6. What is the reason why the paper on the printing cylinder of offset press is not in place?

1. The paper is too thin or too narrow to enter the printing cylinder correctly.

2. The printing paper is curled or folded, and cannot enter the printing cylinder correctly.

3. The paper feeding mechanism of printing paper is not properly adjusted, which leads to the paper not entering the printing cylinder correctly.

4. The paper feed sensor of printing paper is out of order, which makes it impossible to detect the paper position correctly.

5. The transmission mechanism of the printing cylinder is out of order, which makes it impossible to transfer the paper correctly.