Design for Disassembly
(DfD)
Reduce, Recycle, Reuse
by: Jesse Miller
Agenda
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DfD Defined
Why use DfD?
How do you implement DfD?
Workplace examples of DfD
Is it easy to disassemble your product?
Reading list
Design for Disassembly (DfD) Defined
• A process by which a product and its parts
can be easily:
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Reused
Re-manufactured
Refurbished or
Recycled
DfD Breakdown
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There are two levels of strategy in DfD
1. Product Disassembly
2. Material Disassembly
Product Disassembly
• Breaking a product down for reuse into its
recognizable components
– Disassembling a computer in order to reuse
switches, boards, circuits, etc
Material Disassembly
• Breaking down a product in order to reuse
materials instead of individual components
– Using the plastic in a computer for the outer shell
of another computer, i.e. melting it down
DfD Illustration
http://www.shef.ac.uk/architecture/research/postcur/slf/DfD.html
• The first three levels can be classified as
product disassembly
• The fourth level can be classified as material
disassembly.
Why use DfD?
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Reduce Costs
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Facilitate maintenance and repair
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Facilitate part/component re-use, i.e.
recovering materials
Why use DfD?
• Reduce Waste Disposal
– Assist material recycling
Why use DfD?
• Increase Product Quality
– Assist product testing and failure-mode/end-oflife analysis
How do you implement DfD?
• Parts Connection
– Use joints, snaps, or screws instead of welding,
soldering or glue
How do you implement DfD?
• Parts Standardization
– The product can be disassembled with minimal
work and use minimal tools, i.e. the same size
screw throughout the whole product
How do you implement DfD?
• Parts Placement
– Put parts that are likely to wear out at the same
time near each other so they can be easily
replaced simultaneously
Workplace Examples of DfD:
• “BMW's 1991 Z1 Roadster, whose plastic side
panels come apart like the halves of a walnut shell,
is an example of a car designed for disassembly.
One of the lessons learned, is that glue or solder in
bumpers should be replaced with fasteners so that
the bumpers can come apart more easily and the
materials can be recycled…Now BMW uses
variations of polyurethane, foam, and rubber so the
panel can be recycled. The portion of a car recycled
is 80% by weight and BMW is aiming for 95%.”
Workplace Examples of DfD:
HP products are designed to be recycled. Recycling design
features include:
• Modular design to allow components to be removed,
upgraded or replaced
• Eliminating glues and adhesives, for example, by using snapin features
• Marking plastic parts weighing more than 25g according to
ISO 11469 international standards, to speed up materials
identification during recycling
Workplace Examples of DfD:
HP Continued:
• Reducing the number and types of materials used
• Using single plastic polymers
• Using molded-in colors and finishes instead of paint,
coatings or plating
• Relying on modular designs for ease of disassembly of
dissimilar recyclable materials
Workplace Examples of DfD:
• GE Plastics is involved in numerous consumer recycling
efforts, from making tea kettles that are easy to disassemble
and recycle to turning old plastic computer housings into
roof tiles for restaurants. It's trying to put that kind of
ingenuity to work for automakers not only in DfD, but also
in design for serviceability (DfS). Greg Jones, GE Plastic's
manager of design development, currently sees more OEM
interest in DfS than DfD, but he sees them as being closely
related.
Is it easy to disassemble your
product?
• When using the checklist, you
may want to apply a weighting
scale; doing so will help you
see your most important parts
of the disassembly process and
interpret your weak and strong
areas.
Evaluate ease of disassembly:
• What are the additional operations required
for disassembly?
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fracturing
drilling
ungluing
heating
lubricating
Evaluate ease of disassembly:
• What are the bonding and fastening methods
of parts and components?
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insert molding
cohesion
adhesion
mechanical fastening
friction fitting
Evaluate ease of disassembly:
• What are the tools required for disassembly?
– special tool
– simple tool
– by hand
Evaluate ease of disassembly:
• What is the level of difficulty for
disassembly?
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technician needed
assistant needed
deformation required
hold-down required
difficult access
difficult to view
Summary
With the growing world demand for manufactured goods,
and the decreasing availability of landfill space, recycling is
becoming more of a necessity than a good idea. By making it
possible to re-use product parts, companies can decrease
their production costs, decrease refuse and landfill materials,
and increase their quality management. A company that can
recycle and re-use their own parts is not only ahead of the
game of the future, which will eventually require compliance
with DfD, DfS, and other green design initiatives, but that
company is also at an advantage compared to others in their
industry who have not considered such changes.
Readings
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S. Thomas Foster, Managing Quality (Prentice Hall 2001)
Beitz W. (1993) Designing for ease of recycling, Journal of Engineering Design, 4(1).
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Boothroyd G. and Alting L. (1992) Design for assembly and disassembly, Annals of CIRP, 41(2).
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Dewhurst P. (1993) Design for disassembly, Boothroyd Dewhurst Inc..
• Dowie-Bhamra, T., 1996: Design for disassembly, Co-design: the interdisciplinary
journal of design and contextual studies, No. 5-6.
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Jackson, T., 1996: Material Concerns. Pollution, Profit and Quality of Life. Routledge, London, p78
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http://dfe-sce.nrc-cnrc.gc.ca/dfestra/dfestra7/dfestra7_2_e.html
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http://www.shef.ac.uk/architecture/research/postcur/slf/DfD.htmlD.html
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http://www.hp.com/hpinfo/globalcitizenship/environment/productdesign/
endoflife.html
http://www.me.mtu.edu/~jwsuther/erdm/lect19.pdf
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