We deal with paper every single day at DPI – printing, processing and shipping it constantly. However, it’s sometimes easy to forget where all this paper comes from.
This week, team members from Daily Printing took a trip to Cloquet, MN (outside of Duluth) to visit the Sappi Fine Paper Mill. It was fascinating to walk through the mill, learn how pulp is made into paper, see the mill machines remove water from the pulp, stand next to large rolls of the new paper and watch the rolls get cut and ready to be shipped.
We weren’t able to take any pictures of the inside of the mill, so here are some fun facts all about the production of paper, how it is distributed and what the Sappi Fine Paper Mill can do:
- The pulp used to create Sappi paper is a mixture of Maple – a very short fiber length – and Aspen – a slightly longer fiber. Short fibers create a solid foundation for the sheet. The longer the fibers that are used, the more disruptive the sheet, even though these long fibers are incredibly strong. The solution? A mix of both Maple and Aspen for the perfect pulp.
- 96% of the water in the pulp is taken out by gravity alone, the last 4% with pressure and force as it is fed through a winding path in the mill machine.
- One single roll of paper coming off the mill machine is 196″ wide and weighs about 3,000 pounds (about the size of a car). It is later cut and measured to various sizes of smaller rolls.
- In order to keep the paper printer-friendly, Sappi makes sure there is a quality formation of the sheet. This includes testing samples of the sheets with ZDT and Scott Bond quality tests to ensure consistent manufacturing characteristics.
- Sappi creates paper for high-end printing, so it produces three finishes: gloss, dull or silk. To create a Gloss finish, they buff the surface with a high amount of pressure and heat. For a dull finish, they reduce the heat and pressure. Finally, a silk finish is created with an almost unnoticeable pattern on the surface of the paper.
- Paper leaves the mill in one of three ways: on a roll, on a skid or in cartons. Automated systems build boxes around the paper into cartons as well as blue shrink wrap rolled, heated and tightened around a stack on a skid.
- The mill runs about 500 tons off of each machine, processes about 1,000 tons and ships 50 semis out of the mill every single day.