Week 11: Material for Design
The first though that entered my mind when we were doing this week Topic was " Didn't we already have an entire module that teaches us on Material for Design which was literally named Material for Design CP5091, which make me wonder if this week topic is meaningless. However, after going through this week topic, I have to say, it was not meaningless... Sure it wasn't insightful and nothing taught was new, but it helps by recapping on knowledge that I am no longer completely sure of, such as modulus of elasticity and stiffness. In Year 1 Semester 1, I would be confident when I say the higher the young modulus, the stiffer it is, but I no longer am confident when I provide the same answer.
There are 3 steps when selecting Material.
Step 1: Define Material requirement for design
Step 2: COWS
Step 3: Choose most economical material (or what I like to call choose cheapest material)
In step 1, we have to define requirement for the design. This is done by first defining the function of the design. In the case of a razor, the function of the blade is to trim hair, while the function of the handle is to hold the blade and allow people to hold. Next, we need to determine the constraints. For example, a razor blade need to be corrosion resistant. (other examples can be find in the table below. Lastly, we need to know the objective of the design, which is the most important constraint, in the case of the razor blade, its most important attribute is to be hard.
| Razor | Body |
Function | Trim hair off body | Holds blade Acts as a handle
|
Constraint | Corrosion resistant to water (razor blade will come into contact with water) High Hardness (Prevent blade from deforming when used) Excellent Sharpness (Easy to remove hair) Non-toxic (does not bring harm user) Stiff (Prevent blade from breaking) | Light-weight (Easy to handle) Stiff (Prevent handle from breaking while shaving) |
Objective | Needs to be Hard | Needs to be light |
In Step 2, we will have to perform COWS analysis. COWS stand for
Criteria
Option
Weightage
Score
Below is the COWS analysis for a razor
Materials selected: Brass, Stainless Steel 304 , Carbon steel
Criteria |
Weightage | Options |
Brass | Stainless steel 304 | High-carbon steel |
Hardness (Rockwell B) | 35% | 69.3 Score:2 | 70 Score:2 | 95.7 Score:3 |
Corrosion-resistant | 10% | Good (B) Score:2 | Excellent (A) Score:3 | Poor (D) Score:1 |
Non-toxic | 25% | Non-toxic Score:3 | Non-toxic Score:3 | Non-toxic Score:3 |
Stiffness (Modulus of elasticity,) | 20% | 106 GPa Score:2 | 198 GPa Score:3 | 200 GPa Score:3 |
Cost | 10% | $625/ton Score:3 | $2000/ton Score:1 | $500/ton Score:2 |
Total | 100% | 235 | 245 | 270 |
Lastly, we need to choose the most economical material, However, as you can see, this step can be integrated to step 2 which my group did.
Overall, this week topic is good for recalling what we learnt in CP5091 MFD.
Week 12: Design for Material
If Material for design is choosing the most suitable material for a certain design, Design for Material would be creating a design for a material.
We started this topic by looking at the timeline of a hairdryer, from the first ever hairdryer created by Alexander-Ferdinand Godefroy that is immovable, to Handy Hannah which became portable, and finally the Hawkins Supreme which is made in plastic.
Next we went to the SP Library online material resource to find a material we like to perform Design for Material:
Name of material | Imago Frozen Fabric |
Chemical Name | Fabric encapsulated in PTEG Resin |
General Description | A sheet of material with interesting visual appearances |
General Properties | Lighter than glass High performance Subtle decoration Scratch resistance |
Opportunities | Exuberant graphics and glass like surfaces while being safer and lighter than glass |
Discuss among the group how this material can be used as a direct replacement to a material in an existing product without any significant changes in the design
Blinds/Partitions/Privacy Windows. Imago frozen fabric can be used to replace the wood or any material to make blinds or partitions. This is because it is lighter than glass, scratch resistant and has a subtle decoration for aesthetics. It is also recyclable. |
Discuss among the group how this material can be used to enhance the functionality of an existing product through some changes in the design.
Imago Frozen fabric can be used to replace glass bowls and bottles. Glass is not scratch resistant while imago frozen fabric is. It is also lighter than glass which makes bowls and bottles easier to hold. Due to it being inconsistent in impact strength, we decided to add handles onto the bowl and bottle thus it is less easy to drop. |
Week 12: Sustainable Design
If I were to describe sustainable design, it would be pretending to care about the earth just because everyone is doing so and saying it is the right thing to do, in order for human to feel righteous even though it is human who created this issue in the first place. This topic have been gone through so much time that I doubt I need to further explain on it . tl;dr Changing the design so its more environmental friendly, such example include using rechargeable battery instead of disposable ones.
The following is my groups Sustainable Design Activity
Discuss and document the modification in design or substituting of certain parts of the product or any other ideas that your team has made. You may include pictures and sketches to aid in the explanation
Product Design: Coffee Maker Using solar panels to power the coffee maker instead of using batteries. However, using solar panels will be extremely costly and it will not fit our budget. It is also difficult to mount the solar panel onto the coffee maker.
Using rechargeable batteries instead of disposable ones. This way, less waste is produced and one can simply recharge the batteries instead of disposing them away after they run out.
Using second hand materials to build the coffee maker. Lesser waste is produced and materials that cannot be recycled can be used for a longer period of time thus being more sustainable.
Using glass to make the exterior of the coffee maker can make it more aesthetically pleasing, however, it can make the coffee maker much heavier and it can cause the heated water in the coffee maker to lose heat easily as glass is not a good insulator of heat.
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