Even if there’s still a lot to be said for using single machine systems for some types of application, for many years now the trend in filling and packaging lines for PET bottles has been gravitating towards increasingly more compact, blocked plant engineering. This is because space is a critical factor for many beverage producers; in addition, conventional air conveyor segments in particular are prone to failure. Blocking offers two important advantages here. It contains loads of technology within a minimum amount of space thereby reducing the footprint by up to 70%. It also makes long conveyor belts and air conveying segments superfluous as the distance between the preform and the filled and labeled bottle now only constitutes a few meters.
Compact and multifunctional
In order to suitably satisfy market demand KHS has now devised the KHS InnoPET TriBlock, a multifunctional PET processing system which incorporates a stretch blow molder, filler, and labeler. Bottles can now be fully conveyed from their point of manufacture to the labeling process through one compact piece of machinery. Under the aegis of Frank Haesendonckx from KHS Corpoplast in Hamburg the system has been built with the help of the filling technology specialists at KHS in Bad Kreuznach and KHS Dortmund’s labeling experts. Their shared objective was to implement the concept in a very short time indeed in order to be able to market the block as quickly as possible. “As we were able to base the new TriBlock on tried-and-tested technology, during development we very quickly obtained convincing results.” This was aided by the fact that the interfaces or interaction between the stretch blow molder and filler had already been tested and optimized and the two drive systems successfully electronically coupled on the proven KHS InnoPET BloFill blow molder/filler block.
The actual development phase, during which a labeling function was added to the stretch blow molder, was successfully concluded within a matter of weeks. The smooth cooperation between colleagues working in filler design, labeling technology, and at KHS Corpoplast played a key role here. In view of the ambitious target everybody was prepared to go the proverbial extra mile and come up with creative solutions. A number of unconventional ideas also contributed to the project’s rapid success, such as the one for a gear wheel for the labeler position sensor which wasn’t available on short notice. The part was printed overnight on a 3D printer based on the 3D data – in plastic, of course – and the machine ran with this part until the original part arrived and could be installed.
At the end of the development phase the stretch blow molding, labeling, and filling processes underwent a performance test. For this purpose labels were brought into position on the machine and a few bottles first slowly run through the labeler and labeled in step-by-step mode before the block was fired up to a rate of 39,600 bottles per hour. “Even the dress rehearsal was a huge success,” smiles Haesendonckx. “At full machine capacity the first bottle alone delivered perfect results. The test runs for a labeler station changeover on the fly, hiding a bottle gap and rejecting unlabeled or incorrectly labeled bottles were also faultless.”
Special preglued technology is used on the labeler which has been developed by a partner in Italy and which KHS has integrated into the TriBlock in cooperation with this partner. Haesendonckx is particularly proud of this process. “By using preglued labels the block ensures that the PET bottles are not subjected to any hot melt vapors during the entire procedure,” he explains.
What’s really spectacular about the new development, however, is that in the InnoPET TriBlock KHS is able to offer the market a stretch blow molder/labeler/filler block which can process lightweight bottles for the first time. This is made possible by a unique feature integrated into the compact system – namely consistent end-to-end neck handling. From the preform to the filled product, the bottles are fed through the machine by their necks, including gripping, stabilizing, and rotating in the labeler. Bottles no longer have to be clamped and held in position during the labeling process as used to be the case. This is an ideal solution which is gentle on the container, especially where very light PET bottles are concerned. This means that the InnoPET TriBlock is able to process lightweight PET – for example, a 0.5-liter bottle weighing much less than eight grams.