AN IMPROVED METHOD OF PREPARING VEGE- TABLE GELATINE OR SIZE FOR PAPER, AND ALSO AN IMPROVED MODE OF APPLYING THE SAME IN THE MANUFACTURE OF PAPER
Year: 1842

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, THOMAS
MIDDLETON, of Loman Street, in the Borough of Southwark and County of
Surrey, Engineer, send greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Royal Letters Patent under the Great Seal of Great Britain, bearing date at
Westminster, the Twenty-third day of May, in the fifth year of Her reign, did,
for Herself, Her heirs and successors, give and grant unto me, the said
Thomas Middleton, Her especial license, full power, sole privilege and
authority, that I, the said Thomas Middleton, my executors, administrators,
and assigns, and such others as I, the said Thomas Middleton, my executors,
administrators, or assigns, should at any time agree with, and no others, from
time to time and at all times during the term of years therein mentioned,
should and lawfully might make, use, exercise, and vend, within England,
Wales, the Town of Berwick-upon-Tweed, and in all Her Majesty's Colonies
and Plantations abroad, and in the Islands of Jersey, Guernsey, Alderney,
Sark, and Man, an Invention of "AN IMPROVED METHOD OF PREPARING VEGE-
TABLE GELATINE OR SIZE FOR PAPER, AND ALSO AN IMPROVED MODE OF APPLYING
THE SAME IN THE MANUFACTURE OF PAPER," being a communication from a
foreigner residing abroad; in which said Letters Patent is contained a proviso
obliging me, the said Thomas Middleton, by an instrument in writing under
my hand and seal, particularly to describe and ascertain the nature of the said
Invention, and in what manner the same is to be performed, and to cause

page_text: the same to be inrolled in Her Majesty's High Court of Chancery within six
calendar months next and immediately after the date of the said in part recited
Letters Patent, as in and by the same, reference being thereunto had, will more
fully and at large appear.
NOW KNOW YE, that in compliance with the said proviso, I, the said
Thomas Middleton, do hereby declare that the nature of the said Invention,
and the manner in which the same is to be performed, are particularly
described and ascertained in and by the following description thereof, reference
being had to the Drawings hereunto annexed, and to the letters and figures
marked thereon (that is to say):-
According to the methods now employed by paper manufacturers for sizing
paper, many difficulties and inconveniences arise, which cannot be entirely
removed, even with the assistance of the most extensive practice and ex-
perience. Now, the object of this Invention is to obviate or ameliorate as far
as possible any evils or difficulties that occur in vat sizing, and render this
operation more certain and effective.
The Invention is divided into two parts, and consists, first, in a new mode
of preparing vegetable gelatine or size for sizing paper or paper pulp; and,
second, in an improved mode and apparatus by means of which the sizing
operation may be performed or the size applied to paper or paper pulp so as
to obtain the exact result that is required, and with any quantity of pulp. The
sizing operation also may, when performed by this apparatus, be stopped
without arresting the progress of the paper machine, and be resumed at
pleasure.
I will first of all describe the improved method of preparing the size, and
in order to explain the process will take the ingredients usually employed for
this purpose, viz³, resin, soda, or potassa and alum; but I do not intend to
confine myself to these ingredients, as others may be introduced which would
produce the desired effect. Instead of dissolving the resin in potash lye under
the action of a strong and steady fire, so as to obtain a brown oily product,
which is put into cylinders, and the potass neutralized by alum, in order that
the latter may act upon the size, the Inventor proposes to proceed in the
following manner :-In a boiler or vessel heated by steam, I introduce in
proper proportions, according to the required strength of the size or the quality
of paper to be sized, pulverized resin, say, for example, fifty pounds weight of
resin for one hundred pounds weight of water, together with a proper quantity
of soda or potassa. If the lye when cold marks ten degrees Beaume's aerometer,
the quantities will be correct. When the potassa or soda lye is in a boiling state,
the resin in a pulverized state must be added, gradually taking care to stir and

