2 - ALU-WEB.DE

6 ROLLING 4 | 12-2009 APT ALUMINIUM NEWS
Important equipment partner for the aluminium industry
BWG: specialist for strip processing plants
During the course of its
50-year history, Duisburgbased
BWG Bergwerk- und
Walzwerk-Maschinenbau
GmbH has developed into a
specialist for strip processing
plants, primarily for the
aluminium and steel industries.
The aluminium industry
is very important for BWG,
accounting for about 40
percent of turnover. BWG’s
development work has resulted
in the company receiving
many notable orders for
projects in this industry in
recent years. They are mainly
based on three product lines
for which BWG has received
worldwide recognition:
■ strip coating lines with a
high degree of flexibility
for small production runs
■ "Levelflex" lines for strip
that is extremely flat
■ continuous strip annealing
lines.
Strip coating lines
After supplying highspeed
canstock lines to the UK
and Germany in the 1980s,
BWG set new standards for
strip coating lines for the aluminium
industry with its socalled
coil coating lines.
The development of
today’s leading technology
began in 2000 with a project
for ThyssenKrupp. An elec-
trolytic galvanising line had
to be converted into a thinfilm
coating unit for producing
high-grade sheet for the
car industry. ThyssenKrupp
decided to co-operate with
BWG with the aim of jointly
developing a new generation
of coater. BWG subsequently
discussed this coater concept
with aluminium customers in
order to modify it to meet the
requirements of the aluminium
industry.
The expertise gained
was used in various projects
in the aluminium industry,
starting with an order from
Alcoa Architectural Products
of Merxheim, France. This
unit is designed for coating
aluminium strip up to two
metres wide, which is mainly
used for architectural appli-
cations. BWG built a further
strip coating line for Alcoa
Samara Metallurgical Plant
in Samara, Russia. This combined
line for can-end stock
and architectural strip in
widths up to 2,100 mm and
thicknesses from 0.15-0.8
mm places particularly great
demands on the flexibility
of the plant. In view of the
required flatness of the strip,
the Samara line was additionally
equipped with the
latest generation of Levelflex
stretch-bend-levelling line.
Strip lacquering plants
newly developed by BWG
have played a role in the com-
BWG lithographc line, finishing line at Alcoa Bohai
Aluminum Industries Company Ltd.
Coil coating line for architectural strip at Alcoa Merxheim, France
pany’s success. In addition to
fully automated adjustment of
the coating rollers, they have
a reversible roller, for which a
patent has been applied. This
makes it possible to choose
between coating in the usual
manner against the roller
or against the strip tension,
which is particularly beneficial
for strip thicknesses less
than 0.3 mm. A novelty with
the Samara plant is the installation
of an automated trimming
shear in a can-end line,
which allows the strip width
to be changed on the fly while
the strip is moving.
BWG is also highly
regarded as a partner for the
modernisation and the conversion
of existing plants.
A new concept is currently
being implemented dur-
ing ongoing plant operation
at Novelis in Nachterstedt,
Germany. The annealing and
coating plant, which went
into operation there in 1997,
was the first continuous line
for the simultaneous annealing
and coating of aluminium
strip with a width of up
to 2,100 mm and thicknesses
from 0.6-3.0 mm for both the
automotive sector and architectural
strip. Now, thanks to
the installation of a new strip
feed and exit system, including
an innovative storage concept
and separate strip flow
for several new process steps,
a new, second, continuously
operating line is being created
within the existing line. After
completion of the conversion,
Novelis will be able, for
example, to handle automotive
strip and canstock at the
same time on both units and
thus significantly increase the
productivity of the plant.
Highest possible
strip flatness achieved
using Levelflexlines
A major consideration
during cold rolling of strip
is its ultimate flatness. In
this field, BWG has acquired
considerable understanding
of the process and developed
its so-called Levelflex lines in
various forms.
For applications with particularly
high demands for
surface quality and absence
of residual stress, BWG uses
its so-called Pure-Stretch-
Levelflex process, a further
development of the conventional
pull–stretch process.
The Pure-Stretch-Levelflex
process avoids the formation
of residual waviness in the
middle of the strip by splitting
the stretching process
into three stretch zones: the
major part of the unevenness
is eliminated in the first zone,
it is reduced further in the se-
cond zone and the final flatness
is reached in the third
zone, together with a minimised
residual curvature.
By using a variable-contour
stretching drum in the final
stretch zone, very wide strip
can also be levelled optimally.
