BLOG entry 5

Hello welcome back to another blog guys! Its a brand new term and I have many new finds that I want to share with y'all.

The term welcomed me with open arms to more interesting prototyping and product development strategies. First was Materials For Design (MFD) followed by Design For Materials (DFM). What weird lesson names right? These mirrored naming are co-related and are as interesting as they sound, so lets get right into it!

Material For Design🎨

Does this sound familiar?? 🤨

That's right! It was a module we had underwent in our year one of chemical engineering. After the introduction to chemical engineering we learnt from MFD many types of basic materials used in the chemical industry and I have to say it was a lot of fun even though it was not that relatable back then. But NOW it really make sense to me about the selections and properties of different materials.

The lesson on MFD had us put on our thinking caps🎩 back on and reviewed the crucial concepts on material choosing and their respective categories. There is a TON of different materials in the market available for use in our daily life. Some are well-known for their aesthetic and sustainability others are known for their durability and portability. Each one of the materials be it organic or synthetic as a purpose to serve when creating a product and so the selection process is extremely important❗❗

Materials chosen should basically be selected to satisfy and meet the functional requirement of the product, so product designers are these experts who are able not just able to optimise but also enhance the functions provided by the product with the materials used.

An example of daily use items are T-shirts. There are many materials made for different occasions and purpose but having a breathable, light and stretchable shirt first comes from which material is used. Metal would be heavy and un-stretchable and wood would be too hard hence synthetic materials like nylon comes into play. It is light allows airflow and is stretchable hence a good fit.

On the other hand, materials used in chemical plants are enlarged and the choice of material will be more crucial. In our group activity our teacher tasked us to select a specific type of material for a disposable potable water. 

My group logically listed a broad classification of requirement on our materials attribute.

Bottle body

Function	Contain drinks
Constraints	Non-reactive to food ingredients Corrosion resistances to slightly acidic and alkaline solutions Non-permeable to liquids
Objective	Low density (Lightweight) Cheap and affordable

Bottle cap

Function	Serves as an opening
Constraints	Non-reactive to food ingredients Corrosion resistances to mild acid and alkalis  Non-permeable to liquids Hard
Objective	Keep the drinks within the bottle (tight)

As it is a disposable bottle carrying liquid it should be easily accessible, lightweight and most importantly cheap to produce. I will not include the COWs matrix for bottle cap as it has the same principle. We are concerned with how our materials may be a treat to the environment by polluting, corroding or posing toxic effects, hence we found some materials that are low in harmfulness shown below.

A recap for COWs matrix. This matrix is to select and evaluate the material candidates that my team have put together, a research is conducted on all materials chosen and their properties, and present them in a COWS (Criteria, Options, Weightage, Score). In this table we rate the functionality of each material to the importance of each physical properties and score it 1-4. We then tabulate the total marks to see which materials is the best fit for our portable water bottle.

Material evaluation(bottle body)

		Options
Criteria	Weightage (%)	Polypropylene (PP)	Polybutylene adipate terephthalate (PBAT)	Polyethylene terephthalate (PET)	Polylactic acid (PLA)
High Young’s Modulus (GPa)	20	4.129 Score: 4 25 x 4 = 10%	0.54 Score: 1 25 x 1 = 25%	3.385 Score: 3 25 x 3 = 75%	3.28 Score: 3 25 x 3 = 75%
Low thermal conductivity (W/m-K)	15	0.2 Score: 3 15 x 3 = 45%	0.2445 Score: 3 15 x 3 = 45%	0.24 Score: 3 15 x 3 = 45%	0.101 Score:2 15 x 2 = 30%
High elongation at break (%0	15	296.5 Score: 4 15 x 4 = 60%	100 Score: 2 15 x 2 = 30%	302 Score: 4 15 x 4 = 60%	57.5 Score: 1 15 x 1 = 15%
Low density (g/cc)	20	1.64  Score: 1 20 x 1 = 20%	1.41 Score: 2 20 x 2 = 40%	1.15 Score: 4 20 x 4 = 80%	1.1 Score: 4 20 x 4 = 80%
Low water absorbability (%)	25	0.5 Score: 3 25 x 3 = 75	0.300 Score: 4 25 x 4 = 100	0.425 Score: 3 25 x 3 = 75	1.03 Score: 1 25 x 1 = 25
Total	100	280	235	320	210

In a 🌰 shell this COWs matrix we could deduce that Polyethylene terephthalate (PET) is the most suitable material for this use.

