Setting the scene
During the summer break prior to undertaking my final year of study I noticed a rising environmental concern with disposable coffee cups. Being an avid coffee and tea drinker (sometimes frequenting coffee shops multiple times a day!) I felt that this was something which I was contributing to and had the desire to try to understand and tackle the issue.
Initial thoughts
At the beginning of my major project, I felt that there were two main areas which I wanted to investigate:
• What makes the disposable coffee cup so damaging to the environment.
• Existing alternatives (including whether they are in circulation, and why they may not be as widely adopted).
I also wanted to undertake first hand research through watching consumers purchasing beverages from coffee shops. I felt that this could highlight areas where I needed to widen my understanding of the subject matter.
This would begin my research.
Research
The research began with a trip to the nearest Costa coffee chain to purchase a coffee. I then dissected the cup to assess the construction methods and materials used.
Traditional disposable coffee cups use layers of card with a cavity between to insulate the drink, keeping the liquid warm whilst preventing the user from being burnt. The card is glued together to hold the coffee cup shape and is waterproofed through lining the inner of the cup with polyethylene.
This lining makes the coffee cup difficult to recycle. There are currently only 5 plants in the UK with the capability to separate the two materials. The lids are constructed by vacuum forming polystyrene. The lid is made from a single material and is therefore easy to process at recycling plants.
Findings
My research showed that alternatives to polyethylene lined disposable cups were available. However, wax coated and biodegradable alternatives have failed to be adopted. This is likely due to the increased cost per cup. Ultimately, this would raise the cost for the consumer.
At the time of writing this, discounts have been introduced to consumers who use reusable cups when purchasing their coffee. I have purchased and used a range of reusable cups to understand what the consumer experiences when taking advantage of this service.
A major issue with using a reusable cup becomes apparent when returning for multiple beverages. Each time the barista will be required to rinse the cup to remove residue from the previous drink, taking time away from producing beverages. This time adds up and ultimately reduces the number of customers which can be served, potentially reducing revenue for the coffee shop.
This act of asking the barista to rinse out their reusable cup was at times...awkward. I felt like I was inconveniencing the staff by adding yet another task for the baristas to undertake whilst working their shift. If unable to rinse out the cup at facilities before returning to the coffee shop, this encounter is inevitable. People suffering from anxiety could be potentially deterred from purchasing multiple drinks due to the experience.
The Decided Brief
Currently, coffee shop environments are geared towards the use of disposable coffee cups. Through creating an environment which encourages consumers who want to use reusable cups, the dependency on disposable cups should decrease.
The decided brief is: To create a reusable cup friendly environment.
A possible solution to remove the residue could be to offer a service to customers which allows them to rinse their used cups, this service would need to be automated to remove the need for the involvement of a barista.
The design would need to be intuitive so that customers wouldn’t struggle to use the service and require a barista to teach them the required operation, potentially lowering productivity for the coffee shop and creating a negative customer experience.
Image top left- Initial models. Exploring various possible alternatives to current disposable cups (most notably aluminium cans due their recycle-ability, and methods of insulating the can due to the transfer of heat). This also shows the early exploration into existing rinsing systems and reusable cups (flat-pack and cups with both a reusable and disposable element).
Image top right- Early rinsing/drying concept models. Playing with simple blocks of each module (rinsing and drying units) to explore possible combinations for a table top unit. Development begins on compact unit designed as an extension on the reusable cup (methods of securing the cup to the unit and wet/dry chambers are being defined).
Image bottom left- Development of a reusable cup to pair with the unit begins. Basic two part form is created and various cup profiles were considered (going as far as to produce a “crumpled” cup to channel the issues surrounding disposable cups, although this would cause issues with water flow and was ultimately scrapped. The first mock-up with working neo-pixel ring was produced, the mock up utilised a curved edge, so that only authorised cups could be used with the unit.
Image bottom right- Form studies. Trying to create a memorable form which would be recognisable as a standard unit within multiple coffee shops. Deciding where the split line would lay when the cup is placed onto the unit. Achieving the correct fillet for the base of the cup was also further developed at this stage, creating a stable base when in use but also a friendly inviting form when placed on the unit.
