|
Problem
|
Caused
|
Solution
|
|
Poor melting quality |
Inadequate temperature profile |
Increase the profile temperatures in the final areas |
| Dirty filters |
Check operation of the resistances. |
| |
Provide maintenance to the equipment |
|
Foreign matter in the melt |
Polluted and/or degraded Polypropylene |
Keep Polypropylene clean |
| Leaks in the header |
Purge to clean the system |
| High temperature in the dosage area and/or in the header |
Check the correct setting of the header
|
| |
Check the temperature regulator system of in the dosage area and/or in the header |
|
Gels in the Parison |
High profile of temperature |
Lower temperature of the barrel |
| Degraded Polypropylene |
Placement and/or cleaning of the filter |
|
Pores or bubbles in the extruded area |
Presence of humidity in the Polypropylene, in the one recycled and/or concentrated of preservatives |
Dry the resin |
| Poor melting quality |
Check the profile of temperature |
| Excessive Cooling in the throat of the chute |
Increase extrusion pressure |
| |
Decrease speed of the screw |
| |
Purge and clean the system |
| |
Decrease the cooling in the throat of the chute |
|
Sharkskin |
Profile of temperature not adapted in the header |
Adjust the heating of the nozzle |
| Possible de-centered of the nozzle |
Increase the fusion temperature |
| |
Check the nozzle is centered |
| |
Decrease the extrusion speed |
|
Parison Waving or pumping effect |
Extremely high temperature in the feeding area |
Decrease the temperature of the feeding area |
| Retention of material in the hopper |
Clean the throat of the hopper |
| Damage equipment |
Increase the pressure in the head of the screw and/or lower temperature in the filters
|
| Slip in the belts and/or pulleys of the motor |
Revise the electric supply and/or slip of the belts
|
|
Low Gloss |
Low temperature in the nozzle |
Increase the temperature of the mold and/or of the last area of the header |
| Extremely cold mold |
Make sure the nozzle is clean |
| Polluted nozzle and/or with defect |
Check possible deteriorations in the nozzle |
| poor copied of the mold |
Increase the pressure of air blow |
| Flaws in the mold |
Check there's no obstruction of the air channels |
| |
Check mold finishing |