Bottle body

• The Young’s Modulus is given a rating of about 20% so that it retains its shape well under high stress. A high Young’s Modulus is desirable as the bottle will be stiffer and more resistant to elastic deformation
• The bottle should also have Low thermal conductivity so that it restricts heat transfer from liquid content or user’s hands.
• The bottle should also not be too brittle as it is subjected to squishes by user’s hand hence the material should be brittle.
• Being ‘portable’ the bottle should be made light which means low in density.
• With low water absorbability the water does not penetrate through the bottle and this is very important as you would not want your bottle to be dripping everywhere.

Bottle cap

• Bottle cap to be stiff and resistant to deformation
• Non-reactive to keep liquid in bottle safe as well as user
• Best to be biodegradable to support sustainability for our world
• Low water absorbability or keep water in and out

Cost Evaluation💰

Cost effective material are preferred over costly materials as they are easier to obtain. With this simple idea we also made a COWs matrix to find out which material is the most cost effective especially to produce tons of these disposable bottles and (PET) has been chosen once again.

Final decision🧠

Based on both the material evaluation table and cost evaluation table, the selected material for the bottle cap is Polyethylene terephthalate (PET).

Despite (PET) having a moderate Young’s modulus, the thermal conductivity, density, water absorbability, Low biodegradability, its high elongation at break, Low cost and consistent moderateness of most material properties makes up for it. There is is deemed as the most suitable material for this product.

Practical🙌

On week 13 we had an interesting hands-on practical🙌. It was about material property that we learnt and now we can visualize them in real life! 

There were 4 material property we investigated:

• Thermal conductivity of a material
• Surface tension of a liquid
• Young's modulus of a material
• Viscosity of a liquid

Basically, these are material properties we recapped on in class. 

1. Thermal conductivity (k) is the ability substance's ability to transfer heat energy through a material. Measured in W/m.K. 

2. Surface tension (Y) is measure in force per unit length. It is a phenomenon where liquid in contact with gas acts as a thin elastic sheet. This is caused by an imbalance of inter-molecular attraction forces or cohesive forces between molecules.

3. Young's modulus also known as elastic modulus or tensile modulus measures the linear elasticity of a solid material like a rod or wire. The elasticity of the material can be deduced by its ability to resist deformation. This can be measured with a formula stress/strain=young's modulus.

4.Viscosity of a liquid describes the resistance for the fluid to flow.

My team was tasked to investigate the theory of heat transfer. We had to find the thermal conductivity of the material holding the ice in this case it is a glass beaker.

My group's hypothesis was that as thermal conductivity increase, the heat transfer will rise.

Our experiment starts as we fill the Atmospheric steam generator with tap water and wait until there is a steady state flow of steam. This can be observed when there is constant dripping to the steam beaker on the most left picture below. 

Next, we place our specimen containing a 20gram ice on the metal tray and started the timer. As we presumed, the ice took a loooooong time to melt as the glass beaker was more of a heat insulator. The middle and right picture below depicts the slow flowrate of the melted ice.

After repeating this experiment twice we were out of time and went ahead with the calculations with our average values and the equation Q=-kA(ΔT/Δx) we found the rate of heat transfer and the k for glass beaker!

Rate of heat transfer= 333.5 x 20.01/1000 

                                   = 6.67KJ

6.67KJ = −kA (ΔT / Δx)

6.67KJ = -k(0.000935)[(0-24)/0.0022]

10.2k = 6.67

k = 1.529W/m.K

From our experiment we calculated that the 20g ice took approximately 25.5 minutes or 1530s to completely with the glass beaker. With the surface being 0.000925m2

Therefore, thermal conductivity of unknown material is 1.529W/m.K.

After the experiments each of the four groups presented their experiments and explain the importance of each physical properties and their usage.

