Zero-waste manufacturing: no raw materials are wasted
Zero-waste manufacturing is a production approach in which all material residues are reused or recycled within the process itself. No raw material is lost as waste sent to an external processor. In plastic injection moulding, this means that flash, rejects and start-up residues are ground up in-house and reused as raw material.
What materials are normally discarded?
Every injection moulding process generates residues. The most common are flash, also known as runners or sprues, which are separated from the moulded parts after each injection cycle. In addition, there are rejected parts from quality control, start-up residues from material changes and test parts from trial runs.
In a conventional company, this goes to an external raw material processor. Sometimes as a valuable stream, sometimes simply as waste. In zero-waste manufacturing, it does not disappear: it is ground internally (online or offline), sorted and returned as raw material to the same or a similar production process.
How this works in our production
Didak Injection has its own grinders on the production floor (= online processing) but also has an offline grinding facility. For this, material residues are sorted by material type immediately after production. That is the key step: contamination renders the material unusable, whereas precise sorting keeps it usable.
The ground residues are checked for quality prior to reuse. Thermoplastics can be melted down multiple times, but their mechanical properties deteriorate only very gradually. That is why we blend recycled material with virgin raw material in a ratio tailored to the requirements of the end product and the customer.
We record this ratio in the material specification dossier for each project. This ensures that every production batch is traceable and demonstrably in line with the agreed product requirements.
Zero waste and green energy reinforce each other
At Didak Injection, zero-waste manufacturing does not stand alone. We produce using 100% green energy, via our own biomass power plant, Albertstroom, and an extensive solar panel programme. This combination is no coincidence.
The production of recycled material requires significantly less energy than the manufacture of virgin plastic. By recycling internally using green energy, we reduce the carbon footprint of every product in two ways: less virgin raw material is needed, and the energy we do use is sustainable.
Measurable, not just claimable
Zero waste is only credible if it is measurable. Didak Injection records the amount of material processed internally per production line and per period. This data is used internally for optimisation and is available to customers who report on ESG targets or need to substantiate supplier requirements.
More and more customers in the food, retail and logistics sectors are being asked to account for their supply chains. When you work with Didak Injection, you have concrete figures available for those reports.
Hot runners: it starts with the mould design
The most effective way to reduce production waste is to eliminate flash using a hot runner system. A hot runner integrated into the mould ensures that no flash is released after each injection moulding cycle. The hot runner ensures that the plastic is fed through a heated channel to the moulded part. This means there is no longer a cold runner leading to the moulded part.
When designing new moulded parts, we also focus as much as possible on plastics and combinations of plastics that can be easily recycled afterwards.
Discover how we demonstrate sustainability in our production.
