DESIGN FOR DISASSEMBLY AS A CIRCULAR ECONOMY CONCEPT STRATEGY FOR PRODUCT SYSTEM AND SERVICE REDESIG

A key principle of circular economy which embodies design process from concept stage to manufacturing stage, use, repair, replacement, disposal, recycling and reuse; and also facilitates business models Product System Service is the design for disassembly.

Design for Disassembly is a design technique which involves designing a product to be disassembled for easier maintenance, repair, recovery and reuse of components/materials. (Chiodo, 2005).

Whilst Ellen MacArthur Foundation towards Circular Economy gives the opportunity to re-design revolution through taught leadership, the method of Design for Disassembly as Circular Economy concept strategy facilitates the easy, cost-effective and rapid separation/dismantling of product at it’s “end of life” so that components can be reused and/or recycled.

Alex Diener defined Design for Disassembly as a design strategy that considers the future need to disassemble a product for repair, refurbish or recycle. Will a product need to be repaired? Which parts will need replacement? Who will repair it? How can the experience be simple and intuitive? Can the product be reclaimed, refurbished, and resold? If it must be discarded, how can we facilitate its disassembly into easily recyclable components? By responding to questions like these, the Design for Disassembly method increases the effectiveness of a product both during and after its life. (Diener, 2010).

Design for Disassembly has become an effective principle for designers and manufacturers in designing for the Environment and sustainability. It’s driven by reduction of materials and recovery, design and manufacturing cost reduction, maintenance, repairability, replacements, recycling and/or disassembly time reduction.

Legislations like WEEE and RoHS have pressurised manufacturers into adopting sustainable product design principles, but Design for Disassembly isn’t just about meeting legal requirements. It is also about reducing waste in manufacturing and recovery processes through design. Finding a way to “close the material loop” can help in material cost reduction,component replacements, repairability and recycling.

Similarly, Ellen MacArthur Foundation catalyses business innovation by collaborating with businesses like B&Q, BT/Cisco,National Grid and Renault to embed circular economy thinking within major sectors of the economy.

For Design for Disassembly as a Circular Economy Concept strategy for product sytem and service redesign, Closed Loop is a sustainable approach to managing the entire life cycle of a consumer product, whereby all material not “totally” consumed in the use of the product is designed to be a valuable input into the same or other processes.

Waste is Food

This means that wastes elements from consumption are taken back and recycled or reused for/in the process of making the same or other products or biodegraded/biocomposted becomes a contribution to the biosphere bigger picture.

In Design for Disassembly process, close examination and analysis of product architectural structure, often reveal components that can be combined, eliminated altogether or modularised. This saves material and production costs. In addition, when products can be combined and modularised, the material separation time and process at disassembly period is simple and the material and production costs are greatly reduced.

Products that disassemble easily often assemble easily.

When product components becomes easily accessible for repair, replacement, recycling or reuse, it saves manufacturing and recycling time for companies involved and reduces the cost of labour. It also keeps consumers happy and saves company’s time and effort on quick disassembly for product repair and refurbishment.

Decreasing variation decreases cost

Imagine a copy machine with 30 different screw types and sizes, the product manufacturing company will have to track, order, and stock the screws and the company workers would need to be trained and supplied with the proper tools to install them. If the design can be accommodated with fewer/ consolidated screw type, material costs, management and labour time will be saved. Or designers can substitute screws with in-mould snap or push fit technology.

Essentially, Products designed with fewer parts and material types are easier, cost effective and quicker to sort and recycle. This “sustainable” range of products design process can be facilitated through Design for Disassembly.

It is imperative for companies to set policies and follow through for the sake of their reputation and also the responsibility placed in their hands. This in Design for Disassembly show consistency and allows for a proper thought through policy that would work in all and for all cases of design.

Design For Disassembly Factors

When designing products with disassembly in mind, there are three important factors which must be considered by the designer

• The selection and use of materials Reduced separation times for disassembly can be achieved through the careful selection of materials. Indeed some parts may not require disassembly at all if they are made from the same or similar materials. Design for Disassembly demonstrates all the possible interconnection and combinations of material for an assembly, and how their properties affect the assembly’s recyclability.

• The design of components and product architecture Design for Disassembly through component design and product architecture shares many of the principles used in design for assembly.

> Minimise the number of components used in an assembly, either by integrating parts or through system re-design.

> Minimise the number of material types used in an assembly.

> Separate working components into modular sub-assemblies.

> Construct sub-assemblies in planes which do not affect the function of the components.

> Avoid using laminates which require separation prior to re-use.

> Avoid painting parts as only a small percentage of paint can contaminate and prevent an entire batch of plastic from being recycled.

• The selection and use of fasteners Fasteners play an integral part in the joining of components and sub-assemblies. Access to the fasteners is also important. Holes which are complete (i.e. follow through the entire section of the component) allow for the fastener (e.g. snap-fastener) to be tapped out as opposed to being pulled out.

These assembly general principles and Roadmap enhances Design for Disassembly in redesigning Circular Economy concept and the framework of steps can be performed in almost any order to achieve the end goal of designing more efficient products.

