To install click the Add extension button. That's it.

The source code for the WIKI 2 extension is being checked by specialists of the Mozilla Foundation, Google, and Apple. You could also do it yourself at any point in time.

Kelly Slayton
Congratulations on this excellent venture… what a great idea!
Alexander Grigorievskiy
I use WIKI 2 every day and almost forgot how the original Wikipedia looks like.
Live Statistics
English Articles
Improved in 24 Hours
Added in 24 Hours
What we do. Every page goes through several hundred of perfecting techniques; in live mode. Quite the same Wikipedia. Just better.

Hollander beater

From Wikipedia, the free encyclopedia

A Hollander beater
A Hollander beater

A Hollander beater is a machine developed by the Dutch in 1680 to produce paper pulp from cellulose containing plant fibers. It replaced stamp mills for preparing pulp because the Hollander could produce in one day the same quantity of pulp it would take a stamp mill eight days to prepare.[1]

However, the wooden paddles and beating process of a stamp mill produced longer, more easily hydrated, and more fibrillated cellulose fibers; thus increasing the resulting paper's strength. The Hollander used metal blades and a chopping action to cut the raw material, resulting in shorter cellulose fibers and weaker paper. Further, the metal blades of the Hollander often introduced metal contaminants into the paper as one metal blade struck another. These contaminants often acted as catalysts for oxidation that have been implicated in browning of old paper called foxing.[1]

Hollander beater patent
Hollander beater patent

In turn, the Hollander was (partially) replaced by the conical refiner or Jordan refiner, named after its American inventor Joseph Jordan, who patented the device in 1858.[1]

A Hollander beater design consists of a circular or ovoid water raceway with a beater wheel at a single point along the raceway. The beater wheel is a centrifugal compressor or radial impeller cylinder parallel to a grooved plate,[2] similar to the construction of a water wheel or timing pulley. Under power, the blades rotate to beat the fiber into a usable pulp slurry. The beater wheel and plate do not touch, as this would result in cutting. The distance between the two is adjusted to increase or decrease the pressure on the fibers when passing through the beater.

The objective of using a beater (rather than another process like grinding, as many wood-pulp mills do) is to create longer, hydrated, fibrillated fibers. (Fibrillated fibers are abraded to the extent that many partially broken-off fibers extend from the main fiber, increasing the fiber's surface area, and hence its potential for hydrogen bonding). Grinding of fibers is not desirable. Therefore, the "blades" are not what might be thought of as "sharpened," and well-designed beaters make it possible to minimize the shear action of the rotating blades against the bottom of the water raceway.

Processing pulp in a Hollander beater (1947)
Processing pulp in a Hollander beater (1947)

YouTube Encyclopedic

  • 1/2
    1 491
    2 767
  • ✪ hollander beater
  • ✪ keith fox hollander beater



  1. ^ a b c Clapp, Verner W. (1972). "The story of permanent/durable book-paper, 1115–1970". Restaurator (Suppl. No. 3): 1–51. ISSN 0034-5806.
  2. ^ Lumiainen, J (2000). "4: Refining of chemical pulp". Papermaking Part 1 (PDF). p. 98. ISBN 952521608X.

External links

This page was last edited on 13 March 2019, at 00:29
Basis of this page is in Wikipedia. Text is available under the CC BY-SA 3.0 Unported License. Non-text media are available under their specified licenses. Wikipedia® is a registered trademark of the Wikimedia Foundation, Inc. WIKI 2 is an independent company and has no affiliation with Wikimedia Foundation.