Circular Economy is one of the focus topics at K 2019 and also the “green thread” running through injection moulding machine manufacturer and system solutions provider Engel's trade fair appearance. Stefan Engleder, the CEO of the Engel Group, emphasises the huge importance of this topic in the run-up to the trade fair as follows: “It is my personal concern to contribute to establishing a circular economy for the plastics industry, which bears a global responsibility that can only be met by companies working together. I therefore welcome the focus on Circular Economy at the most important international industry event. K will give this subject even more impetus”.

“K 2019 will show what is already possible today and what companies in the plastics industry are working on to close increasing numbers of material cycles”, says Engleder. “Circular economy is an innovation driver”. One of the priority tasks on the way to the circular economy is to open up a broader range of applications for processed plastic waste.

At K 2019, five exhibits at three locations demonstrate Engel's contribution as an injection moulding machine manufacturer and system solutions provider. The focus is on processing recycled material, improving process stability, and the trend towards design for recycling.

Greater process stability paves way for wider use of recycled materials

“The stability of the injection moulding processes is key to being able to use recycled materials also for higher quality products”, as Günther Klammer, head of the Plasticizing Systems division and Circular Economy expert at Engel, emphasises. Recycled material is naturally subject to greater batch variations than virgin material. In order to significantly reduce its influence on the process, the intelligent iQ weight control assistance system is being used at Engel's stand to process fully recycled ABS. The software from Engel's inject 4.0 program ensures a constant melt volume during injection and thus a consistently high product quality, even with strongly fluctuating raw material quality. “Intelligent assistance opens the door for recycled materials to a far broader range of applications”, says Klammer. “Industry 4.0 is an important enabler for the circular economy”.

Increasing the proportion of recycled materials in sandwich-moulded components

One further approach to using recycled materials more widely is sandwich components with a core of recycled material embedded in virgin material. The aim is, on the one hand, to design increasing numbers of products for this type of two-component production, while, on the other, increasing the proportion of recycled material in the sandwich structures. The proportion of recycled material that can be used in the core is essentially determined by the geometry of the moulded part and the flow pattern in the cavity. The transport boxes that Engel is producing at its stand using the Engel skinmelt process pose a particular challenge in this respect. But despite this complex component geometry, Engel still succeeds in achieving a very high level of recycled content of over 50% with the skinmelt process. What is also important is the grade purity “ensuring that the sandwich-moulded products can also be easily recycled at the end of their service life”, as Klammer emphasises. Engel is exclusively using polypropylene for the manufacture of the transport boxes; the recycled material here originates from post-consumer collection. Engel collaborates with Der Grüne Punkt (The green dot), Duales System Deutschland (DSD, Germany), to this end.

Considering recycling as early as in product development

Designing for recycling means that the subsequent recycling process is taken into account as early as in the development of a new product, and that the requirements of the circular economy and sustainability are taken into account in the product design. Further examples where this is already working well can be found in the packaging industry and in composite lightweight design. In the production of thin-walled packaging in the IML process, for example, there is a trend towards mono-material systems in which the label and pellets are made of the same material.

Wherever you look in composite lightweight design, thermoplastic-based solutions point the way to the circular economy. In the Engel organomelt process, fibre-reinforced prepregs with a thermoplastic matrix such as organic sheets and tapes are overmoulded with a thermoplastic from the matrix material's material group. The entire composite component consists only of thermoplastic and glass fibres and has the potential to be recycled at the end of its useful life. At its stand, Engel is demonstrating the production-ready process with a demanding automotive application.

Giving fishing nets a second life

At K 2019, Engel is stretching the circular economy lifeline far beyond its main stand. In the outdoor exhibition area between halls 10 and 16, post-consumer waste is being converted into miniature waste containers on an Engel victory injection moulding machine.

Erema's recycling pavilion is located in the immediate vicinity. Another victory machine is producing card boxes from recycled fishing nets there. The polyamide recycled material comes from Chile, where three American machine manufacturers have set up collection points for end-of-life nets. Previously, these nets were often disposed of in the sea due to the lack of available collection infrastructure. In Chile, the nets are recycled on an Erema system and processed into skateboards and sun glasses on Engel injection moulding machines. The project proves how interdisciplinary and international interaction can also be used to close material cycles where there are no comprehensive collection systems to date.

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