2007, Piran, Slovenia

F i / g m -2
300
250
200
150
100
50
0
E/5+CO E/5+200Kb E/5+400Kb
sample
Personal protective equipment
Figure 1: Skin Model tests on ballistic protective compounds: Water vapour absorbency Fi.
It is also interesting to compare both superabsorbent samples. Obviously, a higher amount of
superabsorbent polymers increases the water vapour absorbency, but not linearly. This nonlinear
behaviour can be understood by the dynamic character of the water vapour absorbency.
The test duration was 1 h, but within that time the superabsorbent samples were not saturated.
In fact, a long term measurement with E/5+400Kb exhibited that even after 9 h, the water
vapour uptake was not completed. At that time, this sample absorbed 730 g/m 2 of water.
In Figure 2 it is shown, how a vaporous sweat impulse simulated by the Skin Model at time t
= 0 influences the microclimate humidity rh below the ballistic protective compounds. It can
be seen that the superabsorbent specimens E/5+200Kb and E/5+400Kb are able to keep rh
much dryer and, thus, more comfortable than the construction with cotton layer E/5+CO.
Again, a higher share of SAPs is improving the moisture management characteristics.
In Figure 3, the buffering capacity against liquid sweat impulses Kf, as obtained by the Skin
Model, is given. Again, a significant improvement by using superabsorbents is found.
Whereas the reference sample E/5+CO removes 82 % (Kf = 0.82) of liquid sweat from the
skin, E/5+200Kb and E/5+400Kb buffer 93 or 95 %, respectively.
These promising Skin Model results could be validated by the wearer trials’ data. In Figure 4,
the mean relative humidity rhM in the microclimate of the vests E/5+CO and E/5+400Kb is
given. As a result, rhM is decreased by 9% by using SAPs. This difference is statistically
significant for t ≥ 70 min on a level of p > 0.8 and for t ≥ 80 min on a level of p > 0.9.
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