DESCRIPTION
A series of products, such as candy bars, are fed into the sealing machine equally spaced on a conveyor. A second inline conveyor is lined with plastic wrapping material supplied from a supply spool underneath the conveyor. A second supply spool is above the conveyor. As the product transfers to the second convey the product gets sandwiched between the upper and lower plastic wrap. Heated rolls seal the plastic at the ends of the product while a heated cutter/sealer drum seals and parts the product.
SOLUTION
The EMAX 1-1/2 axis controller is ideally suited for this master/slave application. A servo motor is connected to the seal/cut drum via a precision gearbox. A line encoder is connected to the conveyor system to sense the speed and position of the conveyor. A product sensor is positioned to detect the incoming product and to compensate for slight product pitch variations.
An application program for the EMAX controller is developed using the Emerald Motion Language PC software to create the following sequence:
- The seal/cut drum is positioned so the knives are horizontal and clear of the plastic web.
The conveyor starts running and product is fed onto the second conveyor.
When the sensor detects a product the servo driving the cutter/sealer drum synchronizes to the web motion to cut and seal the leading edge of the first product. - An electronic cam in the EMAX controller driven by the line encoder is used to control the motion of the cutter/sealer drum to create a seal and cut between each product.
- The pitch of the cutter/sealer is electronically adjusted using the product sensor to compensate for product spacing.
- If the product flow terminates or a jam is detected the cutter/sealer drum is positioned horizontally and the heater controls are turned off.
ADDITIONAL APPLICATION FEATURES
- Touch-screen operator interface is utilized for batch count, parameter entry, diagnostics and error messages.
- Control of the conveyor prime mover motor.
- Control of heaters for the cutter/sealer drum and side seal rollers.
