IMPROVEMENTS IN THE MANUFACTURE OF PAPER, MILLBOARD, AND OTHER SIMILAR SUBSTANCES
Year: 1846

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, CHARLES
COWAN, of Valley Field Mills, in the County of Edinburgh, in that part of
the United Kingdom of Great Britain and Ireland called Scotland, Paper
Manufacturer, 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-ninth day of January, in the ninth year of Her reign,
did, for Herself, Her heirs and successors, give and. grant unto me, the said
Charles Cowan, my, exors, admors, and assigns, Her especial licence, full power,.
sole privilege and authority, that I, the said Charles Cowan, my exors, admors,
and assigns, or such others as I, the said .Charles Cowan, my exors, admors,
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 expressed, should and
lawfully might make, use, exercise, and vend, within England, Wales, and
the Town of Berwick-upon-Tweed, the Invention of "IMPROVEMENTS IN THE
MANUFACTURE OF PAPER, MILLBOARD, AND OTHER SIMILAR SUBSTANCES," partly of
my own Invention, and partly communicated to me from abroad; in which
said Letters Patent is contained a proviso that I, said Charles Cowan, shall
cause a particular description of the nature of the said Invention, and in what
manner the same is to be performed, to be inrolled in Her said 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.

page_text: NOW KNOW YE, that in compliance with the said proviso, I, the said
Charles Cowan, do hereby declare that the nature of the said Invention,
and the manner of carrying the same into effect, are particularly described
and ascertained in and by the following statement thereof, reference being
had to the Drawings hereunto annexed, and to the figures and letters marked
thereon (that is to say):-
Drawing I. represents a side elevation and an end view of my regulator,
the end view representing it as if the side or end of the chest. had been
removed.
Drawing 2 represents a view of the paper. machine wire cloth, to explain
my plan for a new description of deckles.
Drawing III. contains a side elevation and a top view of apparatus for
giving marks or impressions to paper.
In the first place I will describe the improvement in what I term the regu-
lator (see Drawing I.), the object of which is to supply an uniform quantity of
pulp to the wire cloth according to the thickness of the paper which it is
desired to make, and depending in part upon the speed of the machine.
This
In Drawing I., Figures 1 and 2, is shewn the regulator. (a) is a box
or cistern to contain stuff. This box is placed as near as convenient to the
usual stuff chest or chests; and in the said box the stuff is preserved at an
clevation a little lower than the bottom of the said stuff chest, in order that
the stuff may flow by its own gravity therefrom by the pipe (b). In the orifice
of this pipe (b), which I recommend to be bent as shewn in Figure (1), I apply
a conical valve (c), which when closed prevents the stuff from passing.
valve is attached to a spindle (d), which moves in two guides, and is connected,
as shown in Figure 2, to a lever (e), the extremity of which is connected with
the spindle of a float (f) moving also in two guides. The other end of the
lever is loaded by a balance weight (g). In place of the conical valve
the usual ball cock and float, which is well understood, might be applied. (h)
is a driving pulley on the crank axle (i), the driving pulley having a counter-
poise () placed opposite to the crank for the purpose of equalizing the weight
on the axis (i). To the crank (i) is attached a rod (1), which terminates in
two arms (m) connected with two levers (n), one end of these levers is secured
by studs to blocks (o), which rest upon the fixed framing of the apparatus. A
bucket or cup (p) is attached to a framing (2), which is connected with the
other extremities of the levers (n) by means of studs (r), motion being thereby
given to the said bucket. One of the sides of the bucket consists of a slide (s)
moving in grooves, and connected with an adjusting screw and handle (t), by
which the slide is moved up or down at pleasure in order that the capacity

