The Ever Elettronica SD180/170 series stepper motor drives, which are
available in the UK from Astrosyn, can be used to place web-fed,
self-adhesive labels on fast moving objects such as bottles and cartons
travelling on a conveyor belt. The labelling head, which is driven by a
stepper motor, may be controlled in open or closed loop modes, and DSP
electronics within the drives ensure that the labels are accurately and
consistently applied regardless of container speed. Containers and label
web remain perfectly synchronised throughout the cycle, even during
critical stages such as the conveyor ramping up to speed or when
decelerating.
The drive electronics also include additional functions, enabling various
parameters of the machine cycle relating to different label shapes
(speed, start delay, stop delay, label pre-display, etc) to be stored.
When changing the shape all that is required is to enter the new shape's
code number and the machine is ready for the new cycle. CANbus networking
available on these drives allows label changes to be implemented over the
fieldbus - particularly useful when there are large numbers of labelling
machines installed.