Purging Instructions for Injection Molding
- 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
Temperature Ranges
| Grade | °F | °C |
| Advantage | 350-600 | 180-315 |
| EX | 390-680 | 200-360 |
| UP | 340-570 | 170-300 |
| U | 350-680 | 180-360 |
| E | 320-530 | 160-270 |
| SX | 570-735 | 300-390 |
| SA | 350-680 | 180-360 |
| UE | 350-570 | 180-300 |
Tips to target specific areas of the molding machine
These techniques should be used after performing the above procedures
Nozzle hang-up - Color or carbon
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 – using a large amount of ASACLEAN will not allow the necessary purging pressure to be delivered to the nozzle). Repeat short, high-velocity injections shots until clean.
Check ring - Color or carbon
Feed a small amount of ASACLEAN (less than half barrel capacity – using a large amount of ASACLEAN will not allow the necessary purging pressure to be delivered to the nozzle). Repeat short, high-velocity injections shots until clean.
