Repurposing and reclamation for refurbishment only work when the removal of the components intended for reuse is financially viable. This viability is challenged by anything that complicates that removal. Complications could include: the component is impossible to remove from the assembly; it requires the disassembly of too many other components to access it; or it requires the use of multiple tools because a mix of fastener types was used.
Day-to-day experiences demonstrate that these complications are commonplace. We’ve experienced or read about having to remove a front tire and its fender well liner in order to access a car’s battery or its headlight. How many times have we had to switch between metric and standard tools while working on one product? In addition, consider all the products we buy with plastic cases that have no visible fasteners or snap-fits, the ones that cannot be pried open even with a vise and a screwdriver.
For these and any other products that are difficult to disassemble, it doesn’t matter what pearl of technology is contained within: if it’s not worth the time investment, the product will at best be tossed whole into a shredder and reduced to its component materials, or at worst, end up in a landfill.
Materials recycling can be undone by one element: contamination. For materials like plastic, separation into pure material streams can be extremely difficult. Even metal fragments in plastic, the most basic of separations, can be missed by equipment designed to catch them. A small amount of metal contamination in the plastic can damage an injection-molding machine or a mold, while a mixture of dissimilar plastics can cause material weakness and product failure.
Designing for Disassembly (DfD) can help address these concerns by minimizing the complications of component removal and reducing the opportunities for contamination of materials. I’ve found that DfD principles can be successfully incorporated into the overall design process in eight distinct ways:
1. Combine functions of components within the assembly
- Reduces the number of parts
- May allow the reduction of dissimilar materials
2. Reduce the number of assembly operations by using subassemblies or modules
- Fewer parts to assemble
- Fewer fasteners
- Shorter assembly time
- Allows fasteners to be placed in easily accessible locations
3. Use quick, finger-release fasteners
- Reduces the need for tools
- Speeds removal
4. Use common fasteners when possible and stick to either the English or metric standard and one head type, e.g., Allen or Phillips.
- Reduces the number of tools
- Reduces the number of times tools need to be changed out
5. Plan the internal layout of components to reduce layering
- Quicker access to all components
- Increased visibility of all components