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Newsletter: January
Comfort Factors In Clothing Performance In the 50’s and 60’s PVC and
PU was a popular choice for the use in waterproof garments. It was also
impermeable to water, hence keep us dry. Yet, the inherent problem with PVC
and PU coated fabrics is that moisture vapour couldn’t pass through and end
up creating an uncomfortable wearer environment.
A solution discover in the 70’s, that was the discovery of microporous
coating. In this discovery, moisture vapour was allowed to pass through and
the results significantly keep us comfortable. This was an innovation of its
time and later many other materials were introduced that is followed with
the introduction of Hydrophilic breathable Pu. However, still there was some
shortcoming, particularly performing in wet and cold condition.
The formation of dew point occurs, when outside temperature is low (which is
between 0oC and 10oC) and also
in rain condition. This rapid condition results with the forming of vapour
condensation. A warm body at 37oC inside a garment with cold
saturated air outside struggled to cope with the existing moisture and as a
results wearer in the discomfort zone.
The standard test for measuring moisture vapour transmission (MVT) rates on
waterproof fabrics, either the fabrics coated or laminated, was
fundamentally failed. The test was carried out in such condition; without
any temperature gradient e.g. 35oc outer temperature, 35oC
inner body, 50% humidity and NO RAIN.
Is this realistic ? Many studies have been carried out and this study had
led to improved understanding of clothing performance particularly on how
waterproof breathable fabrics perform when they are subjected to rain and
cold. Question remains as in what condition, the study has to be carried
out, either in actual condition or in laboratory conditions……..
Contributed by : Bachik Abu Bakar,
Zaharah Kunci Mon & Rohani Rahmad Department of
Mechanical Engineering Technology Faculty of
Mechanical & Manufacturing Engineering
Universiti Tun Hussein Onn Malaysia Batu Pahat, Johor |