Week 6

 Week 6 {27.5.2021}

Hi all! Today we mainly focused on environmental sustainability. Environmental sustainability is another important consideration product engineers would need to take into consideration other than materials for design and design for materials, which we touched on in the previous weeks. It is a social responsibility that product designers try to minimize or eliminate the negative environmental impacts that could result from thoughtful product designs. This will then allow for an efficient product life cycle.

So what is a product life cycle and what does it consist of?

There are six stages to a product life cycle, namely the stage of extracting raw materials, manufacturing, packaging, distribution, use, disposal. 

The six stages represent the main activity that most if not all products undergo. Each life cycle stage has its impacts on the environment, but the extent and type of impact could differ from product to product. If the product life stages are in the form of a cycle rather than a chain, this would create a relatively environmentally-friendly product. This is because waste materials can be recycled and reused, reducing pollution or draining of finite natural resources. 

In one of our activities, we were asked to construct a product life cycle for our chemical product which is a coffee maker. We were also required to provide an explanation for each life cycle stage.

Figure 1: Product life cycle of the Coffee maker

Stage 1: Raw material or extraction

The materials stated below are found in the coffee maker and we researched how these materials are obtained.

• Paper

1. Extracted from trees, wood chips are converted into pulp, bleached and refined. 

• Polystyrene

1. Extracted via oil refineries → Crude oil is used to manufacture long-chain polymers such as Polystyrene.

• Aluminum

1. Extracted from bauxite, an ore that is purified to yield a white powder, aluminum oxide, from which the aluminum can be extracted. The aluminum oxide must be melted so that aluminum can be extracted via electrolysis.

• Sheet steel

1. Raw materials such as iron ore, carbon, manganese are extracted from the ground

2. The blast furnace uses coke, iron ore, and limestone to produce pig iron

3. The coal is crushed and ground into a powder and then charged into an oven where it is heated to approximately 1800°F in the absence of oxygen

4. The coke is cooled and screened into pieces ranging from one inch to four inches. The coke is a porous, hard black rock of concentrated carbon (contains 90 to 93 percent carbon), which has some ash and sulfur but compared to raw coal is very strong. The strong pieces of coke with a high energy value provide permeability, heat, and gases which are required to reduce and melt the iron ore, pellets, and sinter.

• Glass

1. Raw material of sand

2. Other materials such as sodium, silicates, calcium are added to make composite glass.

Stage 2: Manufacturing and production

• Plastic molding factories would mold the plastic into shape via injection molding

• The iron sheet obtained can be pressed to form any shape required of the coffee maker such as the metal base or heating element 

• Sand would be charged with heat in a furnace at a temperature of 1700 degree celsius until it melts into liquid glass, from there it is more easily molded into different shapes such as the carafe of the coffee maker

Stage 3: Packaging

Typically, coffee makers are placed in a plastic bag and slotted between 2 styrofoam molds to protect the coffee maker from any damage

It is also placed inside a box where it is easy to carry around the coffee maker, they are typically arranged by the different models of coffee makers

Stage 4: Distribution

The coffee makers are distributed via various modes of transportation such as planes or ships to other countries or trucks in which it is transported to various local businesses and distributed to consumers.

Warehousing and retailing are also considered as part of this stage

Stage 5: Use

The coffee makers are used to make coffees. It is cleaned and reused until the end of its life efficiency(when it spoils/ stops working), or when it is replaced with a newer model.

Stage 6: Disposal

1. Reuse

Give/sell it to other people via various platforms such as online websites or to charities

2. Recycle

Some companies such as Nespresso offers to take the old machines back for repair or to recycle them

3. Disposal

Coffee makers are sent to landfills or incinerators

Moving on to the next part of the lesson we talked about Cradle-to-Cradle design. This is because, though a product “cycle” is desirable, in reality, most of the product life cycles fall in the Cradle-to-Grave product system. This is where products are manufactured from raw materials(Cradle), used, and eventually end up in the Landfills(Grave) disposed of.

A cradle-to-grave product minimizes the negative impact on the environment mostly by the 3Rs namely reducing, reusing, and recycling. This method of recovery is not very effective. This is illustrated by the example of copper. The extraction of 1 tonne of copper causes 600 tonnes of waste. However, only 25% of copper is recycled 20 years after production.

This is where we learned that Cradle-to-Cradle (C2C) design will come in. The C2C design concept is modeled after nature. Similar to how materials return to the biosphere in the form of compost or nutrients, in the product life cycle, waste materials of a retired product will become the raw materials for a new product. In summary, C2C is trying to eliminate the concept of waste through design, which is more efficient than trying to repurpose waste materials through recycling.

Our group then moved on to apply the C2C design to our product life cycle as shown below.

Nutrients become nutrients again

• Glass recycling, instead of manufacturing large quantities of glass can help to make the cycle more sustainable.

• Instead of creating new sheet metal, the manufacturing company could strategically design their coffee maker models to all require similar components derived from sheet metal, that way, when sheet steel is recycled, it can work into their new models.

• Glass parts can be recycled endlessly by crushing, blending, and melting it together with sand and other starting materials like steel and aluminum which are 100% recyclable. 

• At sorting centers, have workers sort out the waste and bring it all to one area for scavenging of recyclable materials.

• For every acre of trees cut down for the manufacture of paper, 2 acres of trees should be planted/eliminate the use of trees to make paper( using other raw material).

Celebrate diversity

• Companies could come up with green initiatives to plant trees or help developing countries build a sustainable source of energy, such as building solar farms in less fortunate regions.

• Manufacturers can explore different biodegradable packaging materials that minimize harm to the environment. 

• The coffee maker manufacturing company can build more local factories in other countries to reduce the transportation costs and promote the coffee makers overseas. 

• Manufacturers can start an initiative to create a carbon sink to offset the environmental impacts of climate change caused by fuel used.

• Other alternatives for aluminum can include magnesium, which is more environmentally friendly and reduces the harmful impact on marine life in terms of the way it is harvested and processed.

• More sustainable alternatives for plastic could be used such as polylactic acid, which comprises plant cellulose to create biodegradable plastic.