1.Open gate

hotrunner manifold 1.1 the hot-runner system has processed plastic material with a certain color.
1.2 cleanup barrel by plastic material with demand color .
1.3 heat each heating zone with the temperature by 15-20 ℃ over normal production temperature .
1.4 shot 10-15 times according to normal procedure .
1.5 move back the the injection unit (barrel),turn off the hot runner system.
1.6 cool down the hot runner system, which method leads to the shrinkage of hot plastic material in the runner channel due to the reduced temperature , and then separated from the channel so the old and new materials could be mixed.
1.7 turn on the hot runner system again and wait until the temperature rise to production demand.
1.8 move back barrel.
1.9 increase the injection speed and repeat injection molding procedure until the color of the product can be accepted.
1.10 gradually restore the process of setting , restore injection speed and temperature to original production process demand.

2.Valve gate

2.1 the hot-runner system has processed plastic material with a certain color.
2.2 cleanup barrel by plastic material with demand color  .
2.3 heat each heating zone with the temperature by 15-20 ℃ over normal production Temperature .
2.4 shot 10-15 times according to normal procedure to clean the barrel (Note:unless hot runner reached the plastic processing temperature ,valve needle need to keep its position otherwise the valve needle and gates could be damaged when clean the barrel.)
2.5 move back the the injection unit (barrel),turn off the hot runner system.
2.6 cool down the hot runner system, which method leads to the shrinkage of hot plastic material in the runner channel due to reduced temperature , and then separated from the channel so the old and new materials could be mixed.
2.7 turn on the hot runner system again and wait until the temperature rise to production demand.
2.8 move back barrel.
2.9 increase the injection speed and repeat injection molding procedure until the color of the product can be accepted
2.10 gradually restore the process of setting , restore injection speed and temperature to original production process demand.

3.Dismantle and Clean the residual mixed color material inside hot runner . Check the injection molding machine nozzle and hot runner gate for the mixed color residual material and repeat the injection to clean that material.