Exile the troublesome and time-consuming maintenance work!

Etching Liquid

ELECTROLY TIC
REGENERATION UNIT
Realized

Utility Model Act
Law number: Act No. 3146425

the release fromthe unglazed cylinder.

The etching solution used in thepretreatment of plastic plating is
circulated and regenerated.
It reduces troublesome maintenance.
There is no decrease in current efficiency due to clogging.
Replacing the unglazed cylinder currently in use is easy.
Contributes to power cost reduction.
The renewal cycle of the cathode solutionis prolonged.
(sulfuric acid)                                                                                      ­   ­­    ­              ­ ­            ­
                 

      

Operation example
Changes in Cr3+ after the introduction of the unit.

Cr3+concentration(g /ℓ)

Cr3+

Working days
*With the cooperation of companies for the purpose of measuring the transition of Cr3+ from adverse conditions,this data has been tested under unusually high concentration conditions.
Thanks to the experience and management technology of our partner companies,
we have made it possible to collect live data through demonstration tests in normal operation.

Effectobtained

・Stable control of Cr3+ value is possible.
・There is little clogging of the membrane.

・Easy maintenance.
・Contributes to power cost reduction.

Cost comparison.
Comparison of cumulative cost trends.

     
                               
 
    

Etching liquid electrolytic regeneration unit
Unbaked cylinder

Cumulative cost

After the third year of use,
there will be a difference incumulative costs.

<Unbaked cylinder /Etching liquid electrolytic regeneration unit>

1styear2ndyear

3rdyear4thyear5thyearYear of use

6thyear7thyear8thyear

Principle of electrolytic regeneration unit
Etching process principle

ABS resin etching < Chromic acid・sulfuric acid >                                 
Cr3+ is an impurity and reduces
the etching ability.

It leads to deterioration ofprocessing quality.

Cr3+
Cr6+

Cr3+
Cr6+

Cr3+
Cr2O72-

Cr3+
Cr6+

Cr3+
Cr6+

ABS RESINIf the oxidation
treatment is not
performed, trivalentchromium increases
and accumulates, andthe etching solution
ages.

Butadiene oxidative
decomposition products

Cr3+old liquid

Cr3+Cr3+ Cr3+ Cr3+ Cr3+Cr3+ Cr3+ Cr3+ Cr3+ Cr3+

By electrolytic oxidation, Cr3+ isoxidized to Cr6+at the anode, andRegenerate the old liquid andreturn it to the etching tank.

ABS RESIN

1 When there is no diaphragm on the cathode.

Step,

If the cathode is electrolyzed with no diaphragm, the Cr6+ oxidized at the anode is reduced
to Cr3+ at the cathode again.
anodeCathode< Electrolysis regeneration tank >Chromic acid / Sulfuric acid

Cr6+

Cr
Cr6+
3+

Cr
Cr6+3+

Cr6+

Cr3+
Cr6+

< Etching tank >Cr3+
Cr3+Cr3+

Cr3+
Circulation

Cr3+

Cr3+
Cr3+

ABS RESIN

Hexavalent chromium produced by oxidation isreduced to trivalent chromium again in one pole.

At the same time as the reoxidation reaction (Cr3+→Cr6+) occurs at the anode,
the reduction reaction (Cr6+→Cr3+) occurs at the cathode.
It is difficult to quickly reduce the Cr3+ concentration.
In order to solve this problem, unglazed or ceramic is applied and put into practical use as a diaphragm.

2 When the cathode is surrounded by [Unglazed cylinder]

Step,

When the cathode is surrounded by a unglazed
cylinder, Cr6+ is not reduced by the cathode. However,dirt in the solution adheres to the unglazed cylinderand causes clogging. As a result, the resistance value
rises and it becomes difficult for the current to flow.
In order to secure the required current, the voltage isincreased to deal with it, but working under high voltage
increases the cost of electricity. Working at high voltage
anode< Electrolysis regeneration tank >Cr< Cathode liquid circulation tank >Sulfuric acid

CathodeUnbaked cylinder

6+

can cause damage to the unglazed cylinder.
Since the oxidation reaction efficiency at the anodedepends on the amount of energization, it is necessary tokeep the performance of the unglazed cylinder constant inorder to secure the amount of energization at the assumedvoltage. Therefore, it is necessary to maintain the unglazed
cylinder on a regular basis. The force or unglazed cylinder isvulnerable to impact and easily cracked.

CirculationOnly Cr3+ oxidation
takes place.

Cr6+
Cr6+Cr3+Cr6+< Etching tank >Dirt

Chromic acid / Sulfuric acidCr3+

Cr3+Cr3+Circulation

Dirt adheres to the unglazed cylinder,
making it difficult for electricity to flow.
Electric power costs are required tosecure the amount of electric power.

Cr3+
Cr3+

ABS RESIN

In order to increase the energization efficiency, the plate thickness is being reduced,
When the thickness is reduced, the mechanical strength is weakened and the risk ofcracking or breakage increases.

3 When the cathode is surrounded byStep,[Etching solution electrolytic regeneration unit]

When the cathode is surrounded by the etchingsolution electrolytic regeneration unit, Cr6+ can supply
current at the cathode.
anode< Electrolysis regeneration tank >Etching liquid electrolytic
regeneration unitCr

6+

It will not be reduced. Furthermore, the adoption of a
special thin film (polymer charged film) enables stable
control of the Cr3+ value.
< Cathode liquid circulation tank >Sulfuric acid

CathodeCirculation

Only Cr3+ oxidation
takes place.

Cr6+
Cr6+

< Etching tank >Chromic acid / Sulfuric acid

Cr3+Cr6+

Since there is little clogging,current easily flows.
Power costs can be reduced.

Cr3+Circulation

Cr3+Cr3+

ABS RESIN

Since this membrane mainly transmits only electricity,
it is less likely to be clogged with dirt. Maintenance is very easy.
(*A small amount of metal ions permeate.)

Unit standard specifications

Main items
Electrolyzed dialysis membrane
Cathoade
Unit body
Mesh protector
Packing
Construction

Material
Strong acid resistant polymer charged membrane
LeadPVDF
Titanium
PTFE soft packing
Cathodic fluid overflow circulation

Total System Plannerfor plating and surface treatment.

NOSAKA ELECTRIC CO., LTD.

2-2-9 Kehinzima, Otaku, Tokyo, Japan, 143 - 0003
TEL : 03 -3790 -1531 FAX : 03 -3790 - 0224
URL http://www.nosaka.co.jp/■RELATED COMPANY■NOSAKA ASIA CO.,LTD.( THAILAND)/ST.NOSAKA CO.,LTD.( THAILAND)/NOSAKA DE MEXICO,S.A.DE C.V.(MEXICO)