Precision control drives the form-fill-and-seal sector
01 August 2009
Butter, jam, honey, cream, cheese spread – all commonly found on a hotel breakfast table – are frequently presented in individual sized packages. Convenience and hygiene are factors currently fuelling a growing demand for this type of packaging and, in turn, this is opening up markets for specialist machine builders
The German packaging machine builder, Remele, is a specialist designer and manufacturer of machines that produce small-portion, form-fill-and-seal packages for the catering trade. For more than forty years, the company has been designing and manufacturing these machines, which are capable of filling pumped viscous products hygienically and efficiently into small, pre-formed portion packs, prior to sealing and separating them for despatch and storage.
The functional sequence of its compact RTZ185L packaging machine, for example, covers all the necessary stages of this process, from the hot deep drawing of the pack shape from a sheet of foil, through precise metering and filling with hot or cold product and subsequent sealing over with a printed foil, to the final punching out of the individual packs.
Marketing drives the shape and style of these portion packs, and there is constant demand from customers for new forms, which Remele is able to satisfy, thanks to the flexibility of its machines. But in order to extend the performance and capacity of its machine and make them more adaptable to market demands, Remele first needed the help of an experienced partner with whom it could jointly develop the necessary electronic and mechanical systems. That partner was Stober, which had a proven record of success in the packaging machine market.
It was clear to Stober from the outset that, due to the extremely dynamic nature of Remele’s machines, drives based on motor/gearbox combinations with conventional coupling adapters were not feasible because of the high inertias presented by the moving parts. And simply specifying a larger motor or higher gear ratio would compromise the performance, and ultimately the output of the machine.
Stober manufactures both the gearbox and motor and incorporates the pinion directly within the latter, thus avoiding the need for an additional coupling adapter – a configuration that meets the desired performance criteria in a much more compact design. Different gearbox features were also required also for individual axes, which presented their own specific demands in terms of performance. However, backlash, reliability and size where common key requirements, so a combination of planetary and helical bevel units was selected.
In all this, Remele was determined that one supplier take full ownership of all drive systems, from motor to gearbox output shaft. As a consequence of this decision, the drive system for the moulding station, filler, sealing station and punching unit uses Stober SMS K helical-bevel geared motors in sizes K1 to K5, in low backlash configuration, while a compact SMS P planetary geared motor in size 4 is used to drive the foil feed unit. All the motors are equipped with multi-turn absolute encoders, which contain an electronic form of the motor rating plate to simplify setup procedures.
The machine axes are controlled by pre-programmed Stober PosiDrive MDS 5000 servo inverters, each featuring a removable ‘ParaModule’ memory module that stores all application specific data – again, for ease of setup and replacement. The various machine cam profiles were also pre-programmed into the drives using Stober’s easy-to-use Optimus Motus motion designer software.
Stober provided all installation and commissioning support for the first machine, and provided full training for Remele staff on the functions and potential of its programming and commissioning software. Indeed, such has been the success of the RTZ185L project co-operation that the two companies plan to work together on future machine innovations.
Contact Details and Archive...