Design for Disassembly

(DfD)Reduce, Recycle, Reuse

by: Jesse Millerby: Jesse Miller

Agenda

• 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:– Reused– Re-manufactured– Refurbished or– Recycled

DfD Breakdown

• There are two levels of strategy in DfD

1. Product Disassembly2. 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?• Reduce Costs

– Facilitate maintenance and repair

– 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-of-life 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 snap-in 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? – fracturing – drilling – ungluing – heating – lubricating

Evaluate ease of disassembly:

• What are the bonding and fastening methods of parts and components? – 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? – 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• S. Thomas Foster, Managing Quality (Prentice Hall 2001)• Beitz W. (1993) Designing for ease of recycling, Journal of Engineering Design,

4(1). • Boothroyd G. and Alting L. (1992) Design for assembly and disassembly, Annals of CIRP,

41(2). • 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.

• Jackson, T., 1996: Material Concerns. Pollution, Profit and Quality of Life.

Routledge, London, p78 • http://dfe-sce.nrc-cnrc.gc.ca/dfestra/dfestra7/dfestra7_2_e.html• http://www.shef.ac.uk/architecture/research/postcur/slf/DfD.htmlD.html

• http://www.hp.com/hpinfo/globalcitizenship/environment/productdesign/ endoflife.html• http://www.me.mtu.edu/~jwsuther/erdm/lect19.pdf