|STAGE ONE: From the Cocoon to
||Silk is produced
by various insects, but by far the largest quantity comes from
the silkworm 'Bombyx Mori'. This is the silk worm, which feeds
on mulberry leaves and forms a cocoon of Silk before pupating.
from several cocoons are subsequently unwound together to form
a single strand of raw silk. This fine thread is the basic component
of all Silk yarn and fabric. Some of the gum, which the silkworm
uses to hold the cocoon together, remains to assist the delicate
fibre during processing. It is subsequently washed away.
|STAGE TWO: Weaving
is the operation that creates a fabric by interlacing the warp
yarns (lengthwise) and the weft yarns. Weaving is carried out
on looms, after a series of preliminary operations including:
· Warping: this
means preparing the warp by rolling all the warp-yarns on
to a beam, under the same tension, strictly parallel to each
other and in a certain order.
· Pirning: the weft
(cross-wise) yarns are put on to a pirn, which is then placed
inside the shuttle in order to lay the weft-yarn between the
In the past twenty years,
enormous strides have been made in improving not only the
machines involved in the preparation of weaving, but in the
loom itself. Non-stop weaving has been made possible by the
introduction of automatic pirnchanging. And there are now
shuttleless looms, (more properly called weaving machines).
These machines use lances, or projectiles, or a jet of compressed
air to shoot the weft-yarn between the warp-yarns, instead
of the traditional shuttle, and at vastly higher speeds. This
increased automation also meant that one weaving-worker can
now look after 20 looms at the same time, instead of only
4 traditional looms. This has consequently led to much greater
yield and productivity.
Some of the modern weaving
machines are large enough to weave fabrics 3 metres wide.
In addition to their greater speeds these machines also offer
the advantage for the weaver of enabling him to divide this
large width into several smaller widths, for example 3 times
Although modem weaving
machinery has made enormous progress, certain specific types
of silk can only be made on ordinary looms, as they are too
complex to be woven on highly-automated machines, running
at very high speeds. This is notably the case for high-novelty
fabrics, and even more so for the reproduction of traditional
fabrics used for wallcoverings, upholstery etc.
Many of these fabrics are
produced on Jacquard looms, called after their Lyonnais inventor,
who in 1801 perfected the existing system of patternweaving,
by the use of perforated cards. The Jacquard loom makes it
possible to weave intricate and multi-coloured patterns directly
into the fabric, and thus create highly elaborate and handsome
As soon as they come off
the loom, the fabrics are thoroughly inspected so as to eliminate
any defects that may have occurred during weaving.
|STAGE THREE: Dyeing, Printing,
are two main types of silk fabrics, each with its own specific
· The first category
includes those fabrics made from yarns which have been dyed
beforehand: these fabrics are known as yarn-dyed or dyed-woven
(eg, taffeta, duchess satin, many pattern-woven fabrics)
· The second type
includes all those fabrics that are dyed after weaving, known
as piece-dyed fabrics (eg, crepes, twills, etc).
In both cases, yarn-dyed
or piece-dyed, the dyeing operation is always preceded by
boiling-off, a process in which the gum (sericin) is removed
from the fibre. This results in a weight loss of 20-25%. In
some cases, this loss is made up for by the addition of vegetable
or mineral substances, which the fibre absorbs in order to
have better "body" when this is required for certain
Up until about 1815-1830, only yarn-dyed fabrics
were woven, as piece-dyeing was still unknown. Yarn-dyeing still
uses the same basic technique, which consists of soaking the
skeins of raw silk in tanks containing the dyestuff..Piece-dyeing,
introduced in Lyon, became an industrial process around 1849,
and for a long time remained a speciality of Lyon Region. There
are several different processes of piece-dyeing. The fabric
can be fed into the dye-bath through two cylinders, or it can
be fixed to a round jig which is immersed in the bath. While
the fabric is attached to the jig, the dyestuff is fixed, and
then the fabric is rinsed and dried.
consists of transferring a pattern to the fabric.
Nowadays, printing is carried out in the following ways:
wooden blocks are engraved with the pattern to be printed, and
the raised parts of the block transfer the dyestuff to the fabrics.
However, this process is slow and laborious, and today is only
used on a very small scale for handicraft fabrics.
the roller-printing method was invented by the Scotsman Bell
in 1785. The fabric is printed mechanically by passing through
two rollers which have been engraved with the required design.
This method is ideally suited to very long runs, and so is
not used very often for silk fabrics.
sometimes knows as "a' la lyonnaise", because the
city of Lyon seems to have been the first to industrialise
this process around 1850. A fine gauze is stretched tightly
over a metal frame, and the design to be reproduced is transferred
to the gauze. By a photochemical process, the "pores"
in the gauze are partially blocked off allowing the dyestuff
to be squeezed through the gauze where the design is to be
printed. This process enables several colours to be printed
one after the other, each colour requiring one frame. The
design is printed on to a white fabric, or on to fabrics already
dyed with a base colour. In this case, the base colour is
not fixed, so that the colours printed through the screen
destroy and replace the base colour. This type of printing
is particularly intended for high-novelty fabrics, which are
usually produced in relatively small quantities. It is, therefore,
very widely used in printing silk fabrics.
the exception of pattern-weavers, all fabrics have to be finished.
It is the finisher who gives satin its shimmering suppleness
and its "hand". Finishing gives a fabric the desired
appearance and feel. There are numerous finishing processes,
physical and chemical. Finishing includes treatments such as
creaseproofing, water-proofing, fire-proofing, etc.