2000 fpm CONVEYOR

[rgajewski]

I work for a web converting company and we need to unwind "mill rolls" at 2000 feet per minute. There are 2 primary methods to "drive" the roll (55" wide x 40" dia x 2800 #s) either core/chuck driving and belt driving. The core/check is equating to about 100 HP as we need to go from 500 fpm to 2000 fpm in 3 seconds. The method aof a "conveyor" belt in contact with the roll to drive is the method we are leaning towards. I have had no experience with belts at those speeds and am looking for recommendations. FYI when we ran another project with a "v" guided belt at 1200 FPM the belt failed continuously. Thanks
Ray

Every once in a while the voices in my head have good ideas.

 

[Compositepro]

Center drive is much simpler and less expensive to implement. You need a good reason to go with a surface drive. That reason is usually how your material can tolerate the forces of acceleration. 2000 fpm is about 25 mph so it should not be a big problem.

Are you only going to use the surface drive to assist in accelerating the roll?

 

[limey1]

Ive seen a few heavy 'parent' or mill rolls with surface drives. One benefit is better control of the web tension while maintaing a constant surface speed as the roll diameter decreases. Ive seen 9' wide paper converting equipment ramp up from 0 - 1900fpm in 8 seconds. Hope this helps.

 

[bklauba]

Duty cycle would be the next Q that any center drive mfr would ask about. How long are going to run at 2000 fpm?

BK

 

[dvd]

I would think that a properly designed series of dancer rolls would allow for a much slower acceleration of your roll and significantly lower horsepower. Oklahoma State University is home of the Web Handling Research Center:

http://webhandling.okstate.edu/

You just missed their spring web handling seminar, but you could benefit from contacting them for consultation. Don't re-invent the wheel.

 

[rgajewski]

The duty cycle is up to 8 times per minute to go from 500 FPM to 2000 FPM. We run at the high speed (2000 FPM) from anywhere between 1/2 second up to 22 seconds, depending on finish roll length. Also, to answer DVD, I was scheduled to go to Oklahoma for the seminar, but this project trumped my availability. Thanks to all who have responded and if you have other questions or answers, please post.
Thanks
Ray

Every once in a while the voices in my head have good ideas.

 

[Compositepro]

Taking a 2800 lb. mill roll from 500 to 2000 fpm 8 times per minute does not seem wise. It sounds like a perfect application for an accumulator. These can be "dancer" rolls but are more commonly called festoons. This will store material feeding into your process so that the mill roll runs at a lower and constant average speed of your process, while the surges are supplied by the accumulator.

 

[bklauba]

I checked with my center drive expert, and they are not too keen on the 2000 fpm (oil cooling and heat transfer to "belt" insufficent, at least for his devices, at that speed) and he mentioned the "dancer" roll approach also.

BK