What are the characteristics and uses of polypropylene blown packaging film?
polypropylene resin is a crystalline polymer. After melting in the extruder, the Yu state structure disappears completely. Due to different cooling conditions, the transparency and physical and mechanical properties of thin films are different. Slow cooling, high crystallinity and poor transparency of the film; Fast cooling, low crystallinity, high transparency of the film, good physical and mechanical properties and good hand feeling of the film, so the polypropylene blown film adopts a down-blowing water cooling production process.