The standard purging procedures for Purgex blends do not always remove liquid colorants. Liquid colorant from the resin being molded tends to deposit on the screw and barrel walls, especially in the first zone. This modified procedure will allow removal of liquid colorant deposits.
Note: When purging the barrel and screw for first time with Purgex, use 3 times the injection capacity. When routinely purging with Purgex, use 1-1/2 times the injection capacity.
Preparation Before Purging
- Increase heaters in inlet zone by 50°F (10°C).
- Empty resin from machine.
- Clean mixing chamber and top of feed throat with a cleaner/degreaser to remove any liquid colorant deposits.
- Load PURGEX into hopper.
- Retract carriage.
- Clean nozzle and sprue bushing.
Purging The Machine
- Adjust shot size to 25% of injection capacity.
Note: The setting change in Step 1 is recommended because it assists Purgex in working more effectively and efficiently.
- In manual mode, purge out barrel and screw with Purgex (approximately 2 to 3 injection capacities).
- With about one half (½) an injection capacity of Purgex still in barrel, stop and thoroughly clean hopper and/or colorant blender.
- Turn on material flow and add next production resin to hopper and/or colorant blender.
- Seat nozzle into sprue bushing.
- Prepare machine for next production run.
- Begin production.
Comments & Recommendations:
Additional purging with Purgex and/or a soak time of 3 to 5 minutes may be required.
Questions? Call our Technical Support team at (800) 803-6242.