page_text: of the bucket may easily be increased or diminished; (u, u,) are two pulleys
attached to the moving framing (q), which pulleys move in guides (v) in such
manner that the bucket is made to rise in a perpendicular direction for about
the first half of its motion upwards, it afterwards takes an inclined position,
and when the crank (i) has reached its upper point the bucket (p) will take
the position (indicated by dotted lines in Figure 1); the position of the lever in
this case being also shewn by a dotted line: the contents of the bucket then
flow out by a shoot or channel (w) either directly into the strainer, or into
the ordinary scoop wheel or box, to be there raised and mixed with the water
in the usual way.
As soon as it is desired to set the paper machine to
work, the workman in charge opens a cock on the pipe (b), which cock, in.
addition to the valve above referred to, I consider it desirable to retain accord-
ing to the usual practice, so as to shut off more completely the stuff while the
machine is stopped. The opening of this cock will allow the stuff to enter and
fill the stuff vessel (a); the level in the latter will always be kept at about
the same height by means of the above-mentioned conical valve and float, or
by means of the ball cock, as the case may be. When the machine is set in
motion the revolutions of the crank axle (i) move the bucket alternately
up and down. When at its lowest point, the bucket being below the level of
the stuff, raises the quantity contained below the top of the slide, according
as the slide (s) has been adjusted by the screw (t) above described. When the
crank (i) has reached its upper point, the contents of the bucket flow out, as
above mentioned, for the supply of the machine. There is a scale engraved
on one of the grooves of the slide which will be found a practical convenience
for noting the quantity of stuff required for the different breadths and thick-
nesses of paper which have been or may be required to be made, care being
taken to preserve the stuff from the engines as nearly as possible at the
same degree of consistency or dilution, and to maintain a sufficient agitation
of the stuff in the chest, as is well understood and practised in paper
manufactories.
Secondly, my improvements consist in a mode of constructing deckles which
are motionless when the machine is at work, and which I believe will be
found equally efficient with the travelling deckles now employed. and are
applied at less expense of construction. (See Drawing II.) Two square
bars (a), as shewn in Figure 1, are secured to the side framing of the machine;
these bars I prefer to make of brass, and to them are fastened the deckles (b),
which are constructed as follows:-A thin plate of brass (c) (Figures 2 and 3),
is provided, and bent in a rectangular position, so that its lower extremity
reaches to about one quarter of an inch from the wire cloth. An iron plate (d)

page_text: is secured by small screws to the brass plate (c), and between these, two plates
is interposed a strip, which I prefer to be of thin calf leather or waterproof
cloth, or other flexible substance; this strip is half an inch broader or deeper
than the bent side of the plate (c), and rests in this position upon the wire.
This strip prevents the spreading of the stuff over the whole surface of the
wire, and thus fixes the breadth of the sheet or web. I prefer that the deckles
should be fitted so as to move easily even when the machine is at work along
the brass bars (a) above mentioned, and being fastened. at pleasure by moving
the pinching screws, as shewn. This enables the width of paper pulp to be
changed at pleasure, without the necessity of stopping the machine. And for
this purpose it will be found convenient to have the brass bars (a) graduated
in inches and eighths of inches; and it is desirable that the square bars (a)
which support the deckles should rest on the side framing in such a manner
that they can be raised or depressed (to the extent of one quarter of an inch
in height will generally be sufficient), so that the lower edge of the bent part
of the plate (c) can be removed from or towards the wire according to the
nature of the stuff employed, and other circumstances, which the practical
paper maker is well able to judge of.
Thirdly, my Invention consists of a mode of making millboard, and similar
substances, by repeatedly applying fresh surfaces of green or uncouched paper
to the surface of previously made yet damp paper. And in order to accom-
plish this part of my Invention, I, in the first place, cause to be made a length
of paper equal to the length of millboard or similar substance which I
desire to make, and I receive it on to a suitable reel, and in place of having
it dried I place the reel in such a position that it may be in front of or other-
wise conveniently situated for the couching rollers; and I conduct the paper
so previously made through between the couching rollers, together with a fresh
surface of pulp or green paper not couched, and receive such conjoined
.surfaces of paper on to a suitable reel, and the two surfaces of paper, owing to
one of them not having being couched, will by the couching process be so
pressed together that they will adhere and become one sheet. again bring
the reel into a position in front of the couching rollers, and conduct one end
between the couching rollers, together with a fresh sheet or surface of pulp
or green uncouched paper; the two will pass between the couching rollers
together, and will thus be made to adhere,, and the conjoined sheet is again to
be received on a reel, and the reel again brought in front of the couching
rollers, and the combined sheet will again receive another sheet of green or
uncouched paper on the surface, and pass with it between the couching rollers.
And it is the repetition of the couching process three, four, or more times,

