Through the semester I have established the basic process and understanding around melting and machining the plastic.
I have been sorting and using HDPE and LDPE plastics to varying success. Due to some failed melts where a foreign plastic has found its way into the tile and not fused, I have come to the conclusion that, if the category is not clearly labeled or recognizable, I should leave it out of the batch as it ends up ruining melt which takes a fair bit of time and effort to prepare. There are way to melt the plastic with things like a burn test, however this would make the sorting process even more time consuming as I would have to test each piece individually, becoming even more unlikely when applied to the tiny shards and scraps that environmental plastic waste is found in.
Each plastic piece is hand cut with scissors. For the future I will have to invest time into fabricated a shredder as the time I spend hand cutting plastic