-
Process flow and raw materials of aluminum
and
aluminum alloy anodic oxidation
tinting
Procedure specification on
aluminum and aluminum alloy anodic oxidation
tinting
1.
Procedure specification(line drawing)
Substrate
→
Mounted
hanging
→
Degreasing
→
Alkaline
etching
→
Neutralization
→
Anodic oxidation
→
Electrolytic
coloring
→
Sealing
→
Electrophoretic coating
→
Curing
→
Unloading
packaging
→
Warehousing
2. Mounted hanging
:
2.1 preparations before mounted
hanging.
2.1.1
Check
the
conductive
parts
like
conductive
beams
and
bars.
They
should
be
regularly
polished, cleaned
or repaired.
2.1.2 Get ready
conductivity of aluminum and aluminum wire.
2.1.3 Check the pneumatic tools and
related equipment.
2.1.4 Check whether
or not requirements like length, count, color,
thickness on the flow paper or
production task list are consistent
with the order drawing and actual materials.
2.1.5 Depending on the specifications
(size of circumscribed circle, external surface
area, etc.) to
determine the count and
space. To control the pigment spacing about 1.2
times than the horizontal
width of the
material shaped, and the white material spacing
about 1 time than the width.
2.1.6
Choose the appropriate rack, and ensure that hook
number of negative and positive hangers
is the same with the count of materials
shaped.
2.2 Mounted hanging:
2.2.1
When
hanging,
fix
the
topside
one
first,
and
then
the
bottom
one,
and
then
arrange
the
remaining sections in
the middle, and tighten the screws.
2.2.2 Before hanging, placing one
aluminum sheet between the material and aluminum
screw p so
that it can prevent poor
conductivity impacting oxidation, coloring and
electrophoresis.
2.2.3 When hanging, it
is not allowed to hang all the materials in the
lower or upper rack.
2.2.4
The
hanged
materials
should
recline
more
than
14
degrees
in
order
to
facilitate
air
exhausting in electrophoresis or
coloring, and reduce the air bubbles.
2.2.5 When hanging, considering the
facing of the decorative surface and groove to
prevent the
color shading, bubbles,
pitting appearing in the decorative surface.
2.2.6 Like some flexible and easily
deformed materials, put one more rack or aluminum
wire in
the middle to prevent friction
between the materials or touching tank plate, and
that may abrade or
burn the surface.
2.2.7 When selecting vice-bar rack, the
plug rod is preferred. When using aluminum
banding, they
must be evenly spaced,
and the outcrops should be less than 25mm.
2.2.8 Materials with great disparity of
cross-section size and shape are prohibited to
hang in the
same row.
2.2.9
When
hanging
and
handling
equipment,
you
must
wear
clean
gloves,
gently
and
well
protecting the surface.
2.2.10
When
hanging
or
handling
equipment,
workers
should
strengthen
self-examination
and
cross-examination, the
failure materials are non-mounted, and take
appropriate measures to deal
with the
surface stained with oil or aluminum burrs
2.2.11 After eliminating
unqualified ones, you must make them up in time by
order.
2.2.12 In hanging area,
materials should not be stored for too long time,
to prevent corrosion of
the surface.
2.2.13
Filling
the
hanging
record
and
oxidation
process
card.
Accurately
calculating
and
fill
in
oxidation
of each linked area, checking models, count and
color by orders at any time.
2.2.14 Do
a good job in shift procedures and keep the work
area clean.
3. Preparation
before oxidized production units:
3.1
Checking the level of the liquid in the process
tank. According to test report card, to adjust the
concentration of the bath solution and
ensure that bath solution is always in line with
technical
requirements. Workers should
frequently sweep the dirt from the bath solution.
3.2
Checking
the
vehicle,
freezer,
rectifiers,
circulating
acid
pump,
water
pump,
transfer
cars,
furnace and other
equipment, any exception should be immediately
solved.
3.3 Check PH (or conductivity)
and cleanliness in the pure water washing tank and
running water
washing
tank.
If
it
does
not
meet
the
technical
requirements,
workers
should
change
it
and
hydrating overflow.
