Page 165 - Design for Environment A Guide to Sustainable Product Development

144 Cha pte r Ei g h t

FIGURE 8.7 Example of a disassembly tree for electronic products.

Using mathematical optimization techniques, it is possible to maxi-
mize the net value recovered through product disassembly, based on
information about the likely condition of the components, material
and component salvage values, and average disassembly times.

Component Accessibility
At any stage of disassembly, the ability to remove a component or
part is a key consideration. For example, parts that are embedded
cannot be recovered easily for reuse. Moreover, if a part is embedded
in an incompatible material, it makes it difficult to recycle the as -
sembly. If the design does not allow for easily separable parts, then
embedded parts should be constructed of recyclable and compatible
materials. Likewise, separability of dissimilar materials is a key factor
in the efficiency of disassembly operations (see Section C.3, Design
for Recyclability). The following guidelines will contribute to speed-
ing up the disassembly process and recovering a larger proportion of
system components:
• Avoid springs, pulleys, and harnesses which complicate the
disassembly process.
• Minimize the use of adhesives and welds between separable
components or between incompatible materials. Adhesives
introduce contaminants, can detract from quality due to the
potential for bond failure, and increase the costs associated