Thursday, June 12, 2014

Carpet and Rug Care

We are a member of the woolsafe group, Please read their newsletter.

 WOOLSAFE NEWS Summer 2014
WoolSafe Research
The Effect of Maintenance on Carpet Appearance
The positive effect that regular maintenance has on the overall appearance of
textile floor coverings is well-known within the cleaning industry. Vacuum
cleaning removes accumulated dry soil and lifts the pile, improving appearance
to a certain degree. Periodic wet or dry extraction cleaning removes sticky dirt
that vacuuming does not.
However, there are still people in positions to influence carpet buyers and
owners, who believe that wool carpets don't really need cleaning. In fact, they
say once you (wet) clean a wool carpet it will never be the same again – one way
or the other.
We therefore designed a set of experiments to see whether we could clearly
show the benefits of regular maintenance on the overall appearance of carpet.
Pieces of a light coloured, 80% wool 20% nylon, tufted, cut-pile carpet were
repeatedly soiled on the Kappasoil laboratory soiling machine with standard
carpet soil. This accurately reproduces the type and level of soiling experienced
in real life situations. The machine drops quantities of soil at regular intervals
and “walks” it into the carpet. This is called 1 soiling cycle. Duplicate samples of
the soiled carpet were then cleaned by different methods and at varying
The treatments we compared were:
1. vacuum cleaning only
1.a after every soiling cycle
1.b after every 3rd soiling cycle
2. vacuum cleaning followed by professional (wet) cleaning
2.a after every soiling cycle
2.b after every 3rd soiling cycle
2.c after the 9th soiling cycle only
Vacuum cleaning was done by a domestic upright vacuum cleaning machine
with a brush to simulate normal domestic routine. For the wet cleaning a
professional spray extraction machine and a WoolSafe Approved low foam
detergent was used.
To monitor the carpet samples’ appearance objectively, we measured their
colour at every stage of the experiment with a Minolta colorimeter. Lightness
By Dr. Ágnes Zsednai
and darkness are expressed as L values on a scale of 1 to 100, where 1 is black
and 100 is white. Typical L values for light-coloured wool carpets are around 70.
For each sample the original colour L0, as well as the L value after every
treatment were determined. From these values we calculated the change in
colour (ΔL) at every stage of the experiment. ΔL = L0 –L, so the bigger the number,
the dirtier the carpet looks.
Differences in L values of more than 3 are clearly visible, though if the carpet
is viewed without a reference sample, soiling might not be obvious until much
more deterioration in colour.
The graphs show the change in colour (ΔL) over time after nine soiling cycles.
When only vacuum cleaning was used (Figure 1), it only made a difference to
the appearance at the beginning of the experiment, but later on just a fraction
of the sticky soiling could be removed. It must be noted that vacuuming did
remove some of the dry soil from in between the tufts of the pile, which must
have a positive effect on the wear of the carpet, but did little to maintain its
appearance as regards colour.
Figure 1
Figure 2
After 9 cycles ΔL = 14.5 and was still rising, whilst in the case when professional
cleaning was applied after every soiling (Figure 2), the carpet’s appearance
seemed to stabilise, the maximum colour difference being around ΔL = 8, which
can be successfully controlled by cleaning.
Similar trends were observed between the vacuumed-only and the wet cleaned
samples, when treatment was performed only after every 3rd soiling (see
Figures 3 & 4). Here the overall deterioration of appearance was higher, with no
sign of the soiling levelling off.
After the first 3 cycles, though the soiling was higher, most of it still could be
removed by professional cleaning, but by the end of the tests it could not, and
the change in appearance was about 50% more than in the regularly cleaned
Finally, when we put all the cleaning results on one graph, we could see clearly
the difference regular maintenance gives.
Figure 4
Figure 3
Each of the soiling cycles in these experiments delivered a high amount of sticky
soil that was worked into the carpet. We calculated that it would be the
equivalent of a family of four using a hall carpet for about 4 months.
So Figure 5 shows the effect of cleaning a well-used carpet quarterly, annually or
just after 3 years.
Figure 6 shows how the carpet would look over time before being vacuumed or
wet cleaned.
So, regular vacuuming – dry soil extraction – is important, but it has to be
coupled with periodic deep cleaning (using ‘wet’ or ‘dry’ extraction methods for

No comments: