Process optimization and productivity were on the minds of engineers at Innovative IDM, when one of its clients sought a solution for automatically adjusting a horizontal extrusion die. The die controls the thickness of a 72-inch-wide plastic web.

When a portion of the web moves out of tolerance, the micrometer messages the servo controller via Modbus. As described by IIDM field applications engineer Steward Bissell, adjusting the die required manual adjustment of 72 bolts located across the top of the die. A worker would compare readings taken with a nuclear micrometer to prescribed set points. This process, says Bissell, required a lot of the operator’s attention, time better spent overseeing the machine and its operation.

To avoid this, Bissell and his team devised an automated solution. It incorporates a Yaskawa multi-axis servo controller with four servo amplifiers and motors, and Modbus communication to interface with the micrometer. Two motors mount on each of two heads. Each head comprises a position motor with a gear reducer that travels on a linear gear across the die; and an adjusting motor with a socket mounted to the motor shaft that pneumatically lowers down on each bolt to adjust it.

To teach each head the position of the first bolt, the operator moves the head manually to that position. After the distance between each bolt is programmed into the system, each head travels across the die to learn the positions of each bolt and the rotational position of each bolt head.

In operation, when a portion of the web moves out of tolerance, the micrometer messages the servo controller via Modbus. It identifies the bolt requiring attention and the amount of adjustment needed. The head closest to that bolt then moves to a bolt three bolts away and, alternating between bolts on either side of the offender, begins to adjust the bolts. The outside bolts receive minor adjustments, working up to a full adjustment of the center, offending bolt.