Operation specification steps for changing plastic and color of injection molding machine:

    1. Plastic characteristics and shutdown precautions

    The characteristics of various plastic raw materials are different. Considering the characteristics of this rubber during shutdown can save time and avoid plastic deterioration.

    Method of influence of plastic varieties on plastic properties:

    PS hard has good thermal stability. It will not decompose when heated for a long time at the forming temperature, so it only needs to turn off the electric heating when shutdown

    ABS is a hard adhesive with good thermal stability. It will not decompose when heated for a long time at the forming temperature. Therefore, the shutdown time only needs to turn off the electric heating.

    PE and PP are soft adhesives with good thermal stability. They will not decompose when heated for a long time at the forming temperature. Therefore, the shutdown time only needs to turn off the electric heating

    Due to the temporary shutdown of PC (for example, night work has not started), in order to avoid rubber moisture, it is necessary to keep the barrel about 160. To change the material, PE must clean the barrel, remove the screws, and clean the screws with a copper brush.

    The PVC temperature sensing material turns off the electric heating before shutdown, pushes the PVC until the barrel temperature drops to 150, and finally pushes all the plastics in the barrel with PP, PE and other plastics with good thermal stability.

    PMMA is easy to decompose at high temperature, but it has good thermal stability at normal forming temperature, so it is only necessary to turn off the electric heating during shutdown.

    Nylon PA plastic has good thermal stability. Do not clean the barrel before shutdown, but cut off the power immediately. Otherwise, the plastic may deteriorate after 15 minutes.

    POM is a heat sensitive plastic. When it is shut down, it will turn off the electric heating for 10 minutes before reducing the pressure. Then push the plastic in the barrel and replace it with soft gel.

    2. Change the color of the same material

    When changing colors on the same material, it is easier to change light colors into dark materials and from transparent materials to opaque materials.

    When converting from concentration to concentration and from non transparent to transparent materials, after more than 10 times of engineering, when the color is still impure, remove the inlet, barrel and cylinder head for cleaning.

    3. Replacement of dissimilar materials

    When the temperature is high, the thermoplastic will stick to the metal surface. If the temperature is low, it will not stick. The replacement function is to use this feature to replace the materials to be replaced, stick to the inner wall of the barrel, and replace the dissimilar materials cut with the high viscosity materials of the cooling screws.

    4. Change the plastic and color at the same time

    In this case, select plastics with similar characteristics and use cleaning agent at the same time. Common cleaning agents are screw cleaning agent, kerosene, etc.

    In this case, if the barrel is not cleaned, the inlet and barrel cylinder head shall be cleaned, and the screws shall be cleaned if necessary.