Purging Material for injection molding machine (Plastic purging agent)
- Daicel Miraizu

FAQ [Study cases]

Celpurge contributes cleaning efficiency of the color changeover process for many customers.
Below is an example of how we were able to improve the time it takes to change colors and materials and the problems of black spots and foreign matereial on molded products.

  • Q : It takes 5 days to manually remove off the resin stuck to the machine.

    Extruder TEM37BS

    Target Resin
    PA6 / 280℃ → PP Transparent color / 200℃ 

    Recommended purging method
    In addition to the engineering plastic purging agent AW2, the pull screw purging agent NX-BS was added in two stages (volume 2:1).
    The burden of cleaning up is less than 1/2!

    A manufacturer inform that it would take 5 days for two people to manually remove off the resin that had been stuck for cleaning.
    The resin to be purged is PA6 @ 280 ℃.

    For cleaning, we recommend using two steps of Celpurge AW2 and NX-BS for pull out screw.

    First, use the Celpurge AW2 to clean PA6 and clean the inside of the cylinder.
    Then, wash with NX-BS for screw extraction as well. AW2: NX-BS = 2:1 used without mixing.

    It’s easy to clean, improving work efficiency.
    We were told that it improve to two days for two people to complete the work that previously took five days, which made the cleaning easier.
    Also, they informed that the elimination of foreign material has been greatly improved.
    This is an example of the effect of the excellent cleaning of Celpurge.

  • Q : It takes time to change the PE pink color in the color masterbatch manufacturing.

    Twin screw extruder with a diameter of 36 mm

    Target resin
    PE pink color → PE natural color 

    Recommended purging method
    Maintain the setting temperature, lower the screw rotation speed and charging NX-VN2. In this case, cleaning is completed in 5kg for 15 minutes.

    We received an inquiry from a master batch maker about color change and extruder cleaning in the color masterbatch manufacturing.
    The target material to be cleaned is PE pink. The extruder set temperature during PE manufacturing is 190-210 ℃.

    Since it takes a long time to change colors, we proposed Celpurge NX-VN2, which is suitable for cleaning.

    As a preparation, clean the hopper properly. Before start the purge with NX-VN2, do confirm that the previous material (PE pink) is not remain in the cylinder. Remove the extruder screen mesh from the die head.
    Set the screw rotation speed to 20 rpm (the maximum is up to 30 rpm), and charge 5kg of NX-VN2.
    After the purging time of 15 minutes, the extruded resin had no pink color.

    Next, in order to remove NX-VN2, 5kg of PE virgin was added.
    Gradually switched to PE, and finally there was no pink residue or foreign material was detected.

    It was much more efficient in terms of material usage and cleaning time compared to traditional cleaning methods which is using PE alone. Refer to comparison result (see table).
    This is an example of excellent cleaning by Celpurge.

    Purge material Usage Purge time
    PE 20-30kg 1 hour
    Other company’s purging agent 7-10kg 20-30 minutes
    NX-VN2 5kg 15 minutes