Wool classing is an occupation in
which people are trained to produce uniform,
predictable, low risk lines of
wool. This
is carried out by examining the characteristics
of the wool in its raw state. The characteristics
which a wool classer should examine are:
Breed of the sheep:
Shedding breeds will increase the risk of
medulated and/or pigmented fibres. Any sheep
likely to have dark fibres should be shorn
last to avoid contamination. The age of
the sheep will have a bearing on the fibre
diameter and value of wool, too.
Chemical usage: Ensure that all
rules have been followed.
Brands,
jowls and
shanks:
Must be removed from fleeces and broken.
Stain: Must be removed from fleeces
and identified in a separate line.
Wool crimp: The number of bends
per unit length along the wool fiber approximately
indicates spinning capacity of the wool.
Fibers
with a fine
crimp have many bends and usually have
a small diameter. Such fibers can be spun
into fine
yarns,
with great lengths of yarn for a given weight
of wool, and greater market value. Fine
fibres may be utilised in the production
of fine
garments
such as men's
suits whereas
the coarser fibres may be used for the production
of
carpet and other sturdy products. Crimp
is measured in crimps per inch or crimps
per centimetre. Average diameter or mean
fibre diameter is measured in micrometres
(microns). For generations, English wool-handlers
categorized wool along the above lines estimating
spinning capacity by eye and touch. This
spread worldwide as the
Bradford system.
Wool Strength (also known as
tensile strength) determines wool's
ability to withstand processing. Weaker
wools produce more waste in carding &
spinning. Weaker wools may be used for production
of
felt, or
combined with other fibres, etc.
Wool
color: Indicates whether wool is
able to be
dyed in
light shades. Color may be graded depending
upon the natural color, impurities and various
stains present. Severely stained wool decreases
prices dramatically. However, it is difficult
to assess colour accurately without proper
measurement, since some stains will wash
out in the processing, whereas others are
quite persistent.
The
fleece is skirted to remove excess frib,
seed and burr etc to leave the fleece as
reasonably even as possible in good respects.
The parts of wool taken from a
sheep are
graded separately. The
fleece forming the bulk of the
yield is placed with other fleece wool
as the main line, other pieces such as the
neck, belly and skirtings (inferior wool
from edges) are sold for such purposes where
the shorter wools are required (for example:
fillings, carpets, insulation). Whilst in
some places crimp may determine which grade
the fleece will be placed into, this subjective
assessment is not always reliable and processors
prefer that wools are measured objectively
by qualified laboratories. Some of the superfine
wool growers do in shed wool testing, but
this can only be used as a guide. This enables
wool classers to place wool into lines of
a consistent quality. A shedhand, known
as a wool presser, places the wool into
approved wool packs in a wool press to produce
a bale of wool that must meet regulations
concerning its fastenings, length, weight
and branding if it is to be sold at auction
in Australasia. All Merino fleece wool sold
at auction in Australia is objectively measured
for fibre diameter, yield (including the
amount of vegetable matter), staple length,
staple strength and sometimes colour.
Classers are also responsible for ensuring
that a pre-shearing check is made to ensure
that the wool and sheep areas are free of
possible contaminants. They are to supervise
shed staff during shearing and train any
inexperienced hands. At the end of shearing
classers have to provide full documentation
concerning the clip.