WHAT IS ELECTROPLATED COATING?
Electroplated Coating is the process of coating conductive objects with a thin layer of metal or alloy, such as copper, brass, nickel, chromium, gold, silver, tin, or zinc. This is done for aesthetic and durability purposes, using chemical compounds dissolved in a liquid and an electric current.
HOW IS ELECTROPLATED COATING APPLIED IN A BUSINESS?
The Electroplated Coating process is conducted in a device known as a plating bath or tank, which is typically constructed from polypropylene material. The device comprises two electrodes immersed in a compound (electrolyte), which is dissolved into positively and negatively charged ions to prevent them from touching each other. Once the electrodes are connected to a current source, the resulting voltage (electric field) prompts the ions to move towards the oppositely charged electrode (pole). Atoms or molecules that balance their charge at the opposite pole precipitate at the electrode. In other words, the metal to be coated is connected to one pole (anode) and the product to be coated is connected to the other pole (cathode). An electric current is then applied, with the help of the electrolysis liquid, to ionize the metal product and start to accumulate a homogeneous layer on the product to be coated.
WHAT FACTORS INFLUENCE THE QUALITY OF THE ELECTROPLATING PROCESS?
In the electroplating process, for example, if this is nickel plating, the solution in the plating bath contains nickel sulfate, nickel chloride, boric acid, saccharin, moisturizing products, and organic chemicals that give shine. It is essential that these products are in the correct ratio and balance. During the plating process, at different speeds, there will be a shortage of chemicals. It is essential to monitor the depletion and make the necessary additions on a regular basis. It is essential to maintain the plating bath at a specific temperature and pH level. Concurrently, the appropriate electric current values, which vary according to the product being coated, must be determined and applied. It is essential that the coated product be placed in the coating bath or product bath immediately following the coating process. The product should be dissolved in the liquid when it falls. This results in a metallic contamination that negatively impacts the quality of the coating. This contamination is routinely removed through a process we refer to as the selective process.
Cleaning is required. During the coating process, a sediment is formed as a result of chemical reactions in the liquid. Therefore, it is essential to regularly filter the coating liquid to maintain optimal quality. Furthermore, to achieve optimal coating results, it is essential to utilize a specialized system for both the coating liquid and the product to be coated. Coating chemicals are available in a range of price points and quality levels. Investing in high-quality raw materials is crucial for ensuring superior coating quality. The product to be coated must undergo preliminary treatments, such as cleaning and surface abrasion, before entering the coating bath. It is essential that these processes are carried out correctly and completely in terms of coating quality.
WHAT ARE POTENTIAL ERRORS THAT COULD OCCUR DURING THE ELECTROPLATING PROCESS?
In the event that a decorative coating is applied, the coating may not achieve the desired level of gloss or visual effect. In the event that the coating does not adhere effectively to the surface, there is a possibility of spillage or blistering. The coating may exhibit an undesirable rough surface. Potential issues may arise with coating thickness and the uniform distribution of the coating. The coating may exhibit stains and defects, commonly referred to as "bleed marks." Please note that there may be differences in coating colors. To prevent these issues, it is essential to conduct regular checks at each stage of the coating process. In the event that the product to be coated is required to have a certain corrosion resistance or a certain dimensional tolerance, it must be tested and a report generated on a regular basis.
WHICH TESTS AND HOW IS QUALITY DETERMINED IN AN ELECTROPLATED
COATING?
The most commonly used tests in electroplated coating, i.e. metal plating, are as
follows:
The salt test : A standard procedure used to assess the quality of electroplated coatings. Products are stored in a special machine that meets DIN standards and contains water vapor with 5% sodium chloride. Following a 96-hour period, a product that has not exhibited any issues with the coating is deemed durable for a period of 10 years in an indoor environment and 2 years in an outdoor environment.
The adhesion test : A crucial quality assessment tool that determines the durability and strength of the coating bond. A square scratch is made on the coated product with a cutting tool, such as a falcata. A specialized adhesive tape with a specified adhesion value is attached to the specified area and then removed. The objective is to ascertain whether the coating is firmly attached to the surface.
The thermal shock test: It is conducted to ascertain the coated product's resilience to abrupt temperature fluctuations in the surrounding atmosphere or environment. The product is heated to a specific temperature and then immersed in water at the desired temperature for testing. The part that is subjected to the sudden temperature change is then checked.
Acetone Test: A special lint-free cotton test cloth dipped in acetone is used to wipe the coated product continuously. This process is repeated 50 to 600 times in order to check whether any problems on the surface result from friction.