3.4 Open
the alkaline etching, hot pure water tank, sealing
the steam or cooling water tank; open
the
oxidation
tank,
coloring
tank
and
cooling
system
of
electrophoresis
tank
to
ensure
the
uniformity of bath solution and
temperature complying with requirements.
3.5
Check
the
Roots
blowers,
exhaust
blowers
and
exhaust
fans.
Before
the
production,
they
should be opened.
3.6
Carefully check the oxidation process card,
specifically confirm the production requirements,
and prepare the color palette.
4. General requirements for
oxidation sets operation:
4.1 It is not
allowed to hang t more than two hangings every
time. And keeping a certain distance
between the two hangings to prevent
collision between the materials.
4.2
When materials hung into and hung out of the bath
solution, they must be inclined to 30°
.
4.3 Materials falling into the tank
must be removed promptly and hung up in rafts, the
damage
ones must be promptly notified
to group-to-order equipment to make them up.
4.4
In
addition
to
alkaline
etching
and
coloring,
the
sections
should
be
hung
out
after
the
bath
solution drained away to reduce the
flow of waste and pollution.
4.5 When
the hanging materials must cross other sections,
the transferring ones must maintain the
level of the degree to reduce the flow
of liquid and pollute materials and conductive
beam.
4.6 Each process should be
promptly fill in the oxidation process cards, and
sign them.
5. Degreasing:
5.1 Process Parameters
Composition of bath solution: acidic
degreasing agent 2 to 3%
Temperature:
room temperature
Degreasing time: 1 ~
3min
5.2 Operating requirements:
5.2.1
Check
process
card,
make
production
requirements
clear.
Materials
with
the
same
color,
same model and same order or similar
specification should be suspended into the
degreasing tank
simultaneously or
preferentially, so that it can facilitate the
operation the post-procedure.
5.2.2
When the degreasing is finished, the materials
should be hung out of the tank, preventing the
sand from the surface.
5.2.3
After degreasing, the surface should be well-
distributed and wet, and the materials should be
washed by Level 2 water then turned
into the alkaline etching process.
6. Alkaline etching:
6.1
Process parameters:
Composition of bath
solution: plain-surface alkaline etching, sand-
surface alkaline etching
NaOH: 40 ~ 50g
/ l 45 ~ 60g / l
Additives (NaOH): 1 /
12 ~ 1 / 15 1 / 6 1 / 8
Temperature: 40
~ 45
℃
45 ~ 55
℃
Alkaline
etching time: 1 ~ 3min 10 ~ 30min
6.2
Operating requirements:
6.2.1 When
alkaline etching, the forced draught blowers and
exhaust fans should be opened.
6.2.2
When
alkaline
etching
is
finished,
materials
should
be
hung
out
as
soon
as
possible,
finishing
shedding
immediately
and
transferring
to
the
tank
washing,
so
that
it
can
prevent
straying marking from the surface.
6.2.3 Strictly control alkaline etching
process parameters, to ensure uniform quality of
the surface
after alkaline etching.
6.2.4
Post-alkaline-etching
materials
must
be
washed
by
Level
2
overflow.
The
remaining
alkaline liquid
should be
fully cleared away, so that the raffinate
can
’
t pollute other tanks.
7. Neutralization:
7.1 Process parameters:
Composition of bath solution: HNO3: 120
~ 150g / l
Tank temperature: room
temperature
Neutralizing time: 2 ~ 5min
7.2 Operating requirements:
7.2.1.
When
neutralizing,
the
materials
should
be
moved
up
and
down
and
anti-tilt,
fully
neutralizing exhaust liquor in the hole
and remove appearing dust.
7.2.2 Post-
neutralizing materials must be washed by Level 2
overflow, and turn to the anodizing
tank.
7.2.3
The
surface
quality
inspection
should
be
strengthened
to
check
the
surface
of
the
sand
surface conditions,
mottling, burrs, welding lines and other surface
defects, for timely processing,
reworking.
7.2.4 Regularly
check screws are loose or not, to ensure good
electrical conductivity.
8.
Anodic oxidation:
8.1 process
parameters: