Reality TV for engineers – the challenge of recycling LCDs Print this article

A young Irish engineer/entrepreneur is developing an innovative solution for the recycling challenges facing makers of LCD televisions. The Journal spoke to Dr Lisa O’Donoghue, the Principle Investigator on the research team driving this project at the University of Limerick (UL) and the winner of the Young Entrepreneur of the Year Award 2010

The predicted final global liquid crystal display (LCD) sales figure for 2009 was $64bn, which underlines the growth in the use of LCD panels as the main form of visual display technology (source: iSuppli market research company, www.isuppli.com, accessed on 06/06/2009).

Dr O’Donoghue comments: “LCDs contain many potentially hazardous substances: mercury in the backlighting device, organic components such as liquid crystals, and plastics containing fire retardants, as well as printed circuit boards containing lead. There will be increasing challenges for recycling and disposal of these goods in future years as greater numbers enter the waste stream.”

The problem
Waste LCDs are currently either being stockpiled at recycling facilities to be dealt with later, or are being manually disassembled, which is inefficient both in terms of cost and time.
Researchers at the University of Limerick have reported that the current typical end-of-life disposal method for these LCD displays is landfill or incineration. However, problems are associated with both of these types of disposal. Incineration of organics and plastics may produce dioxins or furans (a furan is one of a group of colorless, volatile organic compounds containing a ring of four carbon atoms and one oxygen atom, obtained from wood oils and used in the synthesis of furfural and other organic compounds) depending on their composition, while mercury and lead have an accumulative effect on the human body and the environment.
Dr O’Donoghue says: “Efficient means of recycling these devices while obtaining a high quality of recycled materials is required to avoid the export of this type of waste from the European Union.”

Finding the solution
The Materials and Automation Research Group (MARG) at the Manufacturing and Operations Engineering Department (M&OE) in UL consists of materials engineers and automation technologists with complementary expertise and skills, who are tackling this growing problem head-on by developing a specialised automated recycling system for handling waste LCD displays.

The team – consisting of Dr Lisa O’Donoghue, Dr Huw Lewis, Dr Alan Ryan, Mr Vincent Warfield, Mr Kevin O’Flanagan, Mr Javi Ruiz and M&OE technical staff –has received funding of €350,000 from the Environmental Protection Agency under the STRIVE programme, to develop a fast, efficient, and environmentally-friendly technology to recycle these displays. “The fact that no optimised recycling process for liquid crystal displays is currently available for purchase already poses a significant problem for recyclers that are obliged by EU law to recycle LCDs. Thus, it is essential to have in place a recycling capability for LCD TVs before they dominate the disposal market,” Dr O’Donoghue warns.
The LCD unit consists of a ‘liquid crystal glass’ unit, diffuser sheets and Perspex, a lightbox unit and tube holders, which fix the fluorescent tubes in place, printed circuit boards and cables. These components are held in place by a series of top and bottom frames, covers and, typically, well over a hundred screws.

The recycling solution being developed at the University of Limerick is a hybrid system that combines an automated and manual system. The combination will help increase throughput and will also allow a degree of flexibility to ensure the system is able to match variations in the LCD displays. The patent-pending technology being developed will recycle the LCD display and offers the potential of a 20-fold increase in the amount of LCDs that can be recycled per hour over manual disassembly.
Once the main components of the LCD are recycled, many downstream processing options become viable for the materials recovery of the LCD display.

Dr. Lisa O’Donoghue is a Research Fellow with the MARG Group, M&OE Dept, UL. She is the recipient of the 2010 Young Entrepreneur of the Year Award for her development of a commercialisation route for LCD recycling.