Today, PET containers account for about 40 percent of Gropper’s total production volume. The success of PET packaging is also reflected in the dairy’s capital expenditure. In 2015, the company decided to significantly increase its capacity for producing in PET containers and launched a wave of investment. That same year, Gropper opened a second plant in Stockach, near Lake Constance, which was followed in 2018 by a plant in Moers as part of a joint venture with Dr. Oetker. Two PET lines from Krones are now in operation at each location. In addition, the Bissingen plant also got two new lines, in 2018 and 2019. Both lines once again feature a PET-Asept D system from Krones, each with a rated capacity of 18,000 1.0-litre containers per hour. This aseptic filler-capper block processes not only milk, dairy drinks, and whipping cream but also coffee beverages, NFC juices, smoothies, and water. The latest filler generation gives Gropper the utmost flexibility in container choice. On earlier models, changing bottle shape meant replacing handling parts. Today, all container types can be processed with a single set of handling parts. Because the clean room no longer has to be opened, cleaning times are also shorter – and the line’s performance has increased by around 25 percent compared with earlier models.
With the PET-Asept D, Gropper has once again consciously chosen to keep the filler and the blow-molder separate. One reason is to clearly segregate packaging material storage from the hygienic space around the filler. Preforms and packaging materials are fed into the lines from a central location at the front end of the bottling hall – and for that reason, the Contifeed preform feed system, the Contiform 3 Pro stretch blow-molders, and the packer are all sited in this part of the hall. The filler stands at the opposite end of the hall. An AirCo air conveyor transfers the molded PET containers along the 60-meter (nearly 200-foot) stretch between the two areas. “The air conveyor also serves as a buffer. Especially when working with higher-viscosity products, we can run slow filling without impacting the thermal process in the blow molder,” explains Burgmeier. Karl Klein, Managing Director Production and Technology at Gropper, chuckles, adding, “At Gropper, we’re obsessed with buffers because our experience has been that block set-ups often result in efficiency losses. We really notice that when one of our buffer towers goes down and has to be bypassed. Efficiency immediately drops by four or five percent.”