Manufacturing and Design Capstone : The PureSet

In my Manufacturing & Design Capstone, my team's carbon-based filtering and storage set, the PureSet, was created to elongate the life of used cooking oil. We saw that many home cooks struggle to conveniently and effectively store used cooking oil leading to messy kitchens and the disposal of good cooking oil - signaling a great opportunity for our human-centered design process.

Through interviews, benchmark and mockup testing, and optimizing our design for manufacturing, we created a product that simplifies the process of reusing cooking oil. The PureSet is a family of products consisting of the PurePress and the PureStore. The PurePress is an attachable funnel that includes a replaceable carbon filter to improve the clarity and odor of the used cooking oil and a plunger to increase filtering speed. The PureStore is a container that the PurePress fits into, and is vacuum-sealed to prevent further degradation of oil.

This project was split up into 3 quarters, starting from need-finding, and ending in a prototype that is ready for production.

Quarter 1:

As a team, we spent the first quarter of the capstone sequence discovering and identifying a problem area and defining a specific whitespace.  Starting with brainstorming 100 ideas, through group discussions, user interviews, and research, we created a screening matrix with 7 criteria that helped us narrow down our problem space to innovating the disposal of used cooking oil (UCO). This included disposal of cooking oil in the restaurant space, as well as the home cook space.

We used the data from our user research to make a decision.

Through one of our user interviews with home cook Curtis, we realized the value of reusing oil and how even an experienced deep fryer can have trouble dealing with UCO, and decided to include it in our problem space moving forward. 

At the end of the quarter, we decided to further focus on UCO management in a home cook (HC) environment as opposed to a small-to-medium restaurant (SMR) environment because of testing, significance of the problem, and the fundamental need.

Quarter 2:

Having chosen the home cook UCO problem space as our focus, the second quarter of the capstone sequence consisted of exploring a number of different possible solutions through prototyping, testing, and evaluation.

We started by frying various foods to obtain used cooking oil. We fried oils of different fat content and also varied the type of batter used (smooth batter, or a panko breadcrumb batter). We tested the different oils obtained with three different quality indicators, a visually guided testing kit, free fatty acid strips, and a TPM % quality indicator. These tests showed us that oil that looks ready to dispose is actually still good to use, and prompted us to focus on a way to extend the life of cooking oil.

We conducted benchmarking testing on 7 best existing solutions and ranked them based on the 6 needs that we identified to be most important in a reusing product.

We used the data from our benchmark testing to start creating mockups that satisfies the needs that unmet from the current solutions. We focused on a solution that is easy to pour oil into, easy to clean, and filters small particles. Our first mockup was a french press adaptation, that used a coffee filter attached to the metal filter to push sediment to the bottom.

As we continued to iterate through our mockups, we realized through user interviews that even if the oil has no sediment, if the color is too dark, or if the oil has a strong scent, that the user will likely still dispose of it, even if it is good. Through research and testing, we found that activated carbon has clarifying properties and incorporated it into our final prototype.

By the end of the quarter, we had a final design direction – the PureSet family of products.

Quarter 3:

With a final design direction, the third and final quarter of the capstone sequence was dedicated to realizing our final design direction as the PurePress and PureStore.

We iterated and optimized the design for manufacturing and assembly.

The funnel and the storage container will be made out of a deep drawn metal insert encased in a injection molded shell. This was done to prevent the transfer of heat to the surface of the product when hot oil is poured in.