Static Data - refrigerator

7.2.1 Disassembly

Part of this analysis consists in physically disassembling the product into its components (Figure 49)¹⁶, to understand how the product and single components work, the ease of performing the disassembly and the tool needed (Figure 50).

Understanding how a refrigerator is made is important not only because of its content on hazardous substances but also because refrigerator contains significant quantities of recoverable materials, such as metals, as addressed in chapter 6. It is considered as a necessary step to retrieve valuable information for both product redesign/optimisation and the design of new products, to orient the design activity towards the minimisation of the environmental impact of products (Movilla et al., 2016). Nowadays the inclusion of disassembly requirements in product design is still more of an exception than usual practice, and no incentives for applying Design for Disassembly approaches are provided. For this reason, policies could turn into good incentives to Management and maintenance

/ save money by reducing inefficiencies (heat dispersion, water overuse)

/ high repairability

/ substitution of parts and components / design wear&tear and lost parts easily

replaceable

/ scheduled maintenance (service) / save money with driven DIY maintenance / provide feedback to prevent breakage and

damage

/ considered and prevent misuses / considered excessive strength applied 132

Integration and upgradability

/ modular design

/ modularity across products

/ add functions using simple components / allow customization of parts and functions / allow combined, fixed or incorporated

upgrades

/ allow functional integration / fullfil projected lifetime / align lifespans

/ consider both hardware and software obsolescence

/ avoid over-reliance on technologies and brands

/ build systems that can be implemented by users

/ avoid obsolescence for lack of technical support

Fig. 48 - Product requirements: resistance, management and maintenance, integration and upgradability.

Resistance

/ ease of cleaning

/ avoid superficial and interstitial condensation

/ avoid space with dust buildup, moisture and dirt

/ resistance to biological damages / resistance to chemicals

/ resistance to accidental damage / resistance to scratches and abrasions / impact resistance

/ load resistance

133

improve product disassembly through the inclusion of ‘push’ (mandatory) and ‘pull’ (voluntary) measures (Movilla et al., 2016). Deconstructing and analysing current products is fundamental to understand how they work. Refrigerators today consist of several basic components: an exterior cabinet including the door, an interior cabinet, insulation between the interior and exterior cabinets, the cooling system, the refrigerant, and the fixtures (Wilson, 2016). As we partially mentioned in chapter 6, when we dealt with the environmental impacts of the material used, we can group the components based on their materials and related production processes as follows:

- The inner and outer cabinets, as well as the door, tend to be made of metal (aluminium or steel, sometimes lacquered or stainless). The

metal is generally purchased in a coil that is either fed directly into the manufacturing process or cut to size and fed sheet by sheet.

Sometimes the inner cabinet is made of plastic (Marton, 2006).

- The insulation consists of fibreglass or poly-foam, made primarily from types of plastic called polystyrene or polyurethane (Wilson, 2016).

- The fixtures in refrigerators consist mostly of thermoset plastic, which cannot be recycled (Wilson, 2016). Almost all the large interior fixtures (door and cabinet liners) are made from vacuum-formed plastic; smaller fixtures (butter compartments, egg trays, salad crispers) are purchased as small plastic blanks

16 components are parts or elements of which the object is composed. Obviously, all artificial physical things are made from other things. These other things might be given, or also are composed of components (Ralph and Wand, 2008).

Analysis of current products through data gathering

Fig. 49 - Leibherr exploded view of their fridge, with the finished product on the right

Source: http://laundry.reviewed.com

134

or in pre-formed pieces (Marton, 2006).

- The components of the cooling system (compressor, condenser, coils, fins) are made of aluminium, copper, or an alloy. The tubing is usually copper, because of that metal's ductility—its ability to bend without breaking.

Liquid refrigerant under high pressure enters the evaporator (made of aluminium tubes) where it absorbs heat from the inside of the refrigerator (and cools it down in the process).

In the process of absorbing heat, the liquid refrigerant evaporates into a gas and then flows into the compressor (made of steel) where it is compressed into a high-pressure gas. The high-pressure refrigerant gas then passes to the condenser (the copper coils outside the refrigerator) and cools back to liquid form.

From the condenser, the liquid refrigerant enters the evaporator, and the cooling system cycle starts all over again. (Wilson, 2016)

Figure 51 shows single components coupled with their materials, reporting for each one if its disassembly is easy, medium or difficult to accomplish and the tools needed. Below, instead, the components were grouped by material, establishing how many connections are reversible or not, how and how many components are made of materials that are irreversibly combined. We have also defined parts that are outsourced and not produced by the appliance industry. For a breakdown of weights and percentage of materials, we refer to chapter 6, p.101.

7.2.2 Accessibility

On the same exploded view of the refrigerator, we can perform the accessibility analysis (Figure 52), by considering the ease of accessing each part for maintenance and replacement purposes. Even in this case, the colours indicate if the task was difficult, medium or hard to perform.

Although shapes and features of refrigerators differ,

expansion valve

Fig. 50 - A refrigerator disassembly. The product is broken down into its single components.

135

we could consider that most domestic refrigerators present a similar structure and characteristics and, hence, similar disassembly processes. The goal of the disassembly study is gaining knowledge about current components, relative weight and materials and then perform the functional analysis. Herein, this study is not intended to be exhaustive, nor providing information on the dismantling activity to manufacturers for improving specific products, although it can be implemented in the future for other purposes. The disassembly time needed for performing the operation of different components was not measured since it would require performing this activity in a recycling facility with experienced treatment operators to obtain meaningful data.

Moreover, the economic profit of material recovery has not been calculated, and no comparative studies on a bigger sample of refrigerators were performed, being out of the scope of this dissertation. I chose to use a standard refrigerator as a case study of

the disassembly tasks, to provide a procedure that can push designers to reflect on how objects are made, divide objects into simple functions that can reconsidered, question whether current objects are functional (not referring to specific performances and measurable indicators, rather in relation to the functions that have been identified). Therefore, this approach is intended for product designers, although studying the indicators listed above may become the object for further investigations, to be carried out with appropriate data setting and collection.

7.2.3 Functional Analysis

The functional analysis comprises activities that enable the understanding of goals. Functional decomposition of a product represents a way of identifying product’s major functional aspects (Alexander, 1964). The functional analysis (Figure 52) allows to group components into functional units abstracting from the fridge concept by defining four

Fig. 51 - Bill of Materials Analysis of current products through data gathering

ENGINE AND CONNECTIONS