Extrusion & Post
8 visualizaciones
Metallocene linear low density polyethylene blown film poor transparency（Variant: Color/Material Change Scenario）
Fenómeno del problema
The film haze is high and transparency does not meet requirements.
Poor transparency affects product appearance and display effect, especially important in packaging films and optical films.In particular, when changing materials or colors, this problem is more prominent and requires key attention.
Análisis de la causa
（1） Metallocene linear low density polyethylene has high crystallinity, crystalline regions scatter light causing high haze\
（2） Melt temperature too low, plasticization insufficient\
（3） Cooling rate slow, crystallinity high\
（4） The raw material contains impurities or gel\
（5） Film surface rough\
（6） When changing materials or colors, process parameter fluctuations or equipment status changes aggravate this problem
Solución
（1） Appropriately increase the extrusion temperature to the higher value within the 190-260°C range, fully plasticize\
（2） Improve air ring cooling efficiency, speed up cooling to reduce crystallinity\
（3） Select grades with good transparency or add a nucleating agent to refine grains\
（4） Strengthen filtration, use 80-120 mesh filter screen to remove impurities\
（5） Polish the die to improve film surface finish\
（6） And do well in cleaning the transition material, paying special attention to parameter stability when changing materials or colors
Conclusión clave
Poor transparency is caused by high crystallinity or impurities, and needs improvement by increasing temperature, speeding up cooling and selecting suitable materials.Targeted preventive measures need to be taken in different production scenarios.
¿Le ha resultado útil?
0 personas encontraron esto útil
¡Gracias por sus comentarios!