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ELECTRO COATING
New high speed flexible machine for the lacquer post-repairing
of easy-open end (electrocoating process) plus Vertical Curing
Oven. Machine is available to bee tooled with two, three or
four lanes. Electrocoating system
PROCESS DESCRIPTION
The E. COATER was designed to electrically coat steel can
ends, mainly for easy open type. This is accomplished by handling
them through a water bath containing the coating solids in
suspension. While in the bath, the ends are connected to the
positive side (anode) of a DC power supply by a special electrode.The
other electrode is immersed in to the bath and connected to
the negative side(cathode). Current flows from the cathode,
through the bath water, to the steel can end.This action causes
the bath solids to adhere to the end, primarily at those locations
where the current flow is the highest, such as score line,
curling cut-edge, moustache, rivet area, tab cut-edge and
scratches or other defects in the existing coating.
SYSTEM DESCRIPTION
The machine consists of four main sections.
buffering feed section,
coating section,
rinse section,
- lacquer curing section.
The description proceeds for one lane system, but all
the sections were designed for two, three or four lanes
and able to handle up to 500 end per minute up to each
lane (with round shape).
Buffering feed
A vertical magnetic buffer receives ends (in flat position
with the curling cut-edge faced to the top), direct from
the conversion press, and accumulates them in a pile above
the down-stacker. Made of a very special alloy steel,
the down stacker splits and drops the ends one by one
on to a syncronised toothed chain which, by a continuous
motion feeds the ends to the bath tank.
Coating
This section contains the bath tank in which a plastic
toothed belt moves ahead synchronised with the anode chain
on top of it. The ends, fed and timed by the chain, are
inserted in to the "pockets" of the plastic
belt. Durlng the immersion they are held in contact with
the "fingers"' attached to the anode chain.
Theese fingers are forced on the curling cut-edge of the
ends and maintain the electric contact for 1,5÷2
seconds, necessary for the electro-deposition of the coating
solid in suspension.
Rinse section
The rinsing chamber is located after the bath tank and,
provided of a special chain, can collect and drive a high
number of ends in vertical position. Deionized water is
supplied to the spray nozzles when required by the machine
logic controller. The water rinses off all the excess
coating material that has not adhered to the end. Following
rinse air nozles both air on both sides of tho ends to
dry them prior the curing action. Water discharged is
very low contaminated and doesn't cause conflicts with
environmental laws.
Lacquer curing section
A stainless steel made vertical oven completes the system.
The chain coming from rinse section drives the ends through
the oven and drops them on the output conveyor. The heaters
are distributed along the path. Special efforts and particular
solutions have been taken to minimise the heating power
acconsumption, guaranteeing the best performance of electrophoretic
process with NO SOLVENT EMISSION and no air contamination.
This is accompilshed by using electric heaters, computer
controlled.
Curing cycle
The oven performs the temperature trend, specified by lacquer
supplier, by a fine thermal - regulation distributed in
eight different sections. The exposition on the ends to
the heat is gradual, curing the lacquer without cracks:
- 50 seconds to increase frorn 20°C to 200°C - 90
second curing at 200° C - 40 seconds to decrease from
200°C to 40°C.
Operating conditions
The suspension bath must be prepared using our Electro coating
lacquer, product code 8389004. The best repairing result
will be achieved following the technical specifications
below.
- Solid 1,2 ÷ 1,7 %
- Conductivity 360 ± 20mS
- Voltage 330 ÷ 370V'
- Temperature (bath) 20 ÷ 25°C
OPTIONAL EQUIPMENT
Water deionizer
The system can be completed with a unit to produce deionized
water.
Ultrafiltration unit
It's a unit connected in parallel to the bath tank in order
to reduce the water and lacquer consumption and keep constant
the bath parameters.
Ultrasonic chain cleaning
This system keeps continuously cleaned the chains of the
rinse and Curing sections from lacquer deposit, causing
an important reduction of maintenance time.
View technical data
and design
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NEW COMPACT SPRAY/ELECTROCOATING SYSTEM