Valued aluminum coil coating line
with foil rolls, recuring furnace, etc.
Color coated plate normally refers to the product of cold rolled or
galvanized plate, whose surface is pretreated (degreased,phosphated
or passivated), then coated (or roller coated) a layer of coating
tobe dried up.
Because of the high intensity, high corrosion resistance, easy
machiningperformance and rich color options etc., color coated
plate is widelyapplicable to the civil construction, communication,
light industries, homeappliance and automobile industries and so
on, particularly the civilconstruction industry, plants,
re-locatable houses, doors and windows haveconsiderable demands of
the plate.Printingand laminating line derived from color coating line can
produce all kinds ofcolors and decorative pattern of color steel
plates with wood grain, leathergrain, marble etc., which has wider
application and higher added value. Theseplates have been widely
used in both inside and outside decoration of thehousehold
appliances and construction industry, especially in places of high
fireprevention requirements like hotels, restaurants, cinemas and
theatres, largevenues and ships etc, and printed coated steel plate
has become the firstchoice.
Cooling and Quenching
Cooling of aluminium strip prior to quenching with water is a
critical part of the line design. In aluminium coating lines this
is typically done with ambient air being applied to the strip at
either the exit zone of the oven or in a separate air cooler
located after the oven and prior to the quench. This is necessary
to avoid thermal shock; created by too rapid cooling of the strip
resulting in a metallurgical change that induces strip shape. Air
cooling is used to reduce the strips PMT (Peak Metal Temperature)
to around 150-170 deg C. The added benefit of this is seen when
incorporating hot film laminating, typically requiring a strip
temperature around 180 deg C.
Water quenching ensures that the colour coated strip is not
recoiled at too hich a temperature. This can lead to coil collaspe,
blocking and marring, common defects associated with poor
temperature control. Water quenches are similar for both steel and
aluminium, however aluminium will cool quicker and it is imperative
to have even cooling by water, as hot spots can create defect
patches on some coatings, especially PVDF’s which are commonly used
in aluminium colour coating.
Line Tensions
Tension control in the strip is a critical aspect of any process
line, however aluminium requires a high degree of control,
especially for lighter gauges. Aluminium colour coated coil can be
as light as 0.18mm (equivalent to 0.06mm steel). Strip tear offs /
breaks will occur unless excellent tension control is applied. This
is done by the lines bridles using rubber covered rolls. However,
in some applications the use of tungsten coated rolls may provide
increased coefficient of friction, improving performance, reducing
slip and improved strip tension control.
It is important when considering any process line design to be
realistic about the gauge range to be processed, however, this
becomes more critical for aluminium, as roll sizes and motors power
need to be optimised to provide satisfactory performance throughout
the gauge range.
Technical Parameter| Material | galvanized steel strip or common steel steel strip |
| Line speed | whole line speed 40-150m/min |
| End product weight | 3,500-15,000kg/coil |
| Outer Dia. of coil | φ900-1,800mm |
| Inner Dia. of coil | φ508/φ610mm |
| Thickness of steel strip | 0.2-1.2mm |
| Width of steel strip | 600-1,250mm |
| Energy | produce gas/natural gas/blast furnace gas,steam and electricity |
| Thickness of color plate | thickness of the frontsingle layer dry film can be adjusted between
10-20μm thickness of the reverse single layer dry film can beadjusted
between 5-10μm |
| Color plate quality | comply with the requirement ofnational standard GB/T12754-2006 |
| Coiling staggered layer | one side≤1.0 mm |
