Domtar makes its paper from responsibly managed forests and sustainably produced wood pulp using a combination of age-old craftsmanship and innovative, responsible techniques. Have you ever wondered how we do it? Here’s a peek at the paper-making process at our paper mills.
A paper machine is divided into two main components: the wet end and the dry end. The wet end begins with the forming section. Here, the pulp mixture — 99.5 percent water and .5 percent fiber — is spread across the forming fabric, which resembles a large mesh screen. Gravity and suction remove some water, but when the sheet leaves this section, it’s still about 80 percent water, and it’s extremely fragile.
Domtar paper mills reuse most of the extracted water at the mill. Strict environmental and usage regulations govern the volume and quality of that water.
The other part of the wet end is the press section, where the paper machine removes more water and begins to standardize the sheet’s thickness and smoothness. The paper is squeezed through rolls in continuous blankets called wet felts. Wet felts support the sheet, which is still 60 percent water, on its way to the dryers.
Drying and Sizing
The dry end of the paper machine consists of the dryer section, size press, calendar stack, reel and winder. The sheet passes through a series of steam-heated dryers and leaves with a moisture content of between 2 and 6 percent. The paper then passes through a size press, which applies a starch solution to both sides of the sheet, and additional drying cylinders. This enhances the sheet’s ability to resist water and ink penetration.
Calendaring, Reeling and Winding
After drying, the sheet moves through a calendar stack, which adjusts its smoothness and control thickness. As paper is rolled onto a large reel, a scanner moves across the sheet to check for basis weight, moisture content and caliper (thickness).
The full reel of paper, which weighs about 30 tons, moves along the rack to a winder, where it is cut into smaller rolls. A parent roll will produce approximately 6 million sheets of 8.5 by 11-inch copy paper. The rolls are separated, bar-coded and wrapped for protection. Finished rolls are shipped to customers, or other Domtar facilities, where they’re printed on or converted into a variety of products.
Now you know Domtar’s paper-making process. Watch more videos about Domtar and paper on our YouTube channel.