Bowed Roller Technical
Information
The Rimor Bowed Roller, frequently referred to as a “Spreader
Roller” or “Banana Rollers”, is suitable for all
applicatiofile:///F:/RimorConverting/rollers_tech_info.htmns
in the textile, paper and plastics industries where there
is a requirement to eliminate creases and wrinkles from the material
being processed.
Bowed Rollers are used for a range of different applications. The main
reason for using a Bowed Roller is either to stretch a web (wrinkle
removal) or to redirect the path of the web, such as diverging webs
after slitting. The positioning of the Bowed Roller, the amount of wrap
and the attitude of the bow relative to the web play an important part
if the Roller is to perform well.
How
Does a Bowed Roller Work
When a
flat web of material passes over a roller the direction of travel is
perpendicular to the axis of the roller. With a Bowed Roller the centre
axis is curved, so as the direction of travel of the web is always
perpendicular to the axis the roller will stretch the material thus
removing wrinkles as shown on the diagram.
Bowed Roller Selection
Size of Roller
 Rimor produce
various sizes of Bowed Rollers to allow the user to select a suitable
sized roller for their application. The table shows our recommended
sizes based on the length of shaft and speed. To calculate the speed of
the roller in rpm the following calculation is required:-
Where V is the linear speed in metres per minute (m/min) and D is the
diameter of the roller in mm.
| Material |
Wrap
Angle |
% Bow |
| Paper |
20-70° |
1.25-1.5% |
| Plastic film |
30-90° |
1 - 1.25% |
| Metallised film |
10-30° |
1 - 1.25% |
|
Wrap Angle
The wrap angle is the measure of the amount of contact between the
Bowed Roller
and the web. The amount of wrap angle, although important, does not
have to be
exact, as it does not effect the spreading action directly. The greater
the wrap
angle, the greater the force acting on the roller and the web. |
Driven Bowed Rollers
Bowed Rollers may be fitted with a pulley that is incorporated into the
end cap. The two main reasons for driving the Bowed Roller are when
there is a possibility of the web skidding across the roller, due to a
combination of low wrap angle and low web tension, or when additional
stretching is required.
Roller Coverings
Rimor Bowed Rollers can be supplied with various types of standard
rubber coverings including Hypalon, Nitrile & Neoprene and can be
offered with special coverings Teflon & Anti-static/Conductive
sleeves
Mounting Supports
Adjuster Gearbox units allow easy change of the bow relative to the web
by turning a handle and positioning the bow, which are available as
either pedestal or flange mounting. Fixed
If you require any assistance
with your application, our team of experienced Sales Engineers will
provide a comprehensive on-site service, to survey the requirements and
recommend a suitable solution.
|
