Co-extruded Plastic High Barrier Film Manufacturers

What are the common problems in the production of co-extruded plastic high barrier films? How do these problems affect the performance of the film?

1. Common problems and their causes
Bubble instability
Problem manifestations: bubble bursting, strain hardening, frost line instability, bubble fluttering.
Cause analysis:
Bubble bursting is usually caused by excessive stretching of the molten material when leaving the die, resulting in insufficient melt strength to maintain bubble stability.
Strain hardening is the hardening of the molten polymer when it is rapidly stretched in the longitudinal direction, causing fluctuations in internal bubble pressure and bubble width.
Frost line instability may be caused by changes in melt temperature, which may be caused by improper resin selection, incorrect screw design, screw wear, or heater/thermocouple failure.
Bubble fluttering is caused by high air speeds in the air ring, which forms linear marks on the bubble surface.
Specification changes
Problem manifestations: The specifications of the film, such as width and thickness, change during the production process.
Cause analysis:
Insufficient uniformity of the die gap along the circumference.
Poor or uneven air flow in the air ring causes uneven cooling of the high barrier film.
Uneven melt temperature may be caused by improper screw design or wear.
Interface instability
Problem manifestation: Instability occurs at the interface between the two layers, such as zigzag interface instability and wave interface instability.
Cause analysis:
Zigzag interface instability is usually caused by excessive shear stress on the interface, resulting in a ""zigzag"" deformation of the film surface along the transverse direction. This may be due to significantly different shear viscosities between the materials that produce the interface, or an inappropriate layer ratio, which makes the interface too close to the mold wall.
Wave interface instability is caused by uneven elongation deformation at the interface between the two materials, resulting in a wavy pattern when the bubble is squeezed out of the mold.
2. Impact of the problem on film performance
Bubble instability
Impact on performance:
Bubble rupture will cause the film structure to rupture, reducing the barrier properties and mechanical strength of the film.
Strain hardening will affect the tensile properties and elasticity of the film, making the film more easily deformed or broken when subjected to external forces.
Frost line instability will affect the cooling rate and uniformity of the coextruded high barrier film, thereby affecting the transparency and barrier properties of the film.
Bubble fluttering will cause defects on the film surface, affecting the aesthetics and use of the film.
Specification changes
Impact on performance:
Specification changes will lead to inconsistent thickness and width of the film, affecting the uniformity and barrier properties of the film.
Excessive thickness deviation of the film will also affect its performance and leakage rate index on the automatic filling machine.
Interface instability
Impact on performance:
Interface instability will lead to decreased adhesion between the two layers, affecting the interlayer bonding and overall strength of the film.
Zigzag interface instability will reduce the flatness and smoothness of the film, affecting the appearance and use of the film.
Wave interface instability will cause uneven deformation of the plastic high barrier film during stretching, reducing the tensile and barrier properties of the film.
3. Advantages and countermeasures of Changxi Packaging Technology
In the face of these common problems, Changxi Packaging Technology (Yixing) Co., Ltd. has built a set of honest quality system with its innovation and professionalism. The company has fully implemented the ERP management system and networked tracking information of the production process, which can monitor various parameters in the production process in real time to ensure the stability and consistency of product quality.
In response to the above problems, the company has taken the following countermeasures:
Optimize resin selection and formulation: Select resins with suitable melt strength and shear viscosity to improve the overall performance and stability of the film.
Improve mold design: Optimize mold gap and fluid channel design to ensure uniform flow and cooling of molten material in the mold.
Strengthen screw maintenance and care: Regularly check the wear of the screw and replace the screw with severe wear in time to ensure the uniformity and stability of the melt temperature.
Optimize air ring design: Adjust the air flow speed and direction in the air ring to ensure uniform cooling and stretching of the film.
Strengthen quality monitoring and testing: Use advanced testing equipment and instruments to strictly test and control various performance indicators of the film to ensure that product quality meets customer requirements.