IMPROVEMENTS IN MACHINERY OR APPARATUS FOR THE MANUFACTURE OF PAPER
Year: 1869

page_text: LETTERS PATENT to Robert Craig, of Nowbattle Mills, near Dalkeith,
in the County of Mid Lothian, Scotland, for the Invention of
"IMPROVEMENTS IN MACHINERY OR APPARATUS FOR THE MANUFACTURE OF
PAPER."
Scaled the 6th April 1869, and dated the 16th January 1809.
PROVISIONAL SPECIFICATION left by the said Robert Craig at
the Office of the Commissioners of Patents, with his Petition, on
the 10th January 1860.
I, ROBERT CRAIG, of Newbattlo Mills, near Dalkeith, in the County
of Mid Lothian, Scotland, do hereby declare the nature of the said Inven-
tion for "IMPROVEMENTS IN MACHINERY OR APPARATUS FOR THE MANUFACTURE
OF PAPER," to be as follows:-
This Invention consists in the application to the paper-making
machino commonly now in uso of a roll or roller coated with vulcanite
and with vulcanized india-rubber, which I shall afterwards describe, and
which roll or roller is substituted by me for the ordinary roll of iron,
brass, or other metal under press roll of the said paper-making machine.
In the ordinary paper-making machino now in uso the pulp for
forming the material of the paper is projected in a very fluid state upon

page_text: an endless wire cloth, and is kept from overflowing at the sides by
endless bands (commonly termed deckle straps), and after having a
greater portion of the water sucked from it by capillary attraction and
the action of air pumps or otherwise, the said pulp passes between a pair
of rollers, called coutching rollers, which rollers are covered with a
woollen covering or jacket, and the upper of which rollers rests with its
own weight, or sometimes additional weights fastened on to it, upon the
under coutch roll which is immediately beneath it. The web of paper
having passed between the upper and under coutch rolls, as above
mentioned, passes between another pair of rollers, commonly called first:
press rolls, which rolls have an endless woollen cloth or felting of open
texture (technically called a wet felt) between the said web of and
paper
the surfaco of the under first press roll, for the purpose of expressing or
discharging the water contained in the paper.
The under press roll is made of iron or brass, as is commonly in use
at present, or it may be made of other metal or wood, but I prefer to
employ iron for this purpose. The said endless woollen cloth or felting,
pa si g between the under press roll and the upper press roll, carries the
web of paper with it between the said upper and under press rolls. In
so passing between the said press rolls the web of paper, as at present
manufactured, is thereby subjected to a considerable degree of pressure,
by which the substance of the paper is made thinner, and the natural
elasticity of the fibrous pulp of which the paper chiefly consists becomes
greatly impaired. The woollen cloth or felting also being subjected to
considerable pressure while passing in a damp state between the ordinary!
iron metal first press rollers, while carrying the moist web of paper as
above described, suffers great tear and wear from the attrition caused by
the hardness and unyielding character of the two metal rollers.
By the substitution of my said Invention of a composite under press
roll or rollers possessing a slight degree of elasticity the web of paper,
in being carried as aforesaid upon the endless woollen cloth or felting
between the said first press rolls, is subjected to less pressure than is
received by the ordinary pair of metal rolls, while at the same time a
sufficient pressure is given to effect the purposes for which the web of
paper is passed through the press rolls, viz., to express or discharge the
water still incorporated with the pulp to a degree sufficient to enable the
web of paper to be led round the drying cylinders of the paper-making
machine. From the slightly clastic and softer character of my under

page_text: press roll the natural elasticity of the web of paper is preserved, and the
fibrous substance of the web of paper not being crushed together, as in
the case of the ordinary metal first press rolls, permits the web of paper
in the succeeding process of drying upon cylinders to become more
bulky, and therefor more valuable than it can become by the ordinary
process, and thereby the character of paper so made by my process
becomes more akin to paper made by hand by the great increase of
body or bulkiness acquired by the freedom from the effects of the sovere
pressuro imposed in the case of the use of ordinary metal first press rolls;
as also the said endless woollen cloth or felting, from being subjected
to an clastic pressure, suffers very much less attrition or tear and wear
in passing over my substituted softer and elastic material of the under
press roll, and the action of the said felting is thoroby such that it goes
much longer without washing, and is not liable to cut by its creasing of
otherwise.
The material of which the said roll so substituted by me is composed
is as follows, viz., a metal roller of the ordinary size, shape, and dimen
sions at present in use has applied to it a first or inner coating of
vulcanite or half or semi-rubber, cured and hardened only to such an
extent or degree as to adhere or stick firmly to the said metal shell of
the rollers which it covers, and an outer covering or coating covering the
Baid coating immediately above described, composed of vulcanite, india-
rubber, or indin-rubber not so highly cured, and therefor of a softer
and more elastic character than the said inner coating first above men.
tioned. With rolls thus covered there is no tendency in the covering to
separate from the metal, and the rollers consequently are thereby much
better fitted to withstand the pressure which they receivo when in use.
Rollers thus covered may also be used as the under coutch roll, and even
for the other rolls of a paper-making machino.