Given environmental and cost constraints, the challenge is as much product de-creation as it is creation. Design for Disassembly as a Circular Economy Concept strategy can be applied throughout the entire design cycle; designers need to educate their team, discover waste, set goals, create solutions, and then monitor results through production, release, use, and end-of-life.

ARE SUSTAINABLE DESIGN AND DESIGN FOR DISASSEMBLY MUTUALLY EXCLUSIVE?

Some products are easy to design for end of life. You can choose to not mix a bunch of materials together like you see in a typical juice box. Instead use an aluminium can, a single simple material that’s recyclable everywhere.

But what about something like a laptop? That’s more complicated. How it ends its life depends largely on how easy it is to disassemble.

Maybe it's user will take it in for repair or upgrade instead of throwing it away. Or maybe an e-waste recycler will extract the valuable metals and plastics, without letting any toxins escape.

Whatever the case, it’s a race against the clock. Users want convenience. Recyclers have very limited time to separate materials and remove hazardous components.

Not all recycling is created equally. Some materials can only be down-cycled and converted to lower-value items. Plastic comes in so many types, with so many additives and colourants, they often just get bundled together and down-cycled.

Recycling allows materials to come back in their new life with the same or even higher value than they had in their last life.

The re-manufacturing strategy which involves reusing whole components of a product rather than just the materials is a better strategy compared to recycling. It is possible to design for re-manufacturing with Design for Disassembly strategy.

These strategies make it easy to design a great end of life for your product. Many of them can also be used to tackle material wastage issues and product end of life issues and push end of life further into the future through repair and upgrade.

Review of industrial design and related industries shows that there are two types of knowledge of relevance to Design for Disassembly. Firstly what are the broad themes that address the issues of why, what, where, and when to disassemble, and secondly what are the specific design principles of how to design for disassembly.

There are three broad themes that significantly impact on the decision making process of Design for Disassembly even in construction for deconstruction. These are: a holistic model of environmentally sustainable design, the reading of some designs as a series of layers or hierarchical assembly with different service lives, and a recycling hierarchy that recognises the different benefits of different end-of-life scenarios.

Before attempts are made to design for disassembly, the consequences must be understood within a wider picture of the environmental impact, and indeed within the global environment. While to design for future reuse will have obvious environmental benefits, there are also potential environmental costs, and while these are almost certainly of a smaller impact, they must be recognised and considered. To manage this process, a model is required that allows the place and role of design for disassembly to be seen within the overall picture of environmentally sustainable design.

The notion of life cycle assessment (LCA) is a well-recognised way of understanding, assessing, and planning a reduction in the environmental consequences of our actions. A life cycle assessment of a system or product identifies all of the inputs and outputs, either beneficial and not, so during the life of that system or product. It is usual to visualise this analysis as a two dimensional graph or matrix that plots environmental resources against the stages of the system or product life. In this way all of the cumulative environmental impacts can be seen and analysed.

This model, with its two axes of environmental resources and life cycle stages, does not however offer strategies for dealing with the unwanted impacts.

Reduced separation times for disassembly can be achieved through the careful selection of materials. Indeed some parts may not require disassembly at all if they are made from the same or similar materials.

Fasteners play an integral part in the joining of components and sub-assemblies. Access to the fasteners is also important. Holes which are complete (i.e. follow through the entire section of the component) allow for the fastener (e.g. snap-fastener) to be tapped out as opposed to being pulled out.

This also determines the materials selection especially where snap fits are used and where material strength is needed for strong fastening.

Certain product requirements (e.g. use in extremely hot temperatures) will take priority over certain elements within the table, although when Designing for Disassembly it is important to know the options available.

Conclusion

Design for Disassembly as a Circular Economy Concept strategy for product system and service redesign will have a great impact in design process if applied through a product’s life cycle. Where material use, life span, environmental impact, recycling; and in the case of strategic materials, possible components reuse is considered from the pre-design process of design concept.

Design for Disassembly as a Circular Economy Concept strategy for product system and service redesign will increase product material recyclability to a larger scale, enhance the extension of product life and help retain rarely manufactured materials in the economy over several cycles of use, thus closing the loop by exploring possible design strategies of accessing materials, reducing material excess and replacing, repairing and maintaining materials in order to encourage scarce material reuse whilst maintaining effective function of products.

Design for Disassembly as a Circular Economy Concept strategy for product service system redesign will contribute towards product sustainability by creating strategies of enhancing effective and efficient recapturing of products and materials, by designing incentivised product service system (PSS) that encourages customers to return used products thereby providing customer/ consumers with a better experience, involving customers in the product life cycle knowledge and creating an opportunity to increase brand value and reduce supply risk for manufacturing companies.

Design for Disassembly as a Circular Economy Concept strategy for product service system redesign will create new product range and product service system (PSS) market through innovative design concept in line with its principles increasing product value and sustainability whilst maintaining effective product use and retaining strategic material for reuse, for the ultimate purpose of closing the material loop.