How Small Changes in Product Design Can Drastically Cut Industrial Plastic Waste
Most plastic waste problems aren’t solved at the recycling facility. They’re created months or years earlier, on a CAD screen. Up to 80% of a product’s environmental impact is decided at the design stage, meaning we should be looking carefully at the engineers and designers making thousands of tiny decisions about things like how thick the plastic walls of a container are.
In reality, they’re the ones deciding how much of that container is ultimately going to litter the landscape or be collected and recycled. The changes needed to be made aren’t redesigns, but countless small, precise adjustments. With scientific rigor and creativity, engineers will discover that using less material saves money, makes things simpler, and makes a responsible business a more successful one.
Getting PCR Resins to Run Reliably in Production
Many businesses encounter difficulties when trying to use post-consumer recycled (PCR) resin in their injection molding processes. Virgin materials have strict, consistent specifications, while PCR resins are more variable in terms of melt flow, color, and minor contamination levels. Standard tooling that works well with virgin materials cannot handle this variability.
However, the solution is not to abandon PCR but instead to design with slightly wider tolerances. This will help the production process adapt to the natural variability in recycled feedstock without rejecting parts or producing excessive scrap. Flow channels can be made slightly thicker, gate placement can be adjusted, and dimensional tolerances can be made slightly more relaxed.
By working with manufacturers like IPL Brightgreen, businesses can obtain access to consistent, high-quality PCR resins that already have stricter specifications in processing than commodity recycled materials. This helps to bridge the performance gap between virgin and recycled resins.
Moreover, this approach provides a long-term solution in terms of supply chain stability. With the rising costs of virgin resins and increasing EPR levies, production lines that are optimized for PCR resins will have a cost advantage.
The Polymer Selection Problem Most Designers Ignore
Many industrial packaging designs contain a variety of materials laminated together. They do this because each material has unique performance advantages (barrier properties, seal strength/flexibility, printability). However, this practice inherently makes recycling nearly impossible because sorting facilities aren’t able to effectively separate materials that are melted and bonded together into a polyethylene film-to-polypropylene base, for instance. The whole assembly gets landfilled or, at best, downcycled.
A particularly easy way to remove this barrier is by designing mono-material packaging, meaning that every part of the structure is the same polymer family. A polypropylene product can flow through the standard municipal recycling stream with no mechanical pre-separation. The performance trade-offs are real, but you can often offset this with geometry size/thickness optimization.
Designers that have worked through this transition almost always report that the performance trade-offs of going mono-material were greater in concept than in practice and that once they identified areas that needed a little re-engineering anyway, it was no big deal. It becomes about ROI on getting to a better solution rather than a conscious weighting of environmental returns vs. traditional business returns.
PP, HDPE, PET, etc., are well suited to this approach because they are thermoplastics capable of being melted and reformed almost infinitely as implied above. In practice, recycling only works in the circular economy if it makes financial sense, not ethical or environmental sense. That makes thermoplastics particularly attractive for any scaled solution.
Color is a Functional Specification, Not Just an Aesthetic One
Natural resin colors or lighter pigments are a much better choice for plastic products when end-of-life recovery is important. Carbon black-pigmented products are currently much more difficult to automatically sort and reprocess. The good news is that many customers now prefer the natural look, and it is easy to find off-the-shelf, natural color resins that are comparable in price to equivalent carbon black-pigmented resins.
Label Adhesives Are Contaminating Your Recycled Output
This issue is very particular and can be solved. Plastic containers, during the recycling wash step, are not cleanly separated by conventional adhesives. That residue stays on the plastic substrate and enters the recycled melt. That contaminant degrades the resulting PCR resin: its clarity drops, its mechanical strength decreases, and the number of applications it can be used for is reduced.
Water-soluble and alkali-soluble adhesives are ready to wash-off exactly in this step. The label separates. The adhesive rinses away. The plastic substrate comes out clean. The downstream PCR resin is higher quality and worth more. This is a single-line specification change in a bill of materials that has measurable impact on the quality of recycled output at scale.
Lightweighting as a Material Reduction Strategy
By performing a structural analysis, wall thickness can be reduced, and load-bearing geometry can be optimized. And there is potential to use up to 20% less plastic in total without compromising the product performance under real operating conditions. As a consequence, the raw material costs will be lower, the energy consumption during the production process is lower, and the environmental footprint is smaller per unit, even before considering recycling.
Life Cycle Assessment tools are available to quantify these savings over the entire production run. The operations team then has the necessary arguments at hand to justify redesign investments to finance and procurement. And the frontrunner companies regarding plastic waste are not the ones that are running sustainability campaigns, but those that are running engineering tighter, and experience that both tend to pay for each other.
