IMPROVEMENTS IN THE MANUFACTURE OF PAPER FROM STRAW AND OTHER ANALOGOUS VEGETABLE FIBROUS SUBSTANCES
Year: 1864

page_text: PROVISIONAL SPECIFICATION left by John Piddington at the Office
of the Commissioners of Patents, with his Petition, on the 25th
January 1864. A communication from abroad by Augustus Heury
Tait, of Jersey City, in the County of Hudson and State of New Jersey,
William Henry Holbrook, of the City and County and State of New
York, and Asahel Knowlton Eaton, of the City of Brooklyn and County
of Kings, America.
I, JOHN PIDDINGTON, of No. 53, Gracechurch Street, in the City of London,
do hereby declare the nature of the said Invention for "IMPROVEMENTS IN
THE MANUFACTURE OF PAPER FROM STRAW AND OTHER ANALOGOUS VEGETABLE
FIBROUS SUBSTANCES," communicated to me from abroad by Augustus Henry
Tait, of Jersey City, in the County of Hudson and State of New Jersey,
William Henry Holbrook, of the City and County and State of New York,
and Asahel Knowlton Eaton, of the City of Brooklyn and County of Kings,
America, to be as follows:-
This Invention consists in subjecting straw and other analogous substances
to a grinding process while in a dry state, and afterwards operating thereon
with weak alkaline, weak acid, and weak chlorine solutions as follows:-
First, the straw or other substance is first cut into short lengths.
Second, the cut straw is then subjected to the action of a burr-stone or
other grinding action, the object of which is to economize the use of chemicals
and shorten the period of boiling by reducing to powder, or nearly so, a large
percentage of silica and other matters, which it would be necessary otherwise
to dissolve out of the straw by such dividing and splitting up the straw

page_text: lengthwise, and by grinding the knots and separating in the form of dust the
earthy matter contained in them, and when such foreign substances are not
capable of being removed by the next described operation of screening,
they are brought into a finely divided state, and are readily acted upon by the
chemicals.
Third, the ground straw is then passed through a winnowing machine or
through sieves or screens in order to separate from it the finely ground particles
of silica and other earthy matters.
Fourth, after which the straw is placed in a vessel containing cold water,
and provided with fire or steam heat (the latter being preferred), and the heat
gradually raised to boiling point, the object of this operation being to discharge
as much of the colouring matter of the straw as is soluble in water.
should be taken not to raise the heat of the mass too rapidly.
Care
Fifth, the next operation is to drain off the coloured water and add a solu-
tion of caustic soda of the strength of 1° Baumé, or caustic potash of
equivalent strength in the proportion of 70 gallons of the solution to 100
pounds of the dry straw, and boil the whole from 5 to 6 hours. After the
boiling is complete the straw is washed thoroughly with hot water to remove
as much as possible of the alkali therefrom.
Sixth, after this cover the straw with a weak solution of muriatic or
sulphuric acid of the strength of 1 gallon of commercial acid with 30 gallons
of water, boil for about two hours, and then drain off the liquor without
washing.
Seventh, next pour into the stock a solution of chloride of lime consisting
of the spent solution used in a previous final bleach, and let it remain for
from 12 to 18 hours, setting free the chlorine from time to time by the
addition of portions of the acid solution above described, taking care that
sufficient acid has been used during the operation to set free all the chlorine
gas, then run off the liquor and wash well with hot water.
Eighth, next boil the straw in a second solution of caustic soda of the
strength of 1° Baume, then proceed,―
Ninthly, to repeat the operation described in paragraph 6 above.
Tenth, next bleach the straw by the use of chloride of lime in the usual
manner.
Eleventh, I would here remark, that in the manufacture of straw paper by "
the above processes and by other known processes, and also in the manu-
facture of paper from wood, a large quantity of alkali is used, which, after
having exhausted its dissolving properties upon the vegetable and earthy
matters of the substance operated upon, thereby becomes charged with said

page_text: matters, and has hitherto been thrown away as unfit for use, thus occasioning
a waste which it is desirable to avoid. Now one of the objects of this
Invention is to recover the alkali after it has been used as above stated.
This object may be accomplished as follows, that is to say:-The solution
of soda after having been used for one or two hours becomes partially
charged with the dissolved particles of the straw or wood. It should
then be drawn off and passed through a filter consisting of alternate
layers of caustic lime and charcoal in a coarse powder. This will purify the
solution sufficiently to enable it to be used again and again. Still the gradual
accumulation of impurities which remain in spite of this treatment makes it
necessary finally to adopt a more perfect mode of purification. This
may be
effected by evaporating the liquor nearly to dryness, adding thereto spent
lime in the proportion of about 5 per cent. of the dried mass; this mass is
mixed well together and then made up in cakes or balls with charcoal dust,
sawdust, peat, or other finely divided organic matter that will serve as fuel.
These cakes of mixed matter by a little further drying become combustible,
and may be used as fuel for any purpose connected with the process.