What To Know About Performance Evaluation Of Water-repellent Fabrics
Most people tend to mistake fabric waterproofing for the process of making fabric water-repellent, but they are very different. A piece of fabric could be water-proof and yet water repellent. Water-repellent fabrics are designed to keep water out, thereby protecting both the material and your body. There are different water-repellent fabrics, and the extent to which each one will keep water out is dependent on some factors. However, some tests can be conducted to evaluate fabrics’ performance when it comes to keeping water out. These tests measure the degree to which different materials repel water
What to know about the process
- The chemicals used in coating matters: the coating used to make fabrics water-repellent are made from different chemicals. Fluorochemicals are the predominantly used chemicals in this industry, but other chemicals are used to confer water and oil repellent properties on a material. Due to this, the degree to which the same types of fabrics will repel water will defer.
- Fabric type matters a lot: The fabric type matters almost as much as the coatings. The type of water-repellent chemicals used are different because they have to be compatible with the fabrics to be used.
- There are two types of tests: The evaluation process using two tests; the physical test and the chemical test.
- The physical test measures such things as, tensile strength, airflow, abrasion resistance, drying speed, and slack.
- The chemical test measures other things such as colorfastness to washing, colorfastness to water, colorfastness to sweat, etc.
- Materials used: The test requires three simple materials: water, a spray tester which is used to spray water, and the fabric itself.
- Ratings/Grading: once the test is complete, the fabric is rated according to the degree to which it retains water. There are six categories of ratings, thus:
- 100: There is no sticking of water or wetting of the outer surface
- 90: There is slight sticking or wetting of water on the outer surface
- 80: Water wets the spray points
- 70: There is partial wetting of the whole outer surface
- 50: There is the wetting of the outer surface
- O: The entire fabric is wet
You should know that simple tests can be done at home to determine how well fabric can repel water. Simply leave water on one side of it for a few minutes then check for wetness, spreading, or sticking.