Extrusion Process Purging Procedures
Overhaul Of Extruders
Using an ASACLEAN purging compound, prior to a maintenance shutdown, greatly reduces the resources required to perform an overhaul of extruders.
Purging Instructions For An Overhaul Of Extruders
Follow these step-by-step instructions when using an ASACLEAN purging compound for an overhaul of extruders:
- Remove as much resin as possible from the barrel by extruding the material from the system.
- Purge following the standard ASACLEAN Mechanical Grade Purging Procedures For Extrusion.A: For cleaning just the screw and barrel, use ASACLEAN EX Grade for maximum deposit removal. A glass-filled grade of ASACLEAN (EX, PX2 and NF Grade) should not be run through polished dies. Contact a Purging Process Expert at ASACLEAN to learn the right procedures for running a filled grade of ASACLEAN through dies with tight clearances.
B: For cleaning extruders with a die attached, use an unfilled grade of ASACLEAN to purge all of the resin from the screw, barrel and die. After removing the die, clean the barrel again, this time with ASACLEAN EX Grade. An unfilled grade of ASACLEAN can be used to clean the screw and barrel, but may not be as effective at removing stubborn deposits.
- For the easiest screw removal and maximum cleaning effect, the screw and barrel should be purged with a melt temperature of 220-300°C (430-570°F). For low-temperature resins, purge with ASACLEAN E or SL, then increase the temperature to 240-260°C (465-500°F) for further cleaning with ASACLEAN EX Grade.
- After the ASACLEAN purge pile appears clean, extrude the remaining ASACLEAN EX. Do not introduce any new material into the machine prior to manual breakdown.
- Turn off the heaters. Pull the screw. Melt temperatures outside this range will result in more effort being required to pull the screw. For unfilled grades of ASACLEAN, the optimum temperature to pull the screw is 195°-205°C (380-400°F).
- Continue following approved breakdown procedure.
Exercise proper safety precautions and use appropriate PPE.
Benefits Of Using ASACLEAN For An Overhaul Of Extruders:
- The force required to pull the screw from the barrel will be significantly reduced.
- ASACLEAN removes almost all deposits from the screw and inner wall of the barrel, so only a minimum amount of effort is required to complete the cleaning. Any remaining deposits or ASACLEAN residue may be easily removed by a wire brush or other standard cleaning tools.
For further insight into our recommended purging procedures, visit the Purging Process Resource Center. This page offers you training videos, guidelines, technical documentation and more to help answer your purging compound questions.
Ready to learn even more about ASACLEAN purging compounds and services? Click here to schedule your free, 10-minute consultation with a Purging Process Expert at ASACLEAN.