IMPROVEMENTS IN PAPER STOCK, AND MEANS OR METHOD OF MAKING PAPER PULP FROM WOOD, STRAW, CANE, ESPARTO GRASS, FLAX, FLAX TOW, HEMP, HEMP Tow, JUTE, JUTE Tow, MANILLA ROPE OR MANILLA TOW, AND ALL ANALOGOUS MATERIAL OR VEGETABLE SUBSTANCES, AND IN THE TREATMENT OF MATERIALS USED THEREIN, AND IN APPARATUS FOR TREATING THE SAME.
Year: 1870

page_text: ETTERS PATENT to Samuel Armstrong Walsh, of the City of New
York, State of New York, in the United States of America, for
the Invention of "IMPROVEMENTS IN PAPER STOCK, AND MEANS OR METHOD
OF MAKING PAPER PULP FROM WOOD, STRAW, CANE, ESPARTO GRASS, FLAX,
FLAX TOW, HEMP, HEMP Tow, JUTE, JUTE Tow, MANILLA ROPE OR MANILLA
TOW, AND ALL ANALOGOUS MATERIAL OR VEGETABLE SUBSTANCES, AND IN THE
TREATMENT OF MATERIALS USED THEREIN, AND IN APPARATUS FOR TREATING
THE SAME. - A communication from Morris Longstreth Keen,
residing at Jersey City, State of New Jersey, in the United States
of America.
"
-
COMPLETE SPECIFICATION filed by the said Samuel Armstrong Walsh
at the Office of the Commissioners of Patents, with his Petition
and Declaration, on the 29th December 1870, pursuant to the 9th
Section of the Patent Law Amendment Act, 1852.

page_text: "
WHEREAS I am in possession of an Invention for "IMPROVEMENTS IN
PAPER STOCK, AND MEANS OR METHOD OF MAKING PAPER PULP FROM WOOD, STRAW,
‘Cane, Esparto Grass, Flax, FLAX Tow, HEMP, HEMP Tow, JUte, Jute Tow,
MANILLA ROPE OR MANILLA Tow, AND ALL ANALOGOUS MATERIAL OR VEGETABLE
SUBSTANCES, AND IN THE TREATMENT OF MATERIALS USED THEREIN, AND IN APPA-
RATUS FOR TREATING THE SAME,' and have petitioned Her Majesty to
grant unto me, my executors, administrators, and assigns, Her Royal
Letters Patent for the same, and have made solemn Declaration that
the same has been communicated to me by Morris Longstreth Keen,
of Jersey City, State of New Jersey, in the United States of America,
aforesaid.
NOW KNOW YE, that I, the said Samuel Armstrong Walsh, do hereby
declare that the following Complete Specification, under my hand and
seal, fully describes and ascertains the nature of the said Invention,
and in what manner the same is to be performed, in and by the
following statement :—
I will first describe the method of treatment as applied to the manu-
facture of paper stock from wood and straw. The other materials named
are treated similar to straw. After wood has been reduced to fine chips
or shavings, or the straw cut by any suitable machine or cutter, the
chips, shavings, or cuttings are put in a close strong boiler, one of
an upright form preferred, fitted with a perforated false bottom inside,
so that the stock under treatment can be drained off by means of a
cock in the bottom of the boiler, communicating with space under
the false bottom. A discharge valve also is fitted to a passage through
both bottoms communicating with the interior of the boiler, so that
the stock of pulp when finished can be discharged or blown out under
pressure into a suitable receiver or tank for said purpose. The boiler
is provided with a top screen or perforated diaphragm fitted across the
inside of the top of the boiler allowing a steam space above the screen.
The boiler is charged either through a man-hole above or below the
screen, a portion of the screen being removed in the former case to
admit of charge. After the boiler is charged with the wood and the
man-hole secured, steam is admitted to the boiler from a separate
generator by means of pipes at the top of the boiler, and manipulated
at pleasure. After steaming the stock for thirty minutes, more or less,
according to the fineness of the shavings or chips, at a temperature of

