26. Mai 2020
BIA optimises finishing process
Depending on the design, mould parting lines can occur during the production of plastic components – so-called burrs. These should not appear in the visible or significant surfaces of decorative components.
This should normally be considered when processing the component data. With increasingly complex component geometries this requirement cannot always be realised in the design. In such cases a targeted manual or mechanical post-processing can help. Depending on the component, polishing of the blank surface is an option. This method is not applicable to all components as it depends on the part geometry and the position of the burr. However, where polishing is possible good results have been achieved.
The challenge in polishing components that are subsequently to be electroplated is to avoid damaging the delicate surface structure of the plastic during the polishing process. In addition, visible surface blemishes such as scratches and grinding marks must be avoided, as should incomplete removal of the mould parting line.
If the parameters are not optimally matched to the component during polishing, a non-homogeneous surface structure will be created during etching – the first step in the plating process. This will lead to a non-uniform initial deposit structure. A homogeneous etch pattern over the entire component surface is essential in order to achieve a uniform layer structure during the plating process.
The correct combination of abrasive material, contact pressure and temperature is paramount in ensuring a homogeneous surface structure after the etch. This combination must be developed and tested individually for most components.
BIA has succeeded in optimising this additional polishing step. As a result, design-related burrs on components can be completely removed while preserving the plateability. So, BIA now has the entire process covered: injection moulding, polishing and electroplating from a single source. BIA thus manufactures burr-free chrome-plated components by eliminating geometry-related mould parting lines on the visible surface of the raw plastic.
You can catch a glimpse of this process in our corresponding TechVideo on the BIA YouTube Channel (BIA Group): https://youtu.be/P0LMVLTq6W8