Processing Machinery
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Severe degradation of PA in the barrel during processing
Fenómeno do problema
Severe degradation of PA occurs in the barrel during processing, and the products show burning, discoloration, and a sharp decline in mechanical properties
Análise das causas
（1）The barrel temperature exceeds the recommended upper limit of polyamide (general-purpose nylon) (above 240-280°C), causing thermal degradation
（2）The residence time is too long and the material is repeatedly heated
（3）Excessive screw shearing accelerates thermal-oxidative degradation
（4）PA6 degrades rapidly above 280°C and PA66 above 300°C
（5）PA46 degrades severely above 330°C
Solução
（1）Strictly control the barrel temperature not to exceed the 240-280°C upper limit
（2）Reduce the residence time
（3）Reduce the screw speed to reduce shear heat
（4）The processing window of PA materials is narrow and requires precise temperature control
（5）Add antioxidants to improve thermal stability
Conclusão principal
PA high-temperature degradation requires strict temperature control and reduced residence
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