1. Corrosion Resistant Coating Sophisticated Zinc Solutions
Highest corrosion
protection attractive look
CL-AK Technology GmbH – Zinc Solutions

2. Profile Founded in Solingen, Germany in 2001
Distributors in 15 countries
Own laboratory for developments & analysis
Our production facility is ISO 9001 certified
CL-AK Technology GmbH –Zinc Solutions

3. Our Vision Continuous development and realization
of innovative plating solutions
resulting in
significant economical benefits
for our customers
CL-AK Technology GmbH – Zinc Solutions

4. Our portfolio Pretreatment Decorative Processes Functional Processes
Corrosion Protection
Degreasers
Etchants and Pickling solutions
Chemical brightening
& Deburring processes
Bright Chrome
Bright Silver
Bright Nickel
Satin Nickel
Tin Nickel
Acid Copper
Tin Cobalt
Cyan. Copper
Semi bright nickel
Hard chrome
Bright Silver (reel-to-reel)
Electroless copper
Tin
Acid zinc
Cyanide zinc
Cyanide free, alkaline zinc
Plating-on-Plastics
Post treatment
Specialties
Technical Services
Acid Copper
Semi bright nickel
High sulphur nickel
Bright nickel
Micro-porous nickel
Bright chrome
Corrosion protection
and anti-tarnish for
different metals.
Technical Advice
and Consulting
Electro polishing processes
Metal strippers
Waste water treatment
Instrumental Analysis
(AAS, HPLC, UV, IR)
CL –AK Technology GmbH – Zinc Solutions

5. Corrosion Resistant Coating Zinc/Zinc-Alloy Plating
The value of zinc/zinc-alloy plating as a rust proof finish for iron and steel has long been appreciated.
Although zinc/zinc alloys are considered to be similar in their galvanic behaviour to iron in most environments. They do differ in many of their physical deposit properties.
These differences should be considered in selecting one coating versus another for a given application.
In recent years electrode position of zinc/zinc alloys has made rapid strides and is now used extensively for finishing all manners of iron and steel products.
CL–AK Technology GmbH – Zinc Solutions

6. Corrosion Resistant Coating Zinc/Zinc-Alloy Plating
The protection afforded to iron and steel is largely due to its behaviour as the anode in any electrochemical reaction that may occur.
From this it might appear that the protection would be of short duration, but in practise rapid corrosion does not occur, as the zinc develops upon its surface a film of oxide which resists further attack.
Corrosion of this sort usually can be minimized by application of chromate conversion finishes.
For general protective purposes it is usual to apply zinc/zinc alloy deposits from 5-25 microns.
CL-AK Technology GmbH – Zinc Solutions

7. Zinc/Zinc Alloy Plating Standard Process Sequence
Soak Cleaner
Rinse
Acid Dip
Electrolytical Cleaner (anodic)
Zinc/Zinc-Alloy Plating
Dragout Rinse
Predip
Passivation
Topcoat
Drying
CL-AK Technology GmbH – Zinc Solutions

8. Zinc/Zinc Alloy Plating Zinc Plating Equipment
Alkaline Solution
These solutions require plastic- or rubber lined mild steel tanks. Rubber lined equipment should be thoroughly cleaned before use.
A means of heating should be provided so that the solution can be raised to working temperature.
Mild steel heating and cooling coils are suitable or mild steel sheeted electric immersion heaters can be used.
For barrel plating the use of fully immersed barrels is advised. The normal barrel speed is 5-7 rpm.
On rack plating tanks it is advantageous to employ mild mechanical agitation, solution circulation or mild air agitation.
Continuous filtration is necessary.
CL-AK Technology GmbH – Zinc Solutions

9. Zinc/Zinc Alloy Plating Zinc Plating Equipment
Acid solutions require equipment which is similar to that uses for bright nickel plating, e.g.rubber lined steel tanks.
For solution heating, resp. cooling titanium steam heating coils may be employed.
The tanks should be fitted with air agitation pipes or mechanical cathode rod movement.
Continuous filtration is generally necessary.
 Acid solutions are very corrosive because of their chloride content, so care should be taken to maintain all items which come into contact with the solution.
Acid Solution
CL-AK Technology GmbH – Zinc Solutions

