PETpla.net Insider 11+12 / 2017

PET planet Insider Vol. 18 No. 11+12/17 www.petpla.net 47 TRADE SHOW REVIEW Engel all-electric e-cap operates with short cycle times and a maximum of good parts Benchmark for energy efficiency by Gabriele Kosmehl At Drinktec, a fully automated e-cap injection moulding machine was producing 26mm HDPE caps including tam- per-proof bands. The cycle time was <2.2s. Michael Feltes, Vice President Business Unit Packaging and Frank Schus- ter, Sales Director Packaging spoke about this machinery in particular and trends in caps & closures in general. PETplanet: At the last Drink- tec in 2013, an e-cap 3440/380 with a 72-cavity mould was presented, which produced a 28mm closure. At that time, the cycle time for the 1.8g cap was <3s. What further develop- ments have contributed to the e-cap 2440/380 model that we see here today? Feltes: Here, we are presenting a production cell as it could be found in manufacturing operations. Our intention is that a specialist sees the system and discovers his every need reflected in the tiniest detail. Since the last Drinktec, we have received lots of feedback from our customers and this has also contributed to further devel- opments. An example here is the topic of plasticising. Thanks to our high-per- formance servo direct drive, the new high-strength HDPE materials can be processed with an MFI significantly lower than 2 or 1g/10 min with a high degree of performance and precision to produce good parts – with very short cycle times. PETplanet: Material develop- ments aim for low part weights. How- ever, many closure manufacturers are meanwhile reporting that they are placing more value on the conveni- ence aspect. But the inevitable ques- tion is: in terms of possible material savings, are we now at the outer limits? Feltes: The trend is still heading towards ever lighter closures. Weight savings of course mean greater sav- ings in terms of material, energy and ultimately cost. On the other hand, the requirements for closure geometry and convenience and hence material selection are growing because the physical properties must be fulfilled and the final product must be usable for the consumer Schuster: Regarded in a purely physical light, still more can yet be gained but in our opinion the limits of lightweighting, with regards to conven- ience, have been reached. However, this is perceived very differently in different regions. For example in Asia, easy handling takes first place for customers and weight plays a rather subordinate role. In the USA however, lightweight remains a significant topic – particularly focusing on CO 2 reduc- tion, which is very important to Ameri- can customers. As a rough estimate, another 1/10 can be saved in weight in the closure market there. And here in Europe, both requirements – light- weighting and convenience – are somewhat in balance. PETplanet: What do the energy needs look like for this fully electric system, based on the current cycle time of <2.2s? Schuster: The specific energy consumption of just the machine is 0.42kwh/kg. The overall system including the chiller is <0.7kwh/kg. These values are setting the bench- mark worldwide. If we accelerate the process, the energy requirements fall per item produced but of course this raises the overall energy costs. Squeezing more out of the cycle time also could result in increased ejector power and clamp force requirements needed for very short cycle times, which will ultimsately also increase the energy requirements. Feltes: Another of our innovations is crucial here: the integrated kinetic energy recovery system! Based on the flywheel principle, braking energy from plate movements is stored in a special configured servo motor and then returned to the system when required for next acceleration. This is primarily an advantage to cut power peaks and reduce overall energy and power consumption . PETplanet: Many thanks for the interesting insights! www.engelglobal.com F.l.t.r.: Gabriele Kosmehl and Heike Fischer, PETplanet, with Frank Schuster, Sales Director Packaging and Michael Feltes, Vice President Business Unit Packaging, Engel, at the Engel Drinktec booth