IMPROVEMENTS IN CLEANING MATERIALS USED IN THE MANUFACTURE OF PAPER WHILST THE SAID MATERIALS ARE IN THE CONDITION OF HALF Stuff.
Year: 1880

page_text: LETTERS PATENT to James Robertson, of Springfield Mills, Polton, in the
County of Midlothian, North Britain, for an Invention of "IMPROVEMENTS IN
CLEANING MATERIALS USED IN THE MANUFACTURE OF PAPER WHILST THE
SAID MATERIALS ARE IN THE CONDITION OF HALF Stuff.'
"
PROVISIONAL SPECIFICATION left by the said James Robertson at the
Office of the Commissioners of Patents on the 11th June 1880.
JAMES ROBERTSON, of Springfield Mills, Polton, in the County of Midlothian,
North Britain. "IMPROVEMENTS IN CLEANING MATERIALS USED IN THE MANU-
FACTURE OF PAPER WHILST THE SAID MATERIALS ARE IN THE CONDITION OF
HALF STUFF.'
" "
This Invention has for its object to mechanically clean the materials used in
making paper whilst the said materials are in the condition technically known as
half stuff," and either before or after the said "half stuff" is bleached, but
preferably before bleaching. Hitherto the said materials, before, in the process of
manufacture they have arrived at the "half stuff" state or condition, have been
cleaned by picking out the grit and other impurities by hand, a method which is
both expensive and unsatisfactory in result, and by straining the pulp after it has
been reduced fine enough for making paper and just before it passes to the paper
making machine. Under this Invention the cleaning of the material is effected
when, in the process of manufacture, it has been boiled, washed, and broken, and
has arrived at the condition of "half stuff," by running the stuff into suitable
chests or vats, from whence it is drawn off and strained through strainers of
ordinary construction, baving slits wide enough to pass the long fibre of the pulp
or "half stuff," but at the same time close enough to keep back the gritty and
other objectionable matters admixed with the said fibre. The cleansing may be
effected by degrees, that is to say, by first passing the "half stuff" through a
strainer or strainers with wide openings or slits, and thereafter through other

