Galvanic process: step by step explanation

The company has a chemical pretreatment line and an electrolytic line. The moulded pieces are placed on special frames and subjected to treatments aimed at obtaining the metallization of the piece, by subsequent immersion in adjacent tanks.

Assembly: the operators place the articles on the dedicated frames, making sure that the grip of the same is optimal and firmly;
Etching: this treatment, carried out using a sulphur-chromic mixture, is used to oxidize the butadiene present on the surface of the material and create surface microporosities, necessary for the subsequent phases;
Neutralization: this phase involves the immersion of the pieces in a strongly reducing solution: this allows the complete reduction of the Cr6+ possibly residual to Cr3+, and is carried out to avoid interference with subsequent treatments;
Pre-catalysis: this phase consists instead in the immersion of the frames in a solution of the same acid / saline base of the catalysis bath, in order to avoid the possible dragging of Cr6+, but above all to avoid any dilutions of the solution present in the next tank;
Catalysis: the pieces are at this point immersed in a tank containing the colloid Palladium – Tin Chloride: this colloid is adsorbed in the microporosities obtained from the previous phases: this operation is carried out in an aqueous solution of HCl or NaCl, saturated in Sn2+ and SnCl2 ions, in order to avoid the hydrolysis of the Sn

Acceleration:it is effected by means of an aqueous solution of Sulfuric Acid and additives, in order to solubilize the colloid and remove from the surface of the piece all the elements not made up of noble metal (Pd);
Metallization with chemical nickel: catalysis and acceleration operations are necessary for the deposition of nickel on the plastic material; nickel is chemically deposited, forming chemical bonds with palladium. This phase is necessary to give conductivity to the plastic piece and thus make possible the subsequent phases of electrolytic deposition;
Electrolytic coppering: an electrolytic deposition of copper is carried out on the treated piece;
Electrolytic nickel plating, chrome plating or gold plating: the electrolytic coppering phase is followed by the nickel plating phase which, depending on the customers' requests, can constitute the final galvanic treatment or can be followed by chrome plating or gold plating. Nickel plating, chrome plating and gold plating are also carried out by electrolytic deposition.
Washing: after each step (except for the steps of pre-catalysis and catalysis) the washing of the pieces is carried out.
Packaging: at the end of the chrome plating process, the items are placed inside the dedicated packaging to best preserve the specifications requested by the customer.