BDM Ltd. provides various post-treatment or secondary services both for plastic and metal CNC parts.
Oil painting, the most common post-treatment both for plastic and metal, is always used for decoration and protection.
It is very easy to get different colors and to a certain extent, it protects the metal from corrosion.
For injection plastic parts, one very important function is to cover the defects. As we know, sink marks, weld lines, etc. is very common in injection molding because of the inappropriate design.
Except the general colors of blue, green etc., gold, silver, rose gold these metallic color are also available, it is more of matte than glossy.
If oil painting will be applied, engineers should take the oil layer thickness (T=0.03~0.05) into consideration during the product design. Enough clearance is necessary for assembly.
Soft touch coating gives the plastic product a very soft touch feeling and a frosted transparent appearance. It is an extra treatment after oil painting, so it is much more expensive. It is often applied for the telecom, gift, decoration, and entrainment etc. product. One very common application is the mouse and the touch control panel of the computer.
UV oil is a kind of transparent substance to harden or brighten the surface of the product under the irradiation e of ultra violet rays. It can be an extra treatment after oil painting or a sole process to protect the surface from scratching.
ABS is the only choice for plastic electroplating.
The function is:
- Plastic Decoration, to get a metallic effect.
- Anti-corrosion, e.g. to protect the screws from getting rust.
- Anti-wearing, e.g. electroplating hard chromium make good for wear resistance.
- Electrical conductivity, e.g. electroplating copper and gold can improve the conductivity property greatly.
- Same as oil painting, engineers should take the electroplating layer thickness (T=0.03 generally) into consideration during the product design.
- Sharp edge is not recommended, electroplating layer will easily peel off.
- Enough wall thickness is necessary to prevent it from deforming during the process.
- Furthermore, engineers should know electroplating will not cover any plastic defects; on the contrary, it will enlarge the defects to make it even worse.
Silk screen printing: flat or small curved surface
Pad printing: 3D surface
Generally, it is not recommended to print 3 colors at the same position because of the positioning difficulty. One time printing for one color, more colors means more cost.
Compared with screws and adhesive, Ultrasonic welding is a clean assembly technology with high efficiency and waterproof functionality.
The principle is to make use of ultrasonic to transfer the vibration energy to melt the energy director to bond with another plastic part.
Here are four common energy directors design overview:
- Basic Energy Director
- Tongue and groove
- Chisel Edge
- Step Joint
Different materials have different bonding effect, BDM Ltd. recommend engineers to use same material to apply this process.
This is a fantastic post-treatment for metal (plastic is not available), especially for CNC aluminum parts.
The function of anadization:
- Forming a oxidation layer to protect metal from corrosion.
- Enhance the wear resistance.
- Make the metal colorful.
- To reach the metal surface insulation purpose.
It is a low cost and very high efficiency process for the big quantity product.
The important application of laser engraving is to engrave the series number for the same batch product to record the detailed information, such as the production date, when it is made, the supplier of the core components, the supplier of the plastic, etc. They are used to deal with customer complaint one day to recall the same lot product. Actually in some countries, it is mandatory to have a product series number when enter the local market.
