*Non-destructive Characterizations of Natural Yarns and Fabrics DOI: http://dx.doi.org/10.5772/intechopen.102587*

**Figure 7.**

*Yarn characteristics obtained from ASTM test standards and XRM-CT methods. (a) Yarn diameter, (b) yarn packing factor (PF), and (c) yarn crimp% [12, 13].*

#### **Figure 8.**

*Fabric characteristics obtained from ASTM test standards, theoretical values and XRM-CT method. (a) Fabric thickness, (b) fabric volumetric density calculated using ASTM thickness and CT thickness, and (c) fabric cover factor calculated using theoretical yarn diameters and CT yarn diameters [12, 13].*

#### **Figure 9.**

*X-ray micro-computed tomographic 2D images of the fabrics studied. (a) P40L, (b) P40H, (c) S40L, (d) S40H, (e) P60L, (f) P60H, (g) S60L, and (h) S60H [12, 13].*

However, despite the different twists in different count-yarns in the fabrics, twist multiplier were nearly the same suggesting the same internal structure (helix angle) of the yarns [12, 13].

With increasing fabric density (thread density), thickness decreased in 40Ne yarnmade fabrics, and increased in 60Ne yarn-made fabrics (**Figure 9**). With increasing fabric density, less twisted and larger diameter 40Ne yarns compressed within the structure, and filled up the voids. This resulted in a closer fiber and yarn packing, and reduced thickness in the 40Ne yarn-made fabrics (**Figures 7b** and **9**). In contrast, finer, tighter (with more twists) and smaller diameter 60Ne yarns had less voids (as discussed above in yarn packing factor). Hence, in the presence of low voids in the 60Ne yarns, the yarns expanded in the thickness direction with increasing fabric density (**Figures 7b** and **9**) [12, 13].

**Fabric Volumetric Density**: Both the ASTM thickness and CT thickness were used to calculate fabric volumetric density (g/cm<sup>3</sup> ) for further comparison (**Figure 8b**), and were obtained by multiplying fabric basis weight (gsm) with thickness. The methods did not exhibit any statistical differences in the measurements (P-value 0.51) [12, 13].

**Fabric Cover Factor**: Fabric cover factor obtained from the theoretical values and the CT method (using CT yarn diameter) were compared and depicted in **Figure 8c**. A further statistical analysis showed that there was no significant difference between the measurements obtained from the two methods (*P*-value 0.62), and satin fabrics

### *Non-destructive Characterizations of Natural Yarns and Fabrics DOI: http://dx.doi.org/10.5772/intechopen.102587*

exhibited higher fabric cover factor. Irrespective of weave design, no significant difference was observed between 40 and 60Ne yarn-made fabrics [12, 13].

Therefore, unlike other classical test methods, the CT method are nondestructive and capable of providing realistic measurements from both the 2D and 3D images. Apart from the structural properties discussed in this Chapter, the CT method can be used for a more advanced analysis of the fabrics such as fiber area distribution [12, 13], porosity analysis [22], surface profile analysis [1] etc. Such in-depth analysis and understanding of the cotton-made yarn and fabric structures will help engineers and scientists optimize the structure and improve the performance of the textiles for diverse applications and end-uses.
