SymSizer/OptiSizer beam setup, after applicator roll change

SymSizer/OptiSizer beam setup procedure – this step is required after every applicator roll change or whenever you feel there is an issue with starch/coating application. The goal is to set the applicator beam parallel with the new applicator roll.

First, the rod and rod bed are removed from the beam. This step is required to allow the alignment test rod to contact the applicator roll.

To begin the alignment process, first close the nip. The nip needs to be closed especially when performing the alignment of the applicator beam mounted to the movable roll. This step guarantees that any unbalanced forces in the roll to roll nip are equalized.

Next, load the beam up to the roll and insert the test rod in the test hole which are located about 20 inches from either end of the beam. Push it in far enough to make good contact with the roll.

Now measure the rod stickout with a vernier caliper. It will measure about 22-23 mm for a typical SymSizer/OptiSizer (check to make sure what your stickout target is before changing alignment).

If the stickout is lower than your target, the beam needs to be adjusted toward the roll more using the alignment screws on the beam bearing assembly. It is easier to adjust these screws with the beam in the open position as you're not turning against any loading pressure. Making adjustments with the beam loaded not only is harder to do, but it can strip the fine threads on the adjusting screw.

It is a good idea to determine how much the beam moves for every revolution, or screw flat, of the adjusting screw to minimize setup time. Most are threaded to move 1.0 mm per revolution. Keep adjusting the tending and drive side screws until you are within 0.5 mm from target and within 0.5 mm apart from front to back.

Next, with the applicator beam loaded, check both ends of the beam travel stops. Both should be seated against their mechanical stops. If there is a gap on either end, there is a mechanical problem with the beam which will affect coating profiles, nip loading, and may create runnability issues.

Periodically use an inclinometer to make sure the front face of the applicator beam and where it mounts to the pivot arm are parallel. This determines what angle the sealing blade will wear at when the beam is set up. If the beam is tipped too far towards the roll, the sealing blade will wear to a sharp bevel and possibly cause wear streaks on the applicator roll.

One more note on sealing blades – they must be straight and free to move in the CD direction. Set the edge dams up with about 1/4 inch clearance to allow for sealing blade thermal growth.

For more information on SymSizer or OptiSizer maintenance and setup, contact your Valmet representative.