Image top left- Further rinsing system development. Mock-ups two and three were produced, again utilising a neo-pixel ring but beginning to take shape with cuts being added for an activation switch. Original cups were designed to fit the standard disposable lids, it was decided that sharing the same diameter lip would result in non-authorised cups being placed onto the rinsing unit.
The decision was taken to create a unique edge to the cup to address this problem. Different size cups were also considered at this stage (large and medium), but was decided that a large cup would allow for any size of beverage to be purchased.
Image top right- reusable cup development. Early reusable cup concepts used the standard 90 degree edge on the inside surface when transitioning to the wall. When used with my rinsing unit, this would likely result in the water not being able to efficiently rinse all surfaces.
Also, over time, stains were beginning to appear in the edges of my reusable cup (which I was using daily for research). This was addressed this through creating a single surface on the inside of the cup, this allowed for the water to glide across all surfaces with ease, but also addressed issues regarding the stained edge.
During development, the cup became heavily weighted towards the lower of the cup. Excess material was removed to create a cavity, this removed weight from the cup and potentially maintained the drinks temperature, as the base of the cup is where the most heat loss occurs when it is placed on a surface.
Image bottom left- Further reusable cup development. To manufacture the cup for commercial application, the structure cannot be moulded in a single piece. This led to the development of a two part construction. Because the cup is manufactured in two parts, it opened up possibilities to vary the material of the inside of the cup from the outside of the cup.
The inside was decided to be a HDPE injection mould, which would then be placed within an anodised aluminium outer. The aluminium was chosen due to its recycling properties, but also its lightweight nature. The entire cup could not be produced from aluminium because of the heat transfer.
Image bottom right- Development of the innards of the cleaning unit. Perforations were added to the rear to allow for water delivery/ejection and power. Due to the rinsing system ejecting water, a physical push button to activate the unit could potentially allow water inside and cause the machine to fail.
It was decided that a seamless surface would be required and research was conducted into capacitive touch. Gauges were produced to assess the optimal fit and position for the capacitive touch sensor.
Tests were also undertaken with fitting a centrifugal fan to potentially dry the cup post rinsing cycle, forcing the moisture out of the cup and into a wet chamber ready for ejection.
Image top left- Capacitive touch tests. Multiple unit bodies were created to find the optimum thickness for the capacitive touch sensor to activate. The recess on the front signalling the location of the activation sensor was also developed at this stage, finding a comfortable and noticeable form whist still allowing the capacitive touch to function.
Image top right- Unit upper. Multiple models were produced to create a tight fit between the unit and the cup. The shape needed a raised edge where the water would be released and a lower centre to direct the water back into the unit.
The raised edge has a full fillet, this is so that the cup self-located when the user places the cup onto the unit. The curved edge on the cup stops the cup from rotating whilst on the unit.
Image bottom left- successful neo-pixel ring test running off of an Arduino Nano. When triggered by the capacitive touch sensor located behind the recess on the front, the neo-pixel ring indicates that the rinsing cycle has begun by turning purple and rotating. When the cycle has finished, the ring turns to a solid green glow to signify to the user that the cup has been rinsed.
Rinsing Machine Proposal
The final solution was designed to create a reusable cup friendly environment, this was done through designing a rinsing machine.
The machine relieves the burden of rinsing cups from baristas and allows the consumer to undertake the task. This also removes the awkwardness associated with consumers asking baristas to rinse their cup when purchasing another beverage.
The machine itself is intuitive to use because it only has a single button for the user to interact with.
Due to the environment being inherently wet, the machine utilises capacitive touch to create a seamless surface, removing the possibility of water (or beverages) entering the casing of the machine.
Finally the machine glows two different colours; flashing red when the machine is rinsing the cup, and green to signal when the cup has been rinsed. This visually communicates the status of the rinsing machine to the consumer.
The light is created through the use of a neo-pixel ring located in the base of the machine.
Pre rinsing service...
Post rinsing service...
Re-usable Cup proposal
The machine has a specifically designed cup; the cups inner surface is domed, this is to aid in the rinsing process directing water flow, this also removes the possibility of staining through creating a single inner surface (unlike other re-usable cups, there is no inner edge).
The cup also features a curved cut to the lip, this is ensures that only the correct reusable cup can be used with the rinsing machine. This encourages a standardisation of reusable cups.