With the decrease in thickness,
the structures become more compact. Contact points among the fibres can be
considered to increase, making the pores more torturous. Rate of evaporation
from a compact structure is relatively slow as compared to an open one. Slow
evaporation will provide prolonged performance. Lower thickness resulting in
denser fabric shows better performance as compared to low density thicker
Nonwoven fabrics containing Super
Absorbent Fibres can be used to increase the protection time against heat.
Protective performance of assembles containing nonwovens as absorbent core has
been evaluated. A number of three layer evaporative cooling fabric assemblies
were designed and effects of various parameters on its performance were
studied. Adding of water to the sample provides better performance than the dry
sample due to evaporative cooling. Neither too high nor too low amount of added
water provides satisfactory performance. Optimum performance was obtained when
the amount of added water was four times the dry weight. Too tight or too much
open construction of the outer layer also does not facilitate the cooling
process to satisfactory level. Increasing the SAF content and basis weight of
absorbent core has positive effect on the protective performance, whereas
increasing the thickness of the core decreases the performances. Evaporative cooling garments can
be designed using different amount of SAF and different basis weight depending
on the end user requirement. Same level of performance can be achieved by using
lower basis weight and higher SAF content as compared with higher basis weight
and lower SAF content, but cost of the product will increase.
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