One of the most effective strategies for better sustainability is reducing raw materials. Every pellet saved reduces environmental impacts and costs, while improving production efficiency. And while material use is heavily influenced by product design, there are still opportunities within operations and processing to reduce waste.
Start with Robust, Stable Processing
One of the most effective ways to reduce material waste is to focus on robust processing, not just fast processing. A cycle time that is one second faster is inefficient if 5% of the parts are scrapped or reworked. A stable process that consistently produces good parts will always be more sustainable. So review and improve settings to optimise the process window and reduce variation, for instance:
- Pack/hold pressure
- Melt temperature
- Mold temperature
- Fill rates
- Clamp force
Invest in Better Process Controls
Modern process control equipment can dramatically reduce material consumption. Gravimetric feed units, gear pumps, gauge controls, and parison thickness controls all help ensure that only the necessary materials are used for each shot or cycle. These systems often deliver rapid payback by reducing over‑pack, eliminating variation, and improving part consistency.
Reduce Scrap at Start‑Up
Set‑up and start‑up are notorious sources of material waste. By reducing set‑up times and improving start‑up procedures, processors can minimise the amount of scrap produced before the process stabilises. Clear procedures, trained operators, and well‑maintained equipment all contribute to faster, cleaner start‑ups.
Improve Inventory and Handling Practices
Material losses don’t just happen at the machine—they happen in storage, transport, and handling. Reducing inventory levels helps prevent shrinkage, contamination, and material obsolescence. Using closed‑system material handling prevents pellets from spilling or becoming contaminated. And investing in proper scrap handling ensures that any scrap produced is clean, contained, and ready for reprocessing rather than swept off the floor and discarded.
Eliminate Unnecessary Material in the Product
Finally, examine the product itself to further reduce raw materials. Removing sprues, runners, tops, and tails (or switching to hot runner systems) can dramatically reduce waste. Also, attempt to minimise internal and external packaging—thereby reducing material consumption and overall environmental impact.
Reducing raw material use is one of the most direct ways plastics processors can improve sustainability. By focusing on robust processing, better controls, smarter inventory practices, and thoughtful product design, manufacturers can reduce waste, lower costs, and deliver more efficient, environmentally responsible products.Â
Each month, we will share some useful, actionable advice with you from leading sustainability consultant Dr. Robin Kent. For more resources, see a full list of publications from Dr. Kent.