10 Bubble Blow-up air inlet Cooling air Cooling air Plastic from extruder Die lip adjusting bolts Die Body Die core Frost line Bubble constantly pulled up Blown-film Die Cross-Section Fig.10.6 The die is often rotated to prevent gauge bands10 Bubble Blow-up air inlet Cooling air Cooling air Plastic from extruder Die lip adjusting bolts Die Body Die core Frost line Bubble constantly pulled up Blown-film Die Cross-Section Fig.10.6 The die is often rotated to prevent gauge bands