Design for recycling (DFR) is a concept that is increasingly being included in recycling policy and regulations. DFR is a product design tool that considers the materials from which a product is manufactured and how these materials are assembled. This approach as described in Environmental Defense (1999) is shown below.
Use recyclable materials
It is generally the case that metals are easier to recycle than non-metals. Consideration should be given to designing products which use materials that can be recycled and for which materials collection and recycling technologies currently exist. Alternatively, it is possible to design and set up an effective materials collection system.
Use recycled materials.
Selecting materials that contain a high percentage of recycled content supports the recycling process for which a product is being designed. Steel and aluminium are materials that are often recycled.
Reduce the number of different materials used within an assembly.
One of the biggest costs in recycling products is in the disassemble process. By reducing the number of materials used to manufacture a product you will be simplifying the separation process and therefore supporting the concept of DFR.
Mark parts for simple material identification.
Although this process is not feasible for all materials or components it is a relatively simple task for plastic components. (Just look at any Lego piece Fig. 1.1). Marking all materials with standard material identification codes can make the process of separation easier and less time consuming thus reducing the costs associated with the process.
Use compatible materials within an assembly. Select materials that do not need to be separated for recycling. Generally, mixtures of dissimilar plastics cannot be recycled. Similarly, non-ferrous metals (eg. aluminium, chromium or zinc) can contaminate and thus decrease the recycability of ferrous metals and vice versa.
Design for Disassembly. This criterion guides a designer away from complicated products and assembly processes. Using snap fits and nut/bolt assembly techniques whenever possible assists in disassembly. Products designed and manufactured using glues in their assembly make it much more difficult to disassemble at the end of the products life.
To be most effective, these criteria should be used as a set, not individually.
Adapted from Norgate, T (2004) Metal recycling: an assessment using life cycle energy consumption as a sustainable indicator; CSIRO
Further reading – Environmental Defense (1999) End-of-life vehicle management: Designs for recyclability: An implementation tool for EPR principles.