Fading away

Richard says that if your customer has a bright location with lots of direct sunlight, help them choose their carpets carefully.

THE carpet had started life pink and most of it had stayed that colour. But some of it had gone a distinct yellow and no-one could agree what had caused this. The most popular theory (but not with the builder) was that a self-adhesive protection film had been applied to the affected areas and left behind a sticky residue that had attracted dirt. But another theory suggested it was the cleaners who’d done it.

There are many reasons carpets sometimes change colour, or at least appear to do so. The most common is shading. Pile yarn always looks a richer colour when you’re looking at it ‘end on’ and a more milky/silvery colour when viewed from the side.

Some yarns have a greater contrast than others, but this characteristic is the reason why carpets appear to change colour as you turn the sample round. It also explains why, when the pile settles randomly, the carpet takes on a patchy appearance even though it’s not changed colour at all.

Then there’s soiling. It’ll happen to any carpet, but the greater the care taken by the customer to avoid soiling and to maintain the carpet, the longer it will stay looking good. The term soiling means any kind of dirt, but some customers can be offended by the term, so use it wisely.

Sticky residues, whether they’re from carpet protection left on for too long, masking tape used when painting skirting boards, or cleaning chemicals not properly rinsed out of a carpet, allow soiling to stick and carpets can soon go black when this happens. This is rarely confused with fading, but just occasionally a customer thinks the rest of the carpet has gone lighter, and doesn’t realise the truth.

Then there’s fading owing to light. It doesn’t have to be direct sunlight. Wool, for example, being a natural fibre, will change colour owing to the ultra-violet in normal daylight. A new wool carpet is very likely to ‘photo-bleach’ or show ‘first fade’ very soon after it has been laid while the fibre colour adjusts to exposure.

This is the same characteristic that makes human hair go lighter in the summer, but as our hair is still attached the faded hair gets replaced from the roots up over a period of time so by winter, it’s back to the colour we expect. In a carpet, however, there’s no new growth so that first fade becomes the new colour of the carpet. In most cases it goes unnoticed unless the customer has part of the carpet covered up for a while.

When it comes to dyed carpets, however, fading can be a fault. Each dye will be tested against the British Standard and given a rating from 1-10.  1 shows the most fading, and is unacceptable, 10 shows the least.

Anything above a grade 4 is a pass but if you think about it, that means under test conditions a carpet can lose up to 65% of its colour and still be acceptable.

The figure is even greater for a pastel coloured carpet. If we encounter fading, an unused sample can be tested by a carpet laboratory (BCTC, FIRA, SATRA, etc) to give a definitive measure to ensure we’re fair to our customers.

Many polyamide (Nylon) carpets are made using entirely white yarn which is then dyed and/or printed to create a coloured or patterned carpet. The dyes have good light fastness but will react if bleach or other chemicals change the pH balance of the carpet.

Wool carpets can be in natural shades (‘Berber’ carpets) but when coloured, it is often necessary to bleach the yarn before dyeing especially to create delicate, pastel shades. Occasionally this bleaching process can weaken the fibres, so they crumble away – I’ve seen traditional carpets that have lost their white or other very pale coloured yarns while the rest of the pattern remains intact. It can take a while to work out why the carpet looks different.

Polypropylene yarn is coloured in a different way. The colour is put into the yarn before it is melted and extruded into fibres because polypropylene cannot be dyed. This is why a polypropylene carpet may be described as ‘bleach cleanable’ – the colour is locked in and bleach or other strong household chemicals can’t change it.

Polypropylene can change colour, though. If the yarn doesn’t have the right amount of inhibitors to prevent damage by ultra-violet light the colour can change dramatically, and this is often accompanied by the fibre becoming brittle and crumbling away into the nozzle of the customer’s vacuum cleaner.

It’s easy to tell when fading is owing to light, whatever fibre is involved: it happens where light falls onto the carpet. The stronger the light, the more fading will occur. If you tease the tufts apart you’ll see the fading is worst at the tips of the tufts and the colour is stronger further down the pile where less light can penetrate.

Occasionally, and this was the case with the pink carpet I mentioned, where only one or a few of the spools of yarn used to make a carpet are faulty, you can have a faded tuft next to an unfaded one, so the problems could show as a straight line or a zig-zag line depending on the method of manufacture of the carpet.

Carpets should be light fast. But if your customer has a bright location with lots of direct sunlight, help them choose their carpets carefully.