page_text: from 300° to 400° Fahrenheit, the drain cock is opened at the bottom
and the condensed water drawn off. Hot water is now injected at a.
temperature of from 300° to 400° Fahrenheit above the screen into the
steam space and percolates freely through the stock, under treatment and
washes out the interstitial matter.. By alternating the treatment from
steam to water every five or ten minutes for thirty minutes or more,.
according to the previous condition and kind of stock, under treatment it
will be found that at least forty to fifty per cent. of the interstitial matter
of straw or dry wood will have been removed and fifty to sixty per cent. of
green wood will have been removed. All dry stock may be steeped with;
advantage in hot or cold water as a preliminary process. The charge is.
now ready for the alkaline treatment, but if thought desirable it can be.
drawn from the boiler and more thoroughly washed, and more of the
interstitial matter thus removed, or it can in this stage be made into
common brown paper. The stock as left in the boiler after the steam
and hot water percolation may be transferred with or without extra
washing to another, boiler, or retained in or returned to the same in
which it was originally steamed, and subjected to the action of alkali
either in a carbonate or caustic form in solutions of the strengths and.
temperatures described below, and as most of the inerstitial matter has.
been previously removed it is easily reduced to a pulp with about thirty-.
three per cent, of the alkali now used by any other of the present
approved manufacture of wood or straw paper, that is to say, a good
pulp can be produced by boiling the stock of wood or straw, &c.
previously cleaned of much of the interstitial matter by the steaming.
and hot water process in solutions of caustic alkali of twenty to twenty-.
five per cent. of wood pulp produced, and in eight to ten per cent. of
caustic alkali to straw pulp. produced. The strength of alkali preferred
for wood is about 10° to. 12° Baumé, that for straw and, other materials
mentioned 6° to 8°; though much weaker solutions will answer nearly as
well. The alkali is first charged for wood, at the rate of one gallon at
8 Baumé to every pound of wood under treatment, and for straw one
gallon at 5° Baumé to every pound of straw under treatment, and the
heat raised in the boiler to a temperature indicated by ten to thirty
pounds pressure on the steam gauge.

page_text: acted on in the manner described by steam and hot water in open
vessels without any pressure whatever. It is however preferred to treat
the stock under the pressure of thirty pounds in a close boiler in caustic
alkali of strength described, as the action desired is obtained under the
heat indicated by that pressure in a shorter time than at a lower
temperature. With most stock this should be continued about one
hour. I do not however confine myself to the pressures or temperatures
as higher pressure can be used to nearly equal advantage, and lower
steaming will answer the purpose, but those named seem to be about
the best for commercial use.
It is important that no considerable quantity of steam be allowed
to condense in the boiler at this stage as it would weaken the strength
of the solution, I therefore prefer to maintain the temperature by the
admission of steam at a proper pressure to an exterior jacket alone, or
to a jacket and coils or other provisions for heating the interior. The
alkali is now drawn off at the drain cock in the bottom of the boiler,
measure for measure, that is, the stock is now freed by percolation, and
a sudden injection of steam in the top of the boiler over the stock. The
stock is now steamed again under high pressure indicated by from
seventy to two hundred pounds by steam gauge, and hot water also
injected at the temperature corresponding to those pressures to which
treatment and which the charge is kept fifteen or twenty minutes, and
then drawn out or blown out into a proper receiving tank drained and
washed by percolation, and assumes the condition of good grey pulp
ready for bleaching by any of the ordinary known methods. The stock
in a cleansed state at this stage of process, prior to its discharge from
the boiler, may be again subjected to percolation by steam and hot
water, so as to remove a great part of that extraneous matter liberated
by the last steaming and hot water treatment, and a solution of weak
chloride of soda, less than 1º Baumé admitted to the boiler which is
raised to a temperature of 300° for ten or fifteen minutes and the stock
then blown out. This greatly improves the color of the stock.
The alkali drained off from the boiler is reserved and replenished for
future use, that is, one-sixth of its original quantity is discarded and
set aside for the recovery furnace, and the quantity by measure at
a strength of from 10° to 12° Baumé for wood, and of the straw
liquor the same quantity one-sixth is discarded and a fresh charge

page_text: or amount of one-sixth new liquor or caustic alkali is added at a
strength of 6° to 8° Baumé or such strength as to maintain the proper
strength in the liquor, and this order is preserved of discarding one-
sixth of alkali used in every boiling and replacing the same with new
alkali. The waste or discarded alkali can be recovered in suitable
evaporating furnaces at a loss of from ten to fifteen per cent. for recovery
of said waste. The materials in the paper stock boiler in the alkaline
treatment may be heated by a coil through which the alkali circulates, to
which coil is attached in an elevated position a large alkali charging
drum, as shown in the Drawing which forms part of this Specification.
In the drum A the alkali is always heated by the coil B prior to charging
the boiler C containing the paper stock, and when the alkali is heated
to the desired temperature the stock boiler C is charged with it, sufficient
alkali remaining in the charging drum A to form a complete circulation
during the alkaline treatment. After the paper stock boiler C has been
sufficiently treated five-sixths of the alkali in use during this process is
returned to the alkali charging drum A. This may be conveniently
effected by steam admitted from the steam and hot water drum and one-
sixth new liquor added to it to form a fresh charge for next operation.
If weak alkaline solutions are employed the entire charge of alkali used
may be discarded and a fresh charge of the weaker solutions of alkali
admitted to charging drum for every subsequent operation. The first
steaming and hot water treatment may be dispensed with and good pulp
produced from straw and very finely reduced woods of non-resinous
character by simply boiling the same in solutions of caustic alkali of
strength indicated with the subsequent percolations and steaming, but
the removal of liquor at subsequent boilings must in such cases be
increased from two to threefold, as the interstitial matter not removed
by first steam and hot water process has to be overcome by extra amount
of caustic alkali,
Although I esteem the above entire and all the several novel parts
thereof more particularly valuable in the application to wood and straw,
I believe it may be used with much benefit on various other, and in
short, nearly or quite all paper material. The first portion of it, to wit,
the extraction of most of the interstitial matter by the alternate steam
and hot water treatment at high temperatures, I propose particularly to
employ in preparing paper stock from hemp, flax, and tow of either or

