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Strategies For Green

Strategies for Green Design

3.3.1 Define design for manufacture (DfM),

Designers design specifically for optimum use of existing manufacturing capability.

3.3.2 Describe why DfM can be a dominating constraint on the design brief and state that it can be conveniently split into design for materials, design for process and design for assembly.

The designer's main objective is to design a product within given set of constraints (financial, specifications etc). It has been said that 70% of the product cost is determined by decisions made during the early stages of the design cycle, 20% during production and a further 10% on other aspects. Due to the high percentage of the product cost it is important that consideration be given in the design brief and thus being a major design constraint. When DfM the designer takes into consideration the existing production systems in order to maximise cost effectiveness. It becomes a design constraint also when the designer must work within an existing production system that cannot be modified greatly. DfM can be broken down into three parts: design for materials, design for process and design for assembly.

"Design for manufacture (DFM) is accepted as an important tool to improve manufacturing competitiveness" from http://www.emeraldinsight.com/journals.htm?articleid=852352&show=html

3.3.3 Define design for materials, design for process and design for assembly.

Design for materials
Designing in relation to materials during processing.
  • Considers the availability of materials locally which can affect choice of manufacturing process or design of the product.
Design for process
Designing to enable the product to be manufactured using a specific manufacturing process, for example, injection moulding.
  • Affecting the choice of material or design of the product.
Design for assembly
Designing taking account of assembly at various levels, for example, component to component, components into sub-assemblies and sub-assemblies into complete products.
  • Simply put, it's an approach to designing products with ease of manufacture in mind. By making things easier to assemble, one also makes the assembly process faster and more cost-efficient. This results in higher profit to the manufacturer, and can also add value for the customer.
  • If a product contains fewer parts it will take less time to assemble, also reducing manufacturing costs
  • wikipeadia reference. Take note of the Xerox saving millions and the Walkman product being one notable product produced this way.
  • A handy site on product development.
DfM ... DfA DfA

3.3.4 Discuss three strategies that designers could employ for DfM.

Strategies include: minimizing the number of components, using standard components, designing components that are multifunctional or for multi-use, designing parts for ease of fabrication, minimizing handling, and using standard sub-assemblies.
  • Minimising the number of components allows for quicker, more efficient manufacturing of a product.
  • Using standard components decreases the amount of time taken to manufacture a product, because less time is spent manufacturing special components.
  • Multifunctional or for multi-use so part or product can be used in a variety of situations. Coasters on chairs can be used on bed side tables etc. This way material optimisation can occur.
  • Ease of fabrication saves time, resources and money.
  • Minimising handling,
  • Using standard sub-assemblies quickens the manufacturing process, improve fabrication, minimise handling of the smaller components.

3.3.5 Describe how designers can modify the environmental impact of the production, use and disposal of their product through careful consideration at the design stage.

  • As with the above strategies early consideration during the design cycle is important.
  • This strategy can be known as Design for the Environment (DfE) where stakeholders work to reduce the risk to people and the environment by reducing the environmental impact of a product during the product life cycle.
  • Design for Materials: The use of recycled materials is increasingly important as more product take-back and producer responsibility legislations are mandated, product labelling programs are adopted, and sustainability goals are being promoted. Materials selection impact distribution, consumer use, repair and refurbishment, and other end-of-life activities.
  • The Australian Environmental website mentions adopting strategies, for Raw materials, manufacturing, end of life, and distribution.
  • This website provides extra information.
  • Design for disassembly: is one aspect of design for materials and will facilitate recycling of products on disposal. Easier to achieve if we design components made from one material or by using thermoplastic adhesives that lose their properties when reheated. By designing snap fittings instead of welding and gluing
  • taking full account of the effects of the end disposal of the product ensuring that the packaging and instructions encourage efficient and environmentally friendly use minimizing nuisances such as noise or smell analyzing and minimizing potential safety hazards.
  • increasing efficiency in the use of materials, energy and other resources minimizing damage or pollution from the chosen materials educing to a minimum any long-term harm caused by use of the product ensuring that the planned life of the product is most appropriate in environmental terms and that the product functions efficiently for its full life

