**6.2. Thermo-physiological comfort**

The effect of structural parameters is same on the air permeability and moisture vapour transmission rate (MVTR). Air permeability and MVTR decreases with increasing the level of both mass per unit area and needle density (Figures 9a, 9b, 10a & 10b). This is due to decrease in size of the air-conducting channels during more punching process and also due to availa‐ bility of more fibres for the entanglement, which decreases the permeability of the air or moisture to the padding. The effect is opposite for the fibre denier where both increase with increase in the fibre denier (Figure 9c & 10c). The density of the padding bandages decreases with increase in fibre denier due to which there is increase in the size of the air channels which provide easy air or moisture flow.

**Figure 9.** Effect of structural parameters of nonwoven on air permeability: (a) effect of mass per unit area (50E4 punch‐ es/m2 ; 2.5 denier); (b) effect of needling density (100 g/m2 ; 2.5 denier); (c) effect of fibre denier (100g/m2 ; 130E4 punches/m2 )

For thermal results, the thermal resistance increases with increase in mass per unit area for same level of needling density (Figure 11a). This is because thickness of samples increases with

be lesser for thick fibre compared to thin fibre. Moreover, padding made from coarser fibre has more porous structure. This all results in more energy absorption and therefore more pressure reduction for the padding made from higher fibre linear density compared to lower

**Figure 8.** Effect of structural parameters of nonwoven on pressure absorbency: (a) effect of mass per unit area (50E4

The effect of structural parameters is same on the air permeability and moisture vapour transmission rate (MVTR). Air permeability and MVTR decreases with increasing the level of both mass per unit area and needle density (Figures 9a, 9b, 10a & 10b). This is due to decrease in size of the air-conducting channels during more punching process and also due to availa‐ bility of more fibres for the entanglement, which decreases the permeability of the air or moisture to the padding. The effect is opposite for the fibre denier where both increase with increase in the fibre denier (Figure 9c & 10c). The density of the padding bandages decreases with increase in fibre denier due to which there is increase in the size of the air channels which

**Figure 9.** Effect of structural parameters of nonwoven on air permeability: (a) effect of mass per unit area (50E4 punch‐

For thermal results, the thermal resistance increases with increase in mass per unit area for same level of needling density (Figure 11a). This is because thickness of samples increases with

; 2.5 denier); (c) effect of fibre denier (100g/m2

; 2.5 denier); (c) effect of fibre denier (100g/m2

; 130E4

; 130E4

; 2.5 denier); (b) effect of needling density (100 g/m2

fibre linear density.

178 Non-woven Fabrics

punches/m2

punches/m2

es/m2

punches/m2

)

)

**6.2. Thermo-physiological comfort**

provide easy air or moisture flow.

; 2.5 denier); (b) effect of needling density (100 g/m2

**Figure 10.** Effect of structural parameters of nonwoven on moisture vapour transmission rate (MVTR): (a) effect of mass per unit area (130E4 punches/m2 ; 6 denier); (b) effect of needling density (300 g/m2 ; 2.5 denier); (c) effect of fibre denier (300g/m2 ; 130E4 punches/m2 )

increase in mass per unit area. Also the thermal resistance of padding decreases with increase in needling density (Figure 11b). For the liquid transport (Figure 7b), the spreading time is lower for the samples having more free spaces in the capillary network. Increasing mass per unit area and needling density reduces the porosity, and stimulates lower rate for fluid transport and takes more time (Figure 12a & 12b). Nonwoven made from coarser fibres results in larger capillaries and shows faster spreading rate and takes lower time (Figure 12c).

**Figure 11.** Effect of structural parameters of nonwoven on thermal resistance: (a) effect of mass per unit area (50E4 punches/m2 ; 2.5 denier); (b) effect of needling density (100 g/m2 ; 2.5 denier); (c) effect of fibre denier (100g/m2 ; 130E4 punches/m2 )

**Figure 12.** Effect of structural parameters of nonwoven on liquid transport (time taken represents the total period tak‐ en by liquid to cover an area 380 cm2 of a circular specimen as shown in Figure 7b): (a) effect of mass per unit area (1300E4 punches/m2 ; 2.5 denier); (b) effect of needling density (300 g/m2 ; 2.5 denier); (c) effect of fibre denier (200g/m2 ; 130E4 punches/m2 )
