Blog Entry #5

🏗️MFD vs. DFM 🏗️

Materials for Design (MFD):

    In week 13, we learnt about Materials for Design (MFD). So what is MFD? It's the process of selecting materials with properties that satisfy the functional requirements of a product. The steps for doing this are as follows:

1. Defining design material requirements.

• This involves identifying requirements that are pivotal in ensuring the product's functions can be achieved. For example, cookware such as pots are required to handle high temperatures for cooking 🍲. As such, to fulfill the functional requirement, the material requirement in this case would be high melting point.

2. Evaluate candidate materials using COWS Matrix 

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• Using the material requirements as criterias, COWS Matrix is then used to determine the most suitable material to be used for the product.

3. Further evaluation by choosing the most economic material.

• The candidate materials are then further evaluated using criterias that determine how economic 💸 they are (cost, etc.).

At the end of the lesson, in order to apply all this information, my group was tasked to select materials for a the inner layer and cover of a Thermoflask .

Following the steps, my group first identified the material requirements.

Step 1. List the material requirements for the inner layer
Function: To contain liquids and hot fluids 🔥.

Requirements:

• The material of the inner side of the thermoflask must be able to retain the heat of liquid that it is containing to keep it at the desired temperature (low thermal conductivity)
• The inner walls must have high melting point such that it will not melt when in contact with liquids
  (high melting point)
• Low density material so user can carry the Thermoflask easily
• The material must be corrosion resistant towards any acidic liquids
  (corrosion resistant)
• The material must have low reactivity with the liquids

Step 2. Select and Evaluate candidate materials using COWS Matrix 

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Based on the requirements, the materials that we shortlisted were as follows:

• 304 Stainless Steel
• Propylene
• Acrylonitrile Butadiene Styrene (ABS)

Thereafter, we performed COWS Matrix.

Step 3: Choose the most economical material.

Conclusion:

    Based on both the COWS Matrix that have been done, the material that we selected is propylene. This is because it has one of the highest scores based on the requirements and the second highest based on the economical requirements out of the three materials.

Design for Materials (DFM)

In Design for Material, it involves changing the design such that a specific material can be used instead. This can typically be done such that more sustainable materials are used.

Our group's way of doing this was to replace cotton in kneepads with microcellular polyurethane material.