SLN Sustainability
Applying sustainable design principles to shape a children’s product built for circularity from day one
The challenge
Sustainability claims are increasingly common in consumer products, from childcare and personal care items to food and drink packaging. However, ensuring that a product is genuinely sustainable rather than merely well-intentioned remains a challenge. Decisions made at the earliest stages of design, including materials choice, product lifespan, and structure, determine up to 80% of a product’s environmental impact, yet companies often face a fragmented landscape of tools and metrics, making it difficult to make confident, evidence-based choices.
SLN Sustainability, a UK start-up founded by Innovate UK Women in Innovation Award winner Katerina Mouliadou, SLN Sustainability, a UK start up founded by Innovate UK Women in Innovation Award winner Katerina Mouliadou, with its brand Lignoo, set out to develop a reusable water bottle for children aged 1 – 3 that is inherently sustainable and circular – ensuring its environmental credentials are built into the product itself, rather than relying on claims alone. Alongside this, the product needed to be safe, durable, intuitive for young children to use, and suitable for manufacture at scale.
To support this ambition, CPI applied the Design for Sustainability and Circularity (DfSC) framework, developed with partners across the High Value Manufacturing Catapult, to embed sustainability considerations from the earliest stages of development. This enabled environmental performance to be assessed alongside safety, usability and manufacturability throughout the design process.
“Working with CPI gave us clarity and confidence at a critical stage of development. The framework helped us make informed design decisions early on and ensured sustainability was built into the product, not added later.”
How CPI helped
- Applied the DfSC framework to guide early-stage product development and decision-making.
- Carried out structured material selection using sustainability, performance and manufacturability criteria.
- Developed and evaluated multiple design concepts to balance circularity, usability and child safety.
- Performed early-stage environmental assessments to understand trade-offs across a wide range of environmental impact categories, beyond carbon alone.
Achievements
- Delivered multiple product concepts designed for sustainability, usability and manufacture at scale.
- Provided clear, evidence-based insight to support final sustainable material and design decisions.
- Delivered CAD models and design rationale suitable for transfer to a manufacturing partner.
- Improved confidence in the product’s potential environmental performance and long-term circularity.
Impact
Children’s products are rarely designed with end-of-life circularity in mind, despite their relatively short usage window as children quickly outgrow them. Through applying the DfSC framework in practice, CPI and SLN Sustainability were able to assess the full lifecycle implications of the product during development and make informed trade-offs between environmental performance, safety and functionality.
This enabled thoughtful down-selection of materials and design concepts during prototype development, ensuring sustainability remained central without compromising product performance or user experience.
SLN Sustainability will now produce prototypes using the product designs delivered by CPI to progress through user trials with children. Feedback from these trials will be used to refine the final design before the company moves into production in 2026 with its chosen CMO. The intention is to bring to market a genuinely sustainable alternative in the children’s drinkware category.
A clear design rationale, material choices and environmental insight also strengthen SLN Sustainability’s position when engaging with manufacturers, partners and future investors.
More broadly, the project demonstrates how structured design-for-sustainability approaches such as DfSC can help early-stage businesses translate sustainability ambition into practical, evidence-based product decisions.
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