10182280RePaint: Valorising Paint Filter Cake into High-Value MaterialsClosedBusiness ConnectInnovate UKThis project turns water-based paint "filter cake"---a sludge generated when cleaning mixing vessels and filling lines---into useful materials for construction and manufacturing. Instead of sending this residue to disposal, we will demonstrate practical, offsite pathways that create value while reducing environmental impact. Our approach combines two complementary routes. First, we apply a proprietary ionic-liquid separation process to selectively recover high-value inorganic components present in the filter cake (for example, pigment- and mineral-rich fractions). The process operates at low temperature, uses recyclable solvents, and is designed to minimise secondary waste. Second, for the remaining solids we will evaluate direct-use options: drying, homogenising and pelletising the material, followed by accelerated CO2 curing to produce carbonated fillers and aggregates suitable for ultra-low-carbon cement, boards and composite products. Over a three-month programme in the UK, we will collect representative filter-cake samples, complete detailed characterisation (including moisture, particle size, mineralogy and organics), run bench-scale trials for both recovery and direct-use routes, and manufacture initial demonstrators such as mortar prisms and composite coupons for independent performance testing. Alongside the technical work, we will deliver a screening techno-economic assessment and life-cycle assessment to quantify diversion from disposal, embodied-carbon benefits and the commercial pathway to scale. What makes this innovative is the combination of selective, low-temperature separations with a robust direct-use route. This dual-path model captures value even when feed composition varies, producing both recovered specialties and circular construction products. Because processing is offsite and engineered for minimal waste, it can be deployed rapidly without changes to existing manufacturing permits. Expected outcomes include product samples, test data and a scale-up roadmap toward pilot and pre-commercial throughput. By transforming paint filter cake into saleable materials, the project aims to cut waste, reduce reliance on virgin raw materials and enable a circular, lower-carbon future for architectural and industrial coatings supply chains.