Textile Wicking is the movement of a liquid through a textile in a specific direction. It can be calculated horizontally or vertically. In this article, we will learn about textile vertical wicking in-depth, its standard, its measurement method in a textile lab, and how it benefits textile manufacturers.
Working Principle of Wicking
Wicking meaning: A fabric specimen hung vertically, with the bottom end dipped in water, is visually inspected as the water moves upwards. The distance covered by the water’s upward movement is recorded after specific intervals, determining the fabric’s behaviour against wicking.
Similar Standards for Wicking
- AATCC-198 – Test Method for Horizontal Wicking of Textiles
- ISO 19074:2015 – Determination of water absorption by capillary action (wicking) (For Leather)
Horizontal and Vertical Wicking
AATCC 197 is the most common method for vertical wicking tests. The specimen is cut into long stripes and vertically hanged. The bottom part of the fabric comes into contact with water. After the required time, the wicking distance is measured by checking the watermark. In this method, fabric with a greater wicking distance is considered better.
Another common method is horizontal wicking, also known as the droplet test, which is measured using AATCC 198. This method is different from vertical wicking. In this method, a fabric is placed on a flat surface, and water is poured on the fabric. Time is noted as the water spreads from the circle’s centre to its 100 mm diameter. Fabric with the minimum time is considered good in this method.
Results obtained by both methods should not be compared due to different processes.
Textile Vertical Wicking
The vertical test method is easy, reliable, and cost-effective. The following is a detailed method for conducting it in a textile lab.
Textile Vertical Wicking Apparatus
- Distilled Water at room temperature
- Soluble ink (Used in dark colours)
- Shallow pan or flask
- Paper clip or clamp ( For light-weight fabrics)
- Template and ruler for markings
- Stop Watch
- Double-sided tape
Textile Vertical Wicking Testing Conditions
The conditioning of samples requires specific standard atmospheric conditions, as mentioned in ASTM D1776, i.e., 21 ± 2°C Temperature and 65± 5% Relative Humidity. The specimen is placed for about 4 hours. Don’t stack the samples over each other; place each sample separately.
Textile Vertical Wicking Test Procedure
This test can be performed in two ways. Vertical wicking can be measured either by calculating the time it takes to reach a marked distance or by measuring the distance covered by the liquid after a specific interval of time.
- By Calculating time
Vertical Wicking
- Mark each test specimen across the width at 5 ± 1 mm from the
- Mark the specimen at 20 and 150mm with the above marking as a reference. You can mark according to your ease of measuring and end-use.
- Hang the specimen so that the lower end of the specimen is submerged in water.
- Lightweight fabric or hydrophobic fabrics sometimes float on the water surfaces. Attach a paper clip or clamp at their end as weight, as shown in Figure 2.
- Start the stopwatch when the water reaches the first marking, i.e., 5mm. Monitor the water’s upward movement as the water level reaches the marking.
- Monitor the water’s upward movement. If the water does not ascend at 5 mm marking in 5 minutes, or if it takes more than 30 minutes to reach 150 mm marking, terminate the test. Also, mention the reason for terminating the test.
- Repeat the process for all test samples.
- By Measuring Distance
Textile Vertical Wicking
- Take an elongated pan, preferably made of glass or clear plastic, and fill it with 1.5 inches of distilled water or soluble ink.
- Now, take a ruler and stick it to the back side of the pan. The ruler should be placed so that the water surface mark is at 0 mm on it, as shown in Figure 3.
- Hang the specimen so that its lower end just touches the water surface.
- Start the timer/stopwatch.
- Some lightweight or hydrophobic fabrics float on the surface of water. Attach a paper clip or clamp at their lower end so that they can be submerged. Mention this in the report.
- After 2 minutes, use a ruler to measure the distance travelled by water in mm. Again record the rise of water after 10 minutes.
- The distance can be recorded at other times, but it should be the same if results are compared.
- If the water does not rise after 10 minutes, or if it takes more than 30 minutes to reach at last marking, terminate the test in both cases. Record the time and distance travelled when the test is stopped. Also, mention the reason for terminating the test.
- Repeat the process for the remaining test samples.
Textile Vertical Wicking Test Results
Calculate wicking rates by using the formula
where
W = wicking rate (mm/s)
d = wicking distance (mm)
t = wicking time (s)
The wicking rate can divided into 2 parts,
Short period rate
(By Calculating time method) Time taken by water to reach 20 mm line.
(By Measuring distance method) Distance travelled in 2 minutes.
Long period rate
(By Calculating time method) Time taken by water to reach 150 mm line.
(By Measuring distance method) Distance travelled in 10 minutes.
Report Formation
After completing the test, make a test report with the following information
- Fabric sample details ( Knitted, woven, chemical finishes if applied)
- Mention the side and direction of the specimen tested
- Mention if a clamp or weight is added
- If the test was performed after washing, mention the number and conditions of washings.
- Number of test specimens
- Test Date
- Also, mention that the test is conducted in accordance with AATCC-197.
FAQs
What is the difference between wetting and wicking?
Wetting is the displacement of a fiber-air interface by a fiber-liquid interface. Wicking occurs when capillary forces cause a liquid to flow spontaneously through a porous medium.
How does wicking enhance comfort and functionality?
In moisture-wicking, capillary action distributes the sweat on a larger area of fabric. Fabric does not absorb moisture or sweat but pushes the moisture to the fabric´s outer surface, thus accelerating the evaporation. This leads to added comfort as the skin remains dry and makes the fabric more functional in sports where sweating is certain.
Related Resources
Capillary Effect Tester YG(B)871C
A Comprehensive Guide About Moisture Wicking and Quick Drying