When every changeover minute counts

PET, glass, cans

Different lines, different options for optimization

The extent to which these processes can be automated depends heavily on the line and the type of changeover involved.  

For non-returnable PET lines, Krones offers LineXpress for a much more comprehensive optimization of changeovers. This solution combines Line Management with UnitXpress modules for fast, largely automated changeovers on all machines. And so, for example, changeover procedures on the stretch blow molder, filler, labeler, inspection system, packer and palletizer can all be supported in a targeted manner – and depending on the specific equipment and changeover type involved, even with fully automatic, operator-free quick-change functionality. This comprehensive, line-wide concept from Krones with the option of guaranteed line changeover times is currently the only one of its kind on the market. 

The UnitXpress modules take over mechanical changeovers that have until now been especially time-consuming – with either fully automatic or operator-supported quick-change functionality depending on the machine type involved. Let’s look at a few examples: 

• On the stretch blow molder, a robotic arm takes care of changing of the molds, independently retrieving them from or putting them into staged magazines. 
• At the filler, too, key changeover tasks can now be performed without any operator intervention: Handling parts and the discharge area of the filler as well as the entire capper are automatically adjusted to match the new container height and diameter. Additional software modules support product changeovers between the Contiflow mixer and the Modulfill filler, thus minimizing product waste and shortening transition times. 
• On the packer, the spectrum ranges from fully automatic rail-width adjustments on conveyors at the infeed and discharge to partially automated adjustments with a digital display and audio and visual assistance.  

All in all, UnitXpress offers a modular toolbox that can – depending on the line and equipment involved – shorten format (handling-parts) changeovers to around 30 minutes and product changeovers with an intermediate flush to 10 to 15 minutes – all with enhanced reproducibility. In PET lines, that can translate to an OEE increase of up to 20 percent. 

The situation is even more complex when it comes to returnable-bottle lines for glass and PET. That’s because there is an added factor here, beyond the product, recipe and packaging. Machine parameters must be loaded, routes selected and automatic emptying, start-up and stopping of the machines initiated, just like on the other line types. Additionally, though, the filling line must be supplied with the correct empty containers and crates at all times (at line start-up, during ongoing production and at the end of production) in order to prevent back-ups and material bottlenecks. So the line personnel must manage the balance of crates between the unpacker and the packer and ensure that empty crates are transferred to the packer just in time. Likewise, the sorting stations must be monitored and, in response to variations in the quality of the empties, additional bulk glass must be fed in from storage at just the right time. This extremely high level of complexity combined with the lengthy time from unpacking to packing means that it is hardly possible anymore for operators to keep track of all areas of the line and control each machine individually.  

This is precisely where the value of a solution like Line Management becomes apparent, as it centrally manages orders, material flows and machine parameters across the entire line. Although it isn’t possible to fully automate every last step as it is with LineXpress PET, individual UnitXpress quick-change options are available for selected machines. 

For canning lines, on the other hand, the emphasis is more heavily on intelligent line coordination. The distance between the can infeed station and the filler is usually large, which frequently causes coordination problems between the machines involved. Often, empty cans continue to be fed into the line right up to the end of the current fill run, which of course means that the conveyor is full of cans all the way to the filler – and these extra cans must be removed and disposed of by hand. That costs time and money and is also bad for the environment. When the can height, diameter and lid remain the same from one run to another – meaning that only the product or can design changes – Line Management can make the transition considerably faster and more structured, stopping the sweep-off depalletizer when enough cans have been fed into the line to fill the product remaining in the tank. That makes the canning line more flexible, particularly for co-packers and manufacturers with numerous SKUs – even without having every individual mechanical process automated. True format changeovers, on the other hand, may still require mechanical interventions, for instance on the seamer. Optional UnitXpress quick-change functionality is also available for certain machines in a canning line. 

The sheer variety of options shows that there is no one-size-fits-all solution. Instead, Krones takes a scalable approach: We focus on those places where a given changeover process offers the greatest potential efficiency gain – whether software, mechanical or a combination of both.  

Flexibility is an asset

Faster changeovers are only part of the benefit. What is equally important is that the processes are rendered more reliable and easier to manage. When orders, machine parameters, materials and cleaning steps are centrally coordinated, the dependence on manual coordination and on the knowledge and experience of individual workers is reduced. 

It enables production managers to plan more reliably. In real conditions, changeover times become more repeatable and on average measurably faster than they would be without digital support. Material needs become more transparent and targets become more precisely achievable. The risk of common errors (such as selecting the wrong variant, incorrect best-before date, forgetting materials or running the wrong cleaning process between two SKUs) is reduced. 

And so, variety in the production portfolio is not automatically an efficiency problem. Manufacturers can better integrate smaller batches, more frequent order changes and short-notice demand from the market into their production planning. Line Management and LineXpress (or UnitXpress quick-change functionality) lay the technical foundation by turning SKU transitions, which have up until now been a manually coordinated process, into a plannable, digitally supported and automated line process – whether only on the line itself or all the way through to the ERP system, the warehouse or quality management systems. Faster, more digital and more transparent than a traditional changeover.