page_text: both. The resulting liquor which is drawn off at this first stage of the
process may be discharged at once or it may by proper treatment be
made to yeild a large part of its pyroligneous acid to be concentrated for
sale and use in other branches, of the arts. I propose to extract this
acid from the liquor after treating any material which yeilds it in
sufficient quantities; it is particularly important in treating wood.. I can
use carbonate of soda or other alkaline carbonates instead of caustic
alkalies. I term the material at each stage of the process paper stock.
I
propose to put it up in bales or other packages for shipment and sale in
this condition ready for the paper manufacturer to use. I believe it is
cleaner at every stage, takes sizing better, is easier to. bleach, and is
better prepared for the manufacture of either brown or white paper than
any stock at present prepared by any other known process..
Confining attention now to. the brown stock resulting from the first
process it will be observed that the shortness of the time and small
number of operations allow my stock to be produced more cheaply than
any before known having the same qualities.. This is a distinction and a
most important one commercially between my product and any others.
It differs also mechanically in the combination or aggregation of the
following qualities:-1st., it is brown or unbleached; 2nd., it is dull or
void of brilliancy; 3rd., it is soft or cottony; 4th., its fibres appear
under magnifying power almost perfect and unbroken as compared with
other stock.
I claim as my Invention in the pulping or preparation of paper stock
from wood, straw, cane, esparto grass, flax, flax tow, hemp, hemp
tow, jute, jute tow, Manilla rope or tow, and all analogous vegetable
substances,―
1st. The process of treating the material by a succession of stages,
pure steam, and water and steam at a high temperature being employed.
at one stage and caustic alkali at a lower temperature at another;
stage.
2nd. The percolation of steam downward through the mass of partially
treated fiber, so as to hasten the removal of the chemical as specified.
3rd. The triple treatment, first, with pure steam and water and steam
at about from one to two hundred pounds pressure per square inch;
second, with caustic alkali at twenty or thirty pounds per square
inch; and third, with steam or water again at or near its previous high

page_text: pressure; the several operations being combined and made to succeed
each other in the manner and for the purpose herein set forth.
4th. The process of treating wood and analogous material for making
pulp by steam and water alternately, substantially in the manner
described and for the purpose set forth.
5th. The process of treating the stock by high steam and hot water
prior to discharging the same out of the boiler so as to aid in perfectly
cleaning the fibers of all coloring matter.
6th. The production of pyroligneous acid by extracting it from material
used for paper stock by high steam and hot water treatment in the first
stage process as specified.
7th. The caustic alkali in weak solutions in the proportions of twenty
to twenty-five per cent. for wood pulp produced, and eight to ten per
cent. of straw pulp produced, either at low or high temperatures, when
used in connection with steam and hot water process.
8th. The process of treating wood or straw or analogous material in
caustic alkali under pressure as named as a first process and subsequent
treatment of the stock by steam and hot water as described.
9th. The process of treating wood or straw, &c., by steam and hot
water at a high temperature as described; then the process of treating
the stock in open vessels in caustic alkali as described, and the subse-
quent process of treating the same stock with hot water and steam as
described.
10th. The process of treating the stock with chloride of soda in the
manner and at the stage of the treatment herein set forth.
11th. The alkali heating and circulating coil B and alkali charging
drum A, arranged substantially as specified and for the purpose set
forth.
12th. The brown paper stock herein described made by the first
process, and having the several qualities and peculiarities herein described
put up in any convenient form for sale or use.
13th. The grey paper stock as produced from the brown by boiling
the same in alkaline solutions put up in any convenient form for sale

page_text: 14th. The bleached paper stock as produced from the brown by boiling
the same in alkaline solutions and treating it with any of the well-known
bleaching agents.
In testimony whereof, I, the said Samuel Armstrong Walsh, have
hereunto set my hand and seal, this Fourteenth day of December,
in the year of our Lord One thousand eight hundred and
seventy.
Witness,
SAMUEL ARMSTRONG WALSH. (L.S.)
THOMAS D. STETSON,
Patent Agent,
New York.