page_text: 1
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Sixteenth day of January, in the year of
our Lord One thousand cight hundred and sixty-nine, in the thirty-
second year of Her reign, did, for Herself, Her heirs and successors; give
and grant unto me, the said Robert Craig, Her special license that I, the
said Robert Craig, my executors, administrators, and assigns, or such
others as I, the said Robert Craig, my executors, administrators, and
assigns, should at any time agree with, and no others, from time to timo
and at all times thereafter during the term therein expressed, should
and lawfully might make, use, exercise, and vend, within the United
Kingdom of Great Britain and Ireland, the Channel Islands, and 'Isle
of Man, an Invention for "IMPROVEMENTS IN MACHINERY OR APPARATUS FOR
THE MANUFACTURE OF PAPER," upon the condition (amongst others) that
I, the said Robert Craig, my executors or administrators, by an instru-
ment in writing under my, or their, or one of their hands and scals,
should particularly describe and ascertain the nature of the said Inven-
tion, and in what manner the same was to be performed, and cause
the same to be filed in the Great Seal Patent Office within six calendar
months next and immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said Robert Craig, do hereby declare a
the nature of the said Invention, and in what manner the same is
to be performed, to be particularly described and ascertained in and
by the following statement thereof, that is to say :-
This Invention consists in the application to paper-making machines
of a roll or roller coated with vulcanite and with vulcanized india-rubber, 2
which I shall afterwards describe, and which roll or roller is substituted
by me for the ordinary iron, brass, or other metal under press roll of the
said paper-making machine, and may be used as an under or upper
second press roller, as after.described.
In the paper-making machine now in use the pulp for forming the 3
material of the paper is projected in a fluid state upon an endless wire
cloth, and is kept.from overflowing at the sides by endless bands (com-
monly termed deckle straps) after having a greater portion of the water
sucked from it by capillary attraction and the action of air pumps or
otherwise. The said endless wire cloth carrying the moist pulp upon g
its upper surface passes between a pair of rollers called couch or
couching rollers, and the upper roller of which is usually made to press
upon the under roller by levers or screws. These couch rollers are

page_text: usually covered with a woollen jacket, and also are constructed of metal
in the case of the under and of wood in the case of the upper roller,
but it is quito immaterial for my purposo whether the coutch rolls are
clothed or not, or whether composed of wood, metal, or other suitable
substance. The web of paper having passed between the upper and
under couch rolls, as above mentioned, next passes between another
pair of rollers, commonly called first press rollers, which rollers have
an endless woollen cloth or felting of open texture (technically called a
"wet felt") between the said web of paper and the surface of the under
first press roll for the purpose of expressing or discharging the water
contained in the paper.
The under press roll is made of iron or brass, as commonly in use at
present, or it may be made of other metal or wood, but I prefer to
employ iron for this purpose, the said endless woollen cloth or felting
passing between the under press roller, and the upper press roller carries
the web of paper with it between the said upper and under press rollers.
In so passing between the said press rollers the web of paper, as at
present manufactured, is thereby subjected to considerable pressure, by
which the substance of the paper is made thinner, and the natural
elasticity of the fibrous pulp of which the paper chiefly consists becomes
greatly impaired. The woollen cloth or felting also being subjected to
considerable pressure while passing in a damp state between the ordinary
metal first press rollers carrying the moist web of paper, as above
described, suffers great tear and wear from the attrition caused by tho
hardness and unyielding character of the two metal rollers.
By the substitution of the said Invention of a composite under press
roller possessing a slight degree of elasticity the web of paper in being
carried as aforesaid upon the endless woollen cloth or felting between
the press rollers is subjected to a less pressure than is received by the
ordinary pair of metal rollers, while at the same time a sufficient pressure
is given to effect the purposes for which the web of paper is passed
through the press rollers, viz., to express or discharge the water still
remaining in the pulp to a degree sufficient to enable the web of paper
to bo led round the drying cylinders of the paper-making machine.
From the slightly elastic and softer character of my under press roller
the natural elasticity of the web of paper is preserved, and the fibrous
substance of the web of paper not being crushed together, as in the caso
of the ordinary metal first press rolls, permits the web of paper in the

page_text: succeeding process of drying upon cylinders to become more bulky, and
therefore more valuable than by the ordinary process, and thereby the
character of paper so made by my process thus becomes more akin
to paper made by hand by the great increase of body or bulkiness
acquired by the freedom from the effects of the severe pressure imposed !
in the case of the use of ordinary metal first press rollers; as also the
said endless woollen cloth or felting from being subjected to an elastic
pressure suffers very much less attrition or tear and wear in passing
over my substituted softer and elastic material of the under press roller,
and the action of the said felting is thereby such that it goes much
longer without washing, and is not liable to cut by its creasing or
otherwise.
In those paper-making machines in which a second set of press rollers
is employed I also substitute my composite rubber roller above described
in the place of the second under press roller, except in those machines in
which the second upper press roller serves to carry the wet felt, and which
has the wet felt between it and the paper. In this latter instance my
composite rubber roller will be applied to the second upper press roller, as
it thus performs functions similar to the first under press roller. The
materials of which the said roller so substituted by me is composed are as
follows, viz., a metal roller of the ordinary size, shape, and dimension
at present in use has applied to it a first or inner coating of vulcanite
cured and hardened only to such an extent or degree as to adhero or
stick firmly to the said metal shell (i.e., core) of the roller, which it
covers, and then an outer coating covering the said vulcanite coating
immediately above described, composed of vulcanized india-rubber or
india-rubber not so. highly cured, and therefore of a softer and more
elastic character than the said inner coating first above mentioned.
With rollers thus covered there is no tendency in the covering to
separate from the metal, and tho rollers consequently are thereby much
better fitted to withstand the pressure which they receive when in use,
and in consequence of the interposed coating of vulcanite are not liable
to strip.
Having thus described my said Invention, and what manner the
same is to be performed, I hereby declare that I do not claim as of my
Invention the use of rollers constructed as described, except as first
under press rollers in paper-making machines, and as second under or
upper press rollers, in manner and under the circumstances before
1

page_text: described, neither do I claim the use of press rollers covered with
india-rubber otherwise than in the manner described.
In witness whereof, I, the said Robert Craig, have hercunto set
my hand and scal, this Fourth day of May, in the year of our
Lord One thousand eight hundred and sixty-nino.