Thin-wall injection compression moulding for stack mould technology

 Thin-wall injection compression moulding for stack mould technology

ENGEL’s stand at Fakuma 2021 from 12-16 October in Friedrichshafen, Germany, will put the spotlight on sustainability. The production of decorated monomaterial food packaging and the processing of regrind from labelling waste is supporting circular economy by creating a process chain. At the same time, the company is celebrating the world première of the 4,200 kN version of the ENGEL e-speed injection moulding machine. The sophisticated packaging application combines extreme thin-wall injection compression moulding with stack mould technology.Get more news about compression moulding machine,you can vist our website!

Over the five days of the trade event, an e-speed 420/90 injection moulding machine with integrated in-mould labelling (IML) will be used to produce 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 mould via high-speed, side-entry automation and stacked on a discharge conveyor following camera-based quality control. Corporate partners at the trade show will be MCC Verstraete, Plastisud, Campetella, Mevisco and Borealis.

The continuing trend for reducing wall thickness is leading to ever more extreme flow path/wall thickness ratios that are often in the range of 1:400. From a ratio of 1:300 and above, consistently high component quality in many applications can only be achieved by means of injection compression moulding. Other advantages of injection compression moulding technology include the lower clamping forces and injection pressures required in comparison with conventional compact injection moulding, 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.

Despite this, injection compression moulding tends to be seen as ruling out the use of a stack mould; this is because for many injection moulding machines, the speed of the platen movements is insufficient for a stack mould. For the ENGEL e-speed injection moulding machine – designed to handle the long-term, high-performance output required by the packaging industry – things are different. The electrically driven clamping unit and the toggle lever design facilitate very fast, short compression strokes – 4 mm in the case of the margarine tubs. The parallel movements can be controlled very exactly – the prerequisite for coordinating the compression stroke and injection profile to the necessary degree of precision.