3.3.6 Define reuse, repair, reconditioning and recycling.

Reuse
Reuse of a product in the same context or in a different context.
Repair
The reconstruction or renewal of any part of an existing structure or device.
Reconditioning
Rebuilding a product so that it is in an “as new” condition, and is generally used in the context of car engines and tyres.
Recycling
Recycling refers to using the materials from obsolete products to create other products.
  • Reusing is utilising an object more than one time. This takes into account of conventional reuse where the object is used again for similar purpose, and new-life reuse where it is used for an innovative purpose. An example of reusing is reusing plastic or glass bottles to drink water from.
  • Repairing is to renovate by restoring a piece or placing together what is wrecked. An instance of repairing is replacing a part of a computer that burnt down or became outdated such as the processor.
  • Reconditioning are all actions linked with reinstating and modifying the casing of a manufactured good in such manner that it can be offered to the customer in appealing appearance. An example is fixing up a car or household to sell to a customer.
  • Recycling consists of processing used materials into novel products in order to avert squandering potentially functional materials. Furthermore, it decreases the consumption of unsullied raw resources, trims down energy usage, lowering air and water pollution by dropping the need for "usual" waste discarding, and lastly lowering greenhouse gas emissions. An example of recycling is recycling paper.

3.3.7 Describe how reuse, repair, reconditioning and recycling contribute to the optimization of resource utilization.

  • Promotes the use of less raw materials

Toshiba has on its website the following:

Optimisation of resources pursued from the product design stage
"Development of lighter products and robust products with longer lives saves resources. At Toshiba Group, as well as resource-saving design, we are emphasising greater use of modules so that repairs and upgrades of products are performed simply by replacing modules. Reduction of the number of parts to facilitate disassembly and recycling is another priority."
"Also, we are promoting use of recycled resources in products. For example, 1,800 tons of recycled plastics was used in the manufacture of Toshiba washing machines, Multi-Function Peripherals (MFPs), and other products in fiscal 2006." (http://www.toshiba.co.jp/env/en/products/resource.htm)

3.3.8 Describe how the strategies of reuse, repair and recycling can be applied to the design of products, including packaging.

For example, consider disposable cameras, vacuum cleaners and car tyres.

Especially in packaging, recycling is really important. The container is not the product itself and could therefore easily be created from recycled paper or plastic. Packaging is a huge part of pollution because once the product is in sales and the consumers buy them, the packages get thrown away. Products such as disposable cameras are designed in an eco-friendly manner where it can be reused or torn apart to be recycled.


Activity
Organise the above products and green strategies into a matrix. Then identify parts of the product or ways to apply the strategies. For, example, make the film canister or card of a disposable camera accessible so that it can be reused a few more. times.

Reuse Repair Recycle
Disposable Cameras *Separate the reusable pieces and make them accessible to be reused *Collecting all the cameras that need to be repaired so they can be reused *Melting the plastic pieces and creating other products
Vacuum Cleaners *Pieces can be reused in other products or similar vacuums i.e the hose * motors, or holes in hoses can be repaired. *Metal and Plastic can be melted to form other products
Car Tyres *Tyres that are in good condition could be re sold so they could be reused and reduce clutter *Simple tears and punctures could be repaired and resold to avoid wasting a whole tyre *Melt the tyres to make other ones

3.3.9 List three material groups that can be easily and economically recycled.

Consider thermoplastics, metals and glass.

Thermoplastics A plastic material that can be repeatedly melted and cooled, such as polyethylene or polyvinyl chloride.

  • Thermoplastics make up 80% of the plastics produced.
  • It is one of the easiest materials to recycle.
  • It has week secondary bonds between the long polymer chains so it can be reheated and reshaped.
  • Sometimes, plastics are made up of more than one kind of polymer, which makes recovery difficult.

Metals

  • Precious metals are rarely thrown away, but are reheated and reshaped easily.
  • The metal produced is of equivalent quality
  • Recycled metal has significant economic value.

Glass

  • Glass is used in many household and industrial waste because of its weight and density
  • Glass recycling uses less energy than when glass is manufactured from lime, soda ash and sand.
  • From every ton of waste glass recycled, 315 kg of carbon dioxide are saved.
  • Cullet is crushed glass, ready to be melted again.
  • Glass can be recycled over and over again with no loss in quality.

3.3.10 Describe how many products comprise several different materials, and state that these materials have to be separated to enable recycling.

Identify the materials that are in the refrigerator that can be recycled.

Often products, such as the refrigerator, will be made of many different materials. If they are to be easy to recycle then they should be separated and disposed of into the appropriate recycling bins.

The materials and their recycling process is as follows :

  1. Plastics, which are used for shelves, drawers, and insulation are distributed and recycled along with other plastics and reused for either another refrigerator or any other product consisting of plastic
  2. Glass used in refrigerators may be reused if condition permits after utilisation.
  3. Metals used in refrigerators are separated from other materials then can be recycled and reused for something else.

