Why is the coating binding force still poor after plastic coarsening? In fact, this is related to the state of the plastic matrix. In this issue, we will discuss what is the meaning of the poor state of the plastic matrix? And how it causes poor coating adhesion in plastic electroplating process.
Poor matrix condition?
ABS plastic is acrylonitrile, butadiene, styrene ternary copolymerization, injection molding of the matrix state is poor, refers to ABS plastic polymer B component B particle (that is, butadiene) content is too little or too much, and B particle distribution is in an uneven state, which affects the coating and substrate binding force.
Let's take an example to help you understand that in the pre-treatment process of plastic electroplating, there is a process of chemical coarsing (using coarsing additives), in this process, B particles are dissolved and A, S(acrylonitrile, styrene) skeleton is basically not corroded, so that the surface of the plastic substrate is formed fine micro-pits, Metals (such as nickel and copper) form numerous small buttons in these pits to produce a riveting effect.
Will poor state cause poor binding force?
At this time, if the plastic polymer appears in the following two situations:
① The content of B particles is small, and thick and sparse
② Its content is too much, and too dense
The riveting effect of the coating on the surface of plastic parts will be reduced, and the binding force between the coating and the plastic matrix will be worse. One more thing to say here, if the plastic matrix after injection molding, its surface stress is large, and it is directly used for electroplating without release treatment, it will also reduce the binding force of the coating and the substrate.
Conclusion
Therefore, in the plastic plating process, we must control the state of the substrate, and use Bigely coarsening additives for chemical coarsening, so as to ensure that the coating and the substrate have a good bonding force.
If you are interested in coarsening additives, please feel free to contact us.
