Extrusion & Post
2 views
Head pressure fluctuation of linear low-density polyethylene extruder
Problem Phenomenon
The head pressure gauge reading fluctuates greatly and the pressure is unstable.
Head pressure fluctuation directly causes extrudate dimensional fluctuation and surface defects and is an important indicator of extrusion instability.
Cause Analysis
(1) Screw output is uneven and melt pressure fluctuates
(2) The screen is clogged or damaged
(3) Head temperature fluctuates greatly and melt viscosity changes
(4) The breaker plate is deformed or improperly installed
(5) The raw material contains many impurities, frequently clogging the screen
Solution
(1) Stabilize screw speed and barrel temperature to ensure uniform output
(2) Regularly replace the screen and establish a replacement cycle
(3) Stabilize head temperature, controlling fluctuation within ±3°C (190-250°C range)
(4) Check the breaker plate; replace if deformed and ensure proper installation
(5) Sieve the raw material before use, and install a magnetic rack on the hopper to remove impurities
Key Takeaway
Head pressure fluctuation is caused by unstable output or filtration system problems; extrusion parameters need to be stabilized and the filtration system maintained.
Was this helpful?
0 people found this helpful
Thank you for your feedback!