IMPROVEMENTS IN PAPER OR MILLBOARD MAKING MACHINES TO EFFECT THE INTERLACING OF THE FIBRES
Year: 1884

page_text: I AUGUST LEHMANN of Colberg House, Yew Grove, Cricklewood in the County
of Middlesex paper manufacturer do hereby declare the nature of my Invention
for IMPROVEMENTS IN PAPER OR MILLBOARD MAKING MACHINES TO EFFECT THE
INTERLACING OF THE FIBRES, to be as follows:-
My invention relates particularly to cylinder machines for the manufacture of
paper and millboard, but it can also be employed with advantage for long wire
paper machines where the ordinary shaking apparatus is used.
In making paper or millboard by the Cylinder machine the diluted pulp is run
into a square vat in which the wire cylinder revolves; the pulp settles on, and is
lifted up by the latter in a thin layer which forms the sheet, and is taken off the
cylinder to a felt or wire cloth by means of the couch roll. The diluted pulp in
the vat is kept agitated, usually by two agitators, one in front and one at the
back of the cylinder, and consisting of a revolving shaft with two blades attached
across the whole breadth of the vat. By this arrangement the pulp can be well
agitated, but has the tendency of depositing its fibre on the cylinder longitudinally,
without properly interlacing, and in consequence paper made on this principle very
easily tears lengthways. This is the great drawback in making paper on ordinary
cylinder machines.
To obviate this I employ a number of agitators, consisting of a shaft with a
number of small fans of the form of the screw propellor attached to it at inter-
mediate distances. The fans are made half right and half left, and placed
alternately on the shaft (Fig 1 in the accompanying drawing), and in consequence
of this arrangement the fibre is stirred in oblique directions, crossing and inter-
lacing itself, and depositing a well felted layer on the cylinder. The angles of the
fans should be 45 degrees, and I consider the width of 1 inch, the length of
1/ inches, placed 1 inch apart the most suitable.
As the fibre adheres to the wire-gauze of the cylinder by hydrostatic pressure,
the water inside the cylinder being of a much lower level than the pulp in the
vat outside it, it is obvious that the formation of the sheet commences where the
cylinder enters the pulp and where the pressure begins.
It is therefore important that one of my fan agitators is placed here, 2 or 3
inches below the surface and 2 or 3 inches away from the cylinder, measured from
the ends of the fans next to the cylinder, in order to commence the settlement
of the fibre on the cylinder in an interlaced and well felted condition.

page_text: But, as the hydrostatic pressure of the diluted pulp against the cylinder is
partly or almost entirely released during the passage of the cylinder through that
portion of the pulp which is below the level of the water inside the cylinder, and
by which water a counter pressure is exercised, the result would be that the fibre
settled on the cylinder would get disturbed and partly straightened by friction
with the pulp in the vat.
To prevent this it is advisable to place my fan agitators about 6 inches apart
from the ends of the fans all round the immersed portion of the cylinder, 2 or 3
inches away from the latter, the last one to be 2 or 3 inches below the surface
where the cylinder leaves the pulp with the felted sheet (see Fig. 24 in the
accompanying drawing). It is preferable that all the agitators should rotate in
the opposite direction to that of the rotation of the cylinder, at the speed of
about 75 revolutions per minute, but the speed may be varied.
Though I consider the distances and sizes and arrangement of the fan agitators
as given above to give the best results, good results may be obtained by using one,
two, three or four of my fan agitators only, either alone, or in connection with the
usual agitators, and if only one is used it should be placed in front of the cylinder,
where the sheet leaves the pulp, 2 or 3 inches below the surface. If larger sizes of
fans are chosen the agitators must be placed farther away from the cylinder, and,
the fans must be farther apart from each other.
Instead of the form as in Fig. 1 of my drawing the fans might have a sharp
bend, or they might be straight and placed at an angle of 45 degrees with the line
of the shaft as in Fig. 3.
It is not necessary that the fans should all be in the sanie plain, they can be
arranged in different positions round the shaft. The angles need not be exactly
45 degrees, as the fibre will always deviate from the straight line according to the
inclination of the fans, but I strongly advise the degree of 45 as the most effective.
The shape of the fans may also be altered, and the fans instead of being placed
alternately right and left might be placed all in one direction, with, however,
inferior results.
For long wire machines one or more of my agitators can be placed in the vat
just before the pulp flows on to the wire. By this means the fibre is interlaced
before it settles on the wire, and the usual shaking apparatus can be dispensed
with, or can be used in addition to the agitators.
B
Explanation of drawings: Fig 14 is the side view and the plan of fan agitator
with fans of the ordinary shape of the screw propellor. Fig 24 is a cross section
of vat, a the position of the fan agitators round the cylinder c, i is the influx of
diluted pulp into the vat, p the level of the pulp in the vat, w the level of the
water in the cylinder extracted from the pulp, r the couch roll, and f the felt with
the sheet of pulp from the cylinder. The arrows show the direction of rotation of
cylinder, agitators, and couch roll. Fig. 2B is the plan of vat showing the cylinder
and the two top agitators. Fig. 2° is the side elevation of vat, showing tho
outside gearing of the agitators on a well known principle. Fig. 3 shows an
agitator with straight fans as herein mentioned.
Having set forth the nature of my said invention, and described the manner of
carrying it into effect, I wish it to be understood that I claim the use of agitators
acting on the principle of the screw propellor, thereby stirring the fibre in oblique
directions, and crossing the same by the alternate position of the right and left
fans, substantially as and for the purpose herein described.
Dated this eighth day of September, in the year of our Lord One thousand

