TECTRON (The membrane electrode system)
Tectron Electrode System
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Polytechs has served long in the E-coat industry as a UF and
Membrane Electrode Manufacturer. It has developed tubular cell,
another advanced technology in the membrane cells. We would like to
introduce various features of Tectron System to you, which we
guarantee will benefit your E-coating operation.
In our
Tectron System Design, we consider the following criteria, which are
important for our customers. What arrangement of electrodes will
best suite to attain the film build profile which the customer
desires? Is it possible to attain the film build profile without a
modification of the job construction? Aided by a computer simulation
we will find what type of paint characteristics will best suit to
this particular job. Use only electrodes covered by membrane to
eliminate sludge formation, thus avoiding bits and roughness on
finished surface, particularly on horizontal surface. (Some paint
has very little sludge formation and bare electrodes can be used.)
Design a system which attains best acid balancing. Use two different
types of membranes to attain the goal. Stable acid balance helps
stable film build and UF performance Electrode system design that
assists UF performance. Making best maintenance plan for your
membrane electrodes system.
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There are three kinds of basic shell head constructions. And several kinds
of membrane for election. Type
■ Open type
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■ Closed type
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Installation position; side of ED tank.
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FUNCTION OF TECTRON ELECTRODES
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Installed in the E-COAT tank TECTRON electrodes function as the
opposite electrodes to the articles to be coated. It supplies
electric current which deposits paint solid on the articles to form
film. Another very important function of TECTRON electrodes is to
regulate acid(Neutralizer, or it is also called solbilizer)
concentration in the paint bath. As the paint solid in the bath is
consumed additional paint needs to be replenished to maintain proper
solid concentration level. The replenishment paint contains acids as
well as solid, while the solid is being consumed a large portion of
acid is left in the bath thus increasing acid concentration in the
bath which leads to undesirable finish problems. TECTRON electrodes
remove the excessive acid.
As seen the TECTRON electrodes
have very important function and their failure means failure of
coating operation. Your close attention for maintenance is kindly
requested.
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Advantages of TECTRONTM and the sylinder sharp
--TECTRONTM Schematic Construction-- |
■TECTRON cells can be installed at
anywhere in the ED tank, in vertical and horizontal positions.
Up to 10－meter in length can be installed. At present the
longest installation example is 7 meters. It can be also installed
in horizontal position, such as at the E-tank floor or over the
car-body to obtain better and specified film thickness on entire
car-body.
■Easy installation and
maintenance
Tubular form makes the cell to withstand very high
inside/outside pressure. The weight is only 4kg/meter length, which
makes it easy to handle manually without a lifting machine.
■Long life
Stable membrane
performance in long use, low electrical resistance build up, and a
high mechanical strength.
■Easy
acid balance.
The smooth surface of the Tecton prevents paint
solid settlement on anode cells surface. Low acid removal cell,
PT-LAN, are used with the high corrosion-resistant anode materials.
Combination of two kinds (PT-AN, PT-LAN) can control the acid
balance in the paint bath.
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Membrane area： 0.21m2/m
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Electrode area： 0.15m2/m
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TECTRONTM System Flow Chart
-- Anolyte system Flow Chart--
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SLUDGE PREVENTION & ACID BALANCE IN THE ED TANK
SUS316, SUS317 are most widely used anode materials for
E-coat. Sometimes, in order to keep the acid balance of the paint in the ED
tank, bare anode need to be used. However, electro-erosion will happen, and
also sludge will grow on the surface of bare anode. Depending on
operational conditions and components of the paint, the erosion rate can
vary from 3mg to 200mg per kilo coulomb. This leads to two serious problems
of short anode life and contamination of paint by heavy metals, such as Fe,
Ni. Cr, which are the by-products of eroded anode material. Also the sludge
on the surface of the bare electrode, will break away from the anode surface
and gets into the paint causing rough finish.
To avoid this problem, one may cover all the electrode with membrane.
However, this will lead to excessive acid removal. We have developed a
membrane system, PT-LAN, to solve this problem.
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PT-LAN MEMBRANE
PT-LAN is a kind of low acid removal membrane. Advantages of
PT-LAN are,
1. Avoid sludge growth in the ED tank
2. Reduction of sanding/polishing
work on E-coat film.
