Transparent plastic parts usually have very high requirements on the looking. As the plastic part is transparent, when the plastic part has very small defect will be seen very clearly. The common defects for molded plastic transparent parts are melt spot, silver craze, etc.
Plastic parts transparent defects solution:
1. Filter the raw material, remove the impurity and dry the material sufficiently.
2. Decrease material temperature, adjust the barrel temperature zone by zone, and increase mould temperature accordingly.
3. Increase injection pressure, decrease injection speed
4. Lower preplasticizing back pressure, slower RMP
5. Shorten cycle time, when the product molded, the silver craze can be removed by anneal. For PS you can keep it under a temperature of 78 degree for 15 minutes, or keep it under 50 degree for 1 hour. PC material keep it under 160 degree for several minutres.