Through the rating system of liquid absorbability or resistance based on different surface tension, these test methods can be used to define the oil and water repellency of textile materials.

It is presumed that if we know the degree of fabric absorption, we can get a rough estimate of its stain resistance. If the liquid remains on the surface of the fabric, there will be no stain. If it penetrated into the fabric, it is likely to cause contamination.

The system referred to as liquid should be cooled liquid, such as room temperature liquid, rather than warm liquid such as tea and coffee. Hot liquids can overcome most of the antifouling measures and penetrate into the fabric. Whether they will stain the fabric depends on many factors.

The new standard is based on the DuPont Corporation research and development system for evaluating the anti fouling performance of textile products. The penetration resistance is divided into 0-8 grades, 0 represents no water repellency for pure water, and 8 represents the liquid (water / alcohol mixture) penetration under low surface tension conditions. 8. The classification is based on the premise that the surface tension should be between 59 DIN / cm (0.059 cattle / M) and 24 DIN / cm (0.059 cattle / M).

The oil proofing methods EN 14419:1999 and AATCC 118 with the same effect depended on the surface tension of 31.5 DIN / cm (0.0315 cow / M) and 19.8 DIN / cm (0.0198 cow / M) grease.

Carry out the above two tests on the same fabric and give 2 grades: one is the oil resistance grade and the other is the water / alcohol mixture performance grade; then the comprehensive evaluation of the contamination level caused by the liquid spillage is conducted.