Results 1 to 7 of 7

Thread: Hot runner cleaning

  1. #1
    Join Date
    May 2018
    Posts
    16

    Hot runner cleaning

    Hello´everyone
    how do you clean hot runners when changing color. I tried everything but still the rejected products number is high.

    best regards

  2. #2
    Join Date
    Dec 2016
    Posts
    112

    Re: Hot runner cleanİng

    Hi,

    We use purges 459 Plus and it works pretty well. You have to let it sit for 5 minutes then purge it out. For very tough jobs I would give it two rounds, and still might have to throw away 10 or 20 shots at start up. You can use it on hot manifolds as this was from their website:
    Effectively cleans the barrel, screw, check ring, as well as hot runner systems and is safely processed through hot runner gates as small as .030-inch (.75mm).

    They will likely send you a free 20lb sample as will other companies that make purge compounds.

    Joel

  3. #3
    Join Date
    Dec 2016
    Posts
    112

    Re: Hot runner cleanİng

    Typo Correction........We use Purgex 459 Plus!

    thx, Joel

  4. #4
    Join Date
    Aug 2011
    Location
    Upstate of South Carolina
    Posts
    647

    Re: Hot runner cleanİng

    There are several great purging compounds available but my favorites are PDQ from Slide, Asaclean, and Dynapurge. Though on the last two you need to use the card correct grade for the resin.
    I really think you need to tell us all the steps used when purging because that is the mistake most people make. Last note: Some manifolds are not good at changing colors because the manufacturers were not told that during the start of the project.
    Rick.

  5. #5
    Join Date
    Sep 2019
    Posts
    1

    Re: Hot runner cleanİng

    Hi, everyone

    I recommend AXAclean from Japan.

  6. #6

    Re: Hot runner cleanİng

    If you're trying to clean hot runner, the follow the standard procedure for it. If you're going for open plate cleaning, then I would recommend to follow the below step by step procedure. ---

    Use the ASACLEAN purging compound to clean screw & barrel. Then go as
    Open the mold plates.
    Set up a safety-approved surface for collecting the purgings.
    Verify that the mold safety door is closed.
    Add enough ASACLEAN purging compound into the hopper to fill the barrel approximately ˝ full.
    Extrude ASACLEAN purging compound through hot runner system starting at a medium velocity. Increase screw speed to the maximum safe level for maximum cleaning. Once ASACLEAN is flowing adequately through all of the gates, perform injection shots (air shots) with mold plates open.
    Visually inspect purgings for color and/or carbon contamination.
    If contamination remains, repeat steps 5 through 7 until the ASACLEAN purging compound is visually free of color and/or carbon contamination and has returned to a clean appearance.
    Purge out any remaining ASACLEAN using the maximum safe screw speed. Adjust the temperatures in the barrel and hot runners to the processing conditions for the next resin to be processed.
    Flush the system with the next resin to be processed using the maximum safe screw speed until the next resin is visually free of the ASACLEAN purging compound.
    If you're cleaning when mold plates are closed, then I would suggest the following -
    Clean the screw and barrel have been cleaned using ASACLEAN, set the nozzle into the mold.
    Verify that the mold safety door is closed.
    To reduce the small possibility of ASACLEAN purging compound parts getting stuck in the hot runner cavities, reduce cooling time and spray the cavities with mold release.
    Remove pack and hold pressures and velocities. Inject ASACLEAN purging compound using short-shot molding (use only as much shot as is needed to safely remove parts from cavities – no more than 90% shot size.)
    Eject parts immediately, while they are still warm.
    Visually inspect parts for color and/or carbon contamination until parts are clean.
    If contamination still remains, repeat steps 4 through 6 until the ASACLEAN purging compound is visually free of color and/or carbon contamination and has returned to a clean appearance. Purge out any remaining ASACLEAN using the same method as above. Adjust the temperatures of the barrel and hot runners to the processing conditions for the next resin to be processed.
    Flush the system with the next resin to be processed, molding parts until the ASACLEAN purging compound can no longer be seen in the next resin.
    Resume production using normal production settings

  7. #7
    Join Date
    Oct 2019
    Location
    Harrisburg, PA
    Posts
    2

    Re: Hot runner cleanİng

    Use viscosity to your advantage. Purge compound or not I was told to increase the hot runner 30-40F. This lowers the viscosity of the plastic on the channel wall. Run the material or purge compound at the low end of the temperature range so it's viscosity is higher and will push more.

    I'd alternate speeds. Medium just for the volume of flow but the viscosity will be higher at slower speeds.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •