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Charles Ross - DWR's & all that chemistry stuff on clothing

Charles Ross - DWR's & all that chemistry stuff on clothing

As our tagline “Fusing Fashion with Function and Performance with Style”starts to resonate around the globe, we thought it an idea to start blogging a few informative articles introducing new, existing and potential customers to the world of performance fabrics and highly advanced apparel manufacturing. We would love to get everyone talking about different terminologies such as Durable Water Repellent (DWR), breathability, hydrophobic, humidity, permeability and what they all mean in simple terms. 

If it does go off-piste, forgive us, true jacket tech geeks are born this way!

The past 3 years has seen the birth and growth of the brand, where we have invested heavily into research, designing, manufacturing and developing some of the best fabrics and manufacturing techniques on the planet. The main aim, to create luxurious elevated garments that individually give a unique experience for the wearer, whether that be on top of a mountain snowboarding/mountain biking through to walking the dog in the park or shopping. 

Midway through 2019 I approached Outerwear Designer Chris Vandrill to enquire if he’d be interested in coming onboard. We discussed my creative vision and the direction I saw the brand heading and that was to effectively “bring it home". I knew through industry reputation that Chris was an amazing designer, working for some of the biggest brands in the UK, but for me, I needed someone I could truly work with (24 hours a day, 7 days a week) who believed in where I wanted to take 7L and help me bring that to life. From that day, as a duo, we have never looked back.

Around 6 months ago Chris introduced me to one of the outerwear industries leading experts Charles Ross. Charles is a lecturer in performance sportswear design at Falmouth University. He has taught many of the Millennials who now lead the design of the outdoor industry. His graduates are in Mountain Equipment, Rab, Arc’teryx, Berghaus, Patagonia, Páramo and Montane among others.

We asked Charles if he’d give us his take on DWR’s and all that chemistry stuff and very kindly, he accepted! Therefore who better to kick us off with our 1st technical blog (as 7L moves towards PFC free DWR’s) and the importance of looking after your outerwear than Charles Ross.

Charles Ross writes:

DWR's & all that chemistry stuff on clothing

In the last decade there has been much talk of Durable Water Repellent (DWR) finishes on clothing – what does it all mean and and how will it affect my clothing?

Synthetic chemistry in textiles started in the 1950s in force & having developed (and refined) polyesters, nylons plus the colours, it went onto the fabric finishes. In the 1970s synthetic started to influence performance materials (that decade marked the start of waterproof breathable membranes, the following decade saw the popularity of fleece, spread).

At this time fabric finishes also included a new type of DWR finish. Designed to do two main things: keep the fabric from wetting out and not to wear off that easily; It also had a great side effect – it offered stain resistance.

Performance waterproofs wanted the key DWR aspects but found that the latter effect also kept the garment looking smarter for longer by not showing areas of grass / food / or perspiration. A major part of the chemistry is the Perfluoroinated Compounds. It is this Millennium that these have been shown to not be the best for human health, but they were present on several everyday objects like carpet finishes / clingfilm / electrical cables / non-stick pans. In the last decade there has been a voluntary move by the textile industry to change to short-chain PFCs, with the eventual aim to drop that chemistry altogether. The drawback is that stains are going to be more obvious.

The biggest companies have been putting serious money towards trying to make the DWRs stain resistant (often called green chemistry), but unsuccessfully. The Textile Research Centre at the University of Leeds has been trying to solve this dilemma for more than 15 years. The days of putting on a laboratory coat does not mean that a solution is easily arrived at.

So, what does this mean going forward? Essentially the DWRs will keep working, but the stains will be more obvious for those that do not care for their clothing using best practice. Designers will make greater allowances to hide stains – there will be more tonal & melange colouring, plus colours which are more matt. What the garment owner can do is to clean their product correctly. Machine wash is fine for clothing, but surface dirt can always be sponged off. The key thing is to remove the detritus from layers closer to the skin. Best thing to use is a pure soap (not a detergent – whether Bio or Non-Bio), then to rinse the garments a second time ( and NOT to use fabric conditioner).

For waterproofs it is worth finishing the drip-drying stage with a quick tumble dry or low heat iron (on the outer-surface) as that will reseal the DWR finish (make it much more durable). It is a better known thing that to make your jacket breath better – wash it! You will remove both the sweat residue coming from the inside as well as the contamination from the outside whether that is from scraping against bushes or the city smog. If your garment ‘wets out’ reasonably quickly this is a good sign that it needs a wash – DWRs should last for over an hour. Every 5 or so washes it is worth reproofing the garment (but always wash a product clean before applying a new protective DWR finish) brands like Nikwax produce suitable product.

 The traditional mistake is to take an underperforming garment & just to reproof it – this would be like re-waxing your car, without cleaning it first. If you know how to – always use a machine that has just had a service wash to get rid of all the detergent gunk. A service wash is a hottest temperature wash with nothing in the drum, no washing powder (a cup of vinegar is best), plus to take the detergent drawer out & clean it thoroughly using boiled water (if you turn it over you will see the black residue).

The biggest reason for garments not lasting longer in use is down to Emotional Durability. Physical durability is something that modern yarns are designed to last longer; Fit durability is best illustrated by fast growing kids; but it is Emotional Durability which makes the greatest difference to the environmental footprint. Every garment you buy should last for 30 washes or 3 years to gain the lightest overall impact on carbon, water and waste during the product lifetime.

Hence, to be ahead of the curve – 7L are moving towards product PFC-free DWR's with their new 3L Waterproof hard shell. Not only do they utilise beautiful Japanese recycled fabrics, a recycled hydrophilic membrane, but the jacket is also finished with a C0 PFC free durable water resistant finish. As a young brand they've already moved light years ahead.

Check out our new Layer 6 // 3L Waterproof Outers here:


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