The Chemical Process Of Pulp Production Essay
Raw materials: The three main sources for pulp production are recycled paper, trees (soft and hard wood) and byproducts (ex. wood chips, saw dusts, etc.). The logs are debarked, and some are chipped down and both are delivered to the pulp industry for conversion. Water is also required throughout the process in great quantity.
PRIMARY PRODUCTION (Pulping)
Logs, recycled papers, and byproducts are delivered to pulp industries where they go through the process of being turned into pulp (either mechanically or chemically). In the mechanical process, the materials are grounded to separate the fibres. In the chemical process, heat is added to the materials to remove the lignin. After the materials are broken down, the fibres are washed in two processes. First, brown stock cleaning removes the liquor dissolved waste since they will interfere with the process of bleaching and papermaking later on. During the screening process, materials that will negatively affect the papermaking process or the quality of the paper product that is produced is removed [ex. shives (small fibres bundles), chops (oversized wood particle), and knots (uncooked wood particles)]. Once the washing is done, the pulp is bleached since the pulps produced are too dark to be used to make the majority of paper products made. By bleaching, the pulp is brightened; the fibre is strengthened and other benefits. There are several chemicals (ex. china clay, titanium dioxide, slimicides,…