At the upcoming Fakuma trade show in Friedrichshafen, Germany, Austria-based injection molding machinery manufacturer Engel will be showcasing its latest technology and developments, all under the central theme of sustainability.
A key exhibit will be the new e-speed size 420, offering 4,200 kilonewtons of clamping force, which Engel is unveiling at the show. The e-speed injection molding machines with hybrid injection unit and electric clamping unit combine very short cycle times with maximum precision and very high injection speeds of up to 1,200 millimeters per second; they operate with extreme energy efficiency.
An energy recovery system absorbs braking energy from the platen movements and returns the stored energy to the motor – for example, to accelerate the mold mounting platens again. The toggle lever is encapsulated to ensure particularly low oil consumption and maximum cleanliness, allowing these machines to meet the strict requirements of the food industry as standard.
At the show, an e-speed 420/90 injection molding machine with integrated in-mold labelling will be producing ready-to-use margarine tubs from polypropylene in a fully automated injection compression process. The containers, which have a wall thickness of 0.4 mm, including the label, will be removed from the 4+4-cavity stack mold via high-speed, side-entry automation and stacked on a discharge conveyor following camera-based quality control. The partner companies on this exhibit are MCC Verstraete, Plastisud, Campetella, Mevisco and Borealis.
An injection compression molding process was chosen to ensure quality consistency of molded product. The continuing trend for reducing wall thickness has led to ever more extreme flow path/wall thickness ratios that are often in the range of 1:400. At ratios of 1:300 and above, consistently high component quality in many applications can only be achieved by means of injection compression molding.
Additional benefits of the technology include the lower clamping forces and injection pressures required in comparison with conventional compact injection molding, plus the fact that even high-viscosity materials can be processed in a repeatable manner. Overall, this means reduced energy consumption and competitive unit costs. And while injection compression molding is often held to rule out the use of stack molds, this is not an issue for the Engel e-speed injection moulding machine.
The PP margarine tubs feature interactive labels from MCC Verstraete. These labels are based on digital watermarking techniques developed by Digimarc. Much like a QR code, Digimarc codes can be scanned with any smartphone camera. The codes are invisible, but span the entire label surface, so that the camera can scan any point.