Improved Means for Supporting and Moving a Web of Paper or other Flexible Material for Coating, Drying, or other Purposes.
Year: 1895

page_text: Date of Application, 3rd Sept., 1895-Accepted, 30th Nov., 1895
COMPLETE SPECIFICATION.
Improved Means for Supporting and Moving a Web of Paper or
other Flexible Material for Coating, Drying, or other Purposes.
I, GEORGE JAMES BURNS, of Ayer, in the County of Middlesex and State of
Massachusetts, United States of America, Gentleman, 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 :-
This invention relates to a process in the manufacture of paper by which one
side or both sides of the web are coated with a composition of clay and other
ingredients which, by reason of coloring matter therein, gives to the surface of
the paper any desired color or tint, and when calendered imparts to the surface of
the paper a very high finish which enables it to take impressions from finely
engraved plates, and the like, paper thus prepared being generally used for
illustrated books, magazines, and the like. The coating composition is applied to
and evenly distributed in a plastic or semi-fluid condition upon the surface or
surfaces of the paper, usually while the web of paper is in motion, by suitable
applying and distributing devices. The coating composition has usually been
applied to one side of the paper at a time, while the paper is being carried or moved
upon a rubber apron or cylinder, or other suitable device, and the coating is dried
while the paper is suspended upon sticks or other devices that come in contact with
the dry side of the paper only. It is very desirable, for the sake of economy, to
apply the coating to and distribute it upon both sides of the paper (where both
sides are required to be coated) at one time, and many efforts have been made to
do this practically. In these efforts a serious difficulty has been heretofore
experienced in supporting the paper while being coated and in handling and
moving the web while the coating upon both sides is in a wet or sticky condition ;
for if before the coating is sufficiently dried the surface of the paper comes in
contact with any rigid or solid object, the coating is marred and permanently
marked. It is therefore necessary to move the web of paper through the coating
device under such a tension as will permit the brushes to uniformly apply and
distribute the coating, and to provide a means by which any given portion of the
web shall be caused to occupy such a length of time after leaving the coating
device until it comes in contact with any rigid or solid object that the coating will
have been so dried or hardened as not to be marred or marked by such contact.
My invention has for its object to provide a proper tension for the paper while
the coating material is being applied and distributed, and to provide for the
maximum length of web which may intervene between the coating and the drawing
appliance of a feeding device without coming in contact with any solid object or
support, and at the same time to expedite and secure a uniform drying or hardening
of said coating. To these ends, the invention consists in the combination with
means for supporting and progressively moving a web of paper, said means
including positive supports in contact with the web, of an intermediate pressure-
maintaining apparatus located at one side of a direct line between said supports
and comprising an air-forcing device and an air-guiding device arranged to apply a
deflecting air pressure to the web, whereby the freshly coated portion of the web
is deviated from a direct course and formed into a bight or loop supported and
kept under tension wholly by air pressure.
Of the accompanying drawings, forming a part of this Specification,-
Figure represents a diagrammatic elevation, showing an apparatus embodying

page_text: igure 2 represents a section on The 2-2 of Figure 1, and a pian view of
parts below said line.
Figure 3 represents a sectional view, showing a modification.
Figure 4 represents a side elevation of the said modification.
The same letters of reference indicate the same parts in all the figures.
In the drawings-
a represents a web of paper, the supply portion of which may be in the form of
a roll a from which the web is or may be drawn by a suitable drawing device or
mechanisın. Said drawing device may comprise one or more positively rotated
rolls b with which the web is in contact and by which it is moved progressively in
the direction indicated by the arrows in Figure 1. The web-coating device or
mechanism may be of any suitable character. For the sake of illustration, I have
here shown as the web-coating device two rotary brushes cc, each receiving the
coating composition from a reservoir c', the two brushes being arranged at opposite
sides of the web, so as
to coat both sides simultaneously, and distributing
brushes d d arranged in pairs below the brushes cc, said distributing brushes
serving to distribute the coating applied by the brushes c cc. I do not wish to be
understood, however, as limiting myself to these particular coating and drawing
devices, and may use any other suitable devices or mechanism for moving the web
and for applying the coating thereto.
•
In carrying out my invention, I apply air pressure to the portion of the web
intervening between the coating device and the drawing device, said pressure being
exerted at a point at one side of the direct line between the two devices and being
of sufficient force or power to support the web in the form of a bight or loop the
apex of which is shown at a¹¹. The air pressure is sufficient to entirely support the
web at the point a", so that there is no contact between the freshly coated web and
any solid object between the coating and feeding devices, the pressure at the same
time exerting tension on the web and causing it to pass in a tense flat condition
between the coating brushes.
It will be seen that the air pressure takes the place of a supporting roll or pulley
or a series of such pulleys between the coating and feeding devices, and thus
enables a sufficient length of the web to intervene between said devices to insure
the proper setting or drying of the coating, without subjecting the coating to
contact with any solid object, besides exerting the desired tension on the paper and
facilitating the drying of the coating.
I prefer to provide, as the means for exerting air pressure on the web in the
manner described, an air-delivering nozzle e formed to deliver a blast of air across
the entire width of the web, as shown in Figure 2, said nozzle being connected by
a flue with the casing e² of a fan blower. The blast of air delivered by the
nozzle e in this case constitutes practically an atmospheric or pneumatic pulley
over which the paper passes, and by which its course is diverted from a straight
line between the coating and feeding devices. e³ represents a nozzle arranged to
deliver a blast of air against the under side of the web at a point between the
bend a' of the web and the feeding device, the object being to equally dry both
sides of the web, the supporting blast of air above described acting also to dry the
side of the web against which it is directed.
I do not limit myself to supporting, deflecting, and maintaining the tension of the
web by the direct pressure of air exerted upou one side of it in the manner
described. In Figures 3 and 4 I show a modification in which the bend all of the
web is caused and maintained by an air-exhausting apparatus connected with the
bell-shaped mouth by an air-exhaust pipe. In this case, as will be readily
seen, the result will be to hold the bight of the paper by air pressure created by
the air-exhausting apparatus.
If desired, the portion of the web intervening between the coating and feeding
devices may be deflected or bent at more than one point by air pressure in the
manner described.
Air pressure applied to a flexible strip or web between two points where the

page_text: same is laterally supported may be utilized as a means for deflecting and applying
tension to the strip for other purposes, hence I do not limit myself to its use for
paper coating and drying.
'The blast of air by which the web is supported may be tempered or heated in
such a way as to secure the best drying conditions.
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. The combination with means for supporting and progressively moving a web
of paper, said means including positive supports in contact with the web, of an
intermediate pressure-maintaining apparatus located at one side of a direct line
between said supports and comprising an air-forcing device and an air-guiding
device arranged to apply a deflecting air pressure to the web.
2. The combination with means for supporting and progressively moving a web
of paper, said means including positive supports in contact with the web, of an air-
directing nozzle located out of line with said supports and arranged to direct a blast
of air against a portion of the web between said supports, and an air-forcing device
communicating with said nozzle, the arrangement of the nozzle being such that the
blast delivered thereby holds the web in the form of a bight or loop between said
supports without contact with a solid object.
Dated thie Tenth day of Avant 1805
GEORGE JAMES BURNS.
Haseltine, Lake & Co.,
45 Southampton Buildings, London, W.C., Agents for the Applicant.