What is colloidal palladium used for in the plastic plating process? If you know what you're talking about, you might say, "No need to ask, colloidal palladium is used for activation, stupid! Then if you ask further, why is it necessary to carry out the activation process in the plastic plating process? It is estimated that some plating people will not be able to answer. This issue of the article we will take stock of the logic.
As we know, the surface of the plastic material is roughened with the presence of many tiny pores, increasing the specific surface area while increasing the riveting point of activated palladium, and due to the destruction of the polymer molecules by the strong oxidizing chemical system of chromic acid-sulfuric acid, the surface produces many reactive groups.
The modified plastic surface is equipped to adsorb activated palladium. The activation step of conventional plastic plating pre-treatments is designed with this purpose in mind. The negatively charged palladium/tin gel cluster is to be adsorbed on the plastic surface, generating a large number of palladium active centers and laying the foundation for the deposition of chemical nickel on the surface of the palladium's catalytic centers.
Modern activation technology mostly uses palladium-tin colloids so that sensitization and activation (or catalysis) are carried out simultaneously. The old process generally uses a more cumbersome two-step method, that is, the activated surface of the plastic material is first sensitized and then enter the activation tank for palladium adsorption reduction.
The general colloidal palladium activation solution consists of two parts: hydrochloric acid solution and palladium-tin colloid. Since divalent tin can be oxidized to the more stable tetravalent tin in aqueous solution and hydrolyzed in solution to produce SnO2 precipitate, it is necessary to supplement a certain amount of divalent tin in the activation solution to stabilize the activation solution.
So what are the pain points often encountered when using colloidal palladium for activation processes? The answer is easy leakage of plating and poor bonding of the plating to the plastic. In other words, if these two major pain points can be solved, then the product qualification rate will not fluctuate and can rise linearly!
A good colloidal palladium can do this. Using Bigely colloidal palladium PL-5 in the plastic plating process not only prevents leakage of the plating, but also ensures that the plating layer bonds well to the plastic and does not crack and bubble.