We have two kinds of slitting machines, one can't remove the air bubbles(cheaper one, in the first video), another one can remove most of the air bubbles(the second video). The different market has different requirement for the air bubble, u can search your market first, then choose the suitable one.
Without removing the air bubble:
Removing the air bubble:
Usually, customers buy slitting machine together with other 3 sets of small machines together, it's paper core loader, paper core cutter, small rewinding machine, please check the pics as above.