CRI and the case of the Burgundy Bleeder
December 1st 2006

Dr Eric Brown, head of Cleaning Research International, continues on the pitfalls of carpet mismanagement,and offers some solutions

In my previous column I highlighted the problems encountered by carpet manufacturers resulting from a poor understanding of the requirements of carpet cleaning.

This problem does not stop there. Many a time I have observed manufacturers being blamed for loss of colour when in reality all that has happened is that someone have failed to clean it. Such problems are therefore easily rectified.

However, in some cases the carpet may be ruined by a lack of understanding and training. For example, in one case, I recall an experience in a hotel in Florida where a complaint arose because a deep burgundy yarn in a wool/nylon axminster carpet had bled severely into an adjacent white effect area. This is clearly illustrated in the photograph.

In order to address this complaint the first objective was to determine whether or not the carpet was indeed faulty. There is a simple way to do this. A standard colour-fastness-to-water test will indicate whether the carpet is prone to bleeding and therefore substandard. There is a slight complication for the American market place. In the ISO test used throughout Europe, colour-fastness-to-water involves incubating the carpet at 37°C for four hours adjacent to a number of undyed fabrics. Any bleeding which occurs stains the undyed fabrics and a set of pass/fail criteria enables a judgement to be made.

In the American test the carpet is incubated for 18 hours which is far more severe and in the view of CRI, excessive. Nevertheless the carpet from the Florida hotel performed satisfactorily in the American test and gave the manufacturer the confidence to refute the claim.

In the interest of good customer relations it was decided to invite Cleaning Research International to visit the site in order to investigate further. On site, the first, and to those in the know obvious, test to perform was to determine the pH of the carpet in the affected area.

It was 8.2 as wool/nylon carpets are dyed under acid conditions and after cleaning should remain acidic, otherwise the dye is destabilised. An examination of the chemicals present in the cleaner's cupboard showed that they were highly alkaline products and subsequent testing in our UK laboratory showed that the alkalinity was very stable; sufficiently stable to shift the pH of the carpet to the alkaline side. The resultant destabilisation of the dye was the underlying reason for the bleeding.

Interestingly, in a different hotel in the UK, a cleaner called CRI to explain that a carpet he was attempting to clean was bleeding almost before his eyes. This was occurring even as he treated it with an acid souring agent.

Subsequent colour fastness tests in our laboratories showed that the burgundy coloured effect yarn in the carpet was faulty and this was clearly a manufacturing defect.

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