It is a complex-forming salt for the preparation of cyanide-based silver electroplating bath suitable for both rack as well as barrel plating, the coatings deposited being dull. To achieve a sufficient adhesion of the coatings even to the less noble substrates, it is necessary for the wares to be preplated with a coating of a lower silver content at first. The bath should be started in the concentration of 100 g/litre for the rack plating and 150 g/litre for the barrel one.
Running conditions of the bath:
Bath parameter | Rack plating | Barrel plating |
Cathodic current density | 0,2 - 1,5 A/dm2 | 0,3 - 1 A/dm2 |
Voltage | 0,5 - 1,5 V | 8 - 15 V |
Bath temperature | 20 - 25 °C | 20 - 30 °C |
Bath filtration | Occasionally | |
Anodes | Pure silver | |
Cathode/anode surface ratio | 1:1 | 1:1 to 3:1 |
It is an alkaline cyanide-based hard silver electroplating bath for both rack and barrel electroplating. The coating deposited is made of the alloy of both silver and antimony (1 – 3% Sb) with the hardness value HV20 = 170 – 240 kg/mm2. The coating itself is of semi-bright-to-bright appearance, of high corrosion durability, easy to be soldered and less liable to the touch-induced corrosion compared with dull plated coatings made of pure silver.
The bath should be prepared from the complex-forming salt Pragogal Ag 720 in concentration of 220 g/litre for the rack mode of plating and 260 g/litre for the barrel one, together with 25 – 35 millilitres/litre of the Pragogal Ag 721 brightener and 25 – 35 millilitres/litre of the Pragogal Ag 722 additive respectively.
Running conditions of the bath:
Bath parameter | Rack plating | Barrel plating |
Cathodic current density | 0,3 - 2,5 A/dm2 | 0,5 - 1,5 A/dm2 |
Voltage | 0,5 - 4 V | 8 - 15 V |
Bath temperature | 20 - 25 °C | 20 - 30 °C |
Bath filtration | Occasionally | |
Anodes | Pure silver | |
Cathode/anode surface ratio | 1:1 | 1:1 to 3:1 |
It is a complex-forming salt for the preparation of silver preplating bath suitable for both rack as well as barrel mode of plating. The bath should be prepared by dissolution of 8 kg of the agent in 100 litres of water.
Running conditions of the bath:
Bath parameter | Silver preplating |
---|---|
Bath temperature | 18 - 25 °C |
Cathodic current density | 0,2 - 1 A/dm2 |
Voltage | 2 - 3 V |
© PRAGOCHEMA spol. s r.o. 2018, realization RMsoft.cz