Material Notes:
Pellet, cleaning purge for single and twin screw PVC extruders.APPLICATIONS: During long extrusion runs, some extrusion compounds can thermally degrade and create build-ups inside tooling. Eventually, this degradation can lead to die lines and to yellow streaks on the profile surface. If the compound degradation is moderate, the GEON® LP300 cleaning purge compound can be used to clean out build-ups and remove the compound degradation inside the extruder and the die. By using a cleaning purge compound, customers can avoid the time consuming process of removing the die, dismantling it and cleaning it mechanically. LP300 is optimized to purge both single screw and twin screw extrusion lines. LP300 has superior metal release characteristics and much better thermal stability than convention extrusion profile compounds. LP300 will easily and effectively push out conventional extrusion compounds from most dies. Avoid cross-contaminationCare must be taken to insure that purge compound scrap is not mixed with regular profile regrind and used for profile extrusion. Adding purge to regrind would cause the resulting profiles to be un-fused and brittle. Other GEON Purge Compounds If you are using twin screw extruders, you should consider evaluating the GEON E0100 cleaning purge and the GEON 0916 shutdown purge compounds. These two purge compounds are in powder form and are especially formulated for twin screw extruders. See the GEON E0100 and E0916 data sheets for more details. ________________________________________________________________________________ PROCESSING METHOD: Shut downRemove the regular compound from the extruder hopper and pour purge compound down the throat of the extruder. Do not change the extrusion conditions and keep the die on the extruder.Continue to feed purge compound and to run the extruder screw until the cleaning purge has completely displaced the regular compound from the extruder and the die. The scrubbing action of the cleaning purge compound can be increase by progressively lowering the barrel and screw oil settings. Make sure that the motor current and the backpressure do not become excessive. The physical appearance of the purge compound as it exits the die (color difference and/or crumbly texture) will indicate that the purge cycle is complete. Stop feeding the purge dry blend to the throat of the extruder. At this point, you can:a) return to the normal extrusion conditions and to the normal extrusion compound and resume production or, b) remove, dismantle and clean the die thoroughly before storing it and run the screw until it is empty or, c) you can store the die with the purge compound in it. If you are not planning to take the die apart and clean it before the next run, it is very important that all the regular vinyl compound be displaced from the die before shutting down. Any regular compound left in the die would likely degrade and potentially cause corrosion damage to the die during restarting. Re-StartWhen starting up with a die full of purge, heat the barrel, the screws and the die to the normal extrusion temperature. When the set points have been reached, feed normal extrusion compound and operate the main screws at low RPM until the regular compound has pushed out the purge compound.Resume regular extrusion.Information provided by PolyOne