WEEK 5

This week was our first synchronous lesson online with Dr Noel. It was astray from the normal lesson setting nevertheless we started the lesson off on a good note ending strong. 

💥Brief Summary of the Lesson:

We learnt about how can we change the design of the product so that a particular material can be used make it even better than before. 

Dr Noel explained to us this idea using the hairdryer for example:

He showed us the first hairdryer design which was invented in 1980 by Alexander- Ferdinand Godefroy. The design was huge, its size almost comparable to a human and it was very bulky, made solely out of metal. People used to get intimidated by it and called it "torture device".

(n.d.)

30 YEARS LATER..

The improved design of the hairdryer Handy Hannah was created. It was more compact, its size reduced and now had a wooden handle attached making it more mobile and convenient. However it was extremely heavy, weighing close to 1kg and was extremely accident-prone especially several instances of overheating and electrocution. Moreover the airflow was very weak. 

                                                                  (n.d.)

The third improved design of the hairdryer made in the 1930s, - Hawkins Supreme was made out of only plastic and wood. The substitution of metal with plastic made it safer, more convenient and easy to use as it was more lightweight than before. It was extremely high in demand and favourable amongst consumers due to the modification of plastic in its design.

                                                        (n.d)

As seen from the timeline above and from the 3 different designs being modified each time, we learnt how the design of the hairdryer is improved each time it was designed after considering the impact each design had on the consumers and its performance as a product. Thus we learnt when designing a chemical product, we should not only consider the type of material to use but also what changes we can make to the design to reap the attributes of a certain material where possible. The process is as shown:

(Blackboard, week 5 lecturer slides)

💥Activity 

The task given was to replace a given material in an existing product. Our group chose Recycled Polyethylene to replace Granite in counter-tops for island/dining tables.

Name of material	Recycled PE
Chemical Name	Polyethylene
General Description	Polyethylene is a recycled plastic. It also has a positive effect on the environment, for example every ton of recycled plastic saves on average about 1.5 tons of CO2. One such company recycling plastic is Smile Plastics. The company takes unwanted plastic from sources such as food packaging and offcuts pipes from the construction industry and produces randomly patterned recycled plastic sheets. The process is simple and contains 100% waste plastic, no binding agents or resins are added, it is simply the combination of heat and pressure that transforms the individual chunks or flakes into a complete board.
General Properties	-Marble surface  -Unique patterns  -Lightweight  -Durable
Opportunities	Recycled PE sheets can be used to convey a sustainable image in interiors, furniture or as details in a range of products.
Information extracted from datasheet provided by Chris Lefteri Design Ltd (Singapore; London)  https://eliser.lib.sp.edu.sg/xmlui/bitstream/get/17441/1/Recycled%20PE.pdf

                                    Granite Counter-top (Pros and Cons of Granite Countertops, 2020) 

 

Replacement: 

                                    Recycled PE countertop (Eco Friendly Countertops | CounterTop Guides, 2021) 

 

Application: Counter Tops in Dining Table/Island tops 

Can be used to replace Granite material. 

*Assume Recycled PE (polyethylene) is recycled HDPE 

 

For this task firstly we discussed amongst ourselves how this material can be used as a direct replacement to a material in an existing product without any significant changes in the design as follows:

As more consumers have a shift in attitude in adopting lifestyles that is more responsible to environment needs, it is difficult to find a material for interior of homes that is both durable and environmentally friendly. This material enhances the visual appeal of the counter-top design, making it look very attractive. Additionally, it is very durable making the money consumers spend on products made of this material for interior e.g countertop worthwhile. 

 

Material properties: 

 

Material    Material Properties	Recycled HDPE	Granite
Density (Kg/m3)	946-956  (MatWeb - The Online Materials Information Resource, n.d.)	2660  (MatWeb - The Online Materials Information Resource, n.d.)
Tensile Strength (MPa)	25.1  (MatWeb - The Online Materials Information Resource, n.d.)	7-25
Flexural Modulus/  Modulus of Rupture   (MPa)	1210  (MatWeb - The Online Materials Information Resource, n.d.)	9-37.9  (MatWeb - The Online Materials Information Resource, n.d.)
Hardness (Shore D)	58  (MatWeb - The Online Materials Information Resource, n.d.)	85-100  (MatWeb - The Online Materials Information Resource, n.d.)
Melting point/index (˚C)	>135  (MatWeb - The Online Materials Information Resource, n.d.)	1260  (MatWeb - The Online Materials Information Resource, n.d.)
Thermal Conductivity (W/m.K)	0.3 (average)  (MatWeb - The Online Materials Information Resource, n.d.)	1.20-4.20  (MatWeb - The Online Materials Information Resource, n.d.)

