Purging Compounds Injection Molding - Purging Injection Molding Machine | Purgex

Purging Compounds for Injection Molding


Regardless of the particle size, contamination costs money.  Purgex™ Purging Compounds combine the ability to reach even the smallest area with the strength to clean out stubborn materials.  From big parts such as automotive instrument panels to small medical components, there is a Purgex grade to get the job done with our purging compounds for injection molding.

purging compounds injection molding

  • Whether you need to purge through an open or closed mold, we have developed procedures to make the process fast and easy.
  • Purgex easily rinses out of the machine and doesn’t leave any sticky residue behind.
  • Purgex efficiently cleans hard to reach places in your machine such as check rings, and mixing nozzles.
  • All Purgex grades are capable of passing seamlessly through hot runner systems.


Advantages of Purging Compounds on Injection Molding Machines

  • Reduction of scrap parts after a color/material change
  • reduction of carbon build-up in the barrel
  • elimination of color hanging up within the tool
  • total changeover time is reduced
  • increased uptime of the machine

Purging Procedure for Injection Molding

Purging Prep:

  1. Turn off material flow
  2. Maintain process settings and continue running parts
  3. When last part is completed, retract carriage
  4.  Clean hopper and/or colorant blender
  5. Load Purgex into hopper/feed zone
  6. Clean nozzle and  sprue bushing

Purging Steps:

  1. Adjust shot size to about 25% of injection capacity
  2. In manual mode, purge barrel and screw until Purgex is visible
  3. Stop purging and soak Purgex in the barrel for 3 to 5 minutes
  4. Continue purging until the hopper is almost empty and start normal changeover procedures
  5. Feed 1 to 1-1/2 barrel capacities of the next resin (with colorant on) to rinse out residual Purgex
  6. Inspect purge pile. If Purgex is still visible, rinse with an extra half barrel capacity of resin

Our Purgex 456 Plus and our Purgex 457 Plus purging compounds are great to use on injection molding machines. To see all of the Purgex grades that are effective for purging injection molding machines, visit our product selector page.

Check out our purging compound videos!

The video below shows a red to green color change on an injection molding machine.