Paper mill - Definition and Overview

A paper mill is a factory devoted to making paper from wood pulp and other ingredients using a Fourdrinier Machine or similar apparatus. These establishments have been noted for producing an obnoxious smell in the general surroundings.

The undesirable odour (usually at pulp mills, which are a little different from paper mills) is caused principally by process by-products, specifically the reduced sulfur gases resulting from the cooking process. Thankfully, these airborne particles are not harmful to the health of the community, but they are considered a nuisance. The Kraft process of reducing wood logs to their fibre constituent is primarily responsible for the odour, as opposed to the sulfite process.

Paper mills can be fully-integrated mills or smaller processing mills. The integrated mill will receive the whole forest log (or wood chips), process it down to the individual fiber level and into a 4% (approximately) pulp slurry, then process that pulp slurry into a sheet of paper. Non-integrated mills cannot process the log or wood chips but instead purchase preprocessed pulp slurry in a dried and baled form, known as market pulp, from pulp mills. The pulp bales are then rehydrated into a 4% solution in order to be processed into a sheet of paper.

The modern paper mill uses large amounts of energy, water, and wood in a highly efficient and extremely complex series of processes, using modern and sophisticated controls technology to produce a sheet of paper that can be used in incredibly diverse ways. Modern paper machines are very large and can be 500 feet in length, produce a sheet 400 inches wide, and operate at speeds of over 100 mph.

Mills

• Braviken Paper Mill, Norrköping, Sweden