Products
A Frame Unwind
Unwind Module
The unwind portion of the machine consists of an airshaft with safety chucks, a pivoting dancer roller, and a pneumatic disc drag brake.
The Unwind may be fastened to the entry end of the sheeter with connector plates. There are typically no electrical controls for this assembly. As the web pulls the dancer roller up during an increment of the sheeter, the amount of tension in the drag brake lessens. An optional system can sense the roll diameter optically and modulate the incoming air pressure to the dancer regulator.
Loading the Unwind
The unwind airshaft is assembled with the material roll justified toward the hinged side of the sheeter module. The tilt plate safety chucks will tilt open manually when they are rotated to the up position. The airshaft and roll of material can be vertically lowered into the safety chuck pair. Square bosses on the ends of the airshaft fit into corresponding square openings in the safety chucks. The tilt plate safety chucks are then manually closed by tilting the plates vertical to trap the airshaft in place. An inflation port near the end of the airshaft is used to fill the airshaft with compressed air (90 psi), thereby securing the material roll to the shaft and allowing the drag brake to apply tension.
- Dancer Regulator
The dancer regulator changes the air pressure delivered to the disc drag brake based on the position of the dancer. As the dancer rises, the air pressure is reduced, causing the drag brake tension to decrease. When the dancer lowers, the air pressure is increased, causing the drag brake tension to increase.
Unwind Adjustments
The dancer regulator cam is adjusted at the factory and does not normally need adjustment. An air pressure regulator and gauge may be present to limit the amount of air pressure delivered to the dancer regulator. Use this control to adjust the desired tension limit in the web. Also present may be a pressure regulator for the dancer cylinders. This too can be adjusted to limit the web tension. Usually it is only necessary to change these adjustments when the roll width changes substantially, say from 60” wide down to 30” wide.
Dual Accumulation and De-curler Options Available