Introduction:
Sweat from the human body is a complex chemical containing large amounts of salt. Depending on the human metabolism, it can either be acidic or alkaline. Colorfastness to perspiration is tested using solutions prepared by simulating acidic and alkaline sweat.
Colorfastness to perspiration test determines how resistant a dye is to perspiration in textiles of all kinds. A color fastness level of 3-4 (color change and staining) is required for perspiration (acid and alkaline). This criterion does not apply to white products, products that are neither dyed nor printed, or fabrics intended for furniture, curtains, or other interior decoration purposes. When fabrics that are both light colored (standard depth 1/12) and made of silk or blends with at least 20% silk are permitted to be rated at level 3. It is applied explicitly to sportswear and heavy dresses used primarily for sports. Perspiration tests are also conducted on normal clothes.
Objectives:
- To know about colourfastness to perspiration.
- To know required chemical name for perspiration test.
- Come to learn working procedure of perspiration test.
Colored textiles in contact with other fiber materials (for color transfer) are immersed in simulated acid perspiration solution, subjected to a fixed mechanical pressure, and allowed to dry gradually at a slightly elevated temperature. The specimen is evaluated for the color change, and the other fiber materials are evaluated for color transfer after conditioning. These are the principles of colorfastness to perspiration.
Apparatus:
- Perspiration tester.
- Oven.
- Multifiber test fabric.
- Grey scale for color changing.
- Grey scale for color staining.
- Standard light box.
- Acid and alkaline solution.
- Non-dyeable fabric.
- Glass plates.
- Scissor.
Test specimen preparation:
- Cut two identical 10cm×4cm specimens. If the fabric sample is multi-coloured take as many specimens as necessary to ensure that all colors will be in contact with each of the six fiber bands of the multifiber adjacent fabric.
- Attach the multifiber adjacent fabric of equal size to the test specimens by sewing along one of the shorter sides with the multifber fabric in contact with face of the specimens. This is the composite test specimens.
Required Chemical:
| Chemical name | Acid Perspiration test | Alkaline Perspiration test |
| L-Histidine mono-hydrochloride mono-hydrate (C6H9O2N3HCl.H2O) | 0.5 gm | 0.5 gm |
| Sodium Chloride (NaCl) | 5.0 gm | 5.0 gm |
| Disodium hydrogen orthophosphate dehydrate (Na2HPO4.2H2O) | 2.2 gm | 2.5 gm |
| Distilled water | 1000ml | 1000ml |
| PH (Adjust with 0.1N NaOH) | 5.5 | 8.0 |
Test Procedure of Colorfastness to Perspiration:
- Wet the composite test specimen at room temperature with the mentioned perspiration solution. Leave for 30 minutes with a liquor ratio of 50:1.
- Pour off excess solution and place this composite test specimen between two glasses plates under a pressure of 12.5 KPa and then place in an oven for 4 hour at 37±20 C
- Remove the specimen and hang to dry in warm air not exceeding 600 C.
- Don’t press or iron the specimen or the multifiber test fabric.
- Now, compare specimen and multifiber with color straining and color changing grey scale.
Standard Value for Fastness:
According to ISO-105-E04
| Color fastness grade | Fastness properties |
| Grade-5 | Excellent |
| Grade-4 | Good |
| Grade-3 | Fair |
| Grade-2 | Poor |
| Grade-1 | Very poor |
Result:
Numerically rate the colour change and staining of each test specimen under standard light using the grey scales for color change and color staining.
Conclusion:
The garments which come into contact with the body where perspiration is heavy may suffer serious local discolouration. one precaution of this experiment that, don’t apply the acid and alkaline perspiration testing at a time. However, from this experiment, we came to learn details about colorfastness to perspiration of dyed fabric. we also learnt different chemical name and how to make acid and alkhali solution. We also learnt working procedure of colorfastness to perspiration test. Thanks to our teacher to help us.
