How to resolve tearing or pinhole formation along the seal/cut line of shrink film in heat shrink packaging?

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  The seal-and-cut line on shrink film in heat shrink packaging is prone to tearing or developing tiny pinholes. Solutions include:
  
  

  • Lower the temperature of the constant-temperature sealing knife on the seal-and-cut machine.

  • The seal-and-cut line height is incorrect—it should be positioned at approximately half the height of the packaged item.

  • Uneven pressure from the sealing frame—adjust the horizontal alignment of the sealing frame to ensure uniform pressure distribution.

  • The sealing knife or sealing base may be contaminated—clean both components thoroughly.

  • The thermal insulation pad or adhesive tape on the sealing base may be damaged—replace the insulation pad or tape as needed.

  • The sealing time is too short, causing sealing pressure to release before the film fully bonds—extend the sealing duration to ensure a complete and robust seal.