Thursday, September 17, 2015

Web handling low inertia roll

As a variety of plastic films are developed for wider applications, thinner films are  being produced.
In these production, demand for lower inertia becomes apparent for feeding rollers.  Here we ntroduce our low-inertial roll.

 1.Structure of the low inertial roll
This roll is made up by the core roll and theouter sleeve. Its uniquness is that the core roll does not rotate.  Air goes in from the edge of the core roll axis and goes out of holes along core roll surface.  Due to this air flow the outer sleeve sweels and there appear clearance between the core roll surface and the outer sleeve.  Then the outer sleeve only begins to rotate, free of any resistance.

The outlook of the low inertia roll:  The outer surface is thin metal sleeve.  This sleeve only rotates.  The blue right end is the air inlet.

 2.Conparison of inertia with the conventional web handling rolls
The right one is the conventional roll.  This is made by steel, 1200mm long, diameter 100mm, thickness of the roll area is 6.0mm.  The left one is our low inertial roll, 1200mm long, diameter 100mm, thickness of the outer sleeve is 0.125mm.  When inertia of our roll is 1, inertia of the conventional roll is 48.   

 3.Effects of the low inertia roll
 The big benefit is improved production effectiveness by film conveying speed increase.  In general, when the roll diamer is long and weight is heavy, inertia becomes larger.  Also there appear speec difference between a conveyed film and roll rotation speed.  So there is limitation in film conveying speed.  Our roll is made up by the thin and light outer sleeve.  This light sleeve can follow the film speed, which increase speed of the entire line.
Other merits are 'being clean' and scratches become less due to lower stress between the roll and a film.