|Case Study 1
It Worked Before: Now It Works Better
Weve all heard the saying, "If it works, dont fix it." Its a good thing that Emulsion Technologies, Inc. (Emtech) and Meier Transmission dont think that way.
Meier has been providing power transmission products and controls to Emtech for years. Our relationship is a good one. Dick Fowler, Emtech President, is always looking for a better way to do things. So are we. So when he wanted to add a new production line, he came to Meier.
Emtech manufactures label stock for the pressure sensitive label industry. They had two lines operating and called us for help in setting up a third line. Dick wanted the new line to be outfitted with modern, state of the art technology. He explained, "I knew Meier was doing great work with automated systems and they have always been professional and fair with our business. They were a proven entity and the natural choice to design our automated production."
Emtechs production line function is to unwind paper stock from a roll, coat it with adhesive, cure it in a continuous oven, laminate face material to the adhesive side and them rewind the final product. Three drives and two tension control systems are required for control and coordination as the web is processed. Precision speed and tension throughout the web are imperative for the line to yield consistent quality in the final product.
Meier Sales engineer (and 1991 PTDA Salesman of the Year), Ken Yocum and I zeroed in on the key areas of control. The adhesive coating and the laminating process were targeted as the most important.
The laminator drive was set up as the "master" drive for the line. A Fenner Controls M-Trim digital closed loop motor control, set in the master mode, regulates the speed of the Reliance DC drive and motor on the laminator. The M-Trim allows the line operator to set the line speed directly at the control in user units of feet per minute. The M-Trim can also display the actual speed of the line, and allows control to within +/-.01% of the set speed. A ring kit sandwiched between the DC motor and the reducer provides the information feedback to the master control.
A second Fenner M-Trim was used for the adhesive coating roll drive. This M-Trim is set in the follower mode to allow the coating roll Reliance drive and motor to follow the master drive speed. It is crucial that the adhesive be applied smoothly and evenly across the paper to ensure proper lamination. This control is also closed loop with a ring kit and will regulate motor speed to within +/- .01% of the lamination speed. The line operator can set the ratio between the laminator drive and the adhesive coating drive digitally on this M-Trim. Digital readouts make it easy to view the actual coater roller speed. Setting and checking the speed and coordination of the laminating and coater roll processes is now faster and easier for the operator.
Ken chose to control the unwinding of the paper and the face material with separate Horton Tension Control Systems. Constant, even tension in the web as it moves through the coating and laminating process insures even adhesive thickness and wrinkle free lamination.
The Horton Systems used load cells mounted under the bearings of a "floater" roll to send signals to Hortons TC-240. The operator sets the tension on the TC-240. As the material moves over the floater roll, the control receives the load cell signals, compares it to the set point, then sends a signal to a pneumatic converter which applies brake pressure to a precision tension drag brake mounted to the unwinder roll shaft.
The final product is wound using a Reliance DC variable speed drive and motor with a torque taper option. This option provides even tension to the roll as it builds up in diameter.
With all of the parts working together, its a simple and effective solution.
I designed the control system, built the panels in our shop at Meier and provided Emtech with wiring diagrams and instruction manuals. After the equipment was installed by Emtech electricians, Ken and I provided start up assistance and fine tuning in the plant.
Since then, Emtech has been spinning out rolls of label stock, faster and of a higher and more consistent quality than their other lines. Their scrap rate has decreased to about 1%. Now they have a production line that can automatically compensate for changes. The operator can set the speed and tension of the line easier while monitoring the line performance. And Dick Fowler has a state of the art, automated production line that works better, longer and with greater cost efficiency.
This creative solution is a good example of Meier in Motion. For more information about this or other automated control applications, call Meier. And watch this column for more real-life examples of Meier automated solutions that work.