City University and Sencon to develop quality control tool

Sencon has entered into a £200,000 Knowledge Transfer Partnership with City University London to develop a new measurement tool for improving the quality control of canned food, drink and aerosol products.

The sensor and control systems developer is collaborating with the university to build low-cost optical sensing systems capable of measuring the absolute thickness of coatings on cans.

This will enable manufacturers to more accurately check that cans are the correct colour and provide sufficient defence against contamination.

Manufacturers currently calibrate a film’s thickness using capacitive sensors. This technology relies on electrodes and electronics to detect changes in the amount of stored electric charge – or capacitance – when the sensor is placed near a film.

Prof Panos Liatsis, head of City University’s information engineering and medical imaging group, said the problem with this technique is it can only be used to calibrate a ‘relative measurement of thickness’.

Liatsis said the new optical-based technology will ideally achieve absolute measurements. Their system will be based on a Michelson interferometer, which principally studies the way a light beam changes spectra once it is reflected from an object.

The team believes the wavelength of light reflected from film coatings will give it the data it needs to determine absolute thickness.

Liatsis said the technology has already been proven in the laboratory, but still remains a challenge to bring onto the production line.

‘These sorts of instruments are not used on line because they’re very susceptible to vibration,’ he added.

City and Sencon researchers will develop new software tools, advanced algorithms and signal acquisition technology that will enable the systems to be deployed in bustling manufacturing environments.

Liatsis said a preliminary prototype will be designed by October 2011 and Sencon will start commercialising aspects of the technology within a year.

A final and optimised product will be commercialised by Sencon when the project is complete in two years.

The collaboration, which is part of the UK-wide Knowledge Transfer Partnerships programme, is funded with £136,000 from the Technology Strategy Board.