How digital simulation and material modelling are transforming rPET bottle development
As global sustainability goals accelerate the shift from virgin PET to 100% recycled content (rPET), packaging companies face mounting pressure to adapt — or risk consequences ranging from supply chain vulnerability to regulatory penalties and market irrelevance.
In our recent article for PETplanet Insider, BMT's Reece Armstrong (CAE Engineer) and Ross Blair (Head of Simulation) explore how a data-driven, science-based approach is helping packaging businesses navigate that shift with confidence — combining advanced material modelling, digital simulation, and physical testing to create packaging that is both high-performing and genuinely more sustainable.
Why simulation alone isn't enough
Digital simulation is a powerful tool for predicting how a bottle design will perform, but a simulation is only as trustworthy as the data behind it. That's why validating simulation accuracy against real physical test results is a critical step in BMT's process, not an afterthought.
This involves comparing the results of forming and performance simulations against experimental data, checking that key attributes like mass distribution and structural integrity align with what actually happens in the real world.
A real example: 500ml CSD bottle validation
To illustrate this in practice, BMT evaluated a 500ml carbonated soft drinks (CSD) bottle. Stretch blow moulding (SBM) simulations, based on calibrated material models for rPET, were compared directly against experimental data collected in BMT's own laboratory using BLOWSCAN and free-blow stretch testing, captured through digital image correlation (DIC).
The results demonstrate just how closely a properly calibrated simulation can match real-world performance:
Across every measured section, the simulation predictions sat within a few percent of the physical test results, and top-load performance was accurate to within 2%. For a packaging engineer, that level of accuracy means a digital model can be trusted to inform real design and material decisions, long before a single production mould is cut.
What this means for the shift to rPET
rPET behaves differently to virgin PET under stretch blow moulding conditions, its mechanical and thermal properties vary depending on source, processing history and contamination levels. That variability is precisely why validated simulation matters so much during the transition to higher recycled content.
By characterising material behaviour accurately and validating simulation models against physical test data, packaging teams can move from virgin PET to 100% rPET with genuine confidence, rather than relying on costly, time-consuming trial-and-error production runs to discover problems after the fact.
Driving the future of sustainable packaging
The adoption of digital simulation and data-driven methodologies is helping the wider packaging industry improve efficiency while supporting sustainability goals. Moving away from trial-and-error testing reduces material waste, streamlines production, and minimises carbon emissions, all while maintaining the product performance that brand owners and consumers expect.
BMT's Measure, Digitise, Execute approach — explained in full here — exists to support exactly this kind of confident, data-backed transition to rPET and other sustainable materials. It reflects a broader industry shift toward packaging development that is both environmentally conscious and technically rigorous.
Read the full article in PETplanet Insider, Vol. 26 No. 05/25, or catch up on the BMT Bottle Series for more insight into our approach. Want to discuss how validated simulation could support your rPET transition? Get in touch with our team.