DPR at CCXii
The first DPR session took place at CCXii in May 2024.
The DPR lab was setup in our tool shed which is in a shipping container and included a shredder, a press and a die.
After Jack assembled the missing electrical cable to power our 230v shredder from various electrical components we had on site, we were able to run the shredder successfully and pulverize most plastic items that we fed it.
We had designed and fabricated (with Simas's help) the die so it could be filled with our plastic shreds but we didn't take into account that it would require a lot more pressure and/or heat to successfully create the brick out of the compressed plastic shreds.
We had to find a way to extent the interface of the press, a metal cylinder about 2" diameter, so it could touch the top plate of the die that was pressed down to die to compress the content into a solid brick. We miscalculated that the rating of the press was for the surface of that cylinder which means that the pressure on the 3"x6" plate was much less than 20 tons per square inch.
After compressing the plastic shreds to the maximum of the press capacity we ended-up with a volume that did not hold its shape and broke apart as we tried to extract it from the die. We also slightly misaligned the setup which led to jamming the top plate into the die and bending one of the two support beams. It took many violent attempts to free it up.
Our next step is in 3 parts:
1. Make a smaller die, possibly a 2" diameter cylinder to cast a flat cylinder like a coin;
2. Heat-up the die to slightly melt the plastic;
3. Pre-sort plastics. We were trying to avoid this to keep the process as straightforward as possible but it is a relatively simple step that will allow us greater control over the first two steps.
