ASACLEAN INJECTION MOLDING PURGING INSTRUCTIONS for the removal of high heat resins for pre-maintenance cleaning (Above 360°C, 680°F)
- Upon completion of the molding operation, extrude the high heat resin from the machine, emptying the barrel. Clean the hopper and feed throat.
- Begin dropping the temperature in the barrel to below 700°F (370°C) before purging with the ASACLEAN SX. ASACLEAN SX should not be left idle in the machine at temperatures above 700°F (370°C) for any amount of time as decomposition may occur.
- Feed about 1 barrel capacity of ASACLEAN SX into the hopper.
- With the screw completely forward, increase back pressure to a moderate level (enough to keep the screw forward).
Note: If processing temperatures are at or near the maximum recommended temperature for the SX Grade, low to medium backpressure and screw speed are recommended. Backpressure and screw speed can be increased at lower temperatures within the recommended range to maximize cleaning.
- Start to extrude the ASACLEAN SX at a slow screw speed. When it starts coming out of the nozzle, increase the screw speed to a moderate level (about 50% of the maximum).
- Continue adding ASACLEAN SX, following the above instructions until the purge pile is clean.
- Set all barrel temperatures to 625°F (330°C) and continue extruding ASACLEAN SX at a slow screw speed. Continue adding ASACLEAN SX as necessary to prevent oxygen from entering the barrel. Oxygen will accelerate material decomposition and carbon formation.
- Do not allow the temperatures in the barrel to drop below 570°F (300°C) with ASACLEAN SX in the barrel as overloading of the screw may occur when screw rotation resumes.
- When all of the temperatures are between 600°F-625°F (315°C-330°C), begin feeding ASACLEAN EX into the machine to further remove deposits from the screw and barrel and to make it easier to pull the screw. Follow the standard “ASACLEAN PURGING INSTRUCTIONS for PRE-MAINTENANCE CLEANING and SCREW PULL.” A non-glass-filled grade of ASACLEAN, such as ASACLEAN U, can be used to clean the screw and barrel, instead of the EX grade, but may not be as effective at removing stubborn deposits.