IMPROVEMENTS IN THE MANUFACTURE OP PULP
Year: 1854

page_text: LETTERS PATENT to George Burch, of Waltham Cross, Cheshunt, in the
County of Herts, for the Invention of "IMPROVEMENTS IN THE MANUFACTURE
OP PULP."
Sealed the 23rd February 1855, and dated the 28th August 1854.
PROVISIONAL SPECIFICATION left by the said George Burch at the
Office of the Commissioners of Patents, with his Petition, on the
28th August 1854.
I, GEORGE BURCH, of Waltham Cross, Cheshunt, in the County of Herts,
do hereby declare the nature of the Invention for "IMPROVEMENTS IN THE
MANUFACTURE OF PULP" to be as follows:-
I take chips of wood, by preference cut obliquely to the grain; I then boil,
steam, or steep the chips in hot liquor, either water or alkaline solution, for a
length of time sufficient to soften the wood; I then cause the softened chips to
pass between a series of pairs of laminating rollers, so adjusted that the first
pair shall squeeze them slightly, the next rather more, and so on at each
pair of rollers, until the last shall be quite close, and the chips passing
through them will be rolled out very thin, and the fibres separated into a pulp.
These operations can be performed either with pairs of rollers, plain or
grooved, working as above described, or by friction rollers, which are rollers so
connected by gearing that one shall be turned faster than the other, or by

page_text: single rollers working on a plain surface, by presses, or by the percussion of
hammers, or by two or more of the these methods combined. These rollers
may be arranged to work in troughs in connection with bleaching materials,
instead of water.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said George Burch in the Great Seal Patent Office on the
27th February 1855..
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, GEORGE
BURCH, of Waltham Cross, Cheshunt, in the County of Herts, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-eighth day of August, 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
George Burch, Her special licence that I, the said George Burch, my execu-
tors, administrators, and assigns, or such others as I, the said George Burch,
my executors, administrators, and 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 MANUFAC-
TURE OF PULP," upon the condition (amongst others) that I, the said George
Burch, 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 immediately
after the date of the said Letters Patent.
NOW KNOW YE, that I, the said George Burch, do hereby declare the
nature of the 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 thereof (that is to say):-
These improvements consist in converting wood into pulp, by cutting it
into chips, softening it by boiling, and crushing it until the fibres are separated.
These operations may be performed in the following manner:-The wood is
cut in chips by the ordinary logwood mill, (i. c.,) cut obliquely to the grain. I
put a hundredweight of willow chips in a copper with a solution of caustic
potash sufficient to cover them to the depth of six or eight inches, which

page_text: solution I make by boiling five pounds of potash and two and a half pounds of
quick lime in twenty gallons of water for half an hour, and after allowing the
lime to subside, I pour the clear liquor on the chips, and fill up with water to
the required depth. When it boils, I add two pounds of white soap cut in
pieces, and continue the boiling for eight hours. I next crush the chips by
causing them to pass between powerful rollers, and the following is the
arrangement I prefer :-I use a series of six pairs of cast-iron rollers placed in
a row two feet apart, made to turn simultaneously, each pair geared together
to prevent slipping when the chips are entering. To feed them I use an
endless web of canvas, two feet long, and as wide as the rollers, revolving
towards and nearly touching them; the chips are put in a hopper over it, and
falling upon it, are carried forward to the rollers, the operator regulating the
quantity by closing or enlarging the aperture or space between the hopper and
the web at which they escape, and by raising or depressing a bar placed across
and above the web. The chips having passed the first rollers fall on the second
web, and, being again saturated with the liquor they were boiled in, are carried
to the second rollers, and so on, until they have passed the six, when they fall
into a trough for removal.
When the pulp begins to stick to the rollers, it is removed by scrapers fixed
bohind them, which cause it to fall on the revolving web underneath; and the
attention of the operator must be directed to the laying it evenly on the web
when it happens to come in lumps. The moistening is effected by a small pipe
perforated with fine holes placed above the web, and communicating with a
cistern which must be kept supplied with the liquor.
In arranging the series of rollers, the first pair is so adjusted that the wood
shall be squeezed, without crushing; the next will crush it slightly, and each
succeeding pair being set closer, the chips will be rolled progressively thinner,
and the fibres separated. It must now be washed to remove the alkali, and
bleached in the usual manner, and then washed again. If now the pulp is not
fine enough for the purpose required, it must be moistened with a hot solution
of pearlash and soap, made by dissolving two pounds of pearlash and two
pounds of soap in forty gallons of water; it must be returned to the rollers
to be alternately moistened with the pearlash and soap liquor and rolled as
before, the rollers this time being set close, and the pressure so adjusted
that the fibres are separated without being cut too short. It must now
be washed again, and should any parts of the chips have passed the rollers
without having the fibres separated, the pulp may be strained through a
gauze wire, having from fifteen to twenty holes to the inch, in the following
manner:-

page_text: It is placed in a wheel covered with the gauze wire, and made to revolve
partly in water, being at the same time made to rise and fall in the water to
about a third of its diameter, and making six revolutions to one vertical
movement. The pulp is then to be collected for use, and the remainder
returned to the rollers. A trough is placed under each pair of rollers to catch
the liquor which is squeezed out of the chips, and any pulp which may escape
the web. Although I have named six pairs of rollers, other numbers may
be used, and although I prefer that the crushing should be by means of rollers,
it may be by presses or hammers actuated by any mechanical arrangement.
What I claim is, the manufacture of pulp from wood by the processes
herein described.
In witness whereof, I, the said Georgo Burch, have hereunto set my
hand and seal, this Twenty-fourth day of February, in the year of our
Lord One thousand eight hundred and fifty-five.
Witness,
S. CARPMAEL.
GEORGE BURCH. (L.B.)