:: Specific Design Brief
LOUGHBOROUGH UNIVERSITY:
Reduce, Reuse,
Recycle
LU
7:
SMART MATERIALS -
TO HELP DISASSEMBLY - further information
PRODUCT DESIGN UK
- ISSUES
Plastics are extensively recycled in many countries, with 41% of households in
the UK having access to plastics recycling facilities.
GENERIC DESIGN CONTEXT
It has been recommended for many years that reducing, reusing and recycling
provide many opportunities for environmental improvements in our own and other
countries and in product manufacture. Design and make a product that uses at
least one of those criteria.
SPECIFIC DESIGN BRIEF
Environmental legislation known as the Waste Electrical and Electronic Equipment
(WEEE) Directive will come into effect in August 2006. The WEEE directive aims
to reduce the amount of waste electrical and electronic equipment currently put
into the regular waste stream.
It means that many companies who manufacture electrical and electronic products
(e.g. cookers, telephones, musical socks, watches) will be required to take back
old products, and disassemble them to reclaim materials and components for
recycling or reuse.
Traditionally this has been done automatically (which is cheap but involves
crushing the product) or by hand (which is expensive, but means that fragile
components can be removed). A more cost effective way of taking a product apart
carefully, is to use smart materials in the design of the product. When treated
in a specific way (e.g. heating, cooling) smart materials can be made to expand,
contract, melt, and change colour. These smart materials can be used to force
the product casing apart, and communicate useful messages regarding material
types etc.
Identify a type of product which would benefit from being disassembled at the
end of its life (i.e. to reclaim valuable materials and/or components for reuse
or recycling). Then using one or more smart materials, design a system which
will enable the product to be automatically disassembled at the end of its life.
Environmental legislation for electrical and electronic products from August
2006:
WEEE will require that a certain percentage of all electronic and electrical
products sold, are collected by the manufacturer for recycling and disposal.
Large household appliances 80%
Small household appliances 70%
Consumer equipment 75%
Tools 70%
Toys 70%
IT and telecoms 75%
Lighting 70%
Monitoring & controlling equipment 70%
Automatic dispensers 70%
(Source: ICER, 2001)
WEEE will require that a certain percentage of all electronic and electrical
products sold, are reused or recycled.
Re-use/recycling
Large household appliances 75%
Small household appliances 50%
Consumer equipment 65%
Tools 50%
Toys 50%
IT and telecoms 65%
Lighting 50%
Monitoring & controlling equipment 50%
Automatic dispensers 50%
(Source: ICER, 2001)
Types of Smart materials available:
The types of smart materials that you can use can be found at
www.tep.org.uk
Examples include:
Polymorph: This polymer has all the characteristics of a tough engineering
material yet it fuses and becomes easily mouldable at just 62°C. It can be
heated with just hot water or a hairdryer and moulded by hand.
A 5mm dia. x 12mm (when closed) spring made from shape memory alloy. At room
temperature this spring is soft enough to pull out to approximately 50mm by
applying a small force. When heated to 70°C by passing an electric current
through it, the spring contracts to its original length with a useful pulling
force (equivalent to lifting a 0.5kg weight).
Thermochromic pigment is made up as a liquid paste compatible with any acrylic
media. At normal room temperature the pigment appears coloured but at 27C the
colour disappears. E.g. If the black thermochromic pigment is applied to a white
surface, the surface turns from black to white at the change over temperature.
Some issues that the design must address:
appropriate product selection
the value of the components/ parts to be retrieved after disassembly
safety issues the product must not come apart by accident whilst still in
use
acceptable cost to manufacturers
SUPPORT INFORMATION FOR TEACHERS
The non-destructive disassembly of products allows separation of whole
components and sub-components allowing very high purity of recycled parts and
thus higher profit for recyclers and thus less cost implications for the
manufacturers.
The following types of products might benefit from active disassembly with smart
materials:
Telephones
Mobile phones
Component assemblies
Cameras
Calculators
Electronic games
Personal organisers
Battery chargers
Computer casings
Mice and keyboards
The process is especially suited to small or medium sized plastics dominated
products with its ability to provide a high purity plastics waste stream and
easy separation of the electronic component with minimal input energy. Markets
for recycled plastics are increasing with value heavily dependent on polymer
granulate purity.
References:
Chiodo, J. D., Billet, E. H. and Harrison, D. J. (1999a) Active Disassembly
using Shape Memory Poymers for the Mobile Phone Industry. In IEEE International
Symposium on Electronics and the Environment - ISEE - 1999,Danvers,
Massachusetts, 11 - 13 May 2020, pp. 151 - 156.
Chiodo, J. D., Billet, E. H. B. and Harrison, D. J. (1999b) Preliminary
Investigations of Active Disassembly Using Shape Memory Polymers. In EcoDesign
'99.
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