Plastic Brick Compressor
by Rehaan33 in Workshop > Metalworking
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Plastic Brick Compressor
Background
This is my IB HL Design Technology major project. It is a product that takes plastic waste and transforms it into bricks. This product was specifically designed for rural (developing areas) environments and as such, requires no electricity to operate. The production of plastic bricks in these communities can help to not only clean up their environment but also educate them on the plastic issue, provide sustainable building materials as well as promote social entrepreneurship in these areas.
This is, unfortunately, a very specialized project as requires access to quite a few resources as you might notice when you read through this Instructable. If you have any questions, please do not hesitate to ask them in the comments, and lastly, please vote for this instructable in the Plastics Contest if you enjoyed it!
Supplies
- 4x M5 Bolts
- 4x M5 Washers
- 4x M5 Hex Nuts
- M5 Tapping Screw
- Baking Paper
- Steel 12 mm Thick
- Steel 6 mm Thick
- Old Mortise Drill
The Base: Modified Mortise Drill
The product is built around the mechanism of an old mortise drill. I used a mortise drill as it already had the necessary rack and pinion mechanism. I stripped the drill of all electronics and redundant members as shown in the image on the right.
When proceeding with this part of the process, do not worry if you don't have the exact same type of drill. This is a very flexible project and the process of making should be able to be applied to a variety of drills and presses.
CAD: Designing the Machine
I first developed the product using CAD (Fusion 360 + TinkerCAD). The illustrations above represent my final chosen design based on the shape of the mortise drill.
Downloads
TinkerCAD Design
Modelled Wooden Parts
Before proceeding to the metal prototype, I needed to ensure that all dimensions were accurate and that all the parts fit together. To do this, I made a life-size wooden model where I used plywood to simulate the 10mm thick steel and MDF to simulate the 6mm thick steel. I also used a PVC pipe to model the steel cylinder.
Each part can be found in the images above. This is a very important step in the design process as we can finally see the product coming to life. Any crucial mistakes or errors can also be caught out before we proceed to the next step.
Manufactured Steel Parts
After sending the design specs to an external manufacturer, they were able to reproduce the necessary parts in steel (as displayed in the images above). A few factors to consider here:
- Steel is quite dense and as a result, this contraption is 30 Kg. Take caution when handling components.
- Steel expands when hot. This will allow the sides to expand in the oven ensuring a tight fit for a perfect brick shape. But once cooled, the sides will contract to enable the user to remove them with ease.
- Steel will rust if it is left damp. After use, remember to dry each component and spray WD-40 over each piece if possible.
*Safety considerations: Always wear gloves when handling the machine and watch out for sharp edges. Also, do not breathe in plastic fumes.
Securing the Modified Drill Press to the Base
The 10 mm thick base plate should have M11 sized threaded holes where the base of the drill is meant to be secured to the steel plate. This joint is secured using three M11 bolts as shown in the image above.
Tapping the M5 Threads
I used an M5 tapping screw to create threads in the holes on top of the compression plate. This allowed me to fit and secure M5 hex bolts through the holes for the next step.
Securing the Compression Plate
Once the threads were complete, I fit an M5 hex bolt through each hole and the corresponding holes on the Mortise drill base and seen above. I then added hex nuts to each bolt underneath the joint and securely tightened each bolt using a wrench.
Heating & Compressing the Brick
Now that the product is complete, it is time to test how effective it is.
- I started up the oven setting the temperature at 270 degrees celsius (very hot!) - proceed with care when loading and unloading the brick.
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I took an A4 sheet of baking paper and lined the mold with it so that the brick didn't come in contact with fixed steel sides.
- I used shredded High Impact Polystyrene for the test brick and poured it into the mold until it reached the 100 mm mark. I then folded the paper over the top so that the compression plate didn't come in direct contact with the plastic.
- I loaded the brick mold into the oven and kept it there for 15 minutes (until the plastic was easily compressible).
- I then removed the mold from the oven and place it back under the compression device and pressed the lever down in order to compress the brick. I held it in this position for 20-30 seconds.
Cooling & Removing the Brick
Once the brick was fully compressed, it was time to remove it from the mold:
- I started by placing the mold under a cold stream of water in order to reduce the temperature of the steel allowing it to contract.
- Once sufficiently cooled, I removed the side plates which then allowed me to remove the entire brick with ease thanks to the baking paper.
- I proceeded by scraping the wet baking paper off of the brick and I trimmed the sides in order to make the brick safer to handle.
And that was it! The final brick weighed about 1 Kg and ended being surprisingly sturdy.
Final Notes
While the product and end result was successful, it is important to remember that the design process is not finished, especially with this product. There are still opportunities to make it more self-sufficient and faster when it comes to making bricks. Other plastics should also be tested - however, never mix different plastics when using this product!
I hoped you enjoyed reading this Instructable!