Twinsburg, OH--Bottles feed onto a multi-station carousel table, as many as 500 per minute. One-by-one, the labeling machine pushes them into waiting sleeves, preprinted with the label information. The tubular, polyethylene sleeves unwind from a perforated web. Separated, positioned, and stretched, they snap onto the bottles at a precise distance from the top lip. The machine then places the bottle back on the carousel, which carries it away.
Developed by ITW Auto-Sleeve, the container labeling machine applies labels without using glues of any kind. High-speed throughput depends on a Generation III DSP motion control system designed by ORMEC, Rochester, NY. Used to synchronize the labeling machine's carousel axis with the label-feed axis, the motion controller incorporates electronic gearing and high-speed position capture. Digital signal processing and torque-control servomotors add dynamic response and controllability.
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During operation, one servomotor drives the carousel, or pacer axis. Another
servomotor drives the label-feed axis. Set up as the follower axis, the
label-feed axis controls the electronic gear ratio between it and the carousel
axis. Input from a high-speed sensor continually reads the position of label
reference marks on the moving web.
A special registration algorithm, also designed by ORMEC, allows quick response to changing web position. Implemented using digital signal processor technology, the algorithm constantly compares the position of the web against that of the carousel. This information helps the motion-control system keep the web on track by fine-tuning the gear ratio between the carousel servo motor and the label-feed servomotor that is driving the web.
Once off the web, the label is placed on the vacuum drum and carried to the finger holders for stretching. The registration algorithm and high feedback resolution of the servomotors allow the addition of an offset to adjust label position on the vacuum drum and fingers. This adjustment, in turn, permits incremental corrections to label position via the operator interface, and maintains consistent label position on the bottle during normal stopping and starting conditions.
"The GEN III motion controller," says Victor Deonarine, engineering manager at ITW Auto-Sleeve, "lets us place torque where it's needed, and manipulate that torque's profile. This flexibility gives us the ability to synchronize separate functional parts of the machine that otherwise would be physically prohibitive using mechanical methods."
Because the Generation III system controls the carousel axis, additional features are possible. The controller monitors external events and changes the system to compensate. Should the incoming flow of bottles stop, for example, the system will shut down and wait for more bottles, then start again without operator intervention. If the outgoing bottle rate slows down, the controller will automatically reduce machine speed accordingly.
Its operator enters all adjustments and setup parameters into the GEN III motion controller via the machine's interface panel. Factory network protocol "Modbus" serves as the communication scheme between the operator interface and the controller.
Additional details, motion controller...Contact ORMEC, 19 Linden Park, Rochester, NY 14625, (716) 385-3520, or Circle No. 501.
Additional details, labeler...Contact ITW Auto-Sleeve, 8400 Darrow Rd., Twinsburg, OH 44087, (216) 487-2200.