IM- PROVEMENTS IN THE PREPARATION OR SIZEING OF PAPER, OR THE MATERIALS USED IN THE MANUFACTURE THEREOF.
Year: 1854

page_text: LETTERS PATENT to John Macadam, of Glasgow, in the County of
Lanark, North Britain, Doctor of Medicine, for the Invention of “IM-
PROVEMENTS IN THE PREPARATION OR SIZEING OF PAPER, OR THE MATERIALS
USED IN THE MANUFACTURE THEREOF.'
Lanark, North Britain, Doctor of Medicine, for the Invention of "IM-
PROVEMENTS IN THE PREPARATION OR SIZEING OF PAPER, OR THE MATERIALS
USED IN THE MANUFACTURE THEREOF."
Sealed the 27th February 1855, and dated the 17th November 1854.
PROVISIONAL SPECIFICATION left by the said John Macadam at the
Office of the Commissioners of Patents, with his Petition, on the
17th November 1854.
I, JOHN MACADAM, of Glasgow, in the County of Lanark, North Britain,
Doctor of Medicine, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN THE PREPARATION OR SIZEING OF PAPER, OR THE MATERIALS
USED IN THE MANUFACTURE THEREOF," to be as follows, that is to say :--
This Invention relates to the treatment or preparation and sizeing of paper,
or the materials from which paper is made, in such manner as to secure
economy in manufacturing cost, and superiority of the product, as regards
certain purposes. This system of treatment is essentially applicable to the
manufacture of such kinds or qualities of paper as are partially or totally
rosin sized," or prepared with resinous matter, and machine_mode, and it
consists in the partial or total substitution of aqueous solutions of the uncom-

page_text: bined acids, or of aqueous solutions of single sulphates, or other binary com-
pounds, for the double sulphate of potass and alumina, known by the name of
alum, usually employed according to the existing system of manufacture.
The acids which are found to be best suited for this purpose are the mineral
acids, especially sulphuric acid, such acids being employed in the diluted state
with water, and in quantity sufficient for the neutralization of the whole or
part of the alkali of the resinous or rosin size which is used. The quantity
or proportion of. acidulous matter to be used is accurately determined by
alkalimetrical processes, and such acids or acidulous matter is added to the
paper pulp either before or after the addition of the resinous size. In carry-
ing out the Invention by the aid of single sulphates, other binary acidulous
compounds in the form of aqueous solutions, and suited in quantity to the
alkali present in the size, are used. Paper produced under this system of
treatment is peculiarly suited for the lithographer's purposes, as well as for the
printing of engravings of all kinds, as it possesses an absorbent surface of
a uniform character. It has also a less injurious effect upon the engraver's
plates, and is well suited for letter-press printing, as it is readily susceptible of
uniform damping, and affords clear impressions.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said John Macadam in the Great Seal Patent Office on the
17th May 1855.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
MACADAM, of Glasgow, in the County of Lanark, North Britain, Doctor of
Medicine, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters 2
Patent, bearing-date-the-Seventeenth day of November, in the year of our Lord
One thousand eight hundred and fifty-four, in the eighteenth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said John Macadam, Her special license that I, the said John Macadam,
my executors, administrators, and assigns, or such others as I, the said
John Macadam, my executors, administrators, or assigns, should at any time
agree with, and no others, from time to time and at all times thereafter
during the term therein expressed, should and lawfully might make, use,
exercise, and vend, within the United Kingdom of Great Britain-and-Ireland,
the Channel Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN
THE PREPARATION OR SIZEING OF PAPER, OR THE MATERIALS USED IN THE MANU-