page_text: mix the whole well together. From five to ten minutes are sufficient, according
to the heat of the steam, to effect this object, which is finished when the resin
is in a malleable state.
If the resin continues brittle, it will be necessary to
continue the stirring operation five or ten minutes longer, in order to make the
alkaline lye act upon the resin so as to soften it. Then, after having allowed
the bath to cool, the alkaline lye is to be drawn off or extracted from the
boiler in any convenient manner, and a resinous product will be found at the
bottom of the boiler. This preparation or partial solution of the resin partakes
somewhat of the character of a white resinous soap, and it only remains to
dissolve it entirely in order to make it into size of the proper strength and
quantity for mixing with the paper pulp. This is effected by dissolving this
product in boiling water in the proportion of one pound of the resinous
preparation to eight pounds of boiling water. The result of this will be a
milky solution, the impurities of the resin falling to the bottom of the vessel.
Then a proper quantity of alum is introduced; the proportion will be ascer-
tained by practice, and by the analogy which the improved process bears to the
ordinary ones. The introduction of the alum will produce white flakes, which
indicate that the size is ready for use. The size thus prepared will contain
only the proper quantity of potassa which the resin has absorbed, and which is
necessary to dissolve the resin; and in this state it is ready to be mixed
with the pulp, either in the ordinary manner or by the means herein-after-
described.
I will here remark, that by proceeding in the manner above described, the
proper description and quality of size may always be obtained, because the
employment of the soda or potassa, the treatment of the resin, and the action
of the alum, will always take place in the same manner, and is always subject
to the same rules; whilst the irregular manipulations which cannot be avoided
in the ordinary processes, where it is almost impossible to know the real and
respective quantities of water and of pulp in the cylinders, and thus the proper
employment of the alum, and also the alkaline lye and the resin in proportion
to the pulp, cannot be calculated upon when there is no certain standard to
ascertain their effect and action; and lastly, the alum, instead of being employed
as in the old process to act first upon the potassa or soda to neutralize it,
and then upon the resin to produce the flakes, is in the improved process only
employed for one object, and that is, to act directly upon the resin as the
potassa exists in such a small proportion only as not to be able to injure either
the paper or the size.
The second part of the Invention relates to the apparatus by which the
admixture of size with the pulp is intended to be effected, whether the size

page_text: used be made in the manner above described, or by any of the known processes
already in use. The admixture takes place away from the cylinders, so that
many serious inconveniences are obviated. This improvement consists in
introducing the size, properly prepared and ready for use, into a separate
reservoir, from which it flows through a cock furnished with a regulator or
governor, by means of which the pulp may be sized to any degree required.
The size flows from its reservoir into a sort of vat, into which the pulp is also
introduced, where it is submitted to a final stamping or beating, which serves
also to mix the size with the pulp.
In the Drawing accompanying this Specification I have shewn two views
of an apparatus intended to carry out the second part of the Invention, viz,
applying the size to the paper or paper pulp. Fig. 1 represents a partial
section of the apparatus, and Fig. 2 a plan view thereof. The vessel con-
taining the size is mounted at one end of the sizing vat, as at a, a, and is
furnished internally with a ball b, which by its rod is connected to the cock
of a reservoir not seen in the Drawing, and thereby regulates the quantity of
size in the vessel a, and always maintains it at the same level. The vessel a
is also furnished with a cock c, through which the size flows from the vessel a
into the sizing vat. In order that the quantity of size that flows through the
cock c may be properly regulated at pleasure, it is furnished with an index
and graduated index plate d, so that by turning the handle e the index will
point to a certain figure on the index plate, and the proper quantity be
thereby regulated. A revolving beater or wheel f, furnished with teeth, is
mounted in the sizing vat on the main shaft g, g, which revolves in suitable
bearings. Immediately below the wheel f, a number of rows of teeth are
arranged in a vertical position, so that when the wheel f revolves, it may carry
the pulp against the rows of teeth, and tear, beat, or separate the fibres
thereof. The pulp enters the sizing vat at h, and, passing round the machine
in the direction of the arrows, passes under the beater f, and becomes mixed
with the size which flows from the cock c; then the pulp, continuing its
progress, eventually escapes at i into a box or receptacle below, from whence it
flows into the paper-making machine. One great advantage in this mode of
applying size to paper is, that the pulp is brought from the reservoir in an
unsized state, and sized in the vessel above mentioned to any required degree,
with great exactness, before it enters the paper-making machine. The
quantity of size mixed with the pulp may be increased or diminished, or
altogether stopped, if desired, merely by turning the cock c.
Having now described the Invention that has been communicated to me,
and the manner of carrying the same into effect, it is scarcely necessary to say,

page_text: that the process for making the size may be in some degree varied, and yet
produce the same result. I do not, therefore, confine myself precisely to the
maner above described for making paper size, and I do not claim the
exclusive use of the materials employed in such manufacture, as they have been
heretofore employed for a like purpose; but I claim as the Invention secured
to me by the hercin-before in part recited Letters Patent, first, producing
paper size by causing the resin or other equivalent ingredient to absorb as
much alkali as is required, then drawing off the superfluous alkali, and treat-
ing the product with alum or other suitable materials, whereby a good paper
size is obtained with just the proper proportions of the several ingredients;
and, secondly, I claim sizing the paper or paper pulp either with the improved
size or ordinary size in a separate vessel, into which both the size and the pulp
are brought separately, and mixed in any proportions, which may be easily
regulated, and from which vessel the paper pulp sized to the degree required
flows into the paper-making machine, as above described.
In witness whereof, I, the said Thomas Middleton, have hereunto set my
hand and seal, this Twenty-second day of November, in the year of our
Lord One thousand eight hundred and forty-two.