IMPROVEMENTS IN THE MANUFACTURE OF INK
Year: 1881

page_text: PROVISIONAL SPECIFICATION left by the said Albert Frank Stoddart at
the Office of the Commissioners of Patents on the 21st February 1881.
ALBERT FRANK STODDART, of Sneyd Park, Bristol. "IMPROVEMENTS IN THE
MANUFACTURE OF INK."
At the present time a considerable quantity of spent tanning liquor is produced
in tanneries, and when discharged from the tan pits is a waste product, and
considerable difficulty is frequently experienced in disposing of the liquor in such a
manner as not to create any nuisance.
According to my Invention I employ the spent tan liquor in the manufacture of
ink.
For this purpose I evaporate the liquor so as to reduce it to the required degree of
concentration, the amount of reduction varying according to the amount of gallic acid
originally contained in it, or in some cases use it without evaporation. The
concentrated solution I allow to rest in order to clarify it, or clarify it in other
suitable manner. I then, at a temperature approaching the boiling point, add
copperas (sulphate of iron) and a quantity of gum or other thickening ingredient,
or the gum might be omitted.
The above compound liquid is allowed to stand in order to clarify, or is clarified
any suitable manner. The product is writing or copying ink, according to the
degree of concentration and the ingredients used.
Other ingredients now commonly used in the manufacture of ink may also be
added to the concentrated spent liquor.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Albert Frank Stoddart in the Great Seal Patent Office on the
16th August 1881.
ALBERT FRANK STODDART, of Sneyd Park, Bristol.
MANUFACTURE OF INK."
"IMPROVEMENTS IN THE
At the present time a considerable quantity of spent tanning liquor is produced
in tanneries, and when discharged from the tan pits is a waste product, and
considerable difficulty is frequently experienced in disposing of the liquor in such a
manner as not to create any nuisance. I have found that such waste liquor may
be utilized by employing it in the manufacture of ink, and that the waste liquor can
be made to serve not only as the source from which the gallic acid, but also the
thickening substances requisite in the manufacture of ink, may be obtained.
In carrying out my Invention I proceed as follows:-
"
I take a measured quantity of spent " ooze or tan liquor from the tan pits and
boil it in a boiling pan; if the liquor requires to be concentrated I continue the
boiling until the required degree of concentration is attained, generally I reduce it
to about of its original bulk.
The boiled liquor I draw off into a large tub where it is left to subside. The
subsidence takes place in about 24 hours, but sometimes is not so prolonged. The top
liquor is now drawn off and is found to contain gallic acid and thickening
substances, such that on addition of green copperas, or if necessary green copperas
and a little gum, a good writing or copying ink will be produced. It is not
essential that the boiled tan liquor should be allowed to subside, but a better ink
is obtained by allowing it to subside as described. The top liquor drawn from the
subsided debris is again heated in a vessel to about the boiling point, and the green
copperas is mixed with it; the liquor is kept at about the boiling point until all
the copperas is dissolved, and then if necessary gum is added. The amount of
copperas required to be added varies according to the quality of ink that is being
made, and ranges between, say, from 2 to 5 grains of copperas for every fluid
ounce of unconcentrated liquor. As a general rule no addition of gum is required, but
this depends wholly on the composition of the spent tan liquor employed, which
differs when the liquor is obtained from different tanneries or at different times from
the same tannery.
Other ingredients commonly used in the manufacture of ink may also be added
to the liquor.
From this last mentioned vessel the ink is drawn off and placed into tubs, and
is allowed to stand exposed to the atmosphere for about 3 weeks so that it may
get oxidized to the ferric state and is then ready for use.
Having thus described the nature of my Invention, and the manner of performing
the same, I would have it understood that I claim, the application of spent ooze or
tan liquor in the manufacture of ink, substantially as hereinbefore described.
In witness whereof, I, the said Albert Frank Stoddart, have hereunto set my
hand and seal, this Twelfth day of August, in the year of our Lord One
thousand eight hundred and eighty one.