Let’s talk about the future of the fluorocarbon-free water repellent
The speed of life increases, making the outdoors the ultimate place to blow off steam. People hike, camp, cycle, golf and fish to leave the city behind and to get their working week out of their system. This development has brought the textile industry a new type of customer: the outdoorsman that values comfort. He wants outdoor apparel to be fashionable, breathable, soft and most of all: water repellent. This poses a dilemma, as the most effective water repellent is still based on fluorocarbons, that come with harmful side products PFOA and PFOS. How far are chemists in developing a fluorocarbon-free water repellent? And will it ever meet the highest customer requirements? We’ll tell you here.
The evolution of water repellents
Looking at the evolution of water repellents, you’ll find that the key always lies in surface tension. As long as the surface tension of the textile fibres is lower than the surface tension of the water, the textile fabric is not wetted, enabling it to keep out water. Back in the old days, people used waxes or fish oil to make this happen. Later, manufacturers switched to modified paraffin, which worked better, although the active ingredient was still oily. A few decades ago, chemists achieved a breakthrough by developing fluorocarbons: fully fluoridated carbon chains. They turned them into an emulsion, so they could be used as an auxiliary. When applied to textile, this fluorocarbon emulsion lowers fibre surface tension, creating a highly effective fluorine barrier that repels both water, chemicals and oil.
Usage of fluorocarbons in the textile industry
As the fluorocarbon wall is so strong that it even repels oil and chemicals, fluorocarbon-based water repellents are often used in technical textiles, work wear (e.g. for factories) or apparel to protect wearers from severe weather conditions. But that’s not their only application. As fluorocarbons are very durable, they’re also appreciated by customers who pay a high amount for a fashionable jacket that is claimed to be water repellent, even after multiple washing rounds. Clearly, the issue with fluorocarbons doesn’t lie in its effectiveness. The real problem lies in its two side products, called PFOS and PFOA. Both are PBT (Persistent, Bio-accumulative and Toxic), which is as problematic as it sounds. There’s no way manufacturers produce fluorocarbons without also producing PFOS and PFOA, meaning fluorocarbon water repellents will always equal bad news for the environment.
Two steps in the right direction: from C8 to C6
The good news is there’s a way to limit the negative side effects of fluorocarbons to a minimum. The solution lies in reducing the fluorocarbon chain from C8 to C6. This alternative doesn’t have the exact same properties as the original fluorocarbons, but the side products are way less persistent and bio-accumulative, meaner they’re less harmful. Many chemical companies, including ourselves, have stopped working with C8 altogether, and started working with C6 fluorocarbons exclusively. Moreover, governmental organisations all around the world have strongly commended manufacturers to stop using C8, meaning that in the long run, the chemistry world must look for alternatives anyway.
DWR: the fluorocarbon-free water repellent
In this search for a fluorocarbon-free water repellent, people started to remember the times before fluorocarbons. Chemists got back into the lab and worked on new solutions, based on, for example, hydrophobic polymers. These so-called DWRs (Durable Water Repellents) are not oil or chemical repellent, making them less suitable for workwear, but perfect for environmentally friendly and water-proof outdoor wear. At TANATEX, we currently work with both C6 fluorocarbons and DWRs. We depend our choice on product requirements, as sometimes oil repellence is a must, for example in workwear. In most other cases we work with DWRs, though, and we are working hard on developing a DWR that matches the qualities of fluorocarbon finishes, so we can minimise the usage of fluorocarbons. We do so for three reasons: 1. to meet customer requirements, 2. to comply with governmental regulations and most importantly 3. because we want to. As chemists, we’re at the start of every textile production chain, meaning that we can impact the usage and development of more sustainable products.
Want to know how we contribute to a fluorocarbon-free textile industry? Download the brochure on our HydrECO 3D technology below.