 

From the above material properties,  

• Recycled HDPE is more lightweight than Granite as seen by its lower density. This is advantageous as a countertop as it would be easy to maintain.  

 

• Recycled HDPE and Granite both have similar strength as their Tensile Strength are relatively similar thus in terms of wear and tear or endurance of heavy utensils or weights on a table as a countertop, both would be similar. 

 

• Recycled HDPE has a higher flexibility index than Granite as its Flexural Modulus (which is a property comparable to the Modulus of Rupture i.e., how much can the material stretch till it ruptures) as it can endure 1210MPa till it ruptures while Granite can endure 37.9MPa till it ruptures. This is advantageous for a countertop if it were to be made of Recycled HDPE as many weights/ utensils are usually kept on a countertop moreover people tend to hold or put their weight on the countertop therefore, under all these situations, pressure is applied, and the material would expand or stretch at a molecular level over time. Therefore, the larger the amount of pressure the material can endure before rupturing, the safer and more long-lasting (durable) the countertop would be i.e. in this case a countertop made of Recycled HDPE. 

 

• The melting point of Granite 1260 °C is larger than that of Recycled HDPE >135 °C as typically plastics have lower melting points although with recycled HDPE having a slightly larger melting point than regular plastics. This means that a countertop made of Granite would be more thermal resistant than recycled HDPE countertop. This is disadvantageous for a countertop made of recycled HDPE because typically hot utensils or pots would be kept on a countertop during times when people have meals and under that situation, a countertop made of Granite would be more thermal resistant.  

 

• The Thermal conductivity of Recycled HDPE (0.3W/m.K) is lower than Granite (1.20-4.20W/m.K). This means that Recycled HDPE would conduct lesser heat than Granite and provide better insulation to heat than Granite. Thus, a countertop made from Recycled HDPE would be safer because typically on a countertop hot utensils/ pots would be kept when having meals thus if the countertop has a high thermal conductivity, people sitting around the countertop resting their hands or body parts on the countertop would feel the heat and would be burnt. Therefore, a countertop made from Recycled HDPE is safer. 

 

 

In Conclusion, Recycled HDPE can be used as a replacement to Granite countertops as it is more durable (long-lasting) thus the money spent is worthwhile, attractive (marble-like look), Safer (low-thermal conductivity, comparative tensile strength, higher flexibility index) although the trade-off being, Granite is more thermal resistant than Recycled HDPE. However, as this countertop wouldn't be near the stove or cooking area, the temperature of items kept on this counter-top typically wouldn’t exceed the melting point of recycled HDPE. 

 

References: 

1. CounterTop Guides. 2021. Eco Friendly Countertops | CounterTop Guides. [online] Available at: <https://countertopguides.com/materials/eco-friendly-countertops.html> [Accessed 20 May 2021]. 

2. The Spruce. 2020. Pros and Cons of Granite Countertops. [online] Available at: <https://www.thespruce.com/cost-of-granite-countertops-1822205> [Accessed 20 May 2021]. 

3. http://www.matweb.com/search/DataSheet.aspx?MatGUID=3d4056a86e79481cb6a80c89caae1d90> [Accessed 20 May 2021]. 

For the second part of the task, we discussed how this material can be used to enhance the functionality of an existing product through some changes in the design as follows: 

This material : Recycled Polyethylene, can enhance the functionality of existing phone cover by merging this material with the material used to make a phone cover to enhance the aesthetic of a phone cover by making its appearance more attractive with the availability of vibrant colours which then also gives the phone cover a longer life span as the user would not have to change it too often for a new design which reduces the use of other material.  

💥What we learnt as a whole

Through the lesson that Dr. Noel went through, we started to understand how the choice of materials affects the product's design and thus the user’s experience. We realised that in order to create a newer and modified product that will be very useful, convenient and favourable to consumers, both parameters must be coordinated well together and optimized and that in the process of modifying the product it might provide new features as well. We concluded this from the hairdryer example above.

We also learnt that scientists are rapidly discovering and developing, new materials in today’s world either "accidentally" or intentionally. These materials are deemed as "exotic" as most of them are very new or are unheard of to the public, for example biomimicry materials as we learnt in our Year 1 module, Materials for Design. The activity we did after Dr Noel’s lesson, enhanced our understanding of the direct impact materials have to the design of a product even further as we came across many examples that showed improvements to a product due to the change of material used. Therefore, from this lesson, the group concluded that the big idea of how materials affect the design of a product, can possibly enhance the functionality, convenience and user friendliness of our current products to another level making products more favourable to consumers