At this year’s K fair, ENGEL will demonstrate a production solution for foamed technical parts made from 100% post-consumer recyclate on an all-electric e-mac 220 injection molding machine which produces thick-walled and robust plastic parts for the construction industry on a minimal footprint.

The all-electric ENGEL e-mac 220 injection molding machine.

This demonstration will show an energy-efficient, precisely foamed and fully automated process, combining sustainable production, advanced foaming technology and an intelligent cell layout.

The all-electric e-mac injection molding machine with a clamping force of 2,200 kN uses ENGEL’s foammelt technology to foam components using a blowing agent.

Read more on ENGEL's highlighted exhibits at K 2025.

Mixing

A post-consumer recyclate is processed, originating from the “Gelber Sack”, collected by PreZero and high-quality reprocessed by EREMA. For the foaming process, an additive and blowing agent mixture developed by Moxietec is used, combined with the Vistamaxx additive from ExxonMobil. This creates a homogeneous, finely celled foam core, resulting reduced weight with increased stability.

In the application shown, the ENGEL injection molding cell achieves a weight saving of around 30% with a shot weight of 538 grams, while at the same time increasing the impact resistance of the component by 10%.

Cross-section of the perfectly foamed component made from 100% post-consumer recyclate.

A standard mixing screw from ENGEL also ensures a homogeneous melt. It is specially designed for this type of application and optimized for uniform mixing behavior. In addition, decompression after dosing can be completely omitted, reliably preventing sink marks and air inclusions in the component. This is made possible by a ring non-return valve with a newly developed geometry.

The plasticizing unit of this system uses iQ melt control to deliver an optimally prepared melt for foamed recyclates. The digital assistance system iQ melt control analyzes the plastification process during sampling and suggests ideal setting parameters for screw speed, back pressure and dosing stroke. In this way, iQ melt control supports consistently high part quality with maximum material efficiency.

Dosing

The dosing is carried out via a gravimetric system from Movacolor. The Moxietec formulation ensures a particularly homogeneous distribution of the foam structure and is therefore especially suitable for thick-walled components, where conventional physical foaming processes reach their limits.

Crowned valve wings ensure even greater reproducibility and, in combination with the short-stroke version, significantly faster closing behavior.

Foaming and parts removal

A cold runner system additionally supports the desired foaming behavior. The cycle time on the all-electric ENGEL e-mac using the 2-cavity mold from Moxietec is approximately 120 seconds.

The latest generation of e-temp units operates with just 90 °C water temperature, eliminating the need for separate hot-water piping – which further reduces costs. The digital assistance system iQ flow control actively monitors the temperature control behavior and regulates it dynamically.

In combination with ENGEL’s e-temp devices, this ensures that temperature deviations are detected immediately and automatically corrected. The result is uniform cooling of the entire component – warpage is minimized and dimensional accuracy improved. The system makes a significant contribution to process stability and reduces the energy consumption of temperature control thanks to optimal flow regulation.

A servo sprue picker removes the sprue, while an ENGEL viper 12 linear robot takes out the moulded part and places it on a conveyor belt. The automation is fully integrated into the control system of the injection molding machine and helps reduce cycle times, as iQ motion control independently optimizes the movement sequences. At the same time, it also reduces energy consumption, with savings of up to 85% in temperature control are possible.