Breaking into wrapping machinery

Solbern used PACK EXPO International as a launch pad for its new sandwich wrapping system, which takes advantage of PLC-controlled stepper motors and drives

Wrapping machine
Wrapping machine

Perhaps best known for a variety of canning and food processing technologies, Solbern recently unveiled a roll-fed wrapping and labeling machine for subs and other hand-held foods. It’s available in either single- or twin-station formats, depending on the customer’s output requirements. The machine shown here has two wrapping stations; a single operator picks a submarine-style sandwich from an infeed conveyor and places it into one wrap station and then the other. A Leuze photoeye signals the Rockwell PLC that a sandwich is present and the PLC activates the wrapping sequence. Also important to point out is that Keyence light curtains ensure that only after the operator’s hands are safely out of harm’s way can the wrapping sequence be activated.

In each wrapping station there are four stepper motors. Two HW24-108 steppers are for the side grippers that assist in rotating the sandwich/food product. One HW34-696 stepper is for the roller assembly that rolls the product during the wrapping sequence. The last stepper, another HW34-696, drives the nip roller assembly. Each of the stepper motors, which come from Applied Motion, is governed by its own Applied-Motion ST5-IP-EN programmable drive.

Also part of each wrapping station is a Multivac pressure-sensitive labeler. The label not only identifies what’s in the sandwich, it also serves the purpose of neatly and reliably ensuring that the paper wrap so meticulously folded around the sandwich stays folded through distribution and right into the refrigerated display case at the supermarket or convenience store where consumers encounter the sandwiches.

One other important component in the machine is the pneumatically activated guillotine knife assembly, a Model GC400 from Azco. A wash-down model made of stainless steel and ceramic bearings, it cuts the roll-fed wrapping paper to the appropriate length when signaled by the system’s main PLC. Wash-down capability was also an important performance characteristic in the Applied-Motion stepper motors. As Solbern President Tom Berger puts it, “Others make stepper motors, but not too many make one that has an IP-65 rating.”

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