A New or Improved Process of Charging and Sizing Paper.
Year: 1899

page_text: Date of Application, 16th Mar., 1899-Accepted, 16th Dec., 1899
COMPLETE SPECIFICATION.
A New or Improved Process of Charging and Sizing Paper.
I, LOUIS CAPAZZA, of 11, Place des Martyrs, Brussels, Belgium, Aeronaut, 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:―
This process consists in bringing about a production of calcic carbonate in
the presence of the fibre employed in paper making so that there is a perfect
adherence between the fibre and the carbonate and uniform distribution of the
carbonate throughout the mass of the fibre or paper.
This may be brought about by any of the known ways of producing calcic
carbonate by precipitation. For example it may be produced by a double
decomposition of calcic chloride and sodic carbonate in the cell or in the
agitating receptacle usually found at the head of paper making machines.
There is however a slight inconvenience in the case just described as the paper
is apt to be rendered slightly hygroscopic through the presence of the sodic
chloride produced.
The following method is therefore preferable; -lt consists in employing in
the paste or pulp solution in the refining cell or in the receptacle placed at the
head of the machine, lime water instead of ordinary water and in passing
through the same a current of carbonic acid gas or a gaseous current contain-
ing carbonic acid gas such for example as the waste gases from boilers after
the solid impurities have been washed therefrom or the gases escaping from
the lime burning kilns used in the manufacture of the lime employed in the
manufacture of sugar or of sodic carbonate by the Solvay process.
The quantity of carbonic gas to be injected ought to be such that the pulp
solution is neutralized. As soon as this result is obtained the necessary quan-
tity of resinous soap required for the sizing of the paper is added to the solution
and the injection of carbonic acid gas is continued until a sufficient amount of
the resin is set free to ensure the proper sizing. If need be a little sulphate of
aluminium or other suitable acid reagent may be added.
For a charge of calcic carbonate of 100 kilogrammes the amount of carbonic
acid gas to be passed through the paste or pulp solution should be slightly over
44 kilogrammes and the quantity of carbonic acid gas to be injected after the
addition of the resinous soap to the pulp solution should be about 9 per cent. of
the weight of resinous soap used.
The proportion of resinous soap which requires to be added to the pulp solu-
tion is approximately equal to that usually employed in the art and varies with
the degree of sizing required. The proportional amount of aluminium sul-
phate to be added to the pulp is the same as that employed for ordinary pulps.
The following relative proportions of calcic carbonate resinous soap and
aluminium sulphate may be cited by way of example.
100 kilogrammes of paper pulp.
10 kilogrammes of concentrated solution of resinous soap.

page_text: For a charge of 100 kilogrammes of calcic carbonate the quantity of sodic
carbonate required amounts to 106 kilogrammes and that of calcic chloride to
111 kilogrammes assuming that these two bodies are anhydrous and pure.
Otherwise the quantity must be increased in proportion to the impurity
existing.
1
;
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is
1. Precipitating calcic carbonate upon fibre employed in paper making by
chemical reaction substantially as and for the purpose set forth.
2. For the purpose of charging and sizing paper, injecting carbonic acid gas
or a mixture of gases containing carbonic acid gas into a cell, tank or the like
containing, fibre, lime water and resinous soap substantially as set forth.
3. The double decomposition method substantially as and for the purpose set
forth.
For the Applicant,
J. G. LORRAIN, M.LE.E., M.I.Mech. E.,
Norfolk House, Norfolk Street, London, W.C.,
Chartered Patent Agent.