Alpla, Brink, IPB Printing and Engel collaborate to produce rPET containers in thin wall injection moulding

In cooperation with partners Alpla Group, Brink and IPB Printing, Engel is presenting a quantum leap for the packaging industry at K 2022. For the first time, thin-walled containers made of PET can be produced in a single injection moulding process step. Austrian injection moulding machine manufacturer Engel is processing recycled material (rPET) at its stand. An Engel e-speed injection moulding machine with a newly-developed and extremely powerful injection unit is being used to do this.

Featuring a wall thickness of 0.32, the transparent, round 125-ml containers are representative of a whole genus of packaging, especially in the food industry. Thanks to integrated in-mould labelling (ILM), the containers are ready-for-filling as soon as they leave the production cell. The special feature in this application is the material. The thin-walled containers are produced directly from rPET in a single step. Up to now it has only been possible to process PET in thick-walled parts such as bottle preforms in injection moulding. The final packaging format was created in a second step of the process – by blow moulding for example.

The modified rPET being processed at the K show comes from drinks bottles recycled in the plants of packaging and recycling specialists Alpla Group, who are headquartered in Hard, Austria. Other partner companies involved in the show exhibit are Brink (Harskamp, Netherlands) for the mould and IML automation and IPB Printing (Reusel, Netherlands) for the labels. An Engel e-speed 280/50 injection moulding machine is the heart of the production cell. The company specifically developed this hybrid machine with its electrical clamping unit and hydraulic injection unit for the high-performance requirements of thin-wall injection moulding. The new high-performance injection unit achieves injection speeds up 1400 mm per second at a maximum injection pressure of up to 2600 bar when processing small shot weights with an extreme wall-thickness to flow path ratio. This makes it the most dynamic injection unit on the market worldwide.

To process rPET, ENGEL combines the new injection unit with a plasticising unit from in-house development and production specifically designed for processing recycled material. During plasticising and injection, the viscosity of the PET is configured for thin-wall injection moulding. The new Engel e-speed supports the processing of arbitrary recycled materials up to 100% rPET.

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