1.25 Design for Manufacturing, Maintenance, Repair and Disposal

Question 1

Reducing the number of manufacturing processes

Answer 1

• Use a single redistribution process such as injection moulding rather than multiple addition wastage methods
• Use self-finishing materials such as polymers rather than materials that need finishing
• Reduce the joining processes required by incorporating integral fixings
• Use ribs and webs to create light but strong castings and mouldings
• Incorporate integral snap fittings, posts for self-tapping screws and tactile/aesthetic texture in the mould design of polymer parts
• Buy parts from specialist suppliers rather than using in-house production
• Use adhesives rather than mechanical fasteners

Question 2

Labelling of materials

Answer 2

Labelling of materials to aid separation for recycling is achieved by the use of a standardised system of codes, usually moulded into product.

Question 3

Making products easy to disassemble or separate

Answer 3

Products can be more easily disassemble or separated by adopting strategies such as:

• The ‘cradle to cradle’ approach, keeping the materials in products separate
• Using easily released polymer snap fittings such as the polymer clip-based fastenings that are used in many vacuum cleaners
• Adhering to the End of Life Vehicles (ELV) legislation for car assembly
• Considering the use of smart materials such as SMA and SMP for automatic ‘active assembly’ pf products such as mobile phones

Question 4

What is Six Rs of sustainability

Answer 4

The key points to consider in making products sustainable:

• Reduce
• Reuse
• Rethink
• Recycle
• Refuse
• Repair

Question 5

Reduce

Answer 5

Minimising wastage by using less material or eliminating excessive packaging, for example

Question 6

Reuse

Answer 6

Making it possible to use products again rather than discarding them

Question 7

Rethink

Answer 7

Considering carefully whether there might be more sustainable alternatives

Question 8

Recycle

Answer 8

Recovering parts and materials to be used again when products reach the end of their useful life

Question 9

Refuse

Answer 9

Avoiding designs which, for example, use materials which are harmful to the environment or are difficult to recycle

Question 10

Repair

Answer 10

Designing products that can be repaired rather than those that have to be thrown out if they are damaged

Question 11

Maintenance: temporary and integral fixings

Answer 11

• Temporary joining methods such as screws for access panels encourage home repair
• Integral, tool-free fittings facilities regular maintenance such as battery replacement

Question 12

Maintenance: Use of standardised parts

Answer 12

• These make it easier to use bought-in components to manufacture and repair products
• Manufactures can be sure of parts’ interchangeability, particularly if they are accredited by an independent body such as BSI
• Examples include nuts and bolts, fuses, inkjet cartridges, plumbing fittings and lock barrels

Question 13

Maintenance: allowing for service and repair/replacement of parts

Answer 13

• Aesthetically pleasing adhesive and plastic welding can make product repair impossible
• Components in circuit boards are rarely repaired as replacing the circuit is usually cheaper
• Faulty smartphones are often discarded, but Fairphone 2 is trying to counter this trend
• Fiber-reinforced polymer composite components are difficult to recycle if they fail
• Community initiatives such as the ‘Restart project’ encourage the repair of products

Question 14

Maintenance: ability to upgrade with software downloads

Answer 14

• Updated product firmware (control software), in products from TVs to fridges, improves performance
• Updating smartphones and tablets to the latest operating systems (OS) has the same benefits, but can lead to premature obsolescence due to hardware incomatibility

Question 15

Define disassembly

Answer 15

Taking apart a product, either for repair or when it is no longer required