Monitoring Method for Monitoring a Film Bubble in a Discharge Region Downstream of a Discharge Nozzle of a Blown Film Device

A monitoring device for monitoring a film bubble in a discharge region downstream of a discharge nozzle of a blown film device, comprising an optical detection module for optical detection of at least one contour parameter of a film contour of the film bubble in the discharge region, a comparison module for a comparison of the at least one detected contour parameter with a specific preset value, a determination module for determining a contour deviation between the at least one detected contour parameter and the specific preset value, and an output module for outputting the contour deviation as a monitoring result.

A calibration method for a calibration of a monitoring device for monitoring a film bubble in a discharge region downstream of a discharge nozzle of a blown film device, comprising an optical detection module for optical detection of at least one contour parameter of a film contour of the film bubble in the discharge region, a comparison module for a comparison of the at least one detected contour parameter with a specific preset value, a determination module for determining a contour deviation between the at least one detected contour parameter and the specific preset value, and an output module for outputting the contour deviation as a monitoring result, comprising the following steps:

• arranging the optical detection module in a detection position,
• allocating a detection region which at least partially overlaps with a discharge region of the blown film device.