page_text: «
strainers the openings or slits of which decrease in size successively. After being
strained or cleaned the material may be discharged into the bleaching engine or
"potcher," and thence go through the regular course in the making of paper, or
it may be run off into a simple got up paper making machine and made into paper
direct, either wet or dry, to be afterwards removed to the bleaching engine or
"potcher" and bleached, and thence passed on in the regular course.
What is claimed for this Invention is, that the materials used in making paper
can be cleaned by the process constituting the Invention, when, in the "half stuff"
condition, in a manner superior to, and at much less cost than under the systems
hitherto in use for cleaning the materials at any other stage of the manufacture.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said James Robertson, in the Great Seal Patent Office on the
9th December 1880.
JAMES ROBERTSON, formerly of Springfield Mills, Polton, in the County of
Midlothian, North Britain, now of Bridge Hall Paper Mills, in the County Palatine
of Lancaster. "IMPROVEMENTS IN CLEANING MATERIALS USED IN THE MANU-
FACTURE OF PAPER WHILST THE SAID MATERIALS ARE IN THE CONDITION OF
HALF STUFF.'
"
My said Invention has for its object to mechanically clean the materials used in
the manufacture of paper whilst the said materials are in the condition technically
known as "half stuff," and either before or after, but preferably before, the said
"half stuff" is bleached.
Hitherto the cleaning of the materials used in the
manufacture of paper has entailed great labour and considerable expense to the
paper maker, by reason of the method pursued, which consists in, first, so far as is
practicable, picking by hand the grit and other foreign matters and impurities from
the said materials whilst they are in a raw or crude state, or before, in the process
of manufacture, they have attained the condition of "half stuff," and, second, by
straining the pulp after it has been reduced fine enough for making paper, and
just before it passes to the paper making machine.
Hand picking of the materials, especially esparto, besides being laborious and
expensive, is very unsatisfactory in results, and subsequent straining of the pulp,
as above set forth, before it passes to the paper making machine is therefore a
necessary part of the process hitherto pursued.
Under this Invention hand picking, especially esparto, is dispensed with, the
cleaning being effected after, in the process of manufacture, the materials have
been boiled, washed, and broken into the condition of "half stuff." To facilitato
such cleaning the stuff is run from the breaking engine into suitable chests,
mixers, or tanks, from which it is drawn off and strained through any ordinary
paper makers' strainers, revolving or otherwise, but preferably, for facility of
manipulation, through flat bottomed "jogg" strainers. These strainers are mado
with slits wide enough to pass the long fibre of the pulp or half stuff," but at
the same time sufficiently narrow to prevent the passage of gritty or other
objectionable matters admixed with the said fibre through the strainer.
cleaning may be effected in one or in successive strainings, that is to say, by first
passing the "half stuff" through one or more strainers with comparatively wide
openings or slits, and thereafter through other strainers, the openings or slits
of which decrease in size successively, and by this means the paper making
materials, and especially esparto, are cleaned in a superior manner and at much less
cost than under the systems hitherto in use.
The
After being strained or cleaned the materials may be discharged into the
bleaching engine or "potcher," and thence go through the regular course in the
making of paper, or they may be run off into a simple got up paper making
machine, and made into paper direct, either wet or dry, and afterwards bleached
and passed on in regular course.
It is obvious that to clean or strain the half stuff, as before set forth, the
ordinary flat "jogg," revolving, or other paper maker's strainer employed may be
arranged in many different ways relatively with the breaking engine and other
plant of the mill, and although I do not confine myself to any special arrangement
or construction of the strainers (such constituting no part of my said Invention)
I have hereunto appended a Sheet of Drawings, on which Figure 1, is a sectional
elevation, and Figure 2 a plan of one arrangement suitable for the purpose.
shown by these Figures, the "half stuff" is discharged from the breaking engine A
through the pipe B into the tank C, where it is thinned with water until the
mixture is very fluid, and kept agitated by the rotating stirrer D. From the tank
As

page_text: the "half stuff" is pumped up into the box or tank E, from whence it is discharged
through the stop cock F on to the first or wider strainer G, in passing through the
slits of which the material is separated from the coarser impurities. When it is
possible to arrange the breaking-engine A and the tank C at a higher level than
the strainers, the pump and tank E may be dispensed with. The box bottom
underneath the strainer G communicates with another and finer strainer H, in
passing through the narrower slits of which the finer impurities are separated from
the fibre. Any greater desired number of strainers may be used, their slits
decreasing in width successively. From the last strainer the admixed "half stuff"
and water flows over the shute I (which constitutes a sand trap to catch and retain
any dirt and impurities which may have escaped the action of the strainers) to the
revolving sieve or drum J, where it is separated from a portion of the water, the
latter passing through the meshes into the interior of the sieve, and thence outwards
through an opening at the centre or hub on to the conduit K, and thence into the
box or chamber L, from which it may flow back into the tank C, or on to the first
strainer G, thereby saving water by enabling the same quantity to be utilized
over and over again. From the sieve J the cleaned "half stuff" passes into
another tank M, also provided with a revolving agitator, and it may thence be
discharged into the bleaching or potching engine, or run into a simple got up paper
making machine, and made into paper direct, to be afterwards bleached, as
before set forth.
Having now described and particularly ascertained the nature of my said
Invention, and the system, mode, or manner in or under which the same 'is or may
be used or practically carried into effect, I would observe in conclusion that what
I consider to be novel and original, and therefore claim as the Invention secured
to me by the hereinbefore in part recited Letters Patent, is,-
Cleaning materials used in the manufacture of paper, and especially esparto,
whilst the said materials are in the condition of "half stuff," by the employment
at that stage of ordinary flat "jogg," revolving, or other paper makers' strainers,
substantially as hereinbefore described.
In witness whereof, I, the said James Robertson, have hereunto set my
hand and seal, this Seventh day of December, in the year of our Lord
One thousand eight hundred and eighty.