Reducing waste at Crown Paints

The disposal of wastewater poses significant cost for the paint industry and is under intense environmental scrutiny. For the first time in their 250 year history, Crown Paints partnered with researchers at Lancaster University to address this problem. By combining laboratory-scale experimentation with mathematical modelling, the wastewater produced at Crown Paints has been reduced by thousands of tonnes per annum.

The research was led by Professors Fielden and Martin, at Lancaster University. Professor Fielden (Department of Chemistry) has expertise in particle measurement in water and Professor Martin (Department of Engineering) is an expert in engineering solutions and mathematical modelling around particle removal from water.
Their research has enabled Crown Paints to reduce waste production on the millions of litres of paints that are produced each week and achieve goals set out in their earthbalance® programme. The partnership was motivated by Crown Paints’ ambition to reduce the waste it generates in the paint manufacturing process, with the aim of becoming a net-zero waste paint manufacturer.
Outcomes of the project include:

• Reduced waste production in Crown Paints’ manufacturing process at the Darwen and Hull plants. This affects the millions of litres of paint it produces across both sites each week. An annual saving of £113,000 has been made in the cost of reagents used to remove paint particles from the 30,000 tonnes of wastewater and 120 tonnes of paint.
• New water metering systems were installed at critical points in the manufacturing plant to gain the first accurate inventory of clean water usage and wastewater generation. £145,000 has been invested in the construction and commissioning of new waste paint processing plants at their manufacturing sites.
• Optimised formulation for the Effluent Treatment. This study showed that the filter press was the most efficient dewatering technology for the removal of particulates from paint waste. Subsequently, the wastewater treatment plant at the Darwen site was renewed at a cost of £55,000, and at the Hull site for £70,000.
• Recycling of water and waste products. Experiments revealed that recycled water did not adversely affect the properties of the magnolia matt emulsion paint – the company’s highest-volume product. The project investigated recycling of paint waste “filter-cake” currently sent to landfill and this was shown to have applications as a bulking agent in the manufacture of external masonry paint.