All in all it was super fun hearing all the groups presentation on their little experiments and I definitely learnt many fun facts from the quiz provided.👍

Design For Material🎨

DFM in short is literally what it means. It involves the designing of material used for a specific product and a specific task. By using DFM we are able to modify and create a material with desired physical properties. 

There are a few ways this may be done. 

First when a material is needed, there will be research carried out.

Second desired properties of materials will be altered for each specific use.

Third with different attributes experts will find the purpose and make the best use of it.

Lastly, new materials may be found accidentally as the world of science is developing every single day through discovery.

Real life example👀

Ever wondered why was ceramic knifes suddenly created as a teenager? Me too when i was young most knifes are made with refined sharp blades made with metals of many composites, nowadays ceramic blades are more prevalent. The replacement for metal to ceramic on a blade has its reason rather then making it look pretty.

This table below shows the pros and cons of using ceramic instead of metal and it clearly explains why it is still not as popular despite its advantages.

Pros	cons
non porous ( mitigates bacteria multiplying)	brittle (easily chips or shatter)
very light weight
stays sharp for long time (x10 more then steel)
stains hardly

Hence by sacrificing the physical property (tensile strength) knifes may gain many useful advantages but the cons somehow still outweighs the pro due to safety issues.

With that my team was task to find out more on Non-woven Tyvek paper. The advantages, disadvantages and how it makes an impact in the world of materials.

Name of material	Non-Woven Tyvek® Paper
Chemical Name	Flashspun high-density polyethylene fibres (HDPE)
General Description	Made with polyethylene fibres, Tyvek® is a 100% synthetic material made from high-density spunbond polyethylene fibres. It is a virtually indestructible synthetic paper. It is durable and cannot be ripped apart by hand. This variety has been engineered to have ‘breathable’ qualities, i.e. it lets air and moisture through.
General Properties	Lightweight Breathable Durable Water resistant Puncture and tear resistant Superb UV protection capabilities Cheap Chemical resistant
Opportunities	Tyvek® has qualities of paper, film and fabric that are both appealing to touch and durable, making it ideal for high-end packaging and bookbinding applications.

 

After that our group discussed a good way on how we can use this material and I realise that it would be great to use for a map! As a Scout in my secondary education we have used maps countless time and after prolonged usage, the either get tattered and torn or just crumpled. Hence with this stronger material that easily withstand many folds as well as the elements of weather we picture that it would be a great material for map making!

With this we also did some research on how we can introduce and enhance simple items functionality in our daily lives. We realise that with such a good chemical resistance rating as well as being light weight perfectly helps in the making of coveralls for personal protection in chemical plants…

Sustainable design♻

Sustainable Design is the approach to creating products and services that have considered the environmental, social, and economic consequences from start to end.

Sustainable design seeks to reduce negative impacts on the environment. With the derivations of the 3Rs (reuse, reduce recycle) the basic objectives of sustainability are to reduce consumption of non-renewable resources, minimise waste, and create healthy, productive environments.
We jotted down some ideas on the research we did on sustainability. By using these principles below we believe it will help sustain the materials we use.

▪ Use non-toxic, sustainably produced, or recycled materials. 

▪ Use energy efficient processes. 

▪ Make product last longer. 

▪ Design for reuse and recycling. (e.g. easy to disassemble) 

▪ Consider product life cycle. 

▪ Shift from personal ownership to shared ownership. 

▪ Buy from nearby

Modification

The exterior of the device can be made with recycled plastic.

Plastic is chosen as it provides an aesthetically pleasing shine.

The interior of the device should be made with a chemically inert material as it is involved in the processing of food. Copper alloy can be chosen as it is antibacterial and durable. Parts made with them will not need to be replaced frequently as they will last longer.

Components of the device can be easily disassembled for ease of cleaning and recycling purposes. The components can be sold separately, so that when a component is broken, consumers can just purchase the damaged piece instead of the whole device again. This concept can also reduce waste and improve environmental sustainability.

With that I have concluded what i learnt from the confusing MFD and DFM and hope you found it educational and interesting. This will be the end of blog 5, however stay tuned for a surprise blog 4 coming on soon!