Lithographic strip
lines – a key product
from BWG
With the large number of
lithographic strip lines it has
supplied, BWG has set quality
standards that have made
it the global leader in this
field. The Lithographic Centre
No. 3 at Hydro Aluminium
in Grevenbroich, Germany,
which has been in operation
since 2005, has confirmed this
standing. The unit, which has
received much attention, was
the model for a further line
supplied by BWG to Alcoa
Bohai Aluminium Co. Ltd in
Qinhuangdao in the Chinese
province of Hebei, which was
commissioned at the end of
2008. Among other things,
a special feature of this new
BWG litho strip line is the
three-zone stretcher. It offers
the possibility of adjusting the
individual degrees of stretch-
all Photos: BWG
ing so precisely that highgrade
lithographic strip can
be produced from different
grades of strip feedstock.
Another lithographic strip
line from BWG will be part
of the new aluminium strip
mill at Xiamen Xiashun Aluminium
Foil Co Ltd, which
has a total capacity of 200,000
tonnes a year and starts operation
at the end of 2009. Within
the space of a few years, this
company has developed into
one of the most important
manufacturers of aluminium
foil. Litho Strip Line No.1 at
Xiamen Xiashun is designed
for strip from 850-1,700 mm
wide and 0.12-0.5 mm thick.
The latest BWG technologies
for stretch levelling, side
trimming and degreasing are
incorporated into the line.
Chalco Ruimin in Fuzhou,
China, which is part of the
Aluminium Corporation
of China (Chalco) group, is
also taking advantage of the
benefits of the BWG cleaning
and Levelflex technology
for a new, 70,000 tonnes
a year plant for premium
lithographic printing plate
(for CTP applications). This
BWG Pure-Stretch-Levelflex
line also incorporates patented
innovative technological
features such as a multi-zone
stretcher with variable contour
rollers and a precision
cut-to-length line with direct
gap measurement and width
adjustment on the fly. The line
is designed for aluminium
strip with thicknesses from
0.14-0.5 mm with a maximum
width of 2,150 mm.
Conti-annealing
Continuous strip-annealing
lines have also developed
into a core process technology
at BWG and resulted in
the company winning several
important orders. The first
conti-annealing line supplied
by BWG was for use with steel
strip at the Corus plant in Port
Talbot in Wales. Its output and
EU imposes anti-dumping
tariffs on aluminium foil
The European Union has
imposed five-year duties
on aluminium foil imported
from China, Brazil
and Armenia over alleged
dumping charges.
EU officials declared
that the duties were up to 30
percent as a punishment to
Chinese exporters for selling
the product at a price below
production cost. The tariffs
on Brazilian products are
17.6 percent and on foil from
Armenia 13.4 percent. This
measures hit Companhia
Brasileira de Aluminio and
UC Rusal’s Armenal plant.
The five-year duties came
after six-month provisional
duties expired and went into
effect after published in the
EU’s Official Journal on 8
October. The six-month levies
were up to 42.9 percent.
The EU investigation into
sales of aluminium foil from
the three countries began
in July 2008 after receiving
a dumping complaint by
Eurometaux, the European
Association of Metals, on
behalf of producers representing
a major proportion,
in this case more than 25 per-
reliability were so impressive
that BWG received the order
in September 2000 to supply
all parts of the strip flow
for the continuous annealing
facility at the former Corus
aluminium plant in Duffel,
Belgium (now Aleris). A
special feature of this plant,
which is used to treat strip
up to 2300 mm wide in thicknesses
from 0.5-3.5 mm in
accordance with the strict
guidelines of the automotive
and aviation industries, is the
use of Pure-Stretch-Levelflex
technology.
Based on the experience
gained with the unit in Duffel,
BWG has recently modernised
and supplied two further
continuous annealing lines
for aluminium strip:
■ the partial modernisation
of the existing annealing
line at Alcan Specialty Sheet
in Neuf-Brisach, France
■ the supply of the mechanical
and hydraulic equipment
for a new continuous
annealing line for Hydro
Aluminium Deutschland in
Grevenbroich, Germany.
On 1 August 2009 BWG
established its new Thermal
Strip Treatment division.
With this technology transfer
between VITS and BWG,
BWG is meeting the challenges
of the steel and aluminium
industries. The products of
the new business division
expand BWG’s capabilities in
process technology for stripprocessing
lines in the metallurgical
sector. The Thermal
Strip Treatment division is
thus a logical extension to the
strip-coating and aluminium-annealing
line activities
in order to be able to offer
integrated solutions here,
too. The whole of the newly
formed division is located at
the Duisburg works of BWG
Bergwerk- und Walzwerk-
Maschinenbau.
www.bwg-online.de
cent of the total Community
production of aluminium
foil. Companies located in
China and affected by the
EU decision are Alcoa Bohai
and Alcoa Shanghai with
an anti-dumping duty of
6.4% each, Shandong Loften
(20.3%), Zhenjiang Dingsheng
(24.2%), all other Chinese
companies (30%).
The measure covers
imports of aluminium foil
of a thickness between 0.008
mm and 0.018 mm, in rolls
of a width not exceeding 650
mm and of a weight exceeding
10 kg.