10. Zinc/Zinc Alloy Plating Zinc Plating Solutions
For the electrodeposition of zinc/zinc alloys various solutions are available, these differ considerably both in composition and in characteristics, but may be classified generally as being either of the acid or the alkaline type.
Alkaline non cyanid zinc
This type of solution gives a bright deposit with high efficiency and is used either where effluent requirements are strict and cyanide and organic complex ants cannot be tolerated. Suitable for rack or barrel.
Alkaline zinc-alloys
Offer in general excellent corrosion resistance, harder deposits than conventional zinc.
 Accepts a variety of chromate conversion coatings, easy to operate.
 Barrel has slower plating speed than acid formulation.
CL-AK Technology GmbH – Zinc Solutions

11. Zinc/Zinc Alloy Plating Zinc Plating Solutions
Acid zinc
These can give dull or brilliant zinc deposits and can be used for the direct zinc plating of decorative and industrial iron and steel. The cathode efficiency approaches 100 %, therefore high tensile steel components can be plated with little risk of hydrogen embrittlement. Suitable for rack or barrel.
Acid zinc-alloys
The plating speed is faster than alkaline formulations, allowing barrel plating at faster deposition speeds. Best formulations for reel to reel plating.
Deposit is typically more brittle than alkaline deposits.
Contains Ammonium, needs dual rectification for zinc-nickel.
CL-AK Technology GmbH – Zinc Solutions

12. Salt Spray Hours to white corrosion
Zinc/Zinc Alloy Plating Suggested Standards for Quality Zinc Coatings on Iron & Steel Products
Degree of exposure
Minimum thicknesses
Chromate Finish
Salt Spray Hours to white corrosion
Typical Application
Mild Exposure to indoor atmospheres with rare condensation and subjected to minimum wear and abrasion
5 micron
None Clear Black Iridescent Yellow
12-24
72-96
Screws, nuts, bolts, wire goods, fastener
Moderate-Exposure mostly to dry indoor atmospheres, but subject to occasional condensation, wear or abrasion
8 micron
None
Clear
Black Iridescent Yellow Olive drap
------
Tools Zipper
Shelves
Machine parts
Severe-Exposure to condensation, perspiration, infrequent wetting by rain, cleaners
13 micron
None Clear
Tubular furniture, Window-fittings, Builders Hardware
Very Severe-Exposure to bold atmospheric conditions and subject to frequent exposure to moisture, cleaners and saline solutions plus likely damage by denting, scratching or abrasive wear
25 micron
Plumbing fixture, pole line hardware
CL-AK Technology GmbH – Zinc Solutions

13. Zinc/Zinc Alloy Plating Specifying the finish
A. Thickness Atmospheric exposure tests in several countries have supported the generalization that the protective value of zinc, zinc alloy is proportional to their thickness.
That is, a steel part coated with 10 microns of zinc will be protected from rusting about twice as long as another part coated with 5 microns and exposed for the same time. Thickness is, therefore, a very important item in a quality specification.
B.Chromate
Chromate finishes are the first line of defence against corrosive attack on the plated coating and these thin films do an outstanding job of enhancing the total protective value of the metal coating. The chromate coatings serve to improve appearances of the plated coatings in delaying formation of white corrosion products which might interfere with function of a component.
C.Protective Value
As indicated earlier, specifying a minimum thickness of zinc, zinc-alloy is the best way to guarantee protective value of high performance. Some buyers require additional performance in the standard salt spray test as another acceptance requirement. A different test that is becoming more and more popular in the automotive industry is a cyclic test. In this test, the component parts are subjected to a cycle of salt fog and humidity dictated by the specifier.
CL-AK Technology GmbH – Zinc Solutions

14. Zinc/Zinc Alloy Plating Specifying the finish
C.Adhesion
The coating must remain adherent to the basis metal when subjected to bending, cutting or grinding. There is no accepted standard of adhesion and these tests can only be considered
qualitative.
D.Appearance
Appearance cannot be readily specified because it involves factors which are not easily assessed such as brightness, roughness, uniformity of colour, freedom of blisters, pits and other
surface defects. For chromated finishes the general appearance is automatically specified when the type of finish is selected.
F.Hydrogen Embrittlement
All high strength steel parts are susceptible to embrittlement caused by absorption of hydrogen during the processing of the steel or in cleaning, pickling, plating operations.
To avoid possible failure of such components on the shelf or in service due to delayed cracking, it should be noted that the parts shall be heated within 1-2 hours after plating for 3-4 hours at degrees Celsius.(ASTM B 242)
CL-AK Technology GmbH – Zinc Solutions

