). Afterwards, these woven fabrics have been analyzed in the laboratory to determine their physical and mechanical characteristics using air permeability-meter and KES-F KAWABATA Evaluation System for Fabrics. In this study, the current Booten’s weavability limit and tightness relationships based on Ashenhurst’s, Peirce’s, Love’s, Russell’s, Galuszynskl’s theory and maximum-weavability is reviewed and modifed as new relationships to expand their use to general cases (2D and 3D woven fabrics, all fber materiel, all yarns etc…). The theoretical relationships were examined and found to agree with experimental results. It was concluded that the weavability limit and tightness relationships are useful tools for weavers in predicting whether a proposed fabric construction was weavable and also in predicting and explaining their physical and mechanical properties. Keywords: 2D and 3D woven fabrics, weavability limit and tightness, physical and mechanical characteristic, modeling. http://www.autexrj.com AUTEX Research Journal, Vol. 17, No 1, March 2017, DOI: 10.1515/aut-2015-0056 © AUTEX 73