page_text: increasing the thickness of the millboard or such like substance by the
addition of a fresh layer of pulp or green uncouched paper which constitutes
the peculiar character of this part of the Invention. I would however remark,
that I do not claim the laying together of several surfaces of fresh made paper
generally, as that has before been done in making millboard and buttonboard
when hand moulds are used; this part of my Invention being confined to
machine-made paper where couching rollers are employed, and where any
desired length of paper, and consequently millboard, may be made; and I am
aware that two layers of machine-made paper have been united by pressing
by the couching rollers, but such process has not been extended to repeated
couchings with three, four, or more additions of green paper as herein described,
so as to produce a thickness of mill or other similar board.
Fourthly, my Invention consists of a mode of separating the water from.and
afterwards bleaching the half stuff, and this I do as follows:-In place of
employing the presses heretofore used for such purposes, the half stuff, which
I recommend to be rubbed out or macerated, or rendered shorter than is
generally the case, is caused to flow either from the washing and breaking-in
engine direct, or, what I prefer (if the situation conveniently admits of it),.
from a reservoir or stuff chest upon an endless wire cloth (say, of No. 18 or 20),
which wire cloth is put in motion and supported in a similar manner to the
wire cloth of a paper machine. The half stuff being received and carried
on the wire cloth passes through two pressing rollers, and the water is thereby
pressed out; I recommend the layer of half stuff to be about the thick-
ness of ordinary pasteboard. The half stuff by this mode of treatment will be
found to be in a better condition for the process of bleaching, and the water
more fully expressed from it than by the presses or in the boxes heretofore
used. After the pulp is passed through the pressing rollers above mentioned,
I then pass it through a solution of chloride of lime, or through a pair of
rollers which I term the bleaching rollers, one of which dips in a vessel
containing such solution, so as to convey an adequate supply of the chloride of
lime to the paper stuff. The excess of such solution is expressed from the
stuff by the bleaching rollers at their point of contact, and flows or trickles
down to the trough or vessel containing the solution of the chloride of lime, in
place of being in a great measure lost by the methods previously employed.
I make such rollers of hard wood, and covered with thin sheet lead, though
this covering may be dispensed with. Iron must be avoided where they come
in contact with the solution of the chloride. The strength of the solution of
the bleaching agent must, as heretofore, be judged of by the quality of the

page_text: stuff to be bleached. When desired, as it sometimes is when coarse fibrous
materials are used, a diluted solution of sulphuric acid is to be employed, and
I consider the best mode of doing this is to have a different and separate trough
or vessel with rollers, which I term the souring apparatus, and which is similar
in its construction to that of the bleaching trough and rollers. The web or
pulp of half stuff is made to pass through a solution of sulphuric acid diluted
and thoroughly inixed with about twenty-five times its own measure of cold
water. I may remark that these operations of expressing the water from the
half stuff, and passing the latter through the chloride, and afterwards through
the souring, may be all performed continuously, or the web of half stuff
may be reeled between the separate processes, if more convenient. It is
desirable that the pulp should be passed round a drying cylinder and rendered
partially dry, though not thoroughly so, and that it should enter the solution
of chloride warm, or that the latter should be kept about the temperature
of one hundred and twenty Fahrenheit. If bleaching by gas is to be
applied, the stuff is taken from the passing rollers and either wound on
a reel or allowed to fall into a box or vessel as may be most convenient,
and thence transferred to the gassing chests. By this plan the "opening" of
the stuff, as at present performed, and which cannot easily be done with
perfect regularity. is rendered unnecessary. After the paper stuff has
passed through the bleaching or souring apparatus, or after it has been gas-
bleached, as the case may be, it ought to remain until the desired whiteness
or the maximum degree of whiteness has been reached; after which it is
conveyed to the washing engine, or to rollers revolving in a flow of clear
water, as may be preferred, in order that the chloride may be washed out of
the pulp.
Fifthly, my Invention consists of a new method of impressing marks or
devices upon paper, so that, in looking through the paper to the light, they
shall assume somewhat of the appearance of a water mark. See Drawing III.
In Figure 1. (a) is the framing of the paper machine. (b) is an accurately
turned metal cylinder. Any of the drying cylinders will suffice, but I prefer
the first or second as best fitted to impress the marks, as will be explained.
(c) is an iron spindle, accurately turned. of which the ends are placed in
bearings carried by the two levers (d, d). To this spindle are secured any
desired number of brass rollers (e, e, e,) by wedges or otherwise, which
rollers are easily moved upon and fixed on any part of the spindle where they
may be desired to give the impression. These rollers are not perfectly circular,
but, as the Drawing shews, a portion of the circumference of each is removed,

