Have you ever wondered what the differences are between plating on metal and plating on plastic? Plating both materials have different benefits that you should consider when deciding whether or not to plate your parts.
The process of plating plastic and metal parts is also different. Knowing how the process works can also help you understand the importance of plating your plastic and metal parts.
Plating metal process:
While the process for plating on metals varies, depending on the desired finish and the technique preferred by the plater, generally metal is plated by the following process:
- Cleaning—Parts always need to be free of any contaminating substances that could interfere with the plating process.
- Drying and acid cleaning—The part may need to be rinsed and dried after the cleaning process. Then it needs to be cleaned with an acid before it can undergo etching.
- Etching—This step roughens the surface of the part, increasing its ability to adhere to the metal coating.
- Plating—The part in submerged in an electroplating tank. How long it is submerged for depends on how thick the metal coating needs to be.
- Rinsing and chemical rinsing—Following the plating of the part, the metal needs to undergo a series of chemical rinses, and water rinses at specific temperatures.
Plating plastic process:
After the plastic part that will be plated is molded, the part needs to “metallize.” This helps the plastic part become more adhesive so that it can be plated properly. Next, the part is plated, generally by the following steps:
- Cleaning—The part needs to be free of any substances like dirt or fingerprints that may have been introduced during the manufacturing process.
- Pre-dipping—Plastic parts need to be dipped into a solvent before the next step to protect any poorly molded parts and to make etching the part easier.
- Etching—This important step improves the plastic part’s ability to absorb liquids and increase bonding with the metal finish.
- Conditioning—While conditioning is optional, it can ensure the part is more uniformly plated, improving the overall appearance.
- Neutralizing—A neutralizer needs to be used next in order to remove excess etchant.
- Activating—After using a pre-activator, the part needs to be activated. Activators become a catalyst for the plating process and reduce the drag-out cost for the part.
- Accelerating—While an accelerator reduces the changes of skip plate, its main function is to remove stannous hydroxide, allowing the activator to work.
- Bath immersion—The bath covers the plastic part in a metal coating. The metal chosen to coat the part varies, depending on the desired finish.