Laminated corrugated cardboard is uneven and warped

After corrugated carton lamination, the cardboard ends are warped and uneven, I believe many bosses and starters have encountered this problem, so what is the cause of this, and how can we make a good flatness of the cardboard.

To improve warpage, the following methods are used:

If the face paper is warped, bend the face paper in the opposite direction before putting it on the machine.
2. If the moisture level of the corrugated board is too low, the board is too dry.
3. Use a water stick to hit the corrugated board with water.
4. Adjust the glue to a thicker consistency and slow down the speed of the press tape.
5, wrong pattern laminating, corrugated paper and face paper pattern is crossed to laminating
6, laminated out of the cardboard front and back stacked, each stack as few as possible, the upper side of the weight pressure
7, laminated out of the cardboard to play a good chop, with the winding film fixed