3D nonwovens

Bilayer with 3D nonwoven structure of P3HT nanofibril... 

FIGURE 3.4 (A) Fabrication of polymer solar cell from PEDOTiPSS thin film. (B) Fabrication of a three-dimensional (3D) nonwoven nanofabric-based organic solar cell. (A) Reproduced with permission from reference Oh, J.Y., Shin, M., Lee, J.B., Ahn, J.-H., Baik, H.K., Jeong, U., 2014. Effect ofPEDOT nanofibril networks on the conductivity, flexibility, and coatability of PEDOT PSS films. ACSAppl. Mater. Interfaces 6, 6954-6961. Copyright 2014, Royal Society of Chemistry. 

Ravbala, N., Gong, R.H., 2003. Effects of mould porosity on fibre distribution in a 3D nonwoven process. Text. Res. J. 73, 588-592. 

Nonwoven fabrics having surface features such as apertures or projectimis or both are also called shaped nonwovens. Thus, there are two distinctive types of 3D nonwovens flat structures that have high bulk and shell structures that have 3D contour. 

High-bulk 3D nonwovens can achieve their 3D form, that is, large thickness, during the initial web formation or through layering multiple webs after the initial web formation. 

Figure 8.25 Melt-blown 3D nonwovens process. Adapted from Velu (2003).

Gong, R.FI., Fang, C.Y., Porat, I., 2000. Single process production of 3D nonwoven shell structures part 1 CID modelling of the web forming system. Int. Nonwovens J. 9 (4), 20-24. 

Poillet, P., Le Roy, G., 2003. Needle punched 3D nonwoven structures with technical functions. Asian Text. J. 6, 46 7. 

Wang, X.Y., Gong, R.H., Dong, Z., Porat, I., 2006. Frictional properties of thermally bonded 3D nonwoven fabrics prepared from polypropylene/polyester bi-component staple fiber. Polym. Eng. Sci. 46 (7), 853-863. 

Although fibre orientations in a nonwoven fabric are potentially in any direction in three dimensions, the description of fibre alignments in three dimensions is complex, and its measurement is expensive. It is evident that most of fibres in the nonwoven fabrics are aligned either in the fabric plane or nearly vertical to the fabric plane. Therefore, the stmcture of a 3D nonwoven fabric is frequently simplified into a combination of both multiple layers of 2D stmctures and the fibres in the direction perpendicular to the fabric plane, as shown in Fig. 6.2. Thus, the fibre alignments in 3D nonwoven fabrics can be described by fibre orientations in two dimensions, eg, the fibre orientation in nonwoven fabric plane. ... 

Figure 6.1 Fibre orientation angle in 3D nonwoven fabrics.

---