page_text: and forms a plane. On the circular portion of the surface the marks or devices
are made. The two levers (d) loaded with weights press the rollers on the
drying cylinder. (f) is a screw through each of the levers (d), resting
on the framing (a). These screws have such a position as to allow the pressure
to be given to the rollers, but prevent the falling down of the spindle (c) when
the flat portion of the roller comes opposite the drying cylinder. (g) is a small
pulley connected by a strap or band to any convenient pulley or motion, so
that the speed of the rollers (e, e, e,) when in motion shall be the same as that.
of the drying cylinder. (h) is an arm fixed on the spindle. (i) is a starting
and stopping bolt, resting in two guides, which stops at pleasure the motion of
the spindle (b) by means of the arm (h). produce the marks or impressions
on the paper by forming on the rollers a projected or raised surface of the
form of such intended marks or impressions, or by type or other convenient
means. The distance between the successive impressions (so as to correspond
to the different sizes of paper) is regulated by the sliding bolt (i), which is to be
withdrawn and immediately returned every time an impression is to be given,
and, therefore, the more often these impressions take place during one revolu-
tion of the drying cylinder, the less distance will the impressions be apart:
and the sheets into which the paper will be allowed to be cut up will be of
the smallest size, and so on, according as it is desired that the sheets should
be larger and longer.
Having thus described the nature of the Invention, and the manner in
which the same is to be performed, I would remark that I have not thought
it necessary to describe or to shew the whole of the paper-making machinery,
as the same is well understood; and 1 would state that I do not confine myself
to the details herein described, so long as the peculiar character of either part
of the Invention be retained. But what I claim is.-
First, the mode of arranging mechanical apparatus into a regulator working
by means of a bucket, as described.
Secondly, I claim the mode of constructing deckles, by which they are
rendered fixed or motionless when the machine is in action.
Thirdly, I claim the mode of manufacturing millboard, buttonboard, or such
like substances, by adding three, four, or more layers of fresh or green uncouched
paper, by repeating the process of couching, as herein described.
Fourthly, I claim the mode of separating water from half stuff before.
bleaching, and of applying bleaching and souring liquor, and expressing the
same, as above described.
And, fifthly, I claim the mode of marking paper at intervals, by means of

page_text: rollers, acting at proper times, depending on the sizes of the intended sheets
of paper.
In witness whereof, I, the said Charles Cowan, have hereunto set my
hand and seal, this Twenty-first day of July, in the year of our Lord
One thousand eight hundred and forty-six.
AND BE IT REMEMBERED, that on the Twenty-first day of July, in
the year of our Lord 1846, the aforesaid Charles Cowan came before our
said Lady the Queen in Her Chancery, and acknowledged the Specifica-
tion aforesaid, and all and every thing therein contained and specified,
in form above written. And also the Specification aforesaid was stamped
according to the tenor of the Statute made for that purpose.