page_text: FACTURE THEREOF," upon the condition (amongst others) that I, the said John
Macadam, by an instrument in writing under my hand-and seal, should par-
ticularly describe and ascertain the nature of the said Invention, and in what
manner the same was to be performed, and cause the same to be filed in
the Great Seal Patent Office within six calendar months next and imme-
diately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said John Macadam, do hereby declare the
nature of my said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement, that is to say :-
My said Invention relates to the treatment or preparation and sizeing of
paper, or the materials from which paper is made; in such manner as to secure
economy in manufacturing cost, and superiority of the product, as regards
certain purposes, to which I shall heréin-after more particularly refer. This
system of treatment is essentially applicable to the manufacture of such kinds
or qualities of paper, as are partially or totally "rosin sized," or prepared with
resinous matter, and machine made, and it consists in the partial or total sub-
stitution of aqueous solutions of the uncombined acids, or of aqueous solutions
of single sulphates, or of other binary compounds, for the double sulphate of
potash and alumina, known by the name of alum, usually employed according
to the existing system of manufacture. The acids which are found to be best
suited for this purpose are the mineral acids, especially sulphuric acid, such
acids being employed in the diluted state with water, and in quantity sufficient
for the neutralisation of the whole or a part of the alkali of the resinous or
rosin size which is used. The quantity or proportion of acidulous solution to
be used when free acids are employed is accurately determined by alkali-
metrical processes, and such acids or acidulous solutions are added to the
paper pulp either before or after the addition of the resinous size. In carrying
out the Invention, the aid of single sulphates or other binary compounds in
the form of aqueous solutions, and suited in quantity to the alkali present in the
size, are used. Paper produced under this system of treatment is peculiarly
suited for the lithographer's purposes, as well as for the printing of engravings
of all kinds, as it possesses an absorbent surface of a uniform character. It
has also a less injurious effect upon the engraver's plates, and is well suited for
letter-press printing, as it is readily susceptible of uniform damping, and affords
clear impressions.
And in order that my said Invention may be properly understood, I shall
now proceed to detail more fully the special materials and mode of treatment
which I have found most suitable for the effective working out of my improve-

page_text: ments, as well as the functions of the acids or other acidulous solutions
employed in the preparation of the resinous or rosin size, as ordinarily used.
The resinous matter or rosin is dissolved through the medium of water by
alkaline compounds, carbonate of soda, or carbonate of potash, for example;
the solution thus prepared is that which is commonly used in the treatment
or sizeing of printing paper, and the same solution is adopted when employing
my improved process. For the sake of convenience and certainty I shall
herein-after uniformly term this solution the "size solution." When alum is
added to such a solution in contact with the paper pulp, decomposition of the
"size solution" occurs, the acid of the alum neutralises the alkali which is
present, and the rosin is precipitated in contact with the fibrous matter of the
paper pulp. In sizeing with rosin the antiseptic influence of alum is not
required, as in the case of sizeing paper by the agency of animal matters, or,
if at all necessary, it is so only within a very limited extent.
My Invention, therefore, essentially consists in the application and use of
the free acids or single sulphates, or other binary compounds, by the agency
of which the desired neutralisation of the alkali of the "size solution" is
secured in a more economical manner, and with superior results as regards
the quality of the paper, than when this chemical effect arises solely from the
use of alum in the ordinary way. The agents which I have named are
employed to a greater or less extent in accordance with actual circumstances,
introducing at the same time more or less alum, as may be advisable. When
single sulphates or other binary-compounds are to be used, to, effect by their
contained acid the neutralisation of the alkali of the "size solution," I apply
such substances in accurate atomic proportion. For this end the rosin "size
solution" is constantly prepared from the same proportions of rosin, water, and
alkaline compounds, so that whether commercial carbonate of soda, carbonate of
potash, or soda ash, or other alkaline compound be used, the proportion of alkali
in a given measure of the size solution may be as constant within such narrow
limits as any fluctuations in the percentage of alkaline value of such com-
pounds will admit. The strength of the acid aqueous solution is constant ;
thus, taking sulphuric acid as an example, and I prefer this acid to others of
the same class of compounds, I employ it as an aqueous solution, having the
specific gravity of 1.100, or, in other terms, of 20 degrees of Twaddell's
hydrometer. Whilst this strength is convenient for regulating and measuring
the required quantities, still the degree of dilution is otherwise unimportant;
only it is advisable that this be the minimum amount of dilution.
I also regulate and adjust the required quantity of the dilute acid or
acidulous solution, thus: The "size solution" being constant, or nearly so, in

