There are primarily three types of water repellents, namely, C6, C8 and non-fluorinated ones. They reduce surface tension of fabric and imparts hydrophobicity to synthetic fibers like nylon, polyester and such natural fibers as cotton. As functional finish, they serve to form an invisible coating on the fabric. Instead of permeating fabric, water beads up and rolling off the treated surface. So, they are similar in water repellency.  

Then, what are the difference between them? And in what terms do they outperform each other.

Difference

1. C6 and C8 are fluorochemical water repellents while non-fluorinated is fluorine-free. There are such toxic chemicals in fluorochemical water repellents as PFOA, PFOS and C8 is found to contain higher PFOA and PFOS than C6. So, in terms of environment protection: non-fluorinated >C6>C8.

2. Beside adding liquid-shielding properties to surfaces, C6 and C8 can also repel oil and soil from them too. The function of non-fluorinated ones is single: water repellency.

3. C8 has longer carbon chains than C6 whereas there is none in the non-fluorinated. The more the carbon chains, the stabler the molecular structure and the stronger the compatibility with the residues of other finishes. So, C8 outperforms C6 and non-fluorinated in mechanical stability and compatibility with other textile treating agents.

In terms of stability: C8>C6>fluorine-free.

4. According to years of research and application, C8 is superior to C6 and the non-fluorinated in terms of water repellency. Under the same conditions, to achieve a certain water-resisting effect, the amount of water repellents used: non-fluorinated>C6>C8.

5. Generally speaking, in terms of wash durability, C8> C6> non-fluorinated. Their liquid- shielding ability decreases with the number of washes. One common solution is to use it with cross-linking agent. It helps protect the waterproofing film from being disturbed and thus maintain water-resisting performance.

With increasing number of countries joining the list of prohibiting the use of C8 in fabrics, more and more companies turn to greener water repellents with less environment impact. Technological development will surely contribute solutions to the inbuilt shortages associated with C6 and non-fluorinated water repellents.

Please feel free to contact us if you have demand for water repellents. For inquiry, pls email to: lisa@dyjmhg.com.