The Challenger Disruption
With refillable challenger brands and sustainability demands disrupting the personal care market, Unilever saw an opportunity to transform the deodorant category. They focused on launching a refillable stick for Dove that could rival challengers like Wild (which PPK also manufactures at scale), while maintaining the quality, structural durability, and brand integrity expected of a flagship global beauty brand.
PPK supported the structural engineering, patent development and manufacturing work behind this refillable platform in collaboration with design and innovation consultancy PA Consulting. Discover more about the design journey on the official PA Consulting Client Story.
PPK Mechanical Engineering & Structural Patents
Designing for reuse requires a change in mindset. Unlike single-use packs, the reusable case is engineered for a five-year life cycle. PPK's engineering team designed the internal mechanics, securing multiple core patents for the platform. These include patents for the twist-and-lock cartridge lock mechanism, a secure base cradle that guides cartridge insertion, and the rotating spiral thread mechanism.
The outer case features an anodized aluminum shroud over a high-recycled-content plastic internal structure, minimizing plastic usage. By matching tolerances to within 0.05mm, PPK achieved a smooth, luxurious 'click-and-twist' feedback that elevates the user experience to the premium beauty standard.
Material Innovations: Coated Pulp & PHA
PPK's material science lab developed custom solutions for the consumable refill packs. For the deodorant refill, PPK engineered a proprietary coating for bamboo and sugarcane bagasse pulp. Bamboo and sugarcane bagasse are renewable byproducts, but raw pulp is porous. PPK's PFAS-free coating creates an airtight, moisture-proof barrier that prevents the deodorant formula from drying out or leaking into the fiber walls, while remaining completely biodegradable.
For the antiperspirant variants, which require a much higher chemical barrier to preserve volatile active ingredients, PPK developed a compostable PHA (polyhydroxyalkanoate) bioplastic insert. This dual-material strategy ensures product efficacy while keeping plastic usage 25 times lower than conventional packs.
Scalable Circularity & Compatibility
Engineered for scalable production, the system is designed to work with high-speed manufacturing and assembly requirements. PPK's refillable platform approach helps brands reduce reliance on single-use packaging while maintaining the usability and shelf presence expected in premium personal care.
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