What are the Different Types of Chrome Plating Equipment?
There are several different types of chrome plating equipment. Each classification of chrome plating equipment may differ depending on the manufacturer's intended purpose, be it to restore an automobile’s surface or to manufacture jewelery. The types will also differ between the hexavalent and trivalent chrome plating processes, which are methods used to reinforce metals. Examples of common chrome plating equipment could include anything from a degreasing kit to cleaning supplies, a chrome plating vat, or a rectifier.
Chrome plating is an electroplating process in which chromium ions are moved by means of an electric current to coat a metal electrode. This process is normally intended to bestow various chemical and physical properties of chromium, such as rust resistance, onto the electroplated object. The basic chrome plating equipment setup involves the object to be plated that acts as the cathode in an electrical circuit, a chrome electrode as the anode, and an electrolyte consisting of a dissolved chromium salt. When an electric current is applied from an external source, chromium ions are reduced at the cathode and accumulate in a process known as electrodeposition. In this manner, as the anode gradually reduces in size the concentration of chromium ions while the electrolyte remains constant and the object at the cathode is gradually plated with chromium.
Brush plating is the most favored chrome plating technique due to its portability and superior dexterity. A rectifier is used to convert alternating current into direct current, which passes through the rod while it is connected to the anode. The rod is then dipped in a solution containing chromium ions, and passed over the object to be electroplated, which has been degreased to remove impurities. Differences in electrode absorption cause the chromium ions to accumulate on the anode, plating it with chrome.
Hexavalent and trivalent chrome plating differ in terms of the chemical composition of the equipment used. In both processes, an activation bath is used to remove any scale on the workpiece, and it usually contains chromic acid for hexavalent chrome plating or sulphates in trivalent chrome plating. The latter is considered safer as it prevents toxic trivalent chromium from accumulating near the anodes. Furthermore, both processes use anodes to complete the standard electroplating process. Hexavalent chrome plating uses metal electrodes while trivalent chrome plating relies on inert graphite electrodes.
The most common set of chrome plating equipment would include a degreaser, a sulphate-based electrolyte bath, graphite electrodes and a brush plating setup. There is often a bias towards trivalent chrome plating since hexavalent chrome plating releases excessive toxic chromium, which is a human carcinogen and an air pollutant. Depending on the size of the component to be chrome plated, the power of the rectifier in a brush plating process will also differ. Larger components such as automobiles will require higher-powered rectifiers than smaller ones such as necklaces and rings.
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