AN IMPROVED PROCESS OF REMOVING KNOTS AND OTHER IMPURITIES FROM WOOLLEN FABRICS AND FABRICS DERIVED FROM WOOL
Year: 1878

page_text: LETTERS PATENT to Thomas James Smith, of the Firm of Robertson, Broomaṇ,
and Company, of 166, Fleet Street, in the City of London, Patent Agents, for
the Invention of "AN IMPROVED PROCESS OF REMOVING KNOTS AND OTHER
IMPURITIES FROM WOOLLEN FABRICS AND FABRICS DERIVED FROM WOOL."
A. communication from abroad by Louis Alexandre Margotin, of Reims (Marne),
France, Dresser.
Sealed the 28th December 1878, and dated the 8th July 1878.
PROVISIONAL SPECIFICATION left by the said Thomas James Smith at the
Office of the Commissioners of Patents on the 8th July 1878.
THOMAS JAMES SMITH, of the Firm of Robertson, Brooman, and Company, of
166, Fleet Street, in the City of London, Patent Agents. "AN IMPROVED PROCESS
OF REMOVING KNOTS AND OTHER IMPURITIES FROM WOOLEN FABRICS AND FABRICS
DERIVED FROM WOOL." (A communication from abroad by Louis Alexandre
Margotin, of Reims (Marne), France, Dresser.)
The improved knotting process forming the object of this Invention is applied
more especially to the treatment of half-tinted fabrics, and fabrics dyed in light
colours, such as blue, pink, or rose colour.
The soaking or steeping of these fabrics in acidulated baths in the ordinary way
at 4 degrees had the effect of attacking the colour, especially at certain parts of the
piece, because the sulphuric acid being of greater density than the water, deposited
itself at the bottom of the "bac" or steeping machine, and fixed itself in certain
places.
By this Invention the fabrics are knotted without in any way injuring the
dye by effecting the steeping in a weak acidulated bath, that is to say, containing
only 1 or 1 per cent of sulphuric acid, but in order that this weakly acidulated
bath, which does not attack the dye, may however act upon the straws and burdocks,
its disintegrating action upon vegetable substances is augmented by introducing into
it a current of steam. This current of steam, which arrives by a steam " clearing"

page_text: "
apparatus, maintains the bath in a constantly agitated state; the acid cannot there-
fore deposit or fix itself on certain parts of the cloth. This constitutes the distinctive
feature of this improved process.
The operation is as follows:-The fabrics are first scoured and then rinsed in pure
cold water, as usual; a bath, weakly acidulated, containing 1 to 1 per cent. of
sulphuric acid, is prepared preferably in a "Carcère" washing machine. The fabrics
thus scoured and rinsed are placed in the machine, and the latter immediately put
in motion; at the same instant a current of steam is caused to arrive by a steam
'clearing" apparatus, and the acid cannot deposit at the bottom of the machine.
The steam is distributed uniformly in all the mass in the bath, so that any strain on
the fabric is avoided. This steeping operation lasts about ten minutes.
The fabrics, after being withdrawn from the "Carcère" washing machine, are
dried by passing between copper cylinders heated by steam in their interiors. This
passage between hot cylinders carbonizes the straws.
The cloth then passes between cast-iron rollers. The axis of the upper roller is
acted upon by springs, which create a pressure, and the carbonized straws are crushed
by this passage between the rollers. There only remains to take out the acid by
carbonate of soda, and the proportion of carbonate introduced into the bath would
itself be less than at present, since the quantity of acid is smaller.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Thomas James Smith in the Great Seal Patent Office on the 8th
January 1879.
THOMAS JAMES SMITH, of the Firm of Robertson, Brooman, and Company, of
166, Fleet Street, in the City of London, Patent Agents. "AN IMPROVED PROCESS
OF REMOVING KNOTS AND OTHER IMPURITIES FROM WOOLLEN FABRICS AND FABRICS
DERIVED FROM WOOL" (A communication from abroad by Louis Alexandre
Margotin, of Reims (Marne), France, Dresser.)
The improved process of removing "burrs," pieces of straw, and other impurities
which forms the object of this Invention, is applied more especially to the treat-
ment of dyed fabrics, or fabrics to be dyed in light and blue colours, such as blue,
pink, or rose colour.
The soaking or steeping of these fabrics in acidulated baths in the ordinary
manner at 4 degrees had the effect of attacking the colour, if the fabric was already
dyed; if the fabric is unbleached, the strong acid bath attacks the pieces of straw
and burrs unequally, and after the dying marks or stains are seen on the fabric. In
practice this process will be most advantageously applied to raw or unbleached
fabrics, that is to say, before they are dyed. This unequal action of the strongly
acidulated bath is caused by the fact that the sulphuric acid, in consequence of being
of greater density than water, deposits or settles on the bottom of the "bac" or
steeping machine, and fixes itself in certain places.
According to the present improved process the steeping is effected in a weak
acidulated bath, containing, for example, only 1 to 1 per cent. of sulphuric acid.
But in order that this weak acidulated bath may nevertheless attack or act upon the
straws and burrs, I increase its disagregating action on the vegetable matters by
introducing a current of steam. This steam is introduced by a steam "clearing"
apparatus (barbotteur), and has the further effect of causing a constant agitation of
the bath. The acid cannot therefore deposit nor fix itself on certain parts of the
fabric; its action is uniform on the whole.
The employment of the weak acidulated bath, combined with the agitating action
of the steam to remove the straws and impurities, preferably from raw or unbleached
fabrics, which are intended to be dyed in light colours, constitutes therefore the
distinctive feature of this Invention.
The operation is as follows:-The fabrics are first scoured and then rinsed in pure
cold water, as usual. A weak acidulated bath, containing 1 to 1 per cent. of
sulphuric acid, is prepared preferably in a "Carcere"
The
washing machine.
fabrics thus scoured and rinsed are placed in the machine, and the latter immediately
put in motion; at the same instant a current of steam is caused to arrive by a steam
clearing" apparatus, preventing the acid settling or depositing on the bottom of
the machine; it is evenly and uniformly distributed over the whole.
"
After washing and rinsing the fabric retains no trace of the acid, whereby the
dying is effected in a very regular manner, the colour being in no way injured, and
it preserves its true shade without any stain.
And having now described the nature of the said Invention, and in what manner
the same is to be performed, I declare that I claim, the improved process of removing
straws, burrs, and other foreign matters or impurities, preferably from raw or
unbleached woollen fabrics, or fabrics derived from wool which are intended to be
dyed in light colours, this process being essentially characterised by the combined

page_text: employment of a weak acidulated bath and the agitating action of a current of
steam, as above described.
In witness whereof, I, the said Thomas James Smith, have hereunto set my
hand and seal, this Eighth day of January, One thousand eight hundred and
seventy-nine.
T. J. SMITH. (L.S.)