PaperPaper is a thin sheet material produced by mechanically or chemically processing cellulose fibres derived from wood, rags, grasses, or other vegetable sources in water, draining the water through a fine mesh leaving the fibre evenly distributed on the surface, followed by pressing and drying. Although paper was originally made in single sheets by hand, almost all is now made on large machines—some making reels 10 metres wide, running at 2,000 metres per minute and up to 600,000 tonnes a year.
Kraft processThe kraft process (also known as kraft pulping or sulfate process) is a process for conversion of wood into wood pulp, which consists of almost pure cellulose fibres, the main component of paper. The kraft process involves treatment of wood chips with a hot mixture of water, sodium hydroxide (NaOH), and sodium sulfide (Na2S), known as white liquor, that breaks the bonds that link lignin, hemicellulose, and cellulose. The technology entails several steps, both mechanical and chemical. It is the dominant method for producing paper.
Paper millA paper mill is a factory devoted to making paper from vegetable fibres such as wood pulp, old rags, and other ingredients. Prior to the invention and adoption of the Fourdrinier machine and other types of paper machine that use an endless belt, all paper in a paper mill was made by hand, one sheet at a time, by specialized laborers. History of paper Historical investigations into the origin of the paper mill are complicated by differing definitions and loose terminology from modern authors: Many modern scholars use the term to refer indiscriminately to all kinds of mills, whether powered by humans, by animals or by water.
Paper chemicalsPaper chemicals designate a group of chemicals that are used for paper manufacturing, or modify the properties of paper. These chemicals can be used to alter the paper in many ways, including changing its color and brightness, or by increasing its strength and resistance to water. The chemicals can be defined on basis of their usage in the process. Chemical usage is not only for imparting properties to paper but to handle the water cycles in the process, conditioning of fabrics, cleaning of equipment and several other applications.
SizingSizing or size is a substance that is applied to, or incorporated into, other materials—especially papers and textiles—to act as a protective filler or glaze. Sizing is used in papermaking and textile manufacturing to change the absorption and wear characteristics of those materials. Sizing is used for oil-based surface preparation for gilding (sometimes called mordant in this context). It is used by painters and artists to prepare paper and textile surfaces for some art techniques.
PaperboardPaperboard is a thick paper-based material. While there is no rigid differentiation between paper and paperboard, paperboard is generally thicker (usually over 0.30 mm, 0.012 in, or 12 points) than paper and has certain superior attributes such as foldability and rigidity. According to ISO standards, paperboard is a paper with a grammage above 250 g/m2, but there are exceptions. Paperboard can be single- or multi-ply. Paperboard can be easily cut and formed, is lightweight, and because it is strong, is used in packaging.
