- Aug 31, 2018 -
The main difference between plastic material plating and metal material plating is that the surface of the plastic material needs to be metallized. That is, before the plastic material is electroplated, it is necessary to first apply a conductive metal film on the plastic surface to make it have certain conductivity. Commonly used methods are sprayed conductive adhesive, vacuum vaporized metal layer, electroless plating and chemical spraying. Pre-plating pretreatment of plastic materials usually includes processes such as degreasing, roughening, sensitization, activation and electroless plating.
Pre-plating process of plastic materials:
1. De-stressing: Since there is stress after injection of plastic parts, in order to minimize deformation after electroplating, glacial acetic acid is usually used to soak the plastic parts to remove stress.
2. Degreasing: In order to ensure uniform contact with the solution during roughening, the oil on the plastic part needs to be removed by the medium-low temperature alkaline agent.
3. Coarsening: Generally, the surface of the plastic part is coarsened by using a high chromic acid solution to ensure the contact area with the solution.
4. Neutralization/Reduction/Immersion: The removal of strong acids, strong oxides and impurities remaining on the surface of the plastic part is used to increase the surface affinity of the plastic part prior to activation.
5. Activation: Reducing divalent tin ions on the surface of the plastic part to prepare for activation.
6. Sensitization: In order to illuminate the metal, a layer of catalytically active precious metal such as Ag is adsorbed on the surface of the plastic part.
7. Reduction or debonding: After activation and cleaning, it should be reduced, the surface activity is increased, the deposition is accelerated, and the activation liquid remaining on the surface is removed to prevent decomposition into the electroless plating solution.
8. Electroless plating: Before the plastic plating, a good metal plating layer with good conductivity is formed, the plating layer is uniform and the continuity is good, and the current can be formed into a loop to make the electroplating go smoothly.