3.3.11 Discuss the issues underpinning the economic recycling of materials.

Consider collection, energy and processing considerations, redistribution.

Collection

  • Recycling attitudes of the consumer, willingly separate materials.
  • plastics or metals and glass need to be sorted and currently can only be done by hand so to reduce costs collection systems at point of disposal are needed, i.e tubs or large bins
  • People actually out the right coloured glass or plastic in the right collection bin
  • collection is costly, an Australian study stated that the cost for recycling collection was greater waste collection per household.
  • Collection Systems. There are three main systems of collection used for garbage, “buy-back centres”, “curb-side collection” and “drop-off centres”. Buy-back centres work by selling cleaned recycled material, this would provide inspiration for use and constant supply, and the pre-processed products can then be sold on, creating a profit. Curb-side collection is generally when a waste collection vehicle (garbage truck) picks up the waste, though the process of the recyclables are sorted and cleaned depends on the region. Drop-off centres insist or require the waste producer to carry the recyclable product to a central location, which could be either a mobile or installed collection station, as well as the reprocessing plant. This immediately takes care of the waste, and makes it easy for the community.

Energy and processing considerations

  • Plastics (including types) or metals and glass need to be sorted so the same types can be recycled
  • Products of other materials that need to be removed beforehand
    • both are done by hand so it is slow and costly
  • Glass production is costly and energy intensive using recycled glass reduces the energy needed thus the costs
  • Some materials need to be reprocessed first before recycling
    • Plastics need to be made into pellets.
    • Glass needs to ground into fine granules
    • Paper needs chemicals and water to be broken down before being recycled
  • Naturally, reprocessing and cleaning materials for recycling will require energy, some materials more than others, e.g. plastics

Redistribution

  • Once made into a material that is ready for manufacture it will need to be stored, transported to its new location thus increasing costs and use of recources.

3.3.12 Define design for disassembly.

Designing a product so that when it becomes obsolete it can easily and economically be taken apart, the components reused or repaired, and the materials recycled.

The goal of design for disassembly is designing products in order to minimise their impact on the environment. Design for disassembly enables the product and its parts to be easily reused, re-manufactured, or recycled at the end of the product’s life usage. Designers consider product disassembly early in the product's design stage.

3.3.13 Explain that design for disassembly is one aspect of design for materials and will facilitate recycling of products on disposal.

"Designing products in order to minimise their impact on the environment is becoming increasingly important. Many designers are beginning to recognise this fact and are therefore demanding tools and techniques which enable them to design more responsibly. One technique which can be used is Design for Disassembly - this enables the product and its parts to be easily reused, re-manufactured or recycled at end of life. This paper not only presents this technique but also illustrates its use with a case study. It is hoped that this will encourage designers to consider product disassembly early in the product's design stage". (http://www.co-design.co.uk/design.htm)

DfD is a building design process that allows for the easy recovery of products, parts and materials when a building is disassembled or renovated. The process is intended to maximise economic value and minimise environmental impacts through reuse, repair, re-manufacture and recycling. A DfD process involves developing the assemblies, components, materials, construction techniques, and information and management systems to accomplish this goal.

DfD is a growing phenomenon within manufacturing industries as greater attention is devoted to the management of the end-of-life of products. The effort is driven by the increasing disposal of large amounts of consumer goods, and the resulting pollution and the loss of materials and energy that these products contain.

The DfD building design process also addresses energy recovery from materials and safe bio-degradation. DfD enables flexibility, convertibility, addition, and subtraction of whole-buildings. In this manner DfD may help avoid the removal of buildings altogether.

3.3.14 Discuss two strategies that designers could employ to design for dis-assembly.

Hot glue gun Nuts and Bolts
Snap Fittings A weld is not DfD
Designing components made from one material. Using thermoplastic adhesives that lose their properties when reheated. Designing snap fittings instead of welding and gluing.
  • Due to the molecular structure and properties of thermoplastics ... Thermoplastic adhesives (such as hot glue) when heated will allow the two parts to separate.
  • Snap fittings, bolts, screws etc are non permanent joints therefore the parts can be separated. Welding and glues from permanent joints.

References

Bulleted list and italicised paragraphs are excerpted from Design Technology: guide. Cardiff Wales, UK: International Baccalaureate Organization, 2007.

Images are clickable links to its location.


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Page last modified on March 03, 2013, at 10:48 PM