I was talking with our laminator repair technician today and he offered a great tip that I wanted to pass along.
When laminating thick items such as cardstock or posterboard, it is best to set the speed no higher than 2.
In the past, several users have experienced having laminated items with air pockets or items where the lamination film completely pulls apart. Our technician explained that when documents run through too fast, there is less heat available to help bind the film to the item. The slower speed will allow the item and film to receive more heat, which will also help reduce these problems.
Hope this was helpful-It was a mystery solved for me. Happy Laminating!