Plating Types

Since plastics do not have electrical conductivity like metals, they must first be made conductive in order to be plated. The following steps are taken for this purpose:

Pre-Etching:

The pre-etching bath is used to break the butadiene bonds present in ABS. It contains chromic acid and sulfuric acid, and operates at 62-68 °C.

Activation:

Activation is a solution used to place Sn+2 and Pd2+ ions into the butadiene bonds broken during etching. It forms a tin and palladium film layer on the etched surface.

Electroless Nickel Plating:

This is used to perform nickel plating without using an electric current. The plating is achieved through the chemical reduction of nickel ions by an autocatalytic effect.

The corrosion and wear resistances are very high, and a uniform coating thickness in microns is obtained at every point, regardless of the part shape. Our company uses two types of electroless nickel solutions:

• Hot Electroless Nickel (sulfate-based) ~ 55-60 °C
• Cold Electroless Nickel (chloride-based) ~ 30-40 °C

The plating speed is 12 M/hour.

Used to strengthen and enhance the thin coating on parts plated with electroless nickel. It consists of nickel chloride, nickel sulfate, and boric acid. The operating temperature is around 55 °C. The solution pH should be 3.8 - 4.2. Cathode movement is required.

Electrolytic copper plating is used as the second layer in multi-layer plating systems (Ni+Cu+Ni+Cr) and sometimes for decorative purposes with varnish. It contains copper sulfate (CuSO4•5H2O) and sulfuric acid (H2SO4). Additionally, a brightener is added for a shiny finish. Room temperature is sufficient for the bath operation. Cathode or air movement is required. Filtration is necessary. Special phosphorus-containing anodes should be used.

Electrolytic bright nickel plating, like copper plating, is part of multi-layer plating systems and is placed between copper and chrome plating.

It can also be applied as a top layer with varnish to prevent darkening due to oxidation. Nickel plating has high corrosion resistance and can be easily distinguished from chrome plating by its slightly yellowish appearance.

Unlike matte nickel plating, it contains a brightener in the solution. It operates at 55 °C. The solution pH should be between 3.8 and 4.2. Cathode movement or air movement is required.

This is the final step in multi-layer coatings (Ni,Cu,Ni,Cr) that gives a mirror-like finish. Being a hard coating, it is not recommended to be used alone. It serves as a decorative, finishing layer. The bath contains chromic acid (CrO3) and sulfuric acid in a proportion of 1% of the chromic acid. Catalysts are used to improve penetration into deep areas (recesses). Good ventilation is required in the plating area. Nickel-plated parts should be chrome-plated immediately after rinsing without delay.

This is a type of plating with a lemon-yellow color. By adjusting the proportions of chemicals in the solution, it is possible to achieve yellow tones like gold. It is applied after nickel plating. Plated parts are immersed in a sodium dichromate solution. Plated and dried parts should be varnished immediately.

This is a special nickel bath also known as smoke plating. The plating is in smoke color. The color can be lightened by adjusting the proportions of chemical materials or it can be varnished for protective purposes. It is applied after nickel plating.

This is a special type of plating with a grayish appearance. It is applied over copper or nickel plating. Chrome plating can be applied over it if desired.

Gold, alongside Platinum metal, is a stable element that does not change under any conditions. It does not oxidize on the surface under atmospheric conditions, at room temperature, or at higher temperatures, and is not affected by sulfur compounds like silver.

Plating apparatuses are produced in-house, and outsourcing of hanging and plastisol plating processes is also available.