Schlötter is pleased to present three new processes to the market. The new zinc and zinc-nickel electrolytes, SLOTOLOY ZN 320, SLOTANIT OT 1010 and ZINCASLOT ZA 1020 have been developed in-house at Schlötter by our experienced and innovative Research & Development chemists. The new electrolytes have several key benefits which include improved deposit characteristics, reduced analysis and reduced effluent treatment.

Boric acid free: Zinc-Nickel SLOTOLOY ZN 320

In recent years, there has been a resurgence in the use of weakly-acidic zinc-nickel alloy baths.  Compared with conventional alkaline Zn-Ni processes, the weakly acidic processes perform well in terms of effluent treatment, which is much simpler. Weakly-acidic Zn-Ni processes are operated with soluble anodes. The fact that inert anodes are replaced by soluble anodes removes the need for constant in-line analysis which requires capital investment and external zinc compartments. Schlötter's new weakly-acidic Zinc-Nickel SLOTOLOY ZN 320 which is based on SLOTOLOY ZN 310 is both ammonia and boric acid free. As an additional benefit, the process can also be operated in combined rack and barrel applications.
Key features of SLOTOLOY ZN 320:

• Stable nickel co-deposition of 12-15% in a wide current density area
• Process operates from the start thus reducing the amount of time currently required to get the process operating at optimum capability
• No significant formation of anode sludge
• Direct coating of cast iron parts  is possible
• Satin-matt or bright Zn-Ni alloy layers

Ultra bright: Zinc SLOTANIT OT 1010

Schlötter's weakly acidic zinc SLOTANIT OT 1010 for rack and barrel applications is the latest supplement to our well-known SLOTANIT OT series.  SLOTANIT OT 1010 has no cloud point even at high temperatures and high salt levels which allows an operating temperature of up to 45°C. SLOTANIT OT 1010 deposits haze-free, ultra-bright zinc layers. The process is highly resistant to iron: even if the iron content rises up to 200 mg/l, no dark spots caused by iron contaminations show on the zinc layer.

Excellent metal distribution: Zinc ZINCASLOT ZA 1020

This alkaline, cyanide-free process, Zinc ZINCASLOT ZA 1020 for rack and barrel applications has recently been included in Schlötter's product portfolio. ZINCASLOT ZA 1020 is based on ZINCASLOT 80 and features an enhanced covering power and throwing power.
Additional benefits:

• excellent metal distribution which produces superb deposition results even for parts with complex geometry
• the layers are easily passivated

For post-treatment, we recommend the products from our METAPAS, SLOTOPAS and SLOTOFIN series.

Schlötter responds positively to ECHA announcement 
with new Cobalt Free Passivation Processes

On the 15th December 2010 ECHA (European Chemical Agency) included Cobalt (II) Sulphate to their list of substances that are "of very high concern". As a result, the use of Cobalt (II) Sulphate may be subject to a greater degree of scrutiny in the future. This announcement has led to an increasing demand for cobalt free passivation processes for Zinc and Zinc-Nickel Alloy coatings. 

Schlötter's new cobalt free passivation processes: In response to this development, Schlötter recently announced the market launch of its new cobalt free passivation processes, SLOTOPAS ZNC 50 and SLOTOPAS ZNB 60. Both of these passivation processes exhibit high levels of corrosion resistance which fully comply with the requirements of DIN 50979 for rack and barrel parts with and without previous heat ageing (24 hours at 120˚C). The application of a sealant or topcoat of our SLOTOFIN series further improves corrosion protection.

Key features of our new cobalt-free passivation processes:

Passivation SLOTOPAS ZNC 50

• Cobalt free thick layer passivation process for electroplated Zn-Ni alloy coatings
• Colourful iridescent, Cr(VI)-free passivation layer 

Passivation SLOTOPAS ZNB 60

• Cobalt free passivation process for electroplated Zn-Ni alloy coating
• Intensive blue Cr(VI)-free passivation layer 
• Ideal colour coding for plated parts
• Fluoride free

In addition to SLOTOPAS ZNC 50 and SLOTOPAS ZNB 60, Schlötter continues to offer the well established cobalt free black passivation SLOTOPAS ZN 300 for Zn-Ni alloy coatings, thus further expanding its product portfolio of cobalt free passivation processes.

