Methods of Beating Fibers
needs edits
Purpose - Hydrate and Fibrillate fiber
Hydrduon alters the cellulos fiber to help them absorb water.
Fibrillation - fiber walls are bruised so that the smaller fiber
parts unravel.
Mid Eastern region developed a water driven stamper to beat and
defiber cloth
Both of these help romote chemical bonding.
All material for papermaking--whether cloth, plant fiber, or paper to
be recycled--needs to treated to separate the fibers. Beating is the most
common and quickest way to do so. (Other forms of fiber separation, like
retting and fermentation, are sometimes used in place of or as a
supplement to beating. Cooking material, especially raw fiber, before
beating also helps accelerate the process of separation.)
The earliest papermakers probably beat their material by hand with a
stick (as is still done in some traditional forms of Japanese
papermaking), by the use of simple mortar and pestle euipment, or by the
use of animal-power (used to pull a stone wheel continuously through a
circular stone trough, for example).
More advanced technology for beating material for papermaking came with
the introduction of stampers, which range from foot-powered adaptations of
the mortar and pestle design to enormous mechanical devices, with stamper
heads of different degrees of coarseness in adjacent troughs for
processing the material in stages. In the European mills of the middle
ages and Renaissance,
papermakers constructed large, elaborate, water-powered stamping mills to
process a onsiderable amount of cloth into pulp for papermaking, with
ingenious features like rinse water running through the troughs where the
fiber was being beaten, to remove waste materials throughout the
process.
In the late 17th century, the Dutch invented a mechanical device known
as the Hollander beater. These are still used by hand papermakers today,
although the machine-made paper industry has generally switched to more
chemical ways of breaking down material for papermaking. Hollander beaters
(or Hollanders, as they are commonly known) come in different designs, but
all consist
of an oblong trough with rounded ends in which water and the material
being beaten circulate; a rotating cylinder with dull metal blades (known
as the roll); and a bedplate of raised dull metal blades in the bottom of
the trough, underneath the roll. The roll turns in close proximity to the
bedplate and the material being beaten is forced between the blades,
through the circular movement of the water. Either the bedplate or the
roll are adjustable and one of them is sometimes moveable; these features
allow for variations in the thickness and toughness of the material being
processed. Some Hollanders have a device for removing waste water so that
the fiber can be more effectively rinsed as it is being beaten.
Contemporary hand papermakers also use a variety of tools adapted to
their needs in preparing partially-processed fibers (like cotton linters
and sheets of abaca). These include devices like Whiz Mixers, Hydropulpers,
blenders, and home-made devices of similar ilk, which variously serve to
agitate the pulp or subject it to a garbage-disposal type of treatment.
None of these devices, however, produce pulp as effectively or with the
same force of Hollanders or stampers, as they tend to cut or simply stir
rather than force apart the separate fibers. For beating certain
materials, especially cloth, stampers and Hollanders are the only
practical choice.
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