Test for alkaline and acid
perspiration:
Continuous contact
with the human perspiration also affects the fastness of some the dyed
fabrics. In fact the perspiration is found to be either slightly alkaline
or acidic in nature. When fabric is subjected to this alkaline
or acidic perspiration continuously some times the tone and depth of the
dyed shade gets affected.
We can see how this change can be tested by
artificially simulating the perspiration condition.
|
Perspiration |
Reagents required for Alkaline
perspiration |
Reagents required for Acidic perspiration |
|
Histidine mono hydrochloride monohydrate |
0.5 gram/litre |
0.5 gram/litre |
|
Sodium Chloride |
0.5 gram/litre |
0.5gram/litre |
|
Disodium hydrogen orthophosphate |
2.5 gram/litre |
-- |
|
Sodium dihydrogen orthophosphate |
-- |
2.2 gram/litre |
|
0.1N Sodium hydroxide |
adjust pH to 8 |
|
|
0.1N Acetic acid |
-- |
pH 5.5 |
|
MLR 1:50 |
Dip the fabric in the above recipe for 30
minutes at 30C; allow it dwell for 14hours under 4.5 kg weight of the
perspirometer. |
Dip the fabric in the above recipe for 30
minutes at 30C; allow it dwell for 14hours under 4.5 kg weight of the
perspirometer. |
Take out the fabric, rinse in cold water
and air dry ; compare against grey scale and grade it accordingly.
| 