page_text: alkaline strength, and used in definite and constant quantity for each class of
paper, as sized in any particular engine of the paper makers, works according
to the capacity of such engine. A preliminary experiment is made to ascertain,
by means of a graduated tube, divided into equal spaces, such as is usually
employed in the estimation of the value of aklalies, what number of such
graduated sections or spaces filled with the acid solution are necessary for the
neutralisation of a known proportion of the total amount of "size solution'
as required for the pulp in any particular engine, in accordance with the
special variety of paper being manufactured. The point of saturation is
ascertained by stirring well the size solution on each successive addition of
the acidulous solution, and until the "size solution "so treated slightly reddens
litmus or other test papers. The quantity of ácidulous solution being thus
determined for a known proportion of the "size solution," it is easy to
ascertain by calculation the requisite amount for the whole of the "size
solution" to be decomposed. But a more convenient system for practical
purposes is to have a series of measures, capable of containing the requisite
amount of the acidulous solution to neutralise the alkali present in one, two,
three, or other number of gallons of the "size, solution," so that the treatment
is then reduced to an exceedingly simply form.
In the practical manufacture of paper, I find the following order or sequence
of the applied substances or treatment to be the best, although I may vary the
order more or less:-The paper pulp being introduced into the sizeing engine
with the customary quantity of water, the necessary or determined quantity of
"size solution" is added, and at an interval of about 20 minutes, more or less,
the engine being meanwhile in action, the determined quantity of acidulous
solution is introduced at the expiration of about twenty minutes more, more
or less, and when the neutralisation is complete, and the deposition of the rosin
thus economically accomplished, any alum which is to be applied is added.
This substance for ordinary printing papers is commonly added in proportions
of about two pounds weight to the pulp necessary for the manufacture of each
hundredweight of paper. This proportion varies, however, according to the
required hardness of the surface of the paper, this hardening effect being the
chief result due to the introduction of alum in my improved process. In some
kinds of paper, alum may be entirely dispensed with. In working out this
process, this dispensing with alum applies more particularly to paper used
by lithographers and engravers, for-whose work alum is known to be preju-
licial. After the addition-of-the-materials-to-the-pulp-has-taken place in the
berein-before described order, the usual coloring matter is applied, and at this

page_text: stage also any fine clay or other material with which it may be desired to
impregnate the paper.
The paper made according to my improved process is peculiarly suitable
for the purposes of the lithographer, and the printer of metal or wood
engravings, as it presents a fine absorbent and equable surface, whilst the ink
impressions do not show through the body of the paper. It has besides no
prejudicial action upon metal plates, whilst it is most favorable for letter-press
printers, from its susceptibility to ready and uniform damping, and its acquiring
a clear and well-defined impression.
Having now described and particularly ascertained the nature of the said
Invention, and the 'manner in which the same is or may be used or carried
into effect, I would observe, in conclusion, that I do not confine or restrict
myself to the precise details or arrangements which I have had occasion to
describe or refer to, as many variations may be made therefrom without
deviating from the principles or main features of my said Invention; but
what I consider to be novel and original, and therefore claim as the Invention
secured to me by the herein-before in part recited Letters Patent, is,-
First, the system or mode of preparing or treating pulp for the manufacture
of paper as herein-before described.
. Second, the application and use of incombined acids (as sulphuric acid), or
of "single sulphates and other binary compounds, for neutralising the alkali in
the "size solution," to be used in the preparation of wholly or partially rosin-
sized and machine-made paper, for the purposes herein-before described.
In witness whereof, I, the said John Macadam, have hereunto set my
hand and seal, the Seventeentli day of May, One thousand eight
hundred and fifty-five.