Electroplating / Zinc plating

Both Pragogal Zn 310 and Pragogal Zn 320 technologies are convenient for alkaline cyanide-based zinc electroplating processes. The Pragogal Zn 310 technology is predominantly suitable for the rack mode of plating while the Pragogal Zn 320 for the barrel one. Both technologies may be operated without any brighteners if dull or semi-bright zinc coatings are required. The Pragogal 304 brightener enables deposition of bright coatings at both rack and barrel mode of the bath running. The benefit of this process is reliable and economical operation, along with the superior quality of the coatings deposited.

The zinc plating baths should be prepared from the respective complex-forming salts Pragogal Zn 310 and Pragogal Zn 320 the compositions of which are different in the ratio zinc /sodium cyanide.

For the start-up of 100 litres of the bath it should be employed:

Running conditions of the bath:

The consumption of the Pragogal Zn 304 brightener will depend on the design and shape of the parts to be plated and practically varies within 0,5 – 2 litres for every 10000 Ah.

Weak acid zinc plating bath Pragogal Zn 372 is suitable for both rack as well as barrel plating. The bath must be put into operation from two separate parts – basic surfactant additive Pragogal Zn 371 and brightener Pragogal Zn 372. The coatings deposited are extremely bright within very broad range of current densities. The bath itself has a good levelling ability, good throwing power and excellent coverage ability and is very reliable and versatile in terms of its running and easy to be maintained by the operating staff. The surfactants employed are of high clouding point value (as much as 98oC at the fresh bath introduction) without salting out at higher bath concentrations or elevated temperatures. The necessary bath agitation may be ensured by either cathodic bar motion or by compressed air. The bath enables zinc plating without any problems even at higher current densities compared with if the bath is agitated by cathodic bar motion only. The outstanding feature of the bath is a better utilization of its effective components and brighteners than in common zinc plating bath and, consequently, more economical operation.

The consumption of the Pragogal Zn 372 brightener is ca. 2 – 5 litres per every 10 000 Ah.

The individual bath components for 100 litres bath capacity should be as follows:

Running conditions of the bath:

Weak acid zinc plating bath Pragogal Zn 367 is convenient for both rack and barrel plating in the containers where bath agitation by cathodic bar motion is possible. The bath must be put into operation from two separate parts – basic surfactant additive Pragogal Zn 366 and brightener Pragogal Zn 367. The zinc coatings deposited are highly bright within wide range of current densities and show very good ductility and low internal stress. The bath itself is of excellent levelling ability, good throwing power, outstanding coverage ability and is very reliable and versatile in terms of its running. The clouding point value of the surfactant component is around 48°C. The bath with the Pragogal Zn 367 brightener can be run as a sodium. potassium or ammonium chloride-based composition.

The consumption of the Pragolod 367 brightener is about 3 litres for every 10 000 Ah

The inividual bath components for 100 litres bath capacity should be as follows:

Running conditions of the bath:

It is an alkaline, non-cyanide and bright zinc-plating bath of a new generation, with low zinc concentration and high levelling as well as coverage power suitable for both rack and barrel way of plating. From the bath, the bright and easy-to-be chromated zinc coatings of good levelling power and within broad range of cathodic current densities are being deposited.

Consumption of additives for the charge of 10000 Ah passed trough:
Pragogal Zn 3401: 1,5 - 3,0 l (basic additive)
Pragogal Zn 3402: 0,7 - 2,0 l (brightener)
Pragogal Zn 3403: 0,8 - 1,0 l for every 10 kg caustic soda replenished (a masking additive)

The inividual bath components for 100 litres bath capacity should be as follows:

Weak acid zinc plating bath Pragogal Zn 3700 is suitable for both rack as well as barrel plating. The coatings deposited being extremely bright within broad range of current densities. The bath itself has a good levelling ability, good throwing power and excellent coverage ability and is very reliable and versatile in terms of its operation performance and ease to be maintained by the operating staff. The bath is started up from the basic surfactant Pragogal Zn 3701 and the brightener Pragogal Zn 3702. The new surfactants of enhanced clouding point (above 100°C) will enable the bath operation without the necessity of its auxiliary cooling and better utilization of the bath brighteners and, consequently, their lower consumptions. Besides, new additives employed in the bath are capable to push the maximum cathodic current densities towards the higher values and facilitate plating of more heterogeneous substrates, such as grey cast iron and high-strenght and hardened steels. The bath will reduce degree of the hydrogen embrittlement of the surface plated as well.
The consumption of the Pragogal Zn 3702 brightener is ca. 2 – 5 litres per every 10 000 Ah.

For the start-up of 100 litres of bath to be used as follows:

Operating conditions of the bath