If extreme resistance is required! 
Do you make high demands on the tribological properties of your coatings? 
Then your choice should go for our Electroless Nickel Bath SLOTONIP CT 20.

Key features: 

• the electrolyte is easy to maintain by combined additives 
• free of lead, cadmium and PFOS
• high stability
• light, semi-bright to bright PTFE dispersion coatings
• Teflon® co-depositions of 20 - 30 vol.% are realizeable 
• phosphorus content of 10 - 13 % (related to the pure nickel-phosphorus layer) 
• plating rate approx. 6 - 9 μm/h 
• hardness 300 - 350 HV 0.1 
• friction coefficient μ 0.1 - 0.2 

Picture: Brittle fracture of a electroless deposited nickel-phosphorus-PTFE dispersion layer with a Teflon® co-deposition of approx. 30 vol.% 

The present process is proprietary by the following US patents:
4 997 686, 5 145 517, 5 300 330, 5 863 616, 6 306 466 B1

The new generation of acidic zinc-nickel electrolytes

For barrel- and cast iron plating, acidic zinc-nickel electrolytes are reintroduced to the market. Also in zinc-nickel processes, Schlötter profits from many years of practical experience. With the new Zinc-Nickel SLOTOLOY ZN 310, a process with the following advantages is offered:

• Better starting behaviour for critical cast iron- and barrel parts
• Chloride based process, free of ammonium
• Very stable nickel co-deposition of 12-15% over a wide current density range
• No formation of cyanide or carbonate
• there is no need of expensive peripheral equipment (zinc dissolving compartments or freezing facilities)
• Easier detoxification, compared to alkaline processes
• All common zinc-nickel passivations an sealants are suitable as post-treatment

Perfect sealed
The Post-Dip Solution SLOTOPAS NT 10 combines the characteristics and features of a passivation with the one’s of a sealant. This process generates a second, anorganic conversion layer on an already passivated zinc-nickel coating. This layer is scratch-proof, inhibits corrosion and can improve the appearance remarkably.

Application on zinc-nickel transparent
As known, transparent surfaces are sensitive to fingerprints. This demands an extra careful and therefore time-consuming handling of the finished parts. Parts treated with Post-Dip Solution SLOTOPAS NT 10 can be touched without remaining visible fingerprints.

Application on zinc-nickel black
For several parts e. g. pipes, it is forbidden to use organic sealants. In this case Post-Dip Solution SLOTOPAS NT 10 offers an excellent alternative. There is no formation of tinsel or blistering on the layers. The advantages are shown in the Neutral Salt Spray Test especially in the resistance against red corrosion.

A new generation of trivalent chrome electrolytes

Conventional chromic acid based electrolytes have to be categorized toxically. According to § 1 clause 1 sentence 1, they are subject to the basic obligations of the statutory order on hazardous incidents (German 12. BimSchV) if the quantity is ≥ 5000 kg (≈ 4200 litres) and to the extended ones if quantity is ≥ 20000 kg (≈ 16800 litres). For various applications the ammonium-free trivalent Bright Chrome SLOTOCHROM DR 60 is an adequate alternative. Its use is an enormous improvement on the field of Environment- and Employment Protection. Due to the non-toxic properties of trivalent chromium it is not subject of the statutory order on hazardous incidents. In addition this electrolyte is operated without wetting agents containing PFOS (Perfluorooctane sulfonate).

Bright Chrome SLOTOCHROM 60 is used to chrome plate parts for indoor use. Coverage and throwing power are much better and the contacting of the parts is easier than in the hexavalent process. In comparison with other trivalent processes Bright Chrome SLOTOCHROM DR 60 shows an especially light coloured and reproducible appearance which is very close to the one provided by a hexavalent chromium electrolyte.

- now also chromium (VI)-free on zinc!

Our new black passivation SLOTOPAS Z 60 is a dipping method for producing black, slightly matt chromium (III)-based conversion coatings both on deposited alkaline zinc and low-alloyed zinc/iron layers. The processes proven best for this purpose are those of our ZINCASLOT and SLOTOLOY ZE series.

The subsequent sealing in one of our SLOTOFIN products produces a slightly bright, uniform visual appearance. The sealing may be applied wet on wet or after an intermediate drying process. With a minimum resistance in the salt spray test of 120 h according to DIN EN ISO 9227 even after annealing it offers a convenient substitute for traditional chromium (VI)-based processes.