Cylinder Mould Paper
Making.
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Traditional paper production
on a cylinder mould paper machine start in the vat housing a
mould, that is a stainless steel box in which a cylinder
mould up to 260 cm in circumference and 130 cm in width is
placed. The size of the cylinder is the chief factor in
determining the size of the mouldd-made paper produced.
Hahnemühle Fina Art uses moulds of different structure
to make velin or ribbed paper, with or without watermark.
Hahnemühle has 15 cylinder moulds.
A highly diluted mixture of
pulp and water is fed into the vat with combined uniflow and
contraflow forming a fibrous web on the cylinder mould. The
sheet is transferred to the wet end of the machine with a
suction roll located at the highest point of the cylinder
mould.
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Deckle for hand
papermaking, laid with watermarks
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Detail of image to the
left
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Not only does the cylinder
mould produce genuine watermarks, the paper sheet can also
be divided into smaller sheets. For this purpose, special
bands and metal dividers are attached to the surface of the
cylinder mould with copper wire to mark the size of
individual sheets. Thus also the mould-made paper produced
on a machine can have four ragged edges characteristic of
hand-made paper. Some paper fibres gather on the attached
dackle frames. As the speed of the machine can be
controlled, after the press section, the still wet paper can
be torn along the marked, weaker lines. Only a sheet edge
thus obtained can be treated as a deckle edge characteristic
of mould-made paper. The cylinder mould paper machine is not
only used to make paper sheets, but also to produce paper
rolls, i.e. endless paper web.
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work on the cylinder
mould machine
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Detail of the image to
the left
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The bouble wet press section
consists of a peir of hydraulically loaded rolls connected
with a parallel drive and a common top and bottow felt. To
improve water extraction, the paper web is then gently
heated with an infra-red dryer and introduced to the dryer
section which consists of a series of steamheated cylinders.
Thanks to special felt material used in the first dryer
group, paper does not come into direct contact with the
cylinder surface and thus maintains good surface uniformaty
on both sides.
With a working width of
about 126 cm, the machine has a relatively low speed of 4-15
m/min, but this is required due to high quality requirements
of the end product. A broad range of basis weight from 80 to
350 gsm allows for the production of diverse paper grades
within the Hahnemühle FineArt GmbH product
line.
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