Technology

Sustainable water repellent finishes

Sustainable water repellent finishes
©Taiga, #80320655, 2018, source: Fotolia.com
Resources:
Carbon
Sector:
Textile and clothing
Investment cost:
Low cost
Resource type:
Reducing the production of fluorocarbons
Resource saving:
Using sustainable water repellent finishing offers market advantages, thanks to the production of safer textiles without toxic releases into the environment
Investment cost:
0€ / No investment cost is required
Payback time:
Price will depend on volumes of water repellent products ordered but no upfront investment is required

 Inspired by nature ... for nature

Durable water repellent (DWR) is a finish added to fabrics to make them water-resistant. The pores on the water-repellent fabric remain open so it can 'breathe', making the garments comfortable to wear. DWR wears off over time, so retreatment (e.g. spray-on products for consumers to use) can be necessary. 

The main water repellent finishes available to the outdoor clothing industry contain perfluorinated chemicals (PFCs). These are plasma, C8, C6, dendrimer, wax, silicone, and polyurethane. PFCs are used in DWR finishes because of their water, oil and soil repellent abilities. 

The demand for finishes free of fluorocarbons was highlighted in a 2012 report by Greenpeace called 'Chemistry for any weather'. The report claimed that DWR finishes used on outdoor clothing containing long-chain PFCs are hazardous to human health and the environment. 

Some consumers find it morally wrong that outdoor clothing brands are not taking serious measures to reduce their own environmental impact. The industry also faces a number of legislative restrictions on the production and use of C8 PFCs. Voluntary limits have been suggested by both Bluesign and Oeko-tex, industry standards.

Result
There are a number of PFC-free sustainable technologies available which provide acceptable, but not complete water repellency and light stain resistance. These products have costs comparable to chemical-based products for medium and large enterprises, and they are accessible to bew entries as well as companies more experienced in resource efficiency measures.

Information on a few of the technologies available is provided here.

Bionic Finish Eco

By combining biology and technology, the Bionic Finish Eco from Rudolf delivers hydrophobic properties without the use of fluorocarbon chemistry. Inspired by biomimicry and the water repellency seen in nature, this technology is based on hyperbranched polymers called dendrimers. Using star-like hyperbranched polymers, maximum water, and oil repellent effects can be achieved whilst maintaining reduced fluorocarbon resin content. This hyperbranched structure offers up maximum density of hydrophobic functionality per unit volume. The finish is applied in the same way as any DWR treatment, either as a foam, spray, exhaust or pad application.

Performance is comparable with a C6-based DWR when applied to polyester. As fabric structure and composition can have an effect on the performance, it is suggested that each fabric quality is tested to satisfy performance requirements.

Ecorepel®

Imitating the cuticle of plants, the very outer layer of leaves which protect them from uncontrolled evaporation, ecorepel® bySchoeller Textiles produces a high performance, permanently odourless high-tech finish. The thin film envelopes the fibres of the fabric, allowing water droplets and aqueous dirt to run off the surface. Garments finished with the covering are machine washable.

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