Purgex Plastic Purging Compounds, Agent Purging - Purgex Online - Plastic Purge, Purging Compounds, Agent Purge,

Preparation Before Purging

1. Turn off resin, colorant and additive feeds.
2. Empty the extruder.
3. Clean hopper and feed throat.
4. Remove screen pack
   Note: It is a good practice to change the screen pack periodically. It may be convenient to combine this with purging.
5. Seal vents on extruder.
6. Maintain temperatures and begin run at low screw speed.
7. Load Purgex into the hopper.
   Note: Amount of Purgex needed is equivalent to 10 minutes of residence time.
   (throughput per hour ÷ 60 minutes × 10 minutes)
   (Example:  300 lbs. per hour ÷ 60 minutes × 10 minutes = 50 lbs.)
   

Purging The Extruder

1. Begin feeding Purgex.
2. Increase screw speed until safe pressure limits have been reached.
3. Purge through entire downstream system including die, if possible (die gap must be at least .030 inches).
4. Use maximum safe screw speed (within safe pressure limits) for one minute then vary the screw speed from maximum to low to medium, completing the purge at maximum.
5. Follow the Purgex feed with the next resin, and observe material for acceptability.
6. Repeat steps 1-4 if contamination remains.
7. When acceptable resin appears, prepare extruder for production.
8. Begin production.

Comments & Recommendations:

• When sealing the vent it is advisable to monitor the upstream pressure.
• Vent plugs are available from extruder manufacturers and other suppliers.
• After long runs and/or heavily contaminated barrels and screws, it may be helpful to increase the extruder temperatures by 50°F (10°C).

Questions? Call our Technical Support team at (800)-803-6242.