3. Maintenance of precise acid balance.
We use a
separate anolyte circulation system one for PT-LAN electrodes, and another
for the PT-AN electrodes.
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PT-DSA
If the paint type used is a kind which produce little
sludge, then it is more economical to use bare electrodes with high
corrosion resistance.
ITEM |
SUS316 |
PT-DSA |
MATERIAL |
SUS3162/m |
Precious metal oxide coated on titanium tube2/m |
EROSION RATE |
5-200x10-6g/C2/m |
1-10x10-8g/C2/m |
CONDUCTIVITY OF ANOLYTE |
Under1000μs/cm2/m
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1000-3000μs/cm2/m |
HEAVY METAL IN ANOLYTE |
Cr, Ni, Fe |
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LIFE |
2-4 years |
Average 5 years or more |
MECHANICAL STRENGTH |
Strong impact-resistance |
Weak scratch- resistance |
SHAPE |
48mmx3t tube2 |
28mm round tube2
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AVAILABLE MEMBRANE TYPE
TYPES |
PT-AN |
PT-CA |
PT-LAN |
PAINT TYPE |
Cathodic ED |
Anodic ED |
Both |
SUS316 |
SUS316 |
SUS316 |
PT-DSA |
ACID REMOVAL RATE |
8--9μmol/C |
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< 0.5μmol/C |
AMIDE REMOVAL RATE |
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8--9μmol/C |
< 0.5μmol/C |
WATER
PERMEABILITY INITIAL
WATER PERMEABILIT 1 YEAR USED |
< 0.1cc/A･min |
< 0.1cc/A･min |
< 0.1cc/A･min |
< 0.1cc/A･min |
< 0.1cc/A･min |
< 0.1cc/A･min |
FUNCTION |
Acid removal |
Amide removal |
Acid balance control |
LIFE |
5--8 years |
5--8 years |
2--5 years |
ELECTRICAL RESIS
INITIAL
ELECTRICAL RESIS 1 YEAR USED |
0--10Ω･cm2 |
0--10Ω･cm2 |
0--10Ω･cm2 |
0.1--3KΩ･cm2 |
0.1--3KΩ･cm2 |
0.1--3KΩ･cm2 |
SOLVENT
PERMEABILITY INITIAL
SOLVENT PERMEABIL 1 YEAR USED |
Small |
Small |
Small |
Small |
Small |
Small |
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Comparison with the extruded membrane shell Type
ITEM |
Plastic Injection Type |
TECTRON |
MEMBRANE SHAPE |
cylinder shape |
cylinder shape |
MEMBRANE THICKNESS |
4mm before use, become thicker
after use |
always 0.4mm |
| EXPANSION RATE OF MEMBRANE |
10-15% after used |
almost no change |
| ELECTRIC RESISTANCE OF MEMBRANE |
High |
Low |
CORROSION OF INNER
ELECTRODE |
High |
Low |
| FUNGI CONTROL |
Difficult once found |
Easy to control |
HORIZONTAL
INSTALLATION |
Tend to have much problem |
Many successful
examples
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AFTER SERVICE |
poor by manufacturer |
Excellent by
manufacturer |
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Comparison between Tectron Electrode and Box Electrodes
ITEM |
BOX ELECTRODE |
TECTRON |
MEMBRANE AREA |
0.9m2/m |
0.21m2/m |
EFFECTIVE MEMBRANE
AREA |
0.7m2/m |
0.21m2/m |
ELECTRODE AREA |
0.9m2/m |
0.15m2/m |
EFFECTIVE ELECTRODE
AREA |
0.7m2/m |
0.15m2/m |
MATERIAL OF
ELECTRODE |
SUS316 |
SUS316 other
materials |
WEIGHT OF MEMBRANE
ELECTRODE
(ANOLYTE INSIDE) |
50--100kg |
8--10kg |
INWARD PRESSURE
RESISTANCE |
0.02kg/cm2 |
0.5kg/cm2 |
OUTWARD PRESSURE
RESISTANCE |
0.2kg/cm2 |
0.55kg/cm2 |
MAXIMUM MEMBRANE
AREA INSTALLED PER TANK WALL WIDTH |
0.7m2/m |
1.5m2/m |
INSTALLATION
POSITION |
Only vertical |
Any position |
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