Lubrication-free bearings and drive elements in thermoforming packaging line

Food packaging: good guidance without lubrication thanks to tribo-optimised polymer bearings

In the new generation of PowerPak PLUS thermoforming packaging systems, GEA has combined a number of innovations. Our linear bearings, plain bearings and drive elements helped. Important selection criteria: no active lubrication, long service life, hygienic design and suitability for intensive cleaning processes.

Profile

Thermoforming systemsPowerPak PLUS With the new PowerPak PLUS series of thermoforming systems, GEA meets the requirements of demanding customers in the food packaging industry.

Products used

Problem

In thermoforming, a lower film is formed into a tray shape, the product is inserted and sealed with a top film. Bearing technology was needed here at various points on the PowerPak PLUS packaging plant:
 
Lower film unwinding
On the safety enclosure of the lower film unwinding, a sliding door requires curved linear bearings that follow the roller contour. They have to do without active lubrication and cope with cleaning processes using superheated steam, acids and alkalis or dry ice.
 
Film guide
A 3-metre-wide sliding door at the level of the film guide in the centre section of the system also provides a view of and access to the machine.
 
Tensioning system
An adjustable guide roller maintains the film tension when the film is unrolled and is retracted linearly when the film is changed. For this, as well as for the bearing of the guide roller itself, bearing technology was needed that prevents electrostatic charging of the film and can be operated completely without lubricants.
 
Film edge control
In addition to the film tension, the packaging machine also monitors the longitudinal direction. If the film width changes, a sensor sends this information to an actuator, which adjusts the roller axially via a linear unit.
 
Thermoforming and sealing station
At this station, the lower film is given its shape under the effects of pressure and heat. Lifting stations with linear lift and toggle joint systems ensure the movement of the tools in vertical direction. It needs plain and linear bearings for its axes.
 
Labelling stations
And last but not least, a solution also had to be found for the energy and signal supply of the system's labelling dispenser that could be used under the strict specifications in the food industry.

Solution

To meet the expectations for bearing technology, GEA Food Solutions now uses our bearing technology at various points in its packaging plant:

drylin W linear bearings
The sliding door device's curved contour on the lower film unwinding system is achieved with drylin W linear systems. Sliding elements made of tribo-polymers with incorporated lubricant travel on them and thus require no active lubrication.

drylin W linear bearings
The drylin product range is also used in the sliding system at the level of the film guide. The bearings are also suitable for aggressive cleaning processes.

drylin JUM linear bearings, iglidur bearings, xiros ball bearings
A drylin JUM linear plain bearing performs the tensioning system's linear adjustment. A tribo-polymer bearing made of conductive iglidur F2 prevents the film from electrostatically charging. The xiros polymer ball bearings are used to support the guide rollers. The xiros design eliminates the need for elaborate sealing concepts.

DC motor, drylin trapezoidal lead screw
Roller drums are readjusted in the longitudinal direction by a DC motor that drives a dryspin trapezoidal lead screw, and a nut made of iglidur tribo-plastic axially displaces the roller.

iglidur plain bearings, drylin liners, iglidur linear clip bearings
The axes at the drawing-in and sealing station are supported by plain bearings made of iglidur J and Z materials, which absorb high forces. For the linear strokes at the station, drylin liners and iglidur JUCM linear clip bearings were installed.

Energy chains
And our product range also guarantees reliable energy and signal supply. Energy chains suitable for the food industry are used here.

GEA PowerPak PLUS packaging system Lower film unwinding: Here, the sliding safety enclosure is moved with smooth-operating drylin W linear guides in a curved version.
GEA PowerPak PLUS packaging system Film guide: The large sliding door at the level of the film guide replaces all the old hood bearings. It is opened and closed using drylin W hybrid linear roller bearings.
GEA PowerPak PLUS packaging system Tensioning system: The film web tensioning system consists of drylin linear bearings and electrically conductive iglidur plain bearings. xiros F180 polymer ball bearings are used in the film guide rollers.
GEA PowerPak PLUS packaging system Web edge control: The maintenance-free automatic web edge control with drylin trapezoidal lead screw nut and drylin R liners creates the conditions for processing various film qualities.
GEA PowerPak PLUS packaging system Thermoforming and sealing station: In the lifting stations of the thermoforming and sealing station, iglidur plain bearings take on heavy work and move the tools in a vertical direction.
GEA PowerPak PLUS packaging system Labelling station: In the "TiroLabel" labelling stations, our energy chains provide the energy and signal supply.