Explanation:
The idea is to make a bottle out of ice. The bottle will be made in three steps. First, the inner mold is screwed into the outer mold. Water is poured into the gap between them. Then, after the water has frozen, the insert is removed. Then the bottom mold is filled with water and the ice bottle is placed into the bottom mold to make the bottom of the bottle. After the bottom has frozen, the whole bottle may be removed for filling. This project is a novel project as the idea was to have chilled water through the water holding vessel itself, instead of having to add ice cubes.
Preliminary Designs and Manufacturing Considerations:
The preliminary print of this design will be of PLA material as it is a common material and will provide us with the opportunity to judge how the mold fits together. Using the PLA print as a baseline for water tightness (we are expecting it to not be perfectly water tight, rather have many groves) and it is important to note that PLA is food safe. Going forward, using a food safe filament while minimizing leaks are top priorities. Some food safe filaments are PLA or PET and this requires us to consult Makerspace employees to see what FDA approved materials are available to us.
Another consideration with this design is how to make the mold water tight. Areas of focus in regards to water tightness are design of fill material and/or using a food safe sealant. A sealant, such as Polyurethane, could provide the mold with the water tight characteristic we are looking for while also remaining food safe. Additional manufacturing considerations will include how to minimize the print time by orienting the part optimally. The orientation of our print will also affect the placement of the material, affecting the water-tightness of the print.
Proposed First Print Trial:
Figures 1 and 2 below are images of the bottom and side views of our proposed first print design. We will be printing our first trial in three separate parts, an inner, outer, and bottom mold, which can be assembled later on.
Our proposed semester timeline:
- Week of 3/25/19: Print first trial in three parts
- Week of 4/1/19: Perform water-tightness and shatter-resistance tests on first trial print, making changes to our second trial print based on our findings
- April 5th: First project update due
- Week of 4/8/19: Implement changes suggested from TA and SA’s feedback
- Week of 4/15/19: Finalize our design, and print finalized design
- April 19th: Second project update due
- Week of 4/22/19: Perform tests on final print, write final report – due April 26th.
Figure 1. Image of bottom mold Figure 2. Side image of bottle mold.
We foresee a few interesting problems to work on improving in our subsequent design iterations. We anticipate learning from our testing that we will need to change the dimensions of the bottle to account for the amount the water expands upon freezing. Additionally, we will need to ensure our material is resistant to cracking due to water freezing in addition to being water tight when printed.
To address these potential issues, we plan on performing tests on our first print trial to identify the weak areas in our design and print setup.
- Water-tightness test — if using FFF, we might consider changing the orientation of printing
- Shatter-proof freezing test
Potential changes from testing: (second trial)
- Changing material
- Changing orientation
- Changing slicing settings
- Any attempts to reduce printing time & material reduction
- Redesign the mold for easier removal of ice
- Scale down the design to reduce print times