Pulp (papermaking)

from Wikipedia, the free encyclopedia

As pulp or pulp (English pulp consisting will) fibers existing material referred to, in the preparation of paper , paperboard and cardboard is obtained and further processed. The fibrous materials are mostly obtained from wood by mechanical and / or chemical wood pulping processes . The most important component of the fibrous material in paper production is cellulose .

Classification

Primary fibers are obtained directly from plant material, mostly from the raw material wood:

  • Wood pulps are obtained by mechanical defibration, either purely mechanically (wood pulp) or with chemical and / or thermal pretreatment. Like the wood from which they are made, wood pulps are made of lignocellulose . In addition to cellulose and hemicelluloses, they also contain a large amount of lignin .
  • In the case of semi-pulps , the lignin content is reduced, the cellulose content dominates.
  • Cellulose is obtained by chemical pulping, but also from certain annual plants (e.g. straw and hemp ). Cellulose consists almost entirely of cellulose.

Secondary fiber ( waste paper stock ) is produced from waste paper and used cardboard and cardboard. Recovered paper stock and the papers made from it are also largely based on the raw material wood. Through constant paper recycling , the primary fibers originally obtained from wood are reused several times as so-called secondary fibers. Waste paper is the most important paper raw material in terms of quantity.

Rag fabrics are vegetable fibers obtained from textile waste such as cotton, linen, hemp and flax. They are the oldest and finest paper fibers. Rag (old clothes, rags) were already used for paper production in the Middle Ages. Today rag fabrics are still used for the production of high-quality paper with great toughness, folding and crease resistance (e.g. banknote paper and document paper ).

Synthetic fibers are used to a small extent in the production of certain special papers . Synthetic fibers are produced by spinning or spraying processes and subsequent small cutting. Synthetic fibers have a very high strength, do not absorb water and do not rot. Synthetic papers either consist entirely of synthetic fibers or contain an admixture of cellulose. Application examples are ID cards, driver's licenses and waterproof maps.

use

From the fibers are primarily papers and paperboard and cardboard but also produced, other cellulose products , such as pulp composite elements . Chemical pulp , which is used, among other things, in the chemical industry and must contain particularly high levels of cellulose and few impurities, is classified in a higher quality class .

Fibreboard and insulation materials for thermal insulation are also made from shredded wood (i.e. wood pulp) .

English names

In English, numerous compositions with pulp refer to the various fibrous materials, regardless of the form in which they are present: suspended in water or as wet or damp or dry fibrous material. English pulping means "fraying" (also called wood pulping or general fiber pulping ); Compositions with pulping denote various methods of obtaining the pulp. For example:

  • refiner mechanical pulping (RMP) - Process for mechanical pulping of wood in a refiner
  • refiner mechanical pulp (RMP) - wood pulp produced using the RMP process

These English compound names with pulp and the associated abbreviations such as B. RMP are also used in German terminology. Furthermore, the general term pulp for “fiber” is also used as an English foreign word (with English pronunciation) in German technical language.

Cellulose is called chemical pulp in English , often simply pulp . English pulp and paper industry literally means pulp and paper industry , whereby the simpler term paper industry is common in German . The word pair Pulp & Paper can be found in the names of companies (e.g. Kabel Premium Pulp & Paper GmbH ) or corporate divisions (e.g. Andritz Pulp & Paper ) that are active in the paper industry.

English pulp cannot be equated with German pulp . In papermaking, the German word pulp usually refers to the pulp, the mixture of water and fiber, for example in a Dutchman , a vat or a pulper . The proportion of water in a pulp is much higher than the proportion of pulp.

Web links

Individual evidence

  1. ↑ Jürgen Blechschmidt (Ed.): Taschenbuch der Papiertechnik , Fachbuchverlag Leipzig in Carl Hanser Verlag, 2nd, updated edition 2013, chapter 2.1 (terms), here p. 32, explanation of the term fiber . Quote: "Fiber material, mostly of natural origin, which is prepared from raw materials in such a way that it can be processed into sheet-like paper structures in various processes."
  2. ↑ Paper glossary papyrus.com, see keyword fibrous materials .
  3. ^ Günter Bleisch, Horst-Christian Langowski, Jens-Peter Majschak: Lexicon packaging technology . Behr's Verlag, 2014, p 222. pulp is there with English pulp translated and explained as follows: "pulp from vegetable raw materials for paper production. This includes wood pulp, semi-cellulose, cellulose, H. from rags and from annual plants and waste paper. The H. are processed into the actual paper pulp with the addition of water and auxiliary materials. "
  4. ↑ See Duden online: Pulp
  5. ↑ a b Papers according to the fiber composition mediencommunity.de
  6. ↑ Competence Center for Building with Renewable Raw Materials (KNR): Roof extension with renewable raw materials - safe and convenient (PDF), p. 29 (see also the illustrations for production there).
  7. ↑ Paper Products Glossary afandpa.org. See some examples under the keyword pulp .
  8. ↑ See Properties of Pulp paperonweb.com. See section Dry Content of Pulp for information on the dry substance of the pulp suspension (referred to as pulp density in the papermaking area ). The table lists pulp consistencies in the range from less than 1% to 35%, corresponding to a water content of 65% to over 99%. In the section Moisture Content of Market Pulp (moisture content of cellulose as a commodity), market pulp is described as air dry , corresponding to a water content of around 10%. The term pulp thus encompasses consistencies of around 10% to over 99% water content and thus the whole spectrum from air-dry pulp to highly diluted pulp suspension.
  9. ↑ Wood pulp production papier-machen.de
  10. ↑ Paper glossary papyrus.com, see key word Pulp .
  11. ↑ See examples of translations for pulp at dict.leo.org
  12. ↑ See Carla Meyer, Rebecca Sauer (2015): Paper . Contribution to the Collaborative Research Center 933 “Material Text Cultures” of the German Research Foundation, 2015.