Purging Instructions for Plastic Injection Molding Machines
- Check that all zones are in the proper temperature range for the grade of ASACLEAN being used.
- Retract the injection unit. Run the barrel empty using maximum back pressure. Wipe the hopper and feed throat.
- Feed the required amount of ASACLEAN into the hopper. About one to two barrel capacities of ASACLEAN is required for purging a typical injection molding machine. The actual amount required depends on the difficulty of the application and the condition of the equipment. Start with about one barrel capacity.
- With the screw completely forward, increase the back pressure to the maximum level.
- After ASACLEAN begins coming from the nozzle, increase the screw speed to the maximum safe level.
- Drop the back pressure after the ASACLEAN coming from the nozzle is almost clean.
- Retract the screw and perform short, high-velocity injection shots.
- Repeat steps 1 through 7 if contaminants are still visible.
- The machine is clean and purging is complete when ASACLEAN coming from the machine is visibly free of contamination.
- Displace the ASACLEAN remaining in the machine with the next resin, again, at the maximum back pressure and maximum safe screw speed with the screw completely forward.
- ASACLEAN does not work by chemical reaction. No soak time or hold-up time is required for an effective purge.
- For maximum performance, ASACLEAN should not be diluted with other materials.
- ASACLEAN works best with maximum agitation. Use the maximum safe screw speed and maximum safe back pressure with the screw in the most forward position
These techniques should be used after performing the above procedures
Raise the temperature of the nozzle about 68 – 86 °F (20-30 °C). If running a heat-sensitive resin and heat may only be raised minimally start by raising the temperature up to 50°F (10°C). Feed a small amount of ASACLEAN (less than half barrel capacity). Repeat short high-velocity injections shots until clean.
Check ring – Color or carbon
Feed a small amount of ASACLEAN (less than half barrel capacity). Repeat short, high-velocity injections shots until clean.