TWO GAUGE CONTROL SYSTEMS FROM ADDEX
Addex have developed two, new, patent pending, gauge control systems for blown film lines.
They already have their IGC (Internal Gauge Control) system, which provides users with
automatic gauge control down to as low as +/- 3 - 4% at 3 sigma. This system has always
been restricted to blown film lines with Internal Bubble Cooling and dies larger than
250mm. so they have developed two new solutions that can be used on lines with or without
IBC and also dies smaller than 250 mm dia.
The Addex External Gauge Control System (EGC)
The EGC (External Gauge Control) System is based on Addex's proven state-of-the-art Dual Lip Air Ring design, it still offer the output advantages that this air ring has always provided but is also equipped with the same "teeth" arrangements as the Addex IGC. Positioned in the air - flow channels, they are individually, moved up or down by a single actuator to increase/decrease the amount of air in contact with the film at that particular point on the bubble. This action influences the thickness variation of the film. The actuator is controlled by a computer which is linked to a capacitive sensor positioned on a carousel between the highest frost line and the collapsers continually measuring/ monitoring the film thickness.
Control tolerances with the EGC have been found to be +/- 4 - 6% at 3 sigma. Reason for such accuracy is the number of control zones (approx. 132 on a 300 mm air ring). The cooling efficiency of the air ring is not affected because any air diverted by one control zone is redistributed around the air ring rather than being expelled to the outside.
To prove the theory of the EGC system, Addex built a full scale test model but with manual
adjustment for gauge control. When this was successful, they realized that not only did they
have a new automatic system but also a cheap, manually adjustable, solution for customers who find
that film gauge is important but not important enough to invest in a fully automatic gauge
control system:-
The Addex Manual Gauge Control System (MGC)
The Addex MGC (Manual Gauge Control) System is once again based on their dual lip air ring and has numerous adjustment points (132 in a 300 mm air ring) that, as with the EGC, influence the amount of airflow to the film. The operator knows it's exact position relative to the airflow. the MGC comes with a lockable cover over the adjusters so that only authorized personnel can make alterations.
Gauge can be measured, manually, offline and subsequent alterations made to the MGC or Addex can supply a gauge monitoring system (GMS) consisting of a carousel, capacitive or nuclear sensor and control cabinet with monitor so that any adjustments can be made before too much off spec. film is produced. The GMS system can be upgraded to a fully automatic Gauge control system at anytime simply by adding IGC or EGC hardware.
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