Processing Machinery
1 views
PVC Back Pressure Setting
Problem Phenomenon
After PVC back pressure was set high, the melt turned yellow
Cause Analysis
Shear heat from high back pressure overheats the melt, and PVC's heat sensitivity amplifies the effect; during on-site troubleshooting, verify item by item according to this mechanism to avoid blindly adjusting the machine based only on experience; this mechanism has been repeatedly verified by industry data and should be confirmed first during troubleshooting
Solution
Control back pressure at the low limit of 0.2-0.5MPa; plasticization relies on temperature, not back pressure; after adjustment, continuously sample to verify the effect, and resume mass production after confirming stability; change only one variable at a time and record parameter changes to facilitate locating effective measures
Key Takeaway
PVC back pressure is managed at the low limit; after confirming effectiveness, fix the parameters and practices into the work instruction to prevent recurrence; include this case in the defect archive as a troubleshooting reference for similar problems in the future
Was this helpful?
0 people found this helpful
Thank you for your feedback!