Exploring Prototyping and Mass Production with Custom Soap Molds
In my introduction to 3D printing, I was intrigued by the ability to create a physical object out of a 3D digital design. I enjoy making soap so for my first 3D print, I envisioned creating an object that could be turned into a custom soap bar. I settled on designing a 3D print of an owl on a rectangular box.
When I was able to hold this object in my hand, it led me to a new problem to solve - how might I use 3D printing and mold-based production to mass-produce custom soap bars? This problem inevitably opened up a whole new phase of production and world of silicone mold making and plastics.
After several 3D prints, I saw that 3D printing is best as a prototyping tool to rapidly make things that are too complex, detailed, or unique for a person to make with other materials. Using 3D printing alongside silicone mold making is a strategy to take one unique object and replicate it many times.
This project was also an exploration of volume, which is not something that I’ve thought much about before. When thinking of volume it becomes much more important to consider material costs when filling space instead of simply thinking of length and width.
Reynolds Advanced Materials is a supplier of mold and plastics supplies, which conveniently has a store in Denver. At first glance, it looks like a costume-makers gallery but looking closely I could see the many applications for making complex products from durable plastics and materials. It was an “ah-ha” moment of seeing the next frontier beyond 3D printing a prototype object, which is the world of mold making and mass production.
The materials that I purchased for this project were (1) a paint-on material to smooth out and gloss the 3D print, (2) foam core for making the box, (3) three-boxes of silicone, (4) one box of liquid plastic, (5) and various mixing tools.
For the first step, I painted the 3D print with XTC-3D, which smooths out 3D print lines and provides a satisfying gloss. For mass production and replication, it is nice to remove 3D print lines and make things smooth. I did leave some 3D textures on the chest area to simulate feather textures.
I created a box out of foam core and Tuck Tape (excellent for epoxy and resin projects) and set my owl original inside. The silicone I used is a two-part mixture that takes 6 hours to cure into a rubbery and resilient shape.
In my next step, I aimed to replicate my original shape multiple times using liquid plastic, which is a two-part mixture that solidifies in the most fascinating way. After pouring, it takes moments until there is a chemical reaction, it clouds over with white and then solidifies in seven-minutes into a warm, hard plastic.
At this point, it began dawning on me how important volume was in terms of supplies. Simply, I didn’t have enough liquid plastic to continue to pour the entire owl and under-block it rested on, so I pivoted to just pouring the owl. This helped me to stretch my supplies and complete the necessary 10-shapes I was hoping to achieve.
To replicate the original, which includes a box under the owl-shape, I decided that I would build the box in one large shape. This would also get the owls closer together so the final silicone pour wasn’t so large. The mold was a perfect replica of my mass-produced replicas with just enough along the border to make the mold sturdy, but not over-built.
In my last step, I made a batch of honey-oatmeal soap with the scent of lemongrass and poured it into the mold. It takes several days for it to harden into a form that can be pulled out and cut, then six-weeks until the lye mellows out for it to be used.
Overall, this process was smooth and I pivoted when confronting the challenges of volume. The third dimension of space made me think about how to cut corners so I could stretch my supplies and budget. This process also illuminated the incredible world of plastics and how molds and replicas can lead to producing objects quickly.
Making soap bars is a fun hobby, but it is not what I envision for making a lucrative business. For lessons that I will take into the future, this project provided an amazing way to develop strategies for thinking about volume, cutting-corners, and materials for mass-producing the right products.
