This is a tricky one

[xenith]

At the front & back there is a hole with a chute under it. There are four gears (one each side, and one top & bottom) which turn when the handle is turned.

A piece of paper fed into one end comes out the other looking like this:

Comments

[webfarmer.livejournal.com]

My guess would be something to break fibers of plants. Say sugar cane so that the cane juice could be better extracted. Or maybe flax. Make the final output product more susceptible to processing chemicals.

Just a wild guess. Your agriculture is quite different than ours I suspect.