Improvements in the Treatment of Hair for use in the Manufacture of Felt.
Year: 1891

page_text: Date of Application, 22nd Sept., 1891
Complete Specification Loft,
22nd
June, 1802 Accepted, 30th July 1892
PROVISIONAL SPECIFICATION.
Improvements in the Treatment of Hair for use in the Manufacture
of Felt.
I, EMILE BURG, of 16 Impasse Gaudelet, Paris, France, Chemist, do hereby
declare the nature of this invention to be as follows:-
This invention has for object to obviate the drawbacks resulting from the
employment of nitrate of mercury in carrotting hair intended for the manufacture
of felt.
To this end I subject the hair to be treated, to the action of carrotting liquids
produced by combining sulphuric acid and nitric acid either together, or singly,
with the various metals. By this means I have succeeded in, producing upon the
hair an effect similar to that produced by nitrate of mercury whilst at the same
time admitting of carrotting the hair to various degrees and to various shades.
The composition of some of my carrotting liquids are the following:
In order to produce pale hairs, the following solutions are made :-
I.
Metallic iron
Dissolved in ordinary sulphuric acid
Water-
50 grammes
2 kilos
2 kilos.
II.
Metallic antimony
Dissolved in concentrated hot sulphuric acid
To this is added
Ordinary nitric acid
Water
-
1
20 grammes
-
2 kilos.
->
10 litres.
500 grammes
When the hair is to be of a yellow color, there is added to this solution
Ordinary nitric acid
-
Water
165729
III.
1
Sulphate of soda
Oxalic acid,
-
1 kilo
-
2 litres.
500 grammes
250 grammes
Dissolved in water,
10 litres.
To this is added ordinary sulphuric acid 14 kilos.
"
.
When the hair is to be of a yellow color, the above mixture should be modifi
as follows:-
Nitrate of potash or nitrate of soda
Oxalic acid
Dissolved in water!
500 grammes
250 grammes
10 litres.
To this is added ordinary nitric acid 14 kilos.”

page_text: This solution is employed to obtain yellow hair. In order to meet the require-
ments of hat makers who may desire hair more or less carrotted and of more or
less pronounced shades, I may vary the proportions hereinbefore stated, and I can
combine together some of the elements comprised in my various formula.
The nature of the solutions employed may be variously modified according to the
vigour desired to be imparted to the hair, the nature of the said hair, and the color
thereof to be produced..
The operations of carrotting-with the above described solutions are effected in
the same manner as with nitrate of mercury. The skin is placed on a bench and
the solution applied by means of a brush so as to cause the carrotting agent to
penetrate to the hide. The drying can be effected by means of a stove and at the

page_text: same temperature as heretofore. The other operations to which the hair is to be
treated remain the same as in the process heretofore adopted.
Dated this 22nd day of September 1891.
E. BURG,
By L. W., per. F. B.
COMPLETE SPECIFICATION:
Improvements in the Treatment of Hair for use in the Manufacture
of Felt.
EMILE BURG, 16 Impasse Gaudelet, Paris, France, Chemist, do hereby
declare the nature of this invention and in what manner the same is to be
performed, to be particularly, described and ascertained in and by the following
statement:- -
In order to prepare animal hairs for felting, it has been customary to use salts of
mercury and more particularly nitrate or chloride of mercury. These processes
were applied with great difficulty, because it is only by using special remedies and
by taking the greatest precautions that the workmen can be protected against the
injurious consequences resulting from a continued contact with salts of mercury.
My invention consists in an improvement upon the processes already patented in
which salts of mercury are done away with by using other products.
I employ solutions of some metals hereinafter named in nitric acid, either pure
or diluted.
The said solutions are but slightly injurious to health and may
be employed without special precautions, even by unexperienced workmen.
Practice has shown that the above named saline solutions have the property of
disorganizing the hairs and of imparting to the too smooth surface thereof the
qualities which they are naturally deprived of.
Among the metallic sulphates and nitrates containing free sulphuric or nitric
acid, the most suitable are those in which iron, antimony, soda, potash, tin,
aluminium, copper or zinc is a base. Such combinations are best obtained by
placing the metals, in a free state, in presence of nitric acid, in such proportions
that after the formation of the corresponding salts, there is an excess of free
nitric acid. Sulphuric acid is sometimes employed for the purpose of accelerating
the formation of these salts.
It is sometimes desirable to use other combinations, which are more particularly
pointed out in the following examples, and which serve for special and secondary
purposes.
In this manner, properties are imparted to the hairs; the latter thereby become
well-suited for receiving dark-colored dye-stuff. The dark shades imparted to
the hairs by the new carrotting process are not dyeing operations, they can be
likewise obtained by the mercurial process. The present process has for its sole
object to effect the carrotting action (without mercury) of the hairs intended to
be used in the manufacture of felt.
I will give hereinafter a few examples relating to the application of my
process. The acid carrotting substances of the various metallic salts can be
prepared and applied as and in the proportions hereinafter stated.
FIRST EXAMPLE.
I dissolve 0.050 kilog. of metallic iron in 2-500 kilog. of concentrated nitric acid
and 2 kilog. of water. The solution should be diluted in say 8 litres of water.
:

page_text: SIXTH EXAMPLE.
I dissolve 0.02 kilog. of metallic copper and 0.03 kilog. of metallic zinc in 3 kilog.
of nitric acid and I then add 10 litres of water. This solution gives an average
degree of felting for common hats.
As will be seen from the foregoing examples, sulphuric acid is not indispensable
for this process; it is very slightly used and only for accelerating the formation of
salts which it is too long to obtain with pure nitric acid.
is
When applying the hereinbefore described carrotting liquids, the process
exactly the same as with salts of mercury; likewise, the drying operation of the
skins and hairs after the carrotting process can be effected in the manner hitherto
practised, in a drying room or other suitable contrivance.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
⚫claim is :
The hereinbefore described carrotting process, consisting in treating the hairs
by means of solutions containing a metal combined with nitric acid, and in some
cases, sulphuric acid substantially as herein set forth & for the purposes set forth.
Dated this 22nd day of June 1892.
E. BURG,
By L. W., per F. B.