Injection Molding Purging Procedures

For Overhauling Injection Molding Machines

On this page, you’ll find instructions for overhauling injection molding machines and the benefits of pre-maintenance cleaning.

Cleaning Your Injection Molding Machine Prior To Shutdown

Cleaning your injection molding machine prior to a maintenance shutdown requires significant time and effort. Using an ASACLEAN purging compound prior to a maintenance shutdown significantly reduces the resources required to perform this task.

Follow these step-by-step instructions when using an ASACLEAN purging compound to overhaul your injection molding machine:

  1. Purge following the standard ASACLEAN mechanical grade purging instructions for injection molding. For pre-maintenance cleaning of injection molding machines, ASACLEAN EX Grade purging compound is the most effective grade, due to its high scrubbing power. Other grades may be used, but may not be as effective at removing stubborn deposits.
  2. For the easiest screw removal and maximum cleaning, the screw and barrel should be purged with a melt temperature of 220°C-300°C (430°F-570°F). For resins processed below 220°C (430°F), use ASACLEAN U Grade , UP, NF, NH, MB, NC, or E Grade to remove the low temperature resin, then increase the temperature to 240-260°C (465-500°F) for further cleaning with ASACLEAN EX Grade.
  3. After the ASACLEAN purging compound comes out clean, continue extruding the remaining ASACLEAN until no material is coming from the machine. Do not introduce any new material into the machine prior to manual breakdown.
  4. Turn off the heaters. Pull the screw. Melt temperatures outside this range result in more effort being required to pull the screw. For unfilled grades of ASACLEAN purging compound, the optimum temperature to pull the screw is between 195°C-205°C (380-400°F).

Continue following approved breakdown procedure. Exercise proper safety precautions and use appropriate PPE.

Benefits Of Pre-Maintenance Cleaning:

  • The force required to pull the screw from the cylinder will be significantly reduced.
  • ASACLEAN can remove almost all deposits from the screw and inner wall of the barrel, so only a minimum amount of effort will be required to complete the cleaning. Any remaining deposits or ASACLEAN residue can be easily removed by a wire brush or other standard cleaning tools.

For further insight into our recommended purging procedures, visit the Purging Process Resource Center. This page features training videos, guidelines, technical documentation and more to answer your purging compound questions.

Ready to learn even more about ASACLEAN purging compounds and services? Click here to schedule your free, 10-minute consultation with a Purging Process Expert at ASACLEAN.

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