6% higher OEE: Wavin stabilises processing recycled material via Injection volume

Extreme weather events are increasingly pushing urban drainage systems to their limits. As a world-leading manufacturer of water and climate management solutions, Wavin addresses this with modular rainwater storage systems such as AquaCell and Q-Bic+, which pick up, temporarily store and control the discharge of water.

These components must withstand high mechanical loads, for example in accessible zones for pedestrians or vehicles. They are therefore produced from high-performance compounds.

The sustainability approach is consistently applied across the products:

• AquaCell is made exclusively from recycled Polypropylene

• Q-Bic+ is also available with a very high proportion of recycled material

When processing recycled plastics, the injection volume is a particularly crucial process parameter. It influences component quality, dimensional accuracy and process stability. Wavin was faced with these process-related challenges.

Recycled materials are a central component of sustainable, eco-friendly plastic products. However, they pose particular challenges for injection moulding.

Not all recycled materials are the same: depending on their origin, processing and batch, material properties such as plastic material viscosity, flow behaviour or moisture content can vary significantly.

As Wavin is working with up to 100% recycled plastic in some of its production processes, fluctuating viscosities are unavoidable.

Such material-related fluctuations have a direct impact on the injection moulding process:

• Fluctuating component weights

• Unstable process windows

• Increased rejects

• Additional effort by means of manual corrections

Against this background, it is crucial to specifically compensate for material-related fluctuations in the injection moulding process. The injection volume becomes the central control parameter for reliably processing different batches of recycled material.

With automatic real-time compensation for injection volume deviations caused by recycled material, consistently high quality can be achieved despite varying recycled material properties. This reduces the increased effort involved in manual readjustments, minimises rejects and improves OEE.

iQ weight control is a digital assistance system from ENGEL that automatically adjusts the injection volume shot by shot. It is based on the continuous evaluation of relevant process data, including plastic viscosity, filling speed and pressure profile. The system detects deviations at an early stage and adapts the injection volume directly in the next cycle.

Wavin benefits from:

• constant part weights

• consistent quality despite fluctuations in raw materials

• low intervention by the machine operator

• a robust process also when switching between recycled material batches

Thanks to digital process control, viscosity fluctuations in plastic recyclates can be effectively compensated for, ensuring reliable and reproducible production of heavy-duty, sustainable drainage components.

“iQ weight control helps enormously to compensate for material differences and keep the process stable.” (Eddy Gerritsen, Injection Moulding Manager at Wavin)

To manufacture sophisticated, technical plastic components for water management efficiently and reliably, Wavin has relied on ENGEL machine technology at its Hardenberg location for over 30 years.

For the production of small and medium-sized parts, Wavin relies on ENGEL victory machines with a tie-barless design, which are particularly impressive due to their flexibility and efficiency:

• high mould accessibility

• fast mould changes

• simplified automation

For large-volume components such as AquaCell, the ENGEL duo two-platen machines is relied on:

• The duo 2700, with a clamping force of 27,000 kN, ensures the necessary precision for 15-kg components.

• Thanks to the machine’s consistent performance since putting it into operation, the production process remains reliable even with large, delicate parts.

• System availability is a crucial factor for large components, as downtime is particularly costly in this context.

The combination of high-performance injection moulding machines with a large mould area and digital assistance systems such as iQ weight control ensures stable processes, fast cycle times and repeatable results – regardless of the material.

Wavin has made the effect of the implemented solution measurable: OEE was increased by 6%.

The key to this is the targeted stabilisation of the injection moulding process via precisely controlled injection volume per cycle. This is also maintained at a constant level even when recyclate properties vary.

The lever behind this acts on several levels:

• Reduced rejects, as constant shots and uniform part weights are reproduced

• High machine availability and capacity, as there are less faults, less rework and significantly less downtime

• Recycled material is no longer a risk factor, but a fully controllable standard material

For Wavin, the solution contributes to several aims at once:

• sustainability by means of recycled plastic

• process stability despite fluctuations

• cost-effectiveness through OEE improvement

• planning reliability for large-format parts

In short: thanks to automatically controlled injection volume, iQ weight control not only has a positive effect on component quality, but also specifically helps to improve OEE and thus sustainably increase production efficiency.