Around 18 months ago the design engineering team at Macpac entered into discussions with the Illig engineering team about how they could manufacture more intricate shapes at higher machine speeds and with reduced machine downtime. This was a really a tall order and required some unconventional thinking to achieve. The resulting collaboration addressed the stacking of formed product at the end of the manufacturing process. An innovative and entirely different approach has brought about a world first in stacking and skeletal rewind technology.
Traditional thermoforming machines use an upstacking arrangement at the end of the thermoforming process line. This involves complicated engineering whereby the forming has to be gripped in position and the stack is physically pushed upwards. A major problem for the machine operator is that formings, especially complex shapes, can have a tendency to mis-locate in the stacker causing the machine to be stopped and re-set.
When this becomes more frequent, the downtime becomes significant and adds to the operator’s costs. The collaboration with Macpac utilised its experience in operating a wide variety of Illig’s pressure formers and it was able to provide precise engineering input about the operational difficulties. The new downstacking and rewind arrangement no longer relies on gripping the forming and pushing it upwards. Instead it utilises gravity and a motion control system to allow for the change in height as the stack develops. The key advantage to the thermoformer is that downtime is reduced as fewer formings fail to locate properly in the stacker and much more complex shapes can also be stacked.
The big plus to the thermoformers customer is that the new stacking arrangement facilitates lower cost tooling as the stacker is less complicated to build requiring less engineering. The stacking cage system can be eliminated and products can simply index down onto a generic conveyor. This new technology was incorporated into an Illig model RV74c pressure forming machine. The machine is also the first of this model to be supplied without a ‘blow box’. This offers reduced tooling costs together with easier access to cleaning, an important factor when considering food packaging.
In addition, faster changeovers of tools can be performed for even greater efficiency. The resulting machine was installed in Macpac’s factory and has been used extensively to manufacture a variety of products including Surecel, the companies Starpack award-winning range of self locking clamshell blister packaging. Not content with one world first Macpac then set about a further collaboration with Illig, this time to make improvements to the software system controlling the stacking of formed products. Major improvements have been made that have further reduced downtime and streamlined the manufacturing process.
A spokesman for Illig said: “Working with a company like Macpac that understand the engineering behind thermoforming machinery and how the technology can be developed to meet their customers needs, helps us to extend the boundaries of thermoforming technology.”
Macpac took delivery of a second RV74c in September that features the new and improved technology. The machine was supplied in modules that were commissioned by Illig’s engineers The machine has now been running trouble free for several months enabling Macpac to provide its customers with an even better service of quality goods. For further information please telephone 0161 442 1642 or visit www.macpac.co.uk