PC/ABS alloy is a kind of excellent engineering raw materials for automobiles, communication, medical, home appliances, etc., including general-grade, electroplating grade, weather-resistant scratch-resistant grade, flame retardant grade, spray grade, enhanced grade, etc. It improves PC Stress cracking, workability, excellent heat resistance, impact resistance, chemical resistance and dimensional stability, widely used in automotive instrument panels, automotive parts, mobile phone cases, power tools and other high-strength, heat-resistant products .
As designers increasingly apply functional and decorative metal coatings in their products, the proportion of ABS and PC/ABS alloys used in electroplating is increasing. Plating PC/ABS, mainly for automotive parts (door handles) , grille, trim), gold-plated parts, etc.
To form good adhesion between the metal coating and the plastic base material, the most important step is to soak in the etching solution, which is usually a mixture of chromic acid and sulfuric acid.
The electroplating process of electroplating PC/ABS is as follows:
Plastic parts inspection->stress->hang->de-oil->cleaning->hydrophilic->cleaning->roughening->recycling->cleaning->neutralization->cleaning->ultrasonic cleaning->soaking ->Presensitization->sensitization/activation->cleaning->acceleration->cleaning->chemical nickel->cleaning->preplating copper->cleaning->activation->cleaning->acid copper->cleaning-> Activation->semi-bright nickel->bright nickel->cleaning->electrolytic activation->chrome plating->recycling->reduction->cleaning->drying->hanging deplating
The common methods to improve plating are as follows:
1, Component design and plating process
If stress is applied, there is a certain stress in the plastic parts, which will bring a lot of problems to the roughening of the plastic parts and a series of pre-treatment processes. Therefore, the plastic parts with higher stress must go through this process. For plastic parts with high PC content (PC≥40%), PC material itself has poor self-lubrication, stress cracking tendency, small shrinkage during molding, prone to melt cracking and stress concentration, and need to be removed by annealing.
2, Injection molding process
Such as increasing the mold temperature to reduce the stress of the material.
3, Control ABS and components
In the ABS resin, the 1,3-butadiene rubber particles are in the dispersed phase, and the SAN is the continuous phase. Under the electron microscope, the butadiene rubber phase can be observed to be uniformly spherically embedded in the acrylonitrile-styrene resin phase. In chemical coarsening, the rubber phase is oxidized and eroded, while the continuous resin phase leaves a large number of smiling holes. It is these holes that allow the coating to be anchored to the plastic surface for good bonding. Therefore, Ding Er The concentration of olefin and the dispersion of rubber particles are important for the overall effect. The dispersion of butadiene or large or small particles is considered to be the most important aspect. The ABS plastic used for electroplating requires the content of butadiene at Between 18% and 23%.
4, Increase liquidity
The fluidity of the material is also crucial, because of the high fluidity, the high gloss of the blanks is ensured, and the plating is guaranteed to have no pitting.