Plastic button plating knowledge

2021/05/19

      Apparel Accessories Net News: Plastic electroplating has already formed a large-scale production in the 1950s and industrialization in my country in the 1960s and 1980s. At that time, it was mainly used for small products such as buttons and buckles. That's it. With the development of the times, the application of plastic electroplating has also been expanding, from the original small parts and a small amount of applications to large parts and a large number of uses, from decorative uses to functional engineering uses, etc. Therefore, the requirements for the quality of coatings are getting higher and higher. At present, the quality of plated parts in Guangdong and Zhejiang is relatively high, and their appearance can be comparable to foreign advanced products and meet the quality requirements of foreign-funded enterprises. However, the internal quality is uneven due to the incomplete testing methods and specifications.

Plastic plating problem

Appearance quality. The appearance of plastic plating is smoother than that of metal products, and the brightness can generally be achieved, but there are certain differences in the degree. It is generally considered that a better appearance is “black” and the brightness is “thick”. This macroscopic feeling is determined by the microscopic state of the surface, that is to say, the microscopic surface must be very flat. The coating must not be foggy. It is very slightly foggy. It cannot be found under strong light or when looking at it. It can only be found under a certain angle of light, so it is easy to be ignored. As for defects such as plastic exposure, peeling, burrs, pitting, and poor plating, electroplating is absolutely not allowed.

Internal quality. The electroplating of automobile, motorcycle parts or high-end parts has certain requirements in technical specifications: such as coating adhesion, copper salt acetic acid corrosion test, thermal cycle test and field use test, etc., the assembly of plating parts must have a certain degree of resistance Deformation requirements.

Measures

The quality of the blank before plating should be good. Unqualified blanks are not well plated, and plastic blanks are more difficult to inspect than metal blanks. There will be "pitting" or "star spots" after plating. Of course, the blank can be plated without polishing. The surface of the whole set of injection blanks is very smooth, and the surface of the injection mold is as bright as a mirror. After the plastic parts are injected, they should be separately assembled and never collide.

Do not collide with pre-processed metallized parts. The plated parts in each process of the pre-treatment should not collide, especially the etch roughening process at around 70℃, the softening of ABS plastic will increase, and the hardness will decrease. If high-requirement plating parts, especially relatively large or flat and light plating parts, it is absolutely not allowed to randomly put in the etching solution, and take it out with a net to clean after etching. It is required to install the product on the fixture and etch it until the electroless copper plating or no Electrolytic nickel plating.

 Control of erosion degree. Etching In order to make the surface condition of the plated parts meet the appropriate requirements, insufficient or excessive etching will result in poor finish of the plated product or poor adhesion of the coating. On the one hand, the finish of the coating depends on the bright copper and bright nickel plating, and on the other hand, the control of the degree of erosion cannot be ignored.

The plating solution should not be turbid. The metallization method is generally copper layer or nickel layer, each has its advantages and disadvantages. From an operational point of view, electroless nickel plating is relatively stable and the plating speed is faster. In addition, it can also save the expensive palladium salt, the cost is slightly lower, but the stability is poor. The plating solution must be kept clean and not turbid to prevent the deposition of tiny particles, otherwise the tiny particles will be "enlarged" during bright copper plating and form particle defects.

Electroplating jigs should be used reasonably. The product must not only have appropriate conductive contacts, but also have appropriate tightness. It must have good electrical conductivity and clamp, but it must prevent deformation due to tight clamping, especially after plating. It is not enough to remove parts without deformation after trial clamping. It is necessary to take into account the shape deformation after large-scale electroplating, especially the high temperature deformation of nickel plating. Electroplating tools and fixtures must be well insulated and must not be coated with particles, otherwise it will cause particle burrs on the surface of the plated parts; after chrome plating, the fixture must be withdrawn from the chromium layer, otherwise when the chromium layer is copper-plated, the copper layer will easily become powder and form the surface of the product glitch.