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sheets are then pre-treated with a chemical
and electro-chemical process, without any
chromium salts. Further cleansing and neutralization
complete the chemical action; the
sheets are then cut and successively piled
up. The piles of sheets then feed the Group’s
lithographic lines that fully apply the layer of
“prime” paint; they will then be stamped before
going through the phases of deep-drawing
and other specific operations for the single
capsules, carried out in the different
plants, such as the formation of screws or the
incision of “pilfer-proof” closures.
The plant, as we said, can carry out surface
treatment and degreasing of aluminium before lithography
and stamping, with a Chrome-free process. A
correct and uniform “pre-treated” surface is of the utmost
importance, along with the type of alloy and of the
physical state of the metal, to obtain a good deformability
during deep-drawing, without tears or anisotropies.
For these purposes it is important that the system act as
a “tension leveler” on the ribbon, improving its flatness.
This function on the Magenta plant occurs immediately
before the transverse cut.
Fabrizio Venezia, General Manager of the Magenta plant,
underlines the high innovation level of the plant: “In this
complex set of processes we reached objectives that
Attualità
Dal foglio d’alluminio alle chiusure Hi Tech
in our sector represented targets that had
beensoughtafterforalongtime.Thisisacoil
pre-treatment plant that uses chrome-free
chemical baths that can guarantee the same
efficacy in cleaning the surface and in its conversion
into surface deposit, ensuring the
highest adherence between the sheet and the
paint and ink layers. The reels can host very
large coils enabling high hourly productivity
rates. Besides, the automatic warehouse that
serves the plant allows a great flexibility”.
Your words clearly show that,
during the plant’s study and design
phases, the environmental aspect had
aremarkablerole.
Ecology in general and the importance of respect for the
environment are conditions for any innovative investment.
In our case I think there have never been any doubts as to
the fact that the Group, given its technological and productive
leadership, must be strongly responsible for the
environment in all its actions.
As a tribute to our magazine’s name, could
you tell us what alloys you are currently using?
We mostly use aluminium alloys belonging to the 3xxx
and 8xxx families, in a physical state of medium harden-
Il nuovo impianto di
pretrattamento dell’alluminio
da 28.000 tonnellate l’anno
di coil rafforza ulteriormente
la leadership tecnologica
di Guala Closures Group.
Lo spiega Fabrizio Venezia,
General Manager dello
stabilimento di Magenta
Negliultimi treanni,l’avviodelnuovoedinnovativoimpianto
di pretrattamento alluminio ed il raggiungimento dellesuemassimeprestazionipreviste,hannorappresentatoun
significativo successo strategico per lo stabilimento di Magenta
(Milano) di Guala Closures Group e per l’intero gruppo
italiano ai vertici mondiali nella produzione di chiusure
perbevandealcoliche,vino,acquemineralieprodottifarmaceutici.
L’azienda ha deciso nel 2011 di centralizzare a Magenta,
nello stabilimento allora da poco acquisito, la prima
fase di lavorazione dell’alluminio destinato a tutti gli stabilimenti
di Guala Closures, che producono chiusure metalliche
in diversi paesi quali Argentina, Australia, Cina, Gran Bretagna,
Messico, Nuova Zelanda, Polonia, Spagna, Sud Africa,
UcrainaeaglistabilimentiitalianidiTermoli,SpinettaMarengo
e Vasto.
Ilnuovoimpiantoèstatorealizzatotrail2011eil2012,per
entrare in servizio nel corso del 2013. Il flusso di lavorazioni
chevienesviluppatoaMagentacomprendeunaprimafase
disgrassaggioelavaggiodeicoilprovenienticonprocedure
completamente automatizzate da un magazzino automatico
di inusuali grandi dimensioni. Successivamente, il laminato
vienepretratttato conunprocessochimicoedelettrochimico,esentedasalidicromo.Ulteriorilavaggieneutralizzazioni
completano l’azione chimica, seguita poi dal taglio in
fogliesuccessivoimpilamento.IfogliimpilativannoadalimentarelelineelitografichedelGruppocheapplicheranno
inpienolostratodivernice“difondo”echesarannosuccessivamente
stampati prima di passare, nei vari stabilimenti,
allefasidiimbutituraedalleoperazionispecifichediogni
capsula, quali ,ad esempio, la formazione della vite o l’incisionenellachiusure“pilferproof”.
L’impianto, come detto, è in grado di trattare superficialmente
e sgrassare l’alluminio prima della litografia e della
August 2016 N° 04
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