European Commission logo
English English
CORDIS - EU research results

Eco-efficient designs for end-of-life, anti-counterfeit electronic device recovery

Final Report Summary - SEPARATE (Eco-efficient designs for end-of-life, anti-counterfeit electronic device recovery)

The overall industrial objective of the project SEPARATE was to develop a manufacturing process and cost effective recycling route in response to the European Commission's Waste electrical and electronic equipment (WEEE) directive.

The primary target market for the SEPARATE technology are high technology electropolymeric consumer products with short life spans such as mobile phones, Personal digital assistants (PDAs), digital cameras, toys and laptop computers. The secondary market includes contactless smartcards, RFID tags, mobile phone SIM cards and store loyalty cards, an alarming number of which enter the domestic waste stream.

The technical work has been spread over the tasks in the following Work packages (WP):
- WP 1: Enhancement of scientific understanding of soluble polymers
- WP 2: Creation of new over moulding technological capability to create electronic modules
- WP 3: Development of a new technological capability to semi-encapsulate electronic modules
- WP 4: Industrial validation.

The first step in the development of the SEPARATE technology was to select a suitable water soluble polymer. Polyvinyl alcohol is a non-toxic, biodegradable, water soluble polymer. The performance properties of polyvinyl alcohol are influenced by molecular weight and the degree of hydrolysis. The degree of hydrolysis affects the water sensitivity and the degree of polymerisation determines the molecular weight and hence the processability.

To achieve a target dissolution time of 30 seconds per electropolymeric component, a batch dissolution process was selected. Methods to accelerate dissolution were investigated, and it was demonstrated that the effect of ultrasonics significantly increased dissolution time. It was then validated that the PVAXX polymer could be reused and injection moulded after being recovered from solution without significant degradation of properties. Elongation at break of the test pieces was slightly reduced, this being attributed to a small loss of plasticiser during the drying process. Additional plasticiser can be added to the recovered polymer to address this.

An injection mould tool was manufactured and fully encapsulated electronic modules for a smartcard application were produced. These were shown to be fully functional after over-moulding with PVAXX. Other fully and semi-encapsulated electronic case study components were then selected to represent the targeted market sectors. These included a contact and contactless smartcard, a memory stick and a calculator casing. A generic water soluble electronics fixing clip and mounting plate were also selected that could be used together or alone in all types of equipment requiring circuit board fixing.

Three-dimensional (3D) Computer aided designs (CADs) were generated for a memory stick, a calculator casing, and a mounting plate and fixing clip case study components. Injection mould tools were designed and prototype tools manufactured for each component.

For the production of the over-moulded memory stick, Uniteam Italia SRL utilised their innovative two-shot moulding technology. A 2 + 2 impression tool was designed and manufactured which would initially over-mould a memory stick circuit board with water soluble PVAXX polymer, and then in a second stage this is overmoulded with a soft thermoplastic elastomer which provides a protective coating to the hydrophilic polymer.

Memory stick circuit boards were over-moulded with PVAXX polymer and their functionality examined before the second over-moulding stage. It was established that the pressures involved in the injection moulding process and the flow pattern of polymer over the components on the circuit board could cause distortion of the board and damage to the electronics. It was established that foaming of the PVAXX polymer with a blowing agent significantly reduced the pressures involved and this was found to eliminate damage of the circuit boards.

For an industrial process a multi-impression tool would be required for an efficient moulding process. A design for a production tool with multiple impressions was therefore produced by Uniteam Italia SRL, and a tool sequence demonstrated. A robotic simulation of the injection moulding, handling and subsequent testing of memory sticks was developed to demonstrate a production moulding cell. In the simulation, a cycle time of 9 223 seconds for 4 finished USB-sticks was achieved.

A prototype dissolution, separation and recovery system was designed combining the use of ultrasonics and ultrafiltration technologies. Through trials it was established that polyvinyl alcohol could be concentrated up to 16 % from solution using this method. However, during the ultrasonic tests it was found that dissolution occurred even up to concentrations of 35 % polyvinyl alcohol in water; therefore, an ultrafiltration unit was not necessary after all for the separation system. A simulation was performed to study the industrial scale operation, and a counter-current washing principle was selected to minimise the use of energy and fresh water.

In conclusion, the project has met the objectives to develop a complete suite of innovative processing and reclamation techniques, required to provide a closed loop product manufacturing system. The separation and recovery of electropolymeric case study components has been demonstrated. This has been achieved by semi or fully encapsulating the electronics in a water-soluble polymer, and the development of a disassembly system incorporating ultrasonics to accelerate dissolution, and hence separation and recovery.

The socio-economic impact of the SEPARATE technology is that electropolymeric components manufactured by this technology will address the WEEE Directive. This will reduce the quantities of electropolymeric waste being discarded in Europe, and reduce the environmental and health and safety impact of heavy metals and organic pollutants entering the waste stream.