Plastic granulator production How to prevent plastic discoloration (Ke Rui Te):
Material discoloration is usually due to charred or degraded and other reasons.
① material problems
A. Material contamination;
B. Material is not dry;
C. Too much volatiles in the material;
D. Material degradation;
E. Colorant decomposition;
F. Additive decomposition.
② Extrusion equipment problems
A. Equipment is not clean;
B. Dry matter is not clean;
C. Ambient air is not clean, coloring agent floating in the air, deposited in the hopper and his parts;
D. Thermocouple failure;
E. Temperature control system failure;
F. Resistance electric heating (or far infrared heating device) damage;
G. There is an obstruction in the cartridge to cause the material to degrade.
③ temperature problems
A. Cylinder temperature is too high, lower cylinder temperature;
B. The nozzle temperature is too high to reduce the nozzle temperature.
④ out of the problem
A. Reduce the screw speed;
B. Reduce the back pressure;
C. Reduce the clamping force;
D. Reduce the extrusion pressure;
E. Shorten the extrusion pressure;
F. Shorten the full pressure time;
G. Slow down the extrusion speed;
H. Shorten the extrusion cycle.
⑤ Extrusion die problem
Consider the mold exhaust;
B. Increase the gate size, reduce the shear rate;
C. Increase the nozzle hole, the main channel and the size of the diversion channel;
D. Removal of in-mold oils and lubricants;
Adjust the oiling agent.
In addition, high impact strength of polystyrene and ABS, such as products, stress, but also due to stress and discoloration. Kellett
