Air Ring Is Automated To Offer Segmented Air Volume Control

December, 2001

Extrusion:

Air Ring Is AutomatedTo Offer Segmented AirVolume Control

Davis-Standard has added automation to its WesJet air ring so that it can offer segmented air volume control. Segmented air streams are regulated through a gateway actuator to increase or decrease film thickness at each segment, thereby correcting the profile by 50%.

This is said to eliminate unwanted heating of the die lips, which causes long-term process problems with die lip build-up. It is also said to give processors greater control of the gage profile while maintaining high-performance cooling.

The WesJet can be used on stationary or oscillating dies; it is available on new lines or as a retrofit. It features a wide, tangential sweep design for the air inlets and a machined vane network for air velocity/volume distribution. This allows for lower air pressure and higher air volumes, increasing the cooling effectiveness by 10 to 20%.

A venturi is created as the lower volume secondary air stream meets the primary air stream. The negative pressure field around the bubble surface pulls outwardly on the film, allowing increased air-cooling as the air stream stabilizes the bubble.

Other features include an adjustable deflector gap providing velocity control, as well as built-in oscillation seals and bearings.

Davis-Standard
Pawcatuck, CT Circle 108