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Type of Defect: |
Black Speck (3/3) |
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Description: |
Burnt layers of PC coming and/or peeling off from cylinder or nozzle inner wall |
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Observation Method: |
Visible by the human eye |
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Recommendation Upon Observation: |
Better visibility using a Magnifier (under polarized light / observed without optical stress) |
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Other Evaluation Method: |
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Cause |
Countermeasure |
| Change in parameter of injection molding (also material), cause change in flow rate |
Adjust to an appropiate temperature balance between the melted material and metal surface within the cylinder |
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Change in parameter of injection molding (also material), cause change in flow rate |
Clean the plasticizing unit |
| Change in parameter of injection molding (also material), cause change in flow rate |
Purge the cylinder |
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Cylinder temperature, during interruption of production is insufficient. (too low or turned off) |
Clean the plasticizing unit |
| Cylinder temperature, during interruption of production is insufficient. (too low or turned off) |
Purge the cylinder |
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Cylinder temperature, during interruption of production is insufficient. (too low or turned off) |
see Procedure "Interruption of production" |
