Industry partnership improves detergent powder
Dr Umair Zafar, Research Fellow from the School of Chemical and Process Engineering, completed a 12-month Knowledge Transfer Secondment with Procter and Gamble (P&G) Newcastle Innovation Centre to investigate the segregation tendency of powder mixtures, specifically dry laundry powder, using methods developed by Professor Ghadiri’s innovative and cutting-edge research team based at the University of Leeds.
The secondment, led by Professor Mojtaba Ghadiri from the University of Leeds, was funded by £39,000 from the EPSRC Impact Acceleration Account (IAA) with support from P&G for travel and consumables. The IAA is an institutional award funded by EPSRC to help speed up the contribution that engineering and physical science research makes towards new innovation, successful businesses and the economic returns that benefit UK PLC.
This award allowed the secondee to not only gain expertise in working with a multinational company, but also to transfer key background knowledge of the process developed at the University to P&G.
– Professor Mojtaba Ghadiri
Impact
- Knowledge discovery: identified solutions to segregation issues commonly associated with dry powders, from detergent to medicine.
Key information
- Major funders: Engineering and Physical Sciences Research Council Impact Acceleration Account (EPSRC IAA)
- Partners and collaborators: Procter and Gamble (P&G)
- Disciplines: chemical engineering
- Investigators: Dr Umair Zafar, Professor Mojtaba Ghadiri.
Transferring knowledge to solve industry challenges
Segregation, which is commonly associated with all sorts of powders across various industries, can have an adverse effect on both product quality and performance. Unsurprisingly, reduced product quality and performance has a negative impact on business and consumer interests, leading to dissatisfaction.
For example, the segregation of active components in laundry powder, such as enzyme granules, can significantly impair product performance. For the consumer, this means that their laundered items aren’t cleaned to the standards they would like. Additionally, segregation contributes to variations in both bulk density and chemical composition, which in turn leads to variations in product performance.
To try to overcome the issues created by powder segregation, the current industry-wide solution is to over-pack the dry detergent powder box. This over-packing alone costs P&G US$20 million in dry detergent powder every year.
Knowledge Transfer Secondment
Procter and Gamble has an internal global action plan to address the various elements and mechanisms associated with segregation. A collaborative programme between the University of Leeds and P&G was devised to develop a fast, reliable and simple technique to measure the extent of segregation.
During the secondment, Umair Zafar examined and addressed the phenomenon of powder segregation using the vibration heap approach, a method developed by his predecessor, Massih Pasha, at the University of Leeds in collaboration with P&G. This is a fast method for quantifying the tendency and extent of segregation based on image analysis of vibrated two-dimensional heaps. Numerical simulation tools for modelling the segregation process were also developed and implemented.
For measuring the segregation tendency of binary mixtures of different coloured powders, a user-friendly image analysis method was developed. The only input needed for the software was digital images of the powder heap. A heap test set-up capable of measuring segregation in the horizontal and vertical directions was designed, constructed and used in this work. A vibrating bed set-up was also developed, enabling the measurement of segregation due to vibration, for example, due to transporting the powder.
Particle size, distribution, size ratio, vibration frequency and amplitude as a function of vibration time were all analysed to establish their impact on segregation.
Dr Zafar also examined the effect of the stickiness of powdered surfaces – achieved by adding adhesive coating or binder – on the extent of segregation, along with product properties such as flowability and bulk density for binary mixtures. This involved extensive investigation of:
- mixing sequences
- concentration of materials in the formulation
- fill levels of materials in the mixer
- nozzle types for the injection of non-ionic liquid
- mixing times
- mixing speeds.
The project also looked at the issue of caking and auto-agglomeration of powders during certain vibration conditions.
Impact
While the focus of this secondment was to specifically understand and then identify solutions to the segregation issues commonly associated with dry detergent powders, other industry areas that are negatively affected by segregation could also benefit from the work conducted during this secondment. For example, batteries are adversely affected by variations in porosity. Cough and cold drink sachet remedies are impaired by segregation. As these issues are partly due to segregation, consumers and industry could receive direct benefits in product performance and quality as a result of this secondment.
Given that over 65 per cent of the output of the chemical industry is in particulate solids form and that segregation is often a major issue, the scale of opportunity is huge. Accordingly, this Knowledge Transfer Secondment, which focused on understanding the segregation tendencies of particulate mixtures – particularly where homogeneity is a critical requirement – is of enormous industrial and consumer interest and benefit.
As a direct result of the secondment, industrial partner P&G is continuing this project as part of the Chariot programme supported by AMSCI. One role has been created at P&G, and two additional PhD students are working on this topic at the University of Leeds. The objectives of the Chariot work are to develop mathematical models and further develop measurement methodologies to assess and predict the competing processes of flow and segregation (by percolation and angle of repose mechanisms) for minor particulate ingredients in bulk mixtures.
This project was sponsored by the UKRI Impact Acceleration Account.