Paper Technology Journal 17 - Voith

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Stroke [mm]
25
20
15
10
5
Shake frequency n [min-1 0
150 200 300 400 500
]
600
530 strokes/minute and a constant stroke
of 14 mm, and at a machine speed of
1,000 m/min, a shake characteristic number
of 3,933 is still achieved, of course
without disturbing reaction forces.
The latest generation of the DuoShake is
equipped with a hydrostatically supported
carriage. This contributes considerably to
the reduction of wear.
The technical principle
The DuoShake operates on the physical
center-of-gravity principle. Several masses
moved in a system maintain their
common center of gravity. In a gear unit
housing, masses are arranged in such a
way that the mass center of gravity can
move only in the breast roll axis. If the
shake masses are rotating, the breast roll
responds with a counter movement. The
inertia forces remain in the moving system
and are transmitted only via the
shake rod.
Fig. 1: Performance diagram – stroke.
Fig. 2: Performance diagram –
shake characteristic number.
Shaken mass:
2,000 kg
3,000 kg
4,000 kg
5,000 kg
Drive moment: 150 Nm 250 Nm.
Shake characteristic number SKZ =
6000
n2 2
x s
vwire 5000
4000
3000
2000
1000
0
200 400 600 800 1000 1200
Production speed vwire [m/min]
The stroke length is determined by the
addition of the shake mass forces. Adjustment
is made by changing the angle
between the rotating pairs of masses.
The performance diagram (Figs. 1 and 2)
shows the operating range of the Duo-
Shake taking into consideration the maximum
rod force of 50 kN. Below the limit
curves, any combination of stroke and
frequency is possible.
As Fig. 4 shows, the fact that the Duo-
Shake generates no interfering forces of
reaction makes it possible to install the
DuoShake on the top-wire framing.
Evaluations made by many different customers
have shown that, with the Duo-
Shake, formation can be improved even
at higher PM speeds thanks to the much
higher shake characteristic numbers. In
addition, the DuoShake reduces the tensile
ratio l/q by up to 0.5, which is indispensable
especially for good dimensional
stability. The DuoShake is, therefore, an
17/04
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Fig. 3:
Coating base 1
Coating base 2
News
Envelope
Decor paper 1
Decor paper 2
Label
Abb. 4: DuoShake in use.
Formation Ambertec norm. [ g/m2]
1.3
1.1
0.9
0.7
0.5
with DuoShake
without DuoShake
0.3
1 1.5 2 2.5 3
Tensile Ratio MD/CD [-]
59
economic alternative for formation improvement
and a must whenever a low
tensile ratio l/q is required. In many cases
it is even used in addition to a Duo-
Former D in order to achieve optimal formation
at a low tensile ratio l/q.
For trial purposes, a rental shake is always
available at our Düren location,
which can in most cases be used by the
customer for tests at short notice. Before
purchasing, each customer can test the
effects on his machine and on his special
products under simplified, but realistic
conditions without great expense and
can convince himself of the tremendous
advantages and possibilities of the Duo-
Shake.
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