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

Case studies

Celpurge contributes to the 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 issue of black spots and foreign material on molded products.

  • Case1 : It takes five days to manually remove resin adhered to the machine.

    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 cleaning burden is reduced by more than half!

    A manufacturer informs us that it would take five days for two people to manually remove the adhered resin.
    The resin to be purged is PA6 @ 280℃.

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

    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 ratio used without mixing.

    It’s easy to clean, improving work efficiency.
    We were informed that the cleaning work by two people that previously took five days was completed in only two days.
    Also, they informed that the elimination of foreign material has been greatly improved.
    This is an example of the excellent cleaning properties of Celpurge.

  • Case2 : It takes time to change the PE pink color in the color masterbatch manufacturing.

    Machine :
    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 load with NX-VN2. In this case, cleaning is completed for 5kg in 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.

    In preparation, clean the hopper thoroughly. Before starting the purge with NX-VN2, confirm that no previous material (PE) remains 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 load 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 virgin PE was added.
    Gradually it changed to PE, and finally no pink residue or foreign material was detected.

    This method was much more efficient in terms of material usage and cleaning time compared to traditional cleaning methods using PE alone. Refer to comparison result (see table).
    This is another example of the excellent cleaning properties of 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