Paper dutch
The paper Dutchman , usually called Dutch for short , is a machine that was used to shred rags or rags in historical paper production . It was also known as Dutch dishes . In the pre-industrial papermaking in Germany, the Dutch replaced the stamping or stamping mill , the German crockery, from the 18th century . In the time of industrial paper production , pulp , wood pulp and waste paper were processed in Dutch. Dutch are still used in special areas today.
Working method
The linen and cotton fabrics were first freed of dyes in a septic tank and then mechanically cut into short fiber pieces until a fine fiber pulp suitable for paper production was created, the so-called pulp . In the Holländer, a roller driven by water power and equipped with cutting blades was used for this purpose. The constant circulation of the fiber-water mixture (endless loop) made this mechanical treatment faster and under better controllable conditions than the previously common ramming mechanism. The resulting pulp can be circulated with the roller up to a fiber content of around 3 to 4% (in the water).
The Dutchman remained a universal machine for making paper until the 20th century. He could not only extract fibers from the raw material, but also grind them . It was also possible to mix dyes and other additives into the suspension. The quality of the pulp was easily controllable. A disadvantage of the Hollander compared to the later refiners is that the entire contents of the Hollander had to be constantly circulated until the pulp was completed, while refiners can shred the paper raw material much faster and more efficiently.
Further development
In the 19th century, the growing paper production led to larger constructions, the originally wooden vats made way for masonry containers in which cellulose was also bleached with chlorinated lime . For this purpose, from 1880 the drive for circulating the pulp was switched to propellers, which enabled a higher consistency of 5 to 7%, which meant that less steam was required to heat the fiber-water mixture to the bleaching temperature of approx. 40 ° C.
With the diversification of the types of paper , the job of the Dutch miller became more demanding: He was responsible for the exact mixture of fibers , fillers , dyes and auxiliary materials in the Dutch. The composition was prescribed to him on Dutch notes, along with further information on the paper to be produced, including: type of paper, color, smoothness and degree of grinding of the fibers.
The Dutch only gradually went out of use from around 1960, when the continuously operating cone pulp mills ( refiners ), with which various refiner wood pulps could be produced, became established. Some Dutch are still used today in the manufacture of banknote and other specialty papers.
See also
Web links
literature
Henk Voorn: On the invention of the Dutchman. In: Papiergeschichte , Vol. 5, H. 3 (July 1955), 38–42, DNB 1035949156 .
Individual evidence
- ↑ Paper dictionary . Deutscher Betriebswirte-Verlag, Gernsbach, 1999, Vol. 2, 92; ISBN 3-88640-080-8 .
- ^ Wilhelm Wölfel: The water wheel . Pfriemer, Berlin, 1987, p. 94, ISBN 3-7625-2602-8 .
- ↑ See video paper mill Alte Dombach (2:30 min.). In this short film, from 0:37, the older technology can be seen: a rag mill with hammers and a pounding trough. Then (0:54 to 1:10) the newer technique: a Dutchman with a clearly recognizable knife roller.
- ↑ a b Jürgen Blechschmidt (Ed.): Taschenbuch der Papiertechnik , Carl Hanser Verlag, 2nd, updated edition 2013, p. 282.
- ↑ Ernst Völker: The great pale . Gebr. Bellmer, Niefern, 1992, p. 67.
- ↑ Maximilian Bittner: The cost calculation in the paper, pulp, wood pulp and cardboard industry . Business publisher Dr. Th. Gabler, Wiesbaden 1959, p. 225 f.
- ↑ Jürgen Blechschmidt (Ed.): Taschenbuch der Papiertechnik , Carl Hanser Verlag, 2nd, updated edition 2013, p. 28.