Bottle embryo defects and solutions?
The bottle embryo is yellow
Reason: resin degradation or oxidation degradation, but not to carbide point
1. to reduce the drying temperature, the maximum temperature of 175 DEG C to 2. drying; make raw material specifications meet requirements; 3. to confirm the drying parameters in the range of 160 DEG to 175 DEG C (6h) (4h); 4. lower melting temperature to 280 DEG C - 10 DEG C; 5. to minimize% control, because no feedback control% 6. reduction; extrusion the back pressure, back pressure extrusion can make liquid mixing, too small will have bubbles, in the range of 15 ~ 20bar; 7. screw buffer is not too much to confirm, at least 8. 25mm; confirm the thermocouple and its damage mechanism.
There are black spots on the bottle
Reason: raw material is overheated and degraded to carbonization point
1. reduce the melting temperature to 280 DEG C - 10 DEG C; 2. to minimize% control, because no feedback control% 3. lower; the injection speed, the control in the range of 10 ~ 12g/s/cavity; 4. to reduce the back pressure in the range of extrusion, extrusion pressure in the range of 15 ~ 5. 20bar; reduce the screw speed to reduce the shear force, but in the period. 6.; make raw material specifications meet requirements; 7. to check whether there are impurities at the head, there will be the removal; 8. confirmed whether the damage mechanism and thermocouple.
There is a bubble in the head of the bottle
Reason: gas trapped in molten material can not be ruled out
1. reduce the dew point or increasing drying temperature; 2. confirmed drying parameters in the range of 160 to 175 DEG C (6h) (4h); 3. confirmed the melting temperature at 280 - 10 Deg. C; 4. to ensure that the molten material does not exceed the extrusion screw, if exceeded, would increase the extrusion temperature or increasing cycle time; 5. increase the head cooling temperature (minimum 160 C) 6. confirmed the barrel not blocked; 7. increase the extrusion pressure; 8. screw screw buffer, at least 9. 25mm buffer; reduce the time and location, the return time is =-1s, the distance =-10mm 10.; if the use of recycled materials, particles can not be too big; whether there are impurities 11. inspection machine head, there will be the removal;
The inside of the bottle is slightly concave
Reason: when the bottle embryo is still inside the mold, the mold cooling is faster than the core cooling, which leads to internal shrinkage after external curing
1. ensure the cooling water temperature at 7 to 10 DEG C; 2. ensure the cooling water circulation is normal; 3. to ensure that the valve stem to open normal; 4. to ensure that the pressure to open the valve, the pressure range of 8 ~ 5. 10bar; reduce the cooling time, cooling time is 1s ~ 3S, determined by the wall thickness; 6. increase the holding time increasing coverage; 7. pressure; 8. increase in melting temperature to 280 DEG C - 10 DEG C; 9. to reduce the time and location, the time to return =-1s, =-10mm distance; 10. confirmed die mouth part clean, can make smooth exhaust; 11. to ensure that no condensed water, cooling water temperature lower than the dew point to;