page_text: I AUGUST LEHMANN of Colberg House, Yew Grove, Cricklewood in the County
of Middlesex paper manufacturer do hereby declare the nature of my Invention
for IMPROVEMENTS IN PAPER OR MILLBOARD MAKING MACHINES TO EFFECT THE
INTERLACING OF THE FIBRES and in what manner the same is to be performed,
to be particularly described and ascertained in and by the following statement :--
My invention relates particularly to cylinder machines for the manufacture of
paper or millboard but it can also be. employed with advantage for long wire paper
machines, where the ordinary shaking apparatus is used.
,
In making paper or millboard by the Cylinder machine the diluted pulp is run
into a square vat in which the wire cylinder revolves; the pulp settles on and is
lifted up by the latter in a thin layer, which forms the sheet and is taken off the
cylinder to a felt or wirecloth by means of the couch roll. The diluted pulp in the
vat is kept agitated usually by two agitators, one in front and one at the back of
the cylinder, and consisting of a revolving shaft with two blades attached across
the whole breadth of the vat. By this arrangement the pulp can be well agitated
but has the tendency of depositing its fibre on the cylinder longitudinally, without
properly interlacing, and in consequence paper made on this principle very easily
tears lengthways. This is the great drawback in making paper on ordinary
cylinder machines.
To obviate this I employ a number of agitators consisting each of a shaft with
a number of small fans of the form of the screw propellor attached to it. at
intermediate distances.
>
The fans are made half right and half left, and placed alternately on the shaft
(Fig. 1 in the accompanying drawing) and in consequence of this arrangement the
fibres are stirred in oblique directions crossing and interlacing themselves, and
depositing a well felted layer on the cylinder. The angles of the fans should be
45 degrees, and I consider the width of 1 inch, the length of 11 inches placed
1 inch apart the most suitable for pulp of a long fibre, but for fine pulp it is better
to employ smaller fans placed closer together.
As the fibre adheres to the wire gauze of the cylinder by hydrostatic pressure,
the water inside the cylinder being kept of a much lower level than the pulp in
the vat outside it, it is obvious that the formation of the sheet commences where
the cylinder enters the pulp and where the pressure begins. It is therefore
important that one of my agitators is placed here, from 1 to 3 inches below the
surface and from 1 to 3 inches away from the cylinder measured from the ends of
the fans next, to the cylinder, in order to commence the settlement of the fibre in
an interlaced condition.
But as the bydrostatic pressure of the diluted pulp against the cylinder is partly
or almost entirely released during the passage of the cylinder through that portion
of the pulp which is below the level of the water inside the cylinder, and by
which water a counter pressure is exercised the result would be that the fibre
settled on the cylinder would get disturbed and partly straightened by friction
with the pulp in the vat. To prevent this it is.advisable to place my fan agitators
about 6 inches apart from the ends of the fans all round the immersed portion of
the cylinder, from 1 to 3 inches away from the latter, the last one to be from 1 to

page_text: 3 inches below the surface where the cylinder leaves the pulp with the felted sheet
(see Fig. 2 in the accompanying drawing) It is preferable that all the agitators
should rotate in the opposite direction to that of the rotation of the cylinder, at
the speed of from 75 to 150 revolutions per minute, according to the size of the
fans and the nature of the pulp. The finer the pulp the greater should be the
speed of the agitators.
Though I consider the distances and sizes, and arrangement of the fan agitators
as given above to give the best results, good results may be obtained by using one,
two, three or four of my agitators only, either alone or in connection with the
ordinary agitators, and if only one is used it should be placed in front of the
cylinder where the sheet leaves the pulp, from 1 to 3 inches below the surface.
If larger sizes of fans are chosen the agitators might be placed farther away
from the cylinder, and the fans might be placed farther apart from each other.
Instead of the form as in Fig. 1 of my drawing the fans might have a sharp
bend, or they might be straight and placed at an angle of 45 degrees with the line
of the shaft as in Fig. 3.
It is not necessary that the fans should all be in the same plain; they can be
arranged in different positions round the shaft. The angles need not be 45 degrees
exactly, as the fibre will always deviate from the straight line according to the
inclination of the fans, but I strongly advise the degree of 45 as the most
effective.
The shape of the fans may also be altered, and the fans instead of being placed
alternately right and left might bo placed all in one direction, with, however,
inferior results.
For longwire machines one or more of my agitators can be placed in the vat just
before or where the pulp flows on to the wire web. By this means the fibre is
interlaced before it settles on the wire web, and the usual shaking apparatus can
be dispensed with, or can be used in addition to the agitators.
EXPLANATION OF DRAWINGS,
Fig 14 is the side view and the plan of fan agitator with fans of the
ordinary shape of the screw propellor. Fig. 24 is the cross section of cylinder
and vat, a the position of the fan agitators round the cylinder c, i is the influx of
diluted pulp into the vat, w the level of the water in the cylinder extracted from
the pulp, the couch roll, and f the felt with the sheet of pulp from the cylinder.
The arrows show the direction of rotation of cylinder, agitators and couch roll.
Fig 2 is the plan of vat showing the cylinder and the two top agitators. Fig 2°
is the side elevation of vat, showing the outside gearing of the agitators on the
well known principle of chain pulleys and chain. Fig 3 shows an agitator with
straight fans as herein mentioned.
Having set forth the nature of my said invention, and described the manner of
carrying it into effect, I wish it to be understood that I claim
The use of agitators acting on the principle of the screw propellor, thereby
stirring the fibre in oblique directions and crossing the same by the alternate
position of the right or left fans, or by any other arrangement of the fans
substantially as and for the purpose herein described.
Dated this eighth day of June in the year of our Lord One Thousand eight
hundred and eighty five