Injection Molding
2 views
Black spots on PET injection molded products
Problem Phenomenon
Black or brown spots appear in PET transparent products, seriously affecting appearance qualification rate.
Cause Analysis
Material thermal degradation produces carbonized particles; carbon deposits on the barrel and screw fall off; the raw material is mixed with impurities; the screen is damaged.
Solution
Reduce processing temperature and shorten residence time; regularly clean the barrel using purging material; strengthen raw material quality inspection; replace the screen.
Key Takeaway
PET black spots are a direct manifestation of degradation or contamination; clean production and temperature control are the way to prevent them.
Was this helpful?
0 people found this helpful
Thank you for your feedback!