Unwind Tension Controls
Unwind Tension Controls: A completely mechanical device (with integral cantilevered roll support shaft) for controlling unwind tension on rolls of film, foil, paper, tape, wire, plastics and the like.
Operation: This system consists of a compensating brake inside a protective cover, and a sensing module consisting of two rollers mounted on a pivoting bracket. This bracket is spring loaded and adjustable. A feed-back cable connects the sensing roller bracket and the compensating brake. Since the sensing roller bracket is balanced against the initial spring load (tension setting), the bracket and rollers actually change the floating position by pivoting in response to changes in roll diameter, speed, acceleration and coefficient of friction changes within the brake system. The pivoting motion of the bracket is transmitted by means of the feed-back cable to the brake, constantly adjusting the brake force to keep the system in equilibrium.
The following standard tension ranges are available for the completely mechanical system: 0.75-2.5, 1.5-5, 2-10, 5-15, 7-21, and 8-25 pounds. The powered system can be furnished with a low range of 80-240 grams. All ranges are infinitely adjustable within the high and low limits. It is possible to convert from one range to another through the use of conversion springs.
If a wider tension range is required, the Compensator can be furnished with a low friction air cylinder in the sensing module in place of the normal torsion spring. With this arrangement, it is necessary to supply air to the Compensator at 80 PSI.
Damping System: A fluid type damping system is provided as an included kit. If damping becomes necessary, the kit may be readily installed in the Compensator.
Accuracy of Control: Under normal operating conditions, tension is held to +/- 3% of the
initial tension setting and is maintained from full to empty roll.
Installation: Standard construction units are furnished with 4 machined pads and mounting holes in the casting unit. Dual units, heavy duty construction, and powered units are furnished on plates of 1/2″, 3/4″, or 1″ thickness, depending on size and application. Mounting holes are provided in the plates, and their location and size can be specified by the customer