**3.1.3 Straight cross threads**

The intersection of horizontal line corresponding to *h*1/*D*=1 gives all possible structures ranging from relatively open to jammed configurations. In this case *h*2= 0*, h*1= D; This gives interesting structures which have stretch in one direction only, enabling maximum fabric thickness and also being able to use brittle yarns. The fabric designer gets the options to choose from the several possible fabric constructions. These options include jamming and other non jammed constructions. Using the above logic it is also possible to get fabric parameters for:


Modeling of Woven Fabrics Geometry and Properties 21

1 *n*

**3.2.2 Effect of variation in beta (***d***2***/d***1) on the relation between warp and weft cover** 

Fig. 13a. Effect of *β* on the relation between warp and weft cover factor

An increase in the value of beta from 0.5-2 increases the range of warp cover factors but raises the level for the weft cover factor. This means with an increase in beta higher weft cover factors are achievable and vice-versa. However it may be noted that for cotton fibers having higher fiber density the sensitivity range between the warp and weft cover factor is relatively large compared to polypropylene fiber as shown in figure 13a and 13b. This shows a very important role played by fiber density in deciding warp and weft cover factors for the

i 1 f

*t p*

*<sup>ρ</sup> <sup>p</sup>* (38)

For blended yarns, average fiber density is given by the following

where = avera 

jammed fabrics.

**factor for jammed fabrics** 

ge fiber density ,

*p*i = weight fraction of the ith component, *p*ft = fiber density of the ith component and *n* = number of components of the blend
