WITTMANN solutions for maximum material efficiency with recycled plastics

Closing material loops is essential for more sustainable injection molding. But using recycled material efficiently requires more than simply returning production scrap to the process. Material preparation, process control and part design all play a role in achieving consistent quality with maximum material efficiency. 

WITTMANN brings these elements together in an integrated production solution: from immediate in-line recycling and careful material preparation to intelligent process control and gas injection technology.

The EcoFritz clamp demonstrates how these technologies work together to keep material in the cycle while using as little of it as possible.

The EcoFritz is produced on a servo-hydraulic SmartPower 60 from glass-fiber-reinforced polyamide. Sprues and production scrap are ground directly by an integrated S-Max granulator and mixed back into the raw material.

The material never has to leave the production process: what would otherwise become waste is immediately returned as recycled content, creating a closed-loop material cycle. 

Recycled material can introduce additional dust and fine particles into the process. These can affect dosing and reduce the homogeneity of the plastic melt, making effective material preparation particularly important when consistent quality is required. 

The Feedmax Clean vacuum loader addresses exactly this challenge. Its powerful dedusting system achieves separation rates of up to 80% for particles below 1,000 µm. By carefully removing dust and fine particles, recycled materials can be used reliably even in applications with high quality requirements. 

Recycled material can also bring fluctuations in processing behavior. This is where HiQ Flow comes in.

The digital assistance system continuously analyzes melt viscosity during injection. If it detects a deviation from the set value, it adjusts the changeover point and holding pressure within the same cycle.

This compensates for fluctuations in raw material or environmental conditions and ensures a constant part weight, before a deviation can result in a scrap part. 

Keeping material in the cycle is one part of material efficiency. Reducing the amount required for each part is another.

With Airmould internal gas pressure technology, nitrogen forms a hollow space inside the molded part. This reduces the quantity of plastic required and enables lightweight parts to be produced with short cycle times and good surface properties.

Material displaced by the nitrogen is not wasted either: it is reground together with the sprue and returned to the production process.

The EcoFritz application combines different approaches to material efficiency:

• Production scrap is recycled immediately. 
• Recycled material is carefully dedusted. 
• Process fluctuations are compensated within the same cycle. 
• Airmould reduces the amount of material needed for the part itself.

Together, these technologies demonstrate how recycled material can be processed reliably while making efficient use of every gram of material.