IMPROVEMENTS IN DYEING COTTON FABRICS
Year: 1883

page_text: PROVISIONAL SPECIFICATION left by the said Frederick Albert Gatty at
the Office of the Commissioners of Patents on the 11th August 1883.
FREDERICK ALBERT GATTY of Accrington in the County of Lancaster Calico
Printer and Dyer. "IMPROVEMENTS IN DYEING COTTON FABRICS
"
My improvements relate to dyeing cotton fabrics and consist in precipitating the
oxide of lead upon the cloth, in the wet state, with gaseous ammonia, the object
of my Invention being to dye the cotton fabrics chrome yellow, such fabrics
being either plain, or fabrics which have been previously printed and dyed with
other colours.
In performing my Invention I impregnate the cotton fabrics with a solution of a
salt of lead such as acetate or nitrate containing from four to twelve ounces or
more or less of such salt to each gallon of water according to the depth of colour
required. After coming out of the solution of salt of lead I run the fabrics over
rollers through a box or chamber containing gaseous ammonia and on coming out of
this box or chamber I pass them through a solution of chromate of potash or other
soluble chromate and then run them through water for the purpose of washing
them.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Frederick Albert Gatty in the Patent Office on the 7th February
1884.
FREDERICK ALBERT. GATTY, of Accrington in the County of Lancaster, Calico
Printer and Dyer. “IMPROVEMENTS IN DYEING COTTON FABRICS
""
My improvements relate to dyeing cotton fabrics and consist in precipitating the
oxide of lead upon the cloth, in the wet state, with gaseous ammonia, the object of
my Invention being to dye the cotton fabrics chrome yellow, such fabrics being
either plain, or fabrics which have been previously printed and dyed with other
colours.
In performing my Invention I run the fabrics intended to be dyed through a
solution of a salt of lead of which I give preference to the acetate of lead but other
soluble salts of lead will also answer the purpose. I find that about four to six
ounces of acetate of lead in every gallon of water are required to produce a light
shade of yellow: for darker shades from eight to twelve ounces are required and a
still stronger solution for very full colours. For the latter prefer to use the
subacetate or a mixture of the subacetate and the ordinary acetate. For
impregnating the fabrics with the solution of the acetate of lead I run them open
through the liquid and squeeze out the excess of liquid by passing the fabrics.
between the two rollers of a padding machine or in other- convenient manner.
After coming out of the solution of the acetate of lead, the fabrics are run over
rollers through a box or suitable chamber containing gaseous ammonia: the rollers
are so arranged that the fabrics remain exposed to the gas about one minute but
the time is of no consequence provided that the fabrics smell slightly of ammonia
on.coming out. of. the chamber.
For supplying the ammonia, I run liquid ammonia from the outside through a
pipe into a vessel inside the chamber which is fitted up with a steam pipe in order
to be able to warm it, but if preferred, the ammonia gas may be sent into the
chamber or box from the outside. The quantity is regulated by the smell of the
fabrics, which on coming out of the chamber should slightly smell of ammonia.
After coming out of the ammonia the fabrics are passed through a solution of
bichromate of potash containing from two to three ounces in every gallon of water,
or an equivalent of another soluble chromate for the purpose of dyeing them yellow.
For light shades, the fabrics are simply washed in cold water after coming out of
the chromate but if a strong or orange shade of yellow is required, they are passed
through weak muriatic acid and then washed in water. In cases where a real
orange is required the fabrics may be run through boiling lime water in the usual
way well understood by Dyers and Printers. On coming out of the lime water
the fabrics are washed and dried.
Having now described the nature of my Invention and how I perform the same,
I would have it understood that I do not confine myself to any particular
proportions or apparatus. I am aware that certain printed fabrics are passed in
the dry state through gascous ammonia after printing, for the purpose of neutralizing
free acids, I therefore lay no claim upon this, but-
What I do claim as my Invention and desire to secure by Letters Patent is-
Precipitating or fixing oxide of lead upon cotton fabrics in the wet state,
substantially as herein described for the purposes specified.
In witness whereof I the said Frederick Albert Gatty have hereunto set my
hand and seal this fifth day of February One thousand eight hundred and eighty
four.
F