Print this simple mold in TPU filament, and use it to cast cute, bunny-shaped bars of soap! I used a spool of Polymaker's PolyFlex™ TPU95 that I had won in the 10,000 members giveaway in the Prusa3D Discord server (non-Prusa affiliated).
This model is designed to minimize stringing, so please avoid crossing perimeters or apply an equivalent setting depending on your slicer of choice.
Acquire soap bars with minimal additives and chop them into small pieces. I used 1.5 3.75 oz (106 g) bars per casting. Add to a Pyrex or other microwave-safe container and heat in the microwave for around two minutes. Stir quickly and return it to the microwave for stints of 30 seconds, stirring after each heating cycle. Once reasonably molten, you may introduce additives such as skin-safe pigments, scented oils, and exfoliants like oatmeal or sugar. Stir well and heat once more for a good pour.
Pour carefully to avoid splatter — best done near a kitchen sink. You may need to remelt the soap to complete the pour. Pat it down smooth and flat with parchment paper to reduce air pockets and provide a smooth back. Allow it to cool entirely before demolding. You may choose to place it in a refrigerator or freezer to speed up this process.
Molten soap is hot and can burn you if left on your skin for longer than a few seconds; I recorded around 140 F (60 C). If you have worked with hot glue, the same strategy can be applied to removing molten soap from your skin: rub it off quickly and apply cold water. You may have concerns regarding the glass transition temperature of TPU. I am unsure what the Tg of PolyFlex is, but I had no issues. According to some sources, the Tg of TPU is typically around 60 C, but the molten soap cools quickly, so this is unlikely to be a source of concern. If you experience issues with your TPU molds deforming or melting due to heat, please let the community know what filament you used in the comments.
The author marked this model as their own original creation.