These bubble cages make use of special rolls. Having only one contact point with the film, versus multiple points on traditional bubble cages, eliminates pinching, scratching and any other possible damage to the film.
Also, by placing an insulated socket on the roll, the film temperature is not altered. Thus avoiding heat transfer between the rollers and the film. This will prevent gauge variation due to heat transfer from typical standard Teflon rollers.
Advantages:
No risk of marking the film
No risk of thermal shock
Low inertia bearing allows rolls to run at line speed
No limitations in handling different film thickness'
Inside of cylinders are not affected by extrusion residues
