Customer's Problem

A customer was using a competitor's brake for controlling tension on an unwind stand, making wrappers for shingles. The unwind rollers were mechanically connected to the brake with a Delrin coupling, that had to be attached to the roll with nuts, bolts, and other hardware.

The roll build-up from core to the outside diameter (OD) was limited and it forced frequent roll changes. Shop rules required the disconnection, and reconnection of the mechanical elements of the coupling be performed by a maintenance mechanic, not a machine operator. This requirement caused time delays at each change of the unwind roll and led to high processing costs.

Management wanted to decrease the frequency of roll changes by increasing the OD of the roll, allowing more product to be wound on a single roll. The Nexen Representative was called in to determine if the existing brake would work with the higher torques required by the larger roll diameters.

Nexen's Advantage

The Nexen Sales Representative recommended replacement of the current brakes with Nexen T800A brakes. These brakes provided the increased torque necessary and were very compact. The simple serviceability and maintenance of the brakes was also a plus for this design.

The brakes were supplied with Nexen Safety Chucks and adapter plates, providing a convenient, easy-to-mount package. Use of the safety chuck removed the requirement for a maintenance crew member to be present at each roll change. The customer was also provided with a Nexen Ultra-sonic Sensor to feed roll diameter data back to the PLC used for control of the unwind tension, and a Nexen I-to-P Converter to convert the output signal of the PLC into a variable air pressure signal to the brake.

The customer was very happy with the ease of installation and performance of the system. The initial order for two systems has been followed up by a second order for an additional system.