IMPROVEMENTS IN DYEING WOOL OR OTHER ANIMAL FIBRES IN EITHER THE RAW OR MANUFACTURED STATE
Year: 1886

page_text: Date of Application, 17th July, 1886.
Complete Left; 16th Apr., 1887.
Complete Accepted, 17th May, 1887.
the Raw or Manufactured State.
I FREDERICK ALBERT GATTY, of Hagg Works, Accrington, in the County of
Lancaster, Calico Printer and Dyer, do hereby declare the nature of said Invention for
IMPROVEMENTS IN DYEING WOOL OR OTHER ANIMAL FIBRES IN EITHER THE RAW OR
MANUFACTURED STATE, to be as follows:-
My improvements relate to the fixing of oxide of chromium, or oxide of chromium
combined with a certain proportion of chromic acid upon wool or other animal fibres
in their raw or manufactured state.
In place of boiling the wool or other animal fibre with chromate of soda or chromato
of potash and sulphuric acid or other acid as generally practised in dyeing wool I
apply the chromate of soda or chromate of potash, with the requisite quantity of
sulphuric acid to set the chromic acid free, at the ordinary temperature of the atmo-
sphere or only slightly warmed. After the wool has been worked from one to two hours
in the acid chromate solution it is washed and then subjected to the action of boiling
water or steam to deoxidise the chromic acid fixed upon the wool and thus form oxide
of chromium.
The wool, or other animal fibres, treated as described above is then ready for dyeing
in the usual way.
For certain colours some chromic acid in combination with the oxide of chromium
is required, for such colours the wool prepared with the acid chromate is exposed for a
shorter time to the action of boiling water or steam than the time required for tho
decomposition of the whole of the chromic acid.
In certain cases other substances such as salts of alumina, iron, or tin may be fixed
upon the wool in combination with the oxide of chromium for such colours as require
them either as mordants for dyeing or as self colours.

page_text: Improvements in Dyeing Wool or other Animal Fibres in either
the Raw or Manufactured State.
I FREDERICK ALBERT GATTY of Hagg Works Accrington in the County of Lancaster
Calico Printer and Dyer do hereby declare the nature of said Invention for IMPROVE-
MENTS IN DYEING WOOL OR OTHER ANIMAL FIBRES IN EITHER THE RAW OR MANUFAC-
TURED STATE, and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement:-
My improvements relate to the fixing of Oxide of Chromium or Oxide of Chromium
combined with a certain proportion of Chromic Acid upon wool or other animal fibres
in their raw or manufactured state.
In place of boiling the wool or other animal fibre with Chromate of Soda or Chromate
of Potash and Sulphuric Acid or other acid as generally practised in dyeing wool I
apply the Chromate of Soda or Chromate of Potash with the requisite quantity of
Sulphuric Acid to set the Chromic Acid free at the ordinary temperature of the
atmosphere or only slightly warmed.
After the wool has been worked from one to two hours in the Acid Chromato
solution it is washed and then subjected to the action of boiling water or steam to
deoxidise the Chromic Acid fixed upon the wool and thus form Oxide. of Chromium.
The wool or other animal fibres treated as described above is then ready for dyeing in
the usual way.
For certain colours some Chromic Acid in combination with the Oxide of Chromium
is required for such colours the wool prepared with the Acid Chromate is exposed for
a shorter time to the action of boiling water or steam than the time required for the
decomposition of the whole of the Chromic Acid.
In certain cases other substances such as salts of Alumina Iron or Tin may be fixed
upon the wool in combination with the Oxide of Chromium for such colours as require
them either as mordants for dyeing or as self colours.
And in order that my Invention may be fully understood and readily carried into
effect I will proceed to describe in detail a process for carrying out the same which
process I find in practice gives good results.
The wool or other animal fibres hereinafter referred to as wool only which is to be
dyed according to my Invention may be either in its raw state or spun or made into
cloth and is first cleaned and prepared in the usual way for dyeing. The wool thus
freed from oil and other impurities is then put into a bath prepared as follows.
For each two hundred pounds weight of wool woollen yarn or cloth I dissolve in
three to four hundred gallons of cold or nearly cold water from four to twelve pounds
of Bi-chromate of Potash or Bi-chromate of Soda the proportion of Bi-chromate being
varied according to the quantity of Oxide of Chromium desired to be fixed upon the
wool and to this solution I add from one half to three quarters of a pound of Sulphuric
Acid for every pound of Bi-chromate of Potash or Bi-chromate of Soda dissolved. If
instead of the Bi-chromates the Chromates of Potash or Soda be used the quantity of
Sulphuric Acid must be increased by say one half.
After the wool has been worked or moved about in this solution which I designate
the Chrome bath for from one to two hours or longer if required it is taken out and
slightly washed and is then boiled in water for from two to three hours in order to
more or less deoxidise the Chromic Acid fixed upon the wool.

