Improvements in Machines for Making Millboard or Pasteboard from Wood-pulp.
Year: 1893

page_text: Date of Application, 22nd Nov., 1893-Accepted, 23rd Dec., 1893
COMPLETE SPECIFICATION.
Improvements in Machines for Making Millboard or Pasteboard from
Wood-pulp.
I, DANIEL WESTAD, of Aamot, Modum, in the Kingdom of Norway, Engineer,
do hereby declare the nature of this invention 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 to machines for making millboard or pasteboard from wood-
pulp, whereby the construction of such machines is simplified and only about half
the length of felt used in existing machines is required.
In carrying out my invention instead of, as hitherto, allowing the felt carrying
the pulp from the making-cylinder to pass over the regulating rollers, the tightening
roller and frequently some guiding rollers before it passes onto the size roller or
pasteboard roller, the felt is caused to pass through the shortest possible distance
direct from the making cylinder to the pasteboard-roller upon which the pulp is in
the usual manuer left and finally cut up into sheets.
After the felt has left the pulp it is conducted over a press roller which also
serves as a guide-roller and over a combined tightening and spreading roller back
to the said press roller where it passes between this and another roller, whereby it
receives the necessary pressing, after which the felt is ready to pass to the making-
cylinder in order to carry a fresh mass of pulp to the pasteboard roller and
80 on.
From the following description and the accompanying drawings it will be seen
many of the usual guide-rollers are dispensed with and that the felt by a novel
combination and arrangement of the rollers is subjected to all the necessary
operations in a distance which only is about half that hitherto found necessary.
In the accompanying drawings,
Figure 1 is a front elevation of a machine for making millboard or pasteboard
from wood-pulp constructed according to my invention :
Figure 2 is a side elevation of the same; and,
Figure 3 is a side elevation of some of the rollers and felt illustrating a
modification in the arrangement of the same.
After the wood-pulp has been prepared in the usual manner it is placed in the
vat a whence it is raised by the making-cylinder b. c is the ordinary couching
roller revolving in bearings c¹ adjustable on the rod d pivotted to the frame of the
machine. e is the felt, fa guide-roller, and f the ordinary roller for leaving the
pulp on the pasteboard-roller g. The rollers and g are placed as close as possible
to the making-cylinder 6 and the couching roller c and it will be understood by
reference to the drawings that immediately after the pulp passes from the making-
cylinder onto the felt the latter conveys it a very short distance direct to the
roller g which is in contact with the felt on the roller f and onto which the pulp
passes from the felt e.
g are
The roller g has its bearing in the frame in such a manner that it always presses
the felt between itself and the roller f; this pressure is caused by a lever g¹ which
rests on the movable bearings in the frame in which the pivots of the roller
located. This pressure can be regulated according to the degree of moisture which
the pulp is required to have and the water pressed out is conducted away through
a pipe (not shewn in the drawings).
From the roller the felt passes to the press-roller / which also serves as a guide
roller and thence over the roller i which by means of a movable bearing regulated
by a screw allows of tightening the felt as it becomes slack. The spreading and
straightening of the felt are also effected by the same roller, and for this purpose

page_text: the roller is provided with spiral ribs running in opposite directions from the
middle of its length (as shewn in dotted lines in Figure 1) which ribs during
rotation stretch out the felt laterally. From the roller i the felt passes back
between the pair of rollers h, k and is in its passage acted upon by a fan and
sprinkled from a tube (not shewn on the drawings). Between the rollers h, k, where
the roller & then serves as a press-roller, the felt is pressed so that it passes in a dry
condition over the making-cylinder to take up the pulp and over the rollers
and thus again carrying a fresh supply of the pulp direct to the pasteboard-roller g
and so on.
In Figure 3 I have illustrated a modification in the course of the felt, the roller k
being here placed in front of the roller g and serving with the roller f¹ as a press-
.roller, but the pressing of the felt takes place (as in the arrangement hereinbefore
described) just before the felt passes onto the making-cylinder.
The advantages resulting from the hereinbefore described arrangement of the
rollers, over which the felt is carried and is subjected at the proper places to the
necessary regulating, straightening, tightening, spreading, cleaning and pressing,
will be obvious to anyone acquainted with this branch of industry.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is:-
1. In a machine for making millboard or pasteboard from wood-pulp the arrange-
ment of the rollers in such a manner that the felt, instead of passing through or
over regulating pressing and tightening rollers on its way from the making-cylinder
to the size or pasteboard roller, is simply conducted over a guide-roller direct to the
size-roller which is arranged close to the making cylinder for the purpose of
allowing of employing a felt of minimum length, substantially as hereinbefore
described.
2. In a machine for making millboard or pasteboard from wood-pulp the felt e
passing from the making-cylinder 6 over a roller c direct to the roller f where it
leaves the pulp on the size or pasteboard roller g and further passes over a tightening,
straightening and spreading roller and through a pair of press-rollers back to the
making-cylinder, substantially as set forth and illustrated in Figures 1 and 2 of the
accompanying drawings.
3. In a machine for making millboard or pasteboard from wood-pulp the guide-
roller arranged to serve as a combined press and guide-roller, substantially as
set forth and illustrated in Figures 1 and 2 of the accompanying drawings.
4. In a machine for making millboard or pasteboard from wood-pulp the modifi-
cation illustrated in Figure 3 of the drawings in which the press-roller k is
placed before the size or pasteboard roller g and serves in conjunction with
the guide-roller f¹ as a press-roller for the returning felt, substantially as set forth.
5. In a machine for making millboard or pasteboard from wood-pulp the use of a
combined tightening, spreading and straightening roller such as i substantially as
herein before described and illustrated in Figures 1 and 2 of the accompanying
drawings.
6. In a machine for making millboard or pasteboard from wood-pulp the arrange-
ment of the rollers, substantially as hereinbefore described and for the purpose set
forth.
7. The improved machine for making millboard or pasteboard from wood-pulp
hereinbefore described and illustrated in the accompanying drawings.
Dated this 22nd day of November 1893.
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicant.