The garments which come into contact with the body where perspiration is heavy may suffer serious local dis-colouration. This test is intended to determine the resistance of colour of dyed textiles to the action of acid and alkali perspiration.

SDC recommended multifibre fabric to the test specimen and immersed into water,drained and placed between two plates under a specific pressure and time in a testing device. Any change in colour of the specimen and staining of the multifibre fabric is then assessed with the corresponding Grey scales for colour change and staining.

Apparatus:

SDC recommended multi-fibre fabric
perspirometer
Non-dyeable fabric (eg.Polypropylene)
acid & alkali solution
Grey scale for color changing
Grey scale for staining
oven (to maintain temp of 37+2⁰C
glass or Acrylic plates.
Standerd lighting chamber

Reagent :

	Solution A	Solution B
L-histidine monohydrochloride	0.5g	0.5g
NaCl	5g	5g
Na₂HPo₄.2H₂O	2.5g	2.5g
Distilled water	1000ml	1000ml
P^H	8	5.5

Sample preparation:

The tested sample is prepared as below:

A 10cm × 4 cm dyed sample to be tested is taken.
Another two pieces of fabric sample which are scoured, bleached but unfinished same dimension sample is also taken.
One of the unfinished samples will be of same fibre of the tested sample. Another sample’s fibre type will depend on the type of fibre constitute the tested sample. Here we tested cotton sample and the two other fabric is cotton and multi fibre fabric.
Now the tested sample is placed between the unfinished samples covering and sewn together.

Test procedure:

Immerse each composite specimen in acid or alkali solution in a beaker for 30mins at room temperature,ensure that the specimen are thoroughly wetted out by agitating the samples with stirring rod, Liquor ratio 1:50.
Place the specimen into a resin acrylic or glass plate and draw across with the stirring rod to remove any air bubbles. Place another resin plate (acrylic plate)on top of the specimens to fully enclose it with fabrics uppermost.Place a max ten specimens,ensuing that each specimen is separated by one resin plate.
bring the upper pressure plate of the perspirometer down to rest on top of the resin plates and place the 4.5 kg wt on to the pressure plate and tighten the securing screws. This is equal to the pressure of 12.5KPa being applied on the specimens.
Now place the specimen into a oven at 37+2⁰C / beiow 60^OC for 4hours.
On completion of the test, remove the specimen from the oven & separate them from the resin plates.

Interpretation of result:

Change in colour – From portion of sample change in color is compared with the untreated dyed sample on contrast basis with the help of grey scale. The grade of contrast in grey scale is the water fastness of the sample.
Staining – The staining is measured by staining grey scale. Here the staining of unfinished sample is compared with the original untreated unfinished sample from staining grey scale on the basis of contrast.

Result:

Color change in shade : 4-5
Staining in fabric:4-5

Interpretation of Grade:

The wash fastness of the dyed sample in color change is excellent to good and in staining in cotton is also excellent to good.

Conclusion:

The sample is tested in the method for perspiration fastness without using machine. we only examine one specimen per perspirometer and we use normal treated cotton instead of multfibre fabric.we have not apply acid or alkali perspiration testing at a time. The fastness found is excellent to good found for both fading and staining.

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