An Improved Method of Preparation of a Rosin Soap for Paper Sizing, containing an Admissible Quantity of Free Rosin.
Year: 1898

page_text: Date of Application, 21st Sept., 1898-Accepted, 26th Nov., 1898
COMPLETE SPECIFICATION.
An Improved Method of Preparation of a Rosin Soap for Paper
Sizing, containing an Admissible Quantity of Free Rosin.
We, HEINRICH HAMPEL, Manager of the Paper Mill, Klein, Neusiedl, near Vienna,
and VICTOR ZAMPIS, Manufacturer, of Durergasse 13, Vienna, VI., in the Empire of
Austria, 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 :-
Our invention aims at the preparation of rosin soap permitting a sure and faultless
sizing of the paper in the beating engine.
Our method consists essentially in dissolving the crushed rosin, which has been
mixed in dry state with a hitherto, for this purpose, unknown small quantity (3%) of
soda ash (carbonate of soda) by water, employing a very small quantity of direct steam,
a low temperature (80 to 100 C.) and no steam pressure, whilst during the whole
operation the rosin is continually stirred up. To the so dissolved rosin a further
quantity of soda ash (carbonate of soda) (6-7 %) according to the chemical com-
position of the working water, is added in dry or dissolved state with continual
mechanical stirring without any further addition of steam. By dissolving the rosin
in this way only a part of the rosin is converted into a soap whilst the other part goes
into solution in free state, and at the same time the sizing power and its water-
repelling property is preserved.
The necessary solubility in water is given to the rosin by the addition of carbonate
of soda, whereas in our method, employing no more steam or pressure and a low
temperature the largest admissible percentage of free rosin is obtained whilst on the
other hand the sizing power of the rosin which is very sensitive to high temperature,
is preserved.
To obtain unproportional quantities of free rosin in the rosin as has been laterly
very often tried and regarded as the final purpose of so many people occupied in
making a good rosin size (amongst others also Arledter's German Patent, 95416);
may be looked upon as an abuse of Dr. Wurster's theory which in itself is perfectly
correct, because an unproportional overplus of free rosin in the rosin soaps would at
the moment of its transformation into a sizing milk require so large a degree of
dilution, that the enormous quantity of liquid would practically forbid its use in the
manufacture of paper. If however the sizing milk is not so much diluted, the free
rosin which cannot be kept in suspension in the solution of resinate of soda, deposits
in the tanks as a percipitate, what gives a considerable loss and worse than that gives
the constant danger of rosin specks in the paper and glues all pipes, filters and
utensils connected with the storage of the sizing milk, our experience proved, that
no more than about 38% of free rosin is admissible in the rosin soaps to be used
without danger in the above mentioned sense.
As in our method of dissolving the rosin there are only small quantities of water
employed and as the crushed rosin is added as a dry mixture with soda ash, as
furthermore there is used very little steam, so the required continual stirring is
difficult to do well by handwork and would require larger and damaging use of steam.
Therefore, however not strictly necessarily, a mechanical mixer is preferable. The

page_text: mixture and dissolving action is quicker and more regular, with less steam at lower
temperature which, as already mentioned preserves the sizing property of the rosin.
A special apparatus is recommended for this purpose and shown in the annexed
drawing in Fig. 1 in elevation and Fig. 2 in cross section consisting in an iron vat a
with semicircular bottom. This vat a is crossed by a horizontal shaft b on which are
The steampipe d entering from outside follows the
the bottom of the vat in a T piece e.
fixed 6 pairs of mixing wings c.
inner wall of the vat and ends on
The apparatus is covered by an iron cover f. the front part of which can be lifted.
This front part is fitted with a box g for pouring in the rosin. The shaft makes about
40 revolutions a minute. On the bottom of the vat there is a valve for draining the
finished rosin soap.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed we declare that what we
claim is:-
Method of preparation of a rosin soap for paper sizing containing admissible
quantities of free rosin and characterized by the dissolving of the rosin with only 3 %
of soda ash (carbonate of soda) a little water and direct steam at a low temperature
(only 80-100° C.) without steam pressure and with continual stirring, and by
supplementary addition of just the necessary quantity of carbonate of soda, to make
the rosin soap soluble in water, this supplementary addition being mechanically made
without employing any steam or heat.
Dated this 21st day of Sontember 1800
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