Creating a web of fiber from plant cellulose (or, less commonly, from synthetic fibers). Papermakers today follow the same steps that its inventor, Ts'ai Lun, followed almost two thousand years ago: pulping vegetable matter and leaving the cellulose fibers behind; mixing the pulp with lots of water; draining it; forming paper on a sieve-like mold; pressing the paper to remove some of the water; and drying it to remove the rest of the water. Technology has sped up the process and helped to improve the smoothness, brightness, and printability of the paper, but it hasn't changed the essence of papermaking.
Invented in China by T'sai Lun some 2,000 years ago, papermaking still follows the same basic procedures. Today wood chips are cooked with chemicals to release cellulose fibers and to dissolve lignin, then washed to remove impurities. Most printing papers are then bleached to lighten the color of the pulp. Pigment, sizing and fillers are added, along with large quantities of water. The resulting slurry, which is 99% water, is cascaded onto the continuously moving forming fabric of the Fourdrinier paper machine. Side-to-side shaking distributes the slurry, forming a tangled web of fiber as the water drains off. A wire mesh roller, called a dandy roll, moves over the surface to modulate the turbulence and smooth the top side of the paper. A felt blanket absorbs more water from the paper and sends the sheet on through a channel of hot metal drums that dry and press the paper at the same time to give it a more even sided finish. At this point, the paper is fully dry and ready for off-machine processes such as coating, embossed finishes and supercalendering.