Secondary bubble-sizing cages are used on about 10% of blown film lines that have extra-tall towers or long, thin bubbles or ones that make products like heavy-duty sacks, for which centering the bubble before the collapsing frame is critical. Secondary cages typically have to be tuned from the top of the tower by an operator, using a duplicate control station or mechanical arms, since the secondary cage isn't visible from the operator station below. Now D.R. Joseph in Grand Prairie, Texas, has developed the first automated controls for the secondary cage, which are integrated with the firm's IBC controls. The secondary cage has to be adjusted whenever a change is made in bubble size. When the bubble size increases, the IBC control automatically keeps the cage a safe distance from the bubble, preventing instability.
Joseph, Inc., D.R.
2125 S. Great Southwest Pkwy Grand Prairie, TX 75051
Phone (972) 641-7711 Fax (972) 641-8747