At booth 5204 in hall A5, Engel will run an e-speed 420/90 injection molding machine with integrated in-mold labeling (IML) producing polypropylene-based margarine tubs 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.
As customers request ever-thinner walls, flow path/wall thickness ratios often reach1:400. To achieve consistent quality at ratios above of 1:300, injection compression molding typically is the only processing option, according to Engel. Other advantages of injection compression molding technology include lower clamping forces and injection pressures than conventional molding and the ability to process high-viscosity materials in a repeatable manner. Overall, this means reduced energy consumption and competitive unit costs.
Conventional wisdom tends to rule out the use of stack molds in injection compression molding because the platen movements can’t achieve the required speed. However, the electric clamping unit and toggle lever design of the e-speed press facilitate fast, short compression strokes — 4 mm in the case of the margarine tubs.
The new e-speed 420 offers 4,200 kN of clamping force in an energy-efficient design. The hybrid injection systems and electric clamping units combine short cycle times with precision and injection speeds up to 1,200 mm per second. An innovative 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 low oil consumption and cleanliness, allowing the e-speed series to meet the strict requirements of the food industry.
During the IML demonstration at the stand, the margarine tubs will carry interactive labels from MCC Verstraete. The labels are based on technology developed by Digimarc; much like a QR code, Digimarc codes can be scanned with a smartphone camera. The main advantage over QR codes is that they extend invisibly over the entire label surface, allowing a wide field of vision for the camera. Additionally, Digimarc codes do not interfere with the packaging design.
The margarine tubs and labels produced at Fakuma will be made of polypropylene. At the end of its useful life, the mono-material packaging can be shredded, as can production waste from the manufacturing process, to go into the production of new products. Engel will demonstrate this at the stand by processing waste label offcuts in the form of regrind.