CPT International 01/2019

COMPANY
ring service,” stresses Ploch. According
to Foseco, the advantage of the plant is
cost reduction – thanks to a lower reject
rate and less extra work – as well as
increased productivity and optimized
drying, with positive effects on the quality
of the castings.
An alcohol-based coating is not an
alternative solution for Ploch. “On our
casting line we still use alcohol coatings
for the cope and drag boxes, but
water-based for the cores. The disadvantage
of the alcohol coating is that
the surface of the binder bridges can be
destroyed by the heat, resulting in loss
of mold strength. Water-based coating
is gentler, it does its job, evaporates and
I can work on the core again after eight
hours. There is also less smell.” The iron
foundry uses no-bake furan resin sands
with 20 % of new sand and 80 % of old
sand for the cores.
Ploch is a pragmatist through and
through, and is totally involved with his
job. He is prepared to put up with various
hardships: he lives in Dinklage
during the week, commuting to his wife
and children in Heidenheim, 600 kilometers
away, on weekends and for
family celebrations. In addition to his
profession and family, Ploch has two
other passions: the German Premier
League football club VfB Stuttgart and
Thai boxing. He is also working on professionally
rounding out his rise from
foundry mechanic to Managing Director
with an additional course he is taking in
foundry technology at the German
Foundrymen’s Association (VDG) Academy
in Düsseldorf.
The cope and drag boxes are
put together on the closing
machine, then the casting boxes
are transported to the molding
line opposite, where they are
shot.
The molding boxes are prepared
for casting by workers with respirators.
No-bake furan resin
sand is used.
Induction furnace tandem to
replace cupola furnaces
The replacement of the two cupola furnaces
with induction furnaces is fully
planned, but has not yet received final
approval. Every hour, the cupola furnaces
currently supply ten tonnes of melt
of the alloy GJL 250, the only metal
used at Dinklage. While one furnace is
actively melting, the other receives
maintenance – requiring manpower for
which Ploch must maintain 3-shift operation.
This melting system, especially
suitable for serial casting, is now rarely
found in Germany. Only about 60
cupola furnaces are still operating in
German foundries.
The two cupola furnaces have a
central position in the production hall
in Dinklage. Water constantly flows
over the outer shell and the refractory
material of the melting furnaces to
cool them. Ploch and his team have calculated
that 2-shift operation could be
reintroduced with induction furnaces.
At the same time, although the overall
electricity price is rising, the basic price
for the iron foundry would actually fall
as a result of the higher purchase
quantity: 15 instead of 1.6 MW of electricity
a month. There are, however,
numerous other reasons for changing
the melting technology. For one thing,
there is the problem of the smell
(which annoys residents in the immediate
vicinity of the foundry), as well as
difficulty procuring input material. As
flexible as cupola furnaces are, reasonably
priced input material – Grade 3a
commercial casting scrap, consisting of
old radiators and water pipes, up to
now obtained from Poland, the former
East German states and the Czech
Republic – is becoming increasingly
rare, leading to rising prices. A new
induction furnace tandem would double
melt performance while reducing
the workload and eliminating the
smell problem – arguments for the
change that Ploch considers unbeatable.
He estimates the costs for the furnaces,
the periphery and installation at
5 million euros.
In order to equip the foundry for
the future, Ploch also wants to install a
sixth processing center with a 5-axis milling
machine in the machining shop, as
well as buy a molding sand mixer and a
casting cooler. There should also be a
cooling section for the castings, and
drying furnaces for the cores. Solution
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