Sustainable product service for raising the energy efficiency of injection moulding machines for plastics

Status

completed

Summary

This project aims at performing a feasibility study of establishing a sustainable product service for raising the energy efficiency of injection moulding machines. By this service, waste heat from the injection moulding process can be harnessed and be offered to potential users.

The injection moulding process is an energy intensive process. Approximately 140 GWh of energy is needed for injection moulding processes annually in Austria. On the one hand, high amount of energy is needed during the process and a lot of heat is generated, on the other hand cooling must be ensured to achieve short injection cycles. Thermal management becomes central for high energy efficiency.

Results of energy measurements point out that 80% of the energy input for the drives, the heating system and ancillary units converts to heat which has to be dissipated by the waste hydraulic oil and the cooling water. This heat could be used for further injections. Here for the actual low temperatures of about 15-25 ° C have to be increased by using heat pumps at a higher usable temperature level of about 60 ° C.

Three case studies for using this waste heat have been investigated in more detail: an office building, a nearby one family house and a greenhouse. Considering the losses of the transportation, the available heat for the family house is 40% less than for the nearby office building. Therefore short transportation routes should be chosen. With the heat from the heat pump which is connected to the cooling water, 23 greenhouses can be heated.

Providing this waste heat as a service, the so-called plant contracting has been chosen. In plant contracting, the contractor (e.g. injection moulding machine manufacturers, energy service companies, etc.) builds and operates the additional components needed to use the waste heat. The contractor sells the heat to a purchaser (e.g. machine user). By evaluating this service using sustainability criteria positive effects in all three dimensions, ecology, economy and social, can be observed. Economic benefits can be achieved through the new revenue source or the energy savings. The service also results in positive environmental effects which are achieved by the reduction of the overall consumption of resources.

Implementing this service has to be designed individually for each company. The holistic view of the energy structure of each individual application is essential.

Project management

A.o. Univ.Prof. DI Dr. techn. Wolfgang Wimmer
DI Rainer Pamminger (Project organisation)

Project or cooperation partner

• Engel Austria GmbH
  DI Michael Bauer, Michael.Bauer@engel.at

A.o. Univ.Prof. DI Dr. techn. Wolfgang Wimmer
DI Rainer Pamminger (Projektorganisation)
Technische Universität Wien,
Institut für Konstruktionswissenschaften (E307)
Forschungsbereich ECODESIGN
Getreidemarkt 9, A-1060 Wien
Tel.: +43 (1) 58801 30753
E-Mail: pamminger@ecodesign.at
Web: www.ecodesign.at