IMPROVEMENTS IN THE MANUFACTURE OF PAPER PARCHMENT OR VEGETABLE PARCHMENT
Year: 1885

page_text: I, THOMAS RICHARD SHILLITO of 89 Chancery Lane in the County of Middlesex,
Engineer do hereby declare the nature of said invention for "IMPROVEMENTS IN
THE MANUFACTURE OF PAPER PARCHMENT OR VEGETABLE PARCHMENT, and in
what manner the same is to be performed a communication to me from abroad
by Carl Arnold of Stoitzheim in the German Empire, Engineer to be particularly
described and ascertained in and by the following statement:-
This invention has for object the manufacture of paper parchment or vegetable
parchment in such manner as to effect a saving in the quantity of sulphuric or
other acid (generally sulphuric acid) hitherto required for the process by the re-use
and recovery of the same after use.
In the manufacture of paper parchment or vegetable parchment as usually
conducted about two thirds of the quantity of acid used is lost after being once
used because it is carried off by the jet or sprinkling water in such a diluted state
as to render its further use unprofitable, and the paper under treatment is
sprinkled over and washed continuously during a certain time with always fresh
water, after it has passed out of the acid bath. This loss of acid is almost
completed avoided by means of the apparatus shewn in longitudinal section in the
accompanying drawing.
The paper to be manufactured into paper parchment or vegetable parchment is
drawn through the chest A supplied with a from 54 to 56 per cent sulphuric acid
and is then passed onwards over and under friction rollers into and through the
washing chest B out of which it is carried so as to pass under water jets, after
which it is wound on the roller a.
The process of this invention differs from the ordinary process in that whilst in
the ordinary process all the jet pipes deliver fresh water only for the purpose of
diluting and washing off the acid adhering to and contained in the paper, for the
purpose of this invention some of them only,-in the present case four, indicated
by & supply fresh water, and these come into operation only at the commencement
of the process of manufacture when they supply the collecting tank C of a pump,
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page_text: through a pipe (not shewn in the drawing) connecting the tank E with the tank C,.
so far with water that a pump may be set in motion for supplying temporarily the
cistern O with sufficient water to deliver jets from the pipes s, and again when the
water issuing from the jet pipes shall have taken up a considerable quantity of
acid in which case in order to effect a complete removal of the acid from the paper
under treatment the jet pipes s¹ are caused to deliver water to a small extent, the
solution thus produced passing into the tank E and destined for the supply of the
cistern over again when the solution of acid and water making the circuit of
the apparatus, and resulting from the previous working shall have become strong
enough that is to say when it shall contain from 18 to 20 per cent of acid to allow
of its being drawn off from the cistern O or other part of the apparatus for further
concentration to the end that it may be conducted into the trough or chest A and
used in the manufacturing part of the process. The chest B is kept surrounded
with cold water as shewn in the drawing for the purpose of cooling down the
liquid contained therein which keeps on becoming more and more saturated
with acid.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that what
I claim is
1. In the manufacture of paper parchment or vegetable parchment the method
of washing out the acid from the material under treatment by the repeated use of
the same acidulated water until its degree of concentration has reached a certain
point, for the purpose of the more advantageous recovery of the acid, substantially
as described and illustrated.
2. In the manufacture of paper parchment or vegetable parchment, the arrange-
ment consisting of the chest B which is cooled by fresh water and from which the
acidulated water is continuously removed at that part of its bulk where it is least
saturated with acid and conducted to the jet pipes for the purpose specified
substantially as described and illustrated.