Wednesday, January 30, 2019

Film Handling by Low-Inertia Roll

Film Handling by Low-Inertia Roll

The new technology is progressing rapidly.
Thanks to this, various films used in a wide field have been thinner.
To thin films we can not apply strong tension.
So, when inertia of a transporting roller is large,
contact and synchronicity between a film and the roller are not in good conditions.
This situation causes slipping of the film, then scratches are generated on the film.

This is exactly an issue DYMCO challenges to solve.
Lower inertia of the transport roll is very much expected as manufacturing technology.
Starting from the experimental stage,
at present we are upgrading our low inertial rolls to try for the real production lines.
Now follows this report.

1. Structure of our low inertia roll
The roll body itself does not rotate.  
When compressed air is introduced from the fixed hollow shaft end, 
air is blown out from the radially opened small holes of the roll surface.

The thin-walled metal sleeve is set along the outer diameter of the core roll.
Due to the compressed air coming out of these holes,
the thin-walled sleeve diameter expands and is off the roll core.  
The sleeve is floating.
The thin-walled metal sleeve and side rings* only rotate very lightly.
They is why a film comes to this roll and moves together lightly with this roll.

side rings*: rings to control wandering of the tsleeve in the core roll axis direction.

Low-Inertia Roll Covered with a Thin-Walled Metal Sleeve
2. Comparison between the low inertial roll and the conventional rolls

The table below shows the comparison of the inertia in the central cylindrical part of the same size roll.
In the low inertia roll,  the roll body including the bearing part does not rotate,
while inertia of the conventional roll is fairly large as the entire body rotates.

Inertia Comparison chart: the low inertial roll and the conventional rolls
Low Inertia Roll
Steel Roll
Aluminum Roll
FPR Roll
Thickness (mm)
Specific Gravity
Inertia Ratio

4. Effect of the low inertia roll

The advantage is productivity improvement by speeding up the production line.

Generally, as the roll diameter and the width increase, inertia increases.
Then speed difference between the roll and the film becomes apparent.
We cannot increase speed of the conventional rolls, but can do it with our roll.
Because the low inertial roll can follow the speed of the film.

Other advantage is being clean and scratch-less.

Are you get interested in this? Please be free to send your question to us.