Introduction
Technical textiles are the fastest growing sector in the textile industry. Therefore, it is highly essential to develop all techniques and types of equipment in order to decrease the production time especially with the use of electronically equipped modern looms and communicated with computers.
The automatization of woven design is one of the ways to facilitate the work and to increase the production, especially in the conventional weaving of complex structure, due to the time consuming and difficulties involved in the manual design (e.g., the combination of weaves, seeking of stitches and introducing it, generating of lifting plan, doing cross-sections, etc. However, a number of CAD/CAM fabric woven structures with complicated weaves have been developed and represented in the form of 2D and 3D matrices.
Some of these researches depended on mathematical functions to describe and generate automatically the 2D and 3D weaves. In other words, the algorithm of the Kronecker Product was applied to describe weaves. In addition, other CAD/CAM software’s that deal with geometric modeling of woven structures have been developed to visualize the fabric appearance before weaving (Liao & Adanur, 1998; Lomov, Perie, Ivanov, Verpoest, & Marsal, 2011; Smith & Chen, 2009). However, they do not discuss all the problems due to the wide variety of weaves and stitching ways.
Definition Multilayer fabrics
A multilayer fabric consists of several layers woven above each other with a maximum of 12 woven layers or 22 warp yarn layers and 23 weft yarn layers (unidirectional layers). The connection can be realized by connection yarns in the third dimension or by interlocking. As a result, the delamination resistance of the fabric increases and the manual labor of stacking different layers on top of each other could be decreased. All types of yarns can be used and combined. This combination could be different layers with different types of yarns but also in one-layer different types of yarns can be used.
A multilayer fabric with woven layers consists of a number of woven layers stacked on top of each other and held together with connection yarns in the third dimension (Z-direction). The geometry of the woven layers can be customized.