English 
Español 
Français 
1. Parts condition before finishing
 | Material: Epoxy plastic material Appearance: before processing, the surface of the entire parts are covered with dirt Shape: The plastic coil frame has an elementary geometry. However, the part has small slots so that minimal wear debris or granule will lodge in. Size: 46mm (diameter) X17mm (height) Process before finishing: NA Process after finishing: Assembling |
2. Parts Surface requirement
- Smoothing parts surface without damage parts
- Media does not get stuck at parts slots and holts
- Remove the black layer generate from the die casting process
- The surface is mirror shining and ready for assembly
3. How we process the parts
| Step | (1) Polishing and cleaning | (2) Drying |
| Machine | The centrifugal disc finishing machine | Natural drying |
| Tumbling Speed | 50/60HZ (full speed) | |
| Chip Type | Angle cut triangle super-fine porcelain | |
| Media to Parts Ratio | 3:1 | |
| Compound Type | LC-13, PH 8 (mild grinding compound) | |
| Water Level | Just cover the mass | |
| Tumble Time | 30 minutes | |
| Notes— | Manually take the parts out the machines and rinse them |
4. Parts condition before and after polishing
The epoxy resin parts after long time storage become dirty. So we want to use the mass finishing process to make it clean.
Epoxy resin parts before and after polishing
Walnut shell lodge into parts slotWalnut shell can give a good surface cleaning, but the particles fit nicely inside the slot. And it’s hard to take out one by one. Therefore we have to think about the new way. Also, we have been thinking about using plastic tumbling media. However, the plastic tumbling media is polyester-based material which is more challenging than epoxy. So the surface will wear out if we choose plastic media. So the only media that we can choose is non-abrasive porcelain media. But what size and shape to choose? We have tried several options.
Firstly, we try with zirconia ball. 2mm ball allows it to enter all surfaces, but it cannot polish the parts’ inner side even after 1 hour in a centrifugal disc finishing machine. Then we are thinking if we can use “long” media.
On the second try, we use fine porcelain cylinder media with size 2.5X8mm. This media performance is much better than the ball media, but still slow to remove the parts’ inner side.
On the third try, we use fine porcelain media with angle cut triangle shape 6X6mm. This media can reach deeper parts’ surface and also have some cutting power. In 30 minutes, the body of the entire parts has become white and clean.
Conclusion
In this article, we give an example of epoxy resin parts cleaning and polishing with different media. We have success in superfine porcelain media with triangle shape after several trials.
First, we discuss the condition of the parts before finishing.
Second, we show parts surface requirements from clients.
Third, we show the process that we did for the plastic parts in detail.
Later, we compare the surface before and after mass finishing. Finally, we discuss how we select the media and different media that we trials in the process.