15. Zinc/Zinc Alloy Plating Protective Value
A.Compound Cyclic Corrosion Test
This test is comprised of a series of tests, usually consisting of neutral salt/fog spray, hot air blowing on parts and high humidity. The specifier can specify exactly which cycle is most meaningful. Some use an 8 hour cycle comprised of 4 hours salt fog, then 2 hours hot air blowing on the parts, then 2 hours high humidity. The cycle is repeated again and again until white corrosion and the red corrosion (failure) is observed and recorded. Some specifiers use a cycle that takes 24 hours to complete. The specification will typically detail how many “cycles“ the tested parts must complete to pass.
B.Salt Spray Test
The salt spray test has been used to asses the protective value of zinc coatings. However, the test do not correlate with any given service exposure. Most purchasers do use the salt spray test to assess the quality of chromate treatments on zinc, zinc alloys by specifying the number of hours to appearance of white corrosion products on a significant surface.
C.Lead Acetate Spot Test
The presence of clear chromate finishes is often hard to detect visually. On zinc coatings
such films can be detected by spot testing with a drop of solution containing 5 % lead acetate in water. The time elapsed to the appearance of the coloured spot is compared within the time required for a spot to appear on an unchromated coating.There is no valid correlation with the salt spray test. -
CL –AK Technology GmbH – Zinc Solutions

16. Zinc/Zinc Alloy Plating Suggested Bath Formulation – Operating Conditions
a. alkaline cyanide zinc
g/l zinc
g/l sodium cyanide (free)
60- 75g/l sodium hydroxide
proprietary additive
cathode current density: 1,5 - 3,0 amp/dm2
cathode current barrel: 0,5 - 0,8 amp/dm2
temperature: °C anodes: zinc
b. alkaline non-cyanide zinc
6 -10 g/l zinc
g/l sodium hydroxide
cathode current density: 1,0 - 4,0 amp/dm2
cathode current barrel : 0,5 - 0,8 amp/dm2
temperature: °C anodes: steel
c. acid zinc
30-55 g/l zinc
g/l chloride
cathode current barrel: 0,4 - 0,8 amp/dm2
pH : ,5 - 5,5
temperature : °C
agitation: air/cathode rod anodes : zinc
CL-AK Technology GmbH – Zinc Solutions

17. Zinc/Zinc Alloy Plating Suggested Bath Formulation –Operating Conditions
d. zinc-cobalt alkaline
(0,5% cobalt in deposit)
8-12 g/l zinc
g/l sodium hydroxide
ppm/l cobalt
proprietary additive
cathode current density: 0,5 - 5,0 amp/dm2
temperature: °C anodes: steel
e. zinc-cobalt acid
(0,5 % cobalt in deposit)
20-30 g/l zinc
g/l chloride
20-30 g/l boric acid
ppm/ cobalt
proprietary additives
cathode current density: 1,0 - 4,0 amp/dm2
pH:
temperature: °C anodes: zinc
CL-AK Technology GmbH – Zinc Solutions

18. Zinc/Zinc Alloy Plating Suggested Bath Formulation –Operating Conditions
f. zinc- iron alkaline
(0,5% iron in deposit)
10-25 g/l zinc
ppm/l iron
g/l sodium hydroxide
proprietary additive
cathode current density: 0,5 - 5,0 amp/dm2
temperature: °C anodes: steel
g. zinc- nickel acid
(5-7% nickel in deposit)
20-25g/l zinc
20-25 g/l nickel
g/l chloride
cathode current density: 0,2 - 4,0 amp/dm2
temperature: °C
pH: ,2 - 5,5
movement: air/cathode rod
CL-AK Technology GmbH – Zinc Solutions

19. Zinc/Zinc Alloy Plating Suggested Bath Formulation –Operating Conditions
h. zinc-nickel alkaline
(5-9%nickel in deposit)
6,0-12,0 g/l zinc
1,3-1,8 g/l nickel
g/l sodium hydroxide
proprietary additive
cathode current density: amp/dm2
temperature: °C anodes: nickel or
nickel - plated steel
i. zinc-nickel alkaline
(12-15% nickel in deposit)
cathode current density: amp/dm2
temperature: °C
anodes: nickel or
CL-AK Technology GmbH – Zinc Solutions