page_text: In order to hasten the deoxidising action of the boiling water one to two pounds of
Sulphuric Acid of commerce may be added to every hundred gallons of water employed.
The addition of a certain quantity of a vegetable acid such as Oxalic or Tartaric Acid or
vegetable substance such as sugar or starch will hasten the deoxidation still more but
I prefer the use of boiling water either with or without Sulphuric Acid.
I have stated here and also in describing the composition of the Chrome bath that I
use Sulphuric Acid it will be obvious however to all chemists that other mineral Acids
might be employed instead I prefer however to use Sulphuric Acid as being the best
for this purpose and the most economical.
When the wool has been sufficiently deoxidised and this can be easily seen by the
change of colour from a yellow to a green or greenish shade it is taken out and if only
water has been used it is at once ready for dyeing in logwood or other dyewood or
alizarine or other colouring matter in the usual way. If however Sulphuric Acid has
been used in the boiling operation the wool must be washed in water before being
dyed.
In place of boiling the wool in water after the Chrome bath as hereinbefore
described it may be steamed for from two to three hours which operation will also
deoxidise the Chromic Acid upon the wool like the boiling in water.
In cases where metallic salts are used in combination with the Oxide of Chromium
if the substance required be Iron I put a certain quantity of a Salt of Iron into the
Chrome bath and for this purpose I prefer to use Sulphate of Peroxide of Iron which
answers well but other Salts of Iron may also be used and good results obtained.
Alumina be required I add Alum and if Tin be required I add Oximuriate of Tin to
the Chrome bath.
If
The Oxide of Chromium alone and Oxide of Chromium combined with Oxide of
Iron or Chromate of Iron being colours in themselves for such colours the wool need
only be washed after the boiling in water or the steaming operation and then dried.
Having now particularly described and ascertained the nature of my said Invention
and in what manner the same is to be performed I would have it clearly understood
that I do not confine myself to the proportions given above as the quantity of the
Chromate or Bi-chromate of Potash or Soda and also the quantity of Sulphuric or other
Acid employed may be increased or decreased according to the colour or the shade of
colour required. Neither do I use nor claim to use the operation of boiling the wool
in a mixed solution of either of the said Chromates or Bi-chromates and Sulphuric or other
Acid which boiling operation is the customary mode of using the Chromates or
Bi-chromates in wool dyeing, but what I do claim as my Invention is-
1. Fixing on wool or other animal fibres either in the raw state or spun or as cloth
in the manufactured state by the process herein before described or any substantial
equivalent thereof Oxide of Chromium alone or Oxide of Chromium combined with a
certain proportion of Chromic Acid or Oxide of Chromium combined with other
metallic Oxide to be used either as mordants for a subsequent dyeing process or as
self colours without further dyeing.
2. The hereinbefore described process for embodying my improvements in dyeing
wool or other animal fibres.
3. Wool or other animal fibre whether in the raw or manufactured state on which
has been fixed as described Oxide of Chromium or Oxide of Chromium combined with
Chromic Acid or Oxide of Chromium combined with other metallic Oxide substantially
as and for the purposes herein described.