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The next stage after shearing
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| A suri fleece which has been rolled for storage |
HAVING sheared your fleece, before you
proceed it needs to be skirted and, if you are
sending it for processing rather than for show,
you need to sort it. We have seen that fibre
quality is not the same across the animal and
to get the best from your fleece you need to
be able to recognise and separate out the
different qualities.
It is probably easiest to skirt and sort a fleece
immediately after shearing but this is not
always practical. If it must be done later, the
fleece should be rolled, cut side inside, and
stored in a paper sack or woven nylon
sacking. A fleece must dry when it is shorn as
it will lose its crimp if stored wet and, more
importantly, is likely to go mouldy. The edges
are folded in towards the middle and the
whole thing rolled up from the tail end. Thus,
when it is unrolled later, you can determine
which part is which.
Removing debris: The fleece should be
placed or unrolled onto a flat surface with the
outside (tips) uppermost. Special fleece tables
are available which have a mesh top so that
loose dirt and debris fall through, otherwise lift
the fleece at intervals and brush the debris
away. Shaking the fleece helps to dislodge a
lot of this type of contamination.
Contamination
However, fleece is very tenacious and hangs
on to all sort of twigs, dried grass, dirt and
other foreign matter. More of this will show up
now that the fleece is off the animal. If you are
going to enter the fleece into a show, you
need to take more care when removing
contamination and balance removal of debris
with the need to keep the fleece architecture
as intact as possible. This means maintaining
the staples in the fibre and not pulling them
apart to remove bits and pieces.
The next step is to turn the fleece over to
look for other contamination such as over-long
or short fibres which are removed, along with
'second cuts'. During shearing, a second pass
of the shears may remove more of the fibres
which have already been cut. Second cuts are
very short and have a straight cut across each
end rather than the tapered end of a full
staple. Any second cuts are left in the fleece
will cause slubs in the final yarn, destroying its
smooth feel. Slubs can also occur if the fleece
contains brittle fibres which break and roll up
during processing.
Colour Contamination: As well as dirt and
debris, a fleece can exhibit colour
contamination. This can take the form of white
fibres in a black fleece or fawn patches in a
white one, for instance. Checking for colour
contamination is much easier if you are looking
in good natural light rather than inside under
artificial lamps. When looking at a white fleece,
you will need to decide whether the slightly off-
white areas are actually fawn fibres or just dirt
on the fleece. This can often be determined by
looking at the cut end of the fibres. On the
outside tips, the difference in colour may well
be dirt but near the skin, the fibres are
protected from the environment and you can
see if they are of different colours.
Grading the fleece for processing: The lower
grade fibre is situated around the belly and the
lower legs. When the fleece is spread out, this
will be found along the long side edges and
should be removed. As long as it is not too
matted or contaminated, it need not be thrown
away but can be kept together for felting or
making rugs and carpets. Any very
contaminated fleece, say from around the tail,
should be discarded.
The fibres in the chest or brisket area may be
longer and less fine than those in the blanket
area and will be graded as seconds or thirds.
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| Special sorting tables are available with a mesh top allowing debris and short cuts to fall through |
Seconds come from the neck area and the
better areas of the legs and belly and thirds
from the hairier parts of the chest, legs and
belly.
As an animal gets older, its fleece will
generally get coarser by something like 2-4
microns/year. The female's fleece does not
necessarily deteriorate at a faster rate than
that of the male, although this may be the
case in a breeding female, with her energies
going into producing and nursing the cria.
Fleeces on stud males also tend to deteriorate
relatively quickly particularly compared with
those of geldings. In some cases, the quality
of the fleece may remain good but the overall
fleece weight will decline.
What the breeder is looking for is an animal
with a fine fleece over a large area of the body
which is dense and gives a good yield. On
average, an alpaca fleece will weigh 2-2.5 kg
although it can weigh as much as 6 kg.
Although we are talking about fibres getting
coarser with age, alpaca is inherently soft and
if a fleece contains little guard hair, it can still
feel soft when the diameter is 28 microns.
Fineness
If an animal becomes overweight, it can 'blow
out' and its fibre will become coarser.
Sometimes this can be dramatic, rendering
fleece from an animal of around three years of
age useless. An animal's first fleece is usually its
finest but the longer it can retain this fineness
the better and, crucially from the breeder's point
of view, this characteristic is heritable.
Micron Measurement: As you handle more
fleeces, you will become able to feel and see
the different finenesses of fibre across the
fleece. Taking six samples from different areas
of the fleece - shoulders, mid-side and britch
each side - means you can compare them to
identify the uniformity of your fleece in terms of
both length and fibre diameter. This will help
you to grade fibres of the same fineness and
length together. However, when you first start,
it can be helpful to obtain accurate
measurements.
Fibre diameter is measured in microns by a
testing laboratory. A sample is taken from the
mid-side of the animal and half sent for
testing. The other half is retained in case of
any problems. It is probably easier to take this
sample while the fleece is on the animal. There
are three different methods used for testing
micron count so it is important to use the
same laboratory or ensure that different
laboratories you want to use for comparison
are employing the same method. The testing
laboratory will supply a histogram which
illustrates the number of fibres in the sample
that have a particular diameter.
The more with the same diameter, the higher
the vertical bar. Thus the best fleeces produce
a histogram that is tall, narrow, has straight
sides to the curve and a minimal number of
values recorded outside of the main area. In
other words, the majority of the fibres have a
diameter around a narrow range of values. The
thinner the peak the better as this indicates
that there is a narrow spread of fibre
diameters.
If the curve is like a flat hill, with values
spread along the whole of the diameter range
and no particular high point, this indicates a lot
of variation in the diameters of the fibres
sampled and a lack of uniformity. The average
fibre diameter is calculated by adding together
all the diameters of the fibres sampled and
dividing this by the number of fibres in the
sample.
Generally, the lower the value the better, but
this figure must be considered in conjunction
with the histogram to determine the spread of
the values. The percentage of fibres that are
over 30 microns is also important as this is the
value at which they become uncomfortable
when worn against the human skin. The lower
the percentage the better. The histogram will
also note details of the animal including its age.
Commercial Processing: If you are sending
your fleece for commercial processing, you will
need to gather together sufficiently large
batches of the same colour and similar quality,
including fibre strength and degree of crimp for
huacayas or waviness for suris. Mini-mills can
take small quantities and even process a
single fleece. Other small-scale commercial
mills will need batches of at least 25 kg.
Claire Waring is Society Secretary for the
British Alpaca Society (www.bas-uk.com).
9:16am Wednesday 16th May 2007
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