Paper Technology International 2020 - Journal - Page 97

PAPERTECHNOLOGYINTERNATIONAL
Figure 2: Toscotec’s TT Headbox-SL.
Figure 3: TT Headbox-SL with TT D-Profiler
dilution control system. (Below)
A pulse attenuator is normally installed just before the
inlet of the headbox header to reduce disturbances coming from
the approach flow system, in terms of pressure pulsation in the
incoming stock. The complete headbox and pulse attenuator are
manufactured in solid stainless steel with tight mechanical finish for
all surfaces in contact with the stock.
Toscotec’s new TT Headbox-SL generation design
Toscotec has recently started up a new generation design
TT Headbox-SL for a packaging paper application in Russia. The TT
Headbox-SL is designed to operate on a Fourdrinier machine with
2,830 mm wire width producing fluting and test liner in the range
from 90 to 175 gsm, using 100% mixed recycled and raw fibres. The
headbox was supplied with TT D-Profiler dilution system for precise
bone dry profile control.
The TT Headbox-SL is part of a complete refurbishing twostep plan for the paper machine, where the headbox was planned in
the first step and is prepared for future speed-ups to 900 m/min.
During this first project step, Toscotec also modified the
Fourdrinier table adding new dewatering elements to increase the
drainage capacity of the wire section and supplying a new flume and
the complete approach flow system feeding the new headbox and its
dilution system.
Figure 4: Toscotec’s TT Headbox-PF. (Below)
After the rebuild, the paper machine achieved good paper
formation and the expected performances.
In particular, the headbox was started up with a uniform slice
opening and there was no need to adjust the lip profile using the
profiling screw jacks installed on top of the headbox slice. The TT
D-Profiler dilution control system operated at full capacity from the
first day, delivering immediate response on the profile, in line with
the guaranteed values of two sigma variation below 0,5 COV for all
productions, and all parameters of the system ran according to the
design.
Toscotec was awarded an order for another TT Headbox-SL
with TT D-Profiler dilution control system to be installed in the United
States on an existing MG machine. This new headbox will have a
pond width of 3405 mm and an expected maximum speed of 800 m/
min. Start-up is planned for the last quarter of 2021.
In the first quarter 2022, Toscotec will also start up two
new special TT Headbox-PF operating on new pressure former
units installed on an existing multi-layer board machine. It is worth
mentioning that these special headboxes feature a dilution control
system specially developed for this project. The target of this rebuild
is to increase machine production and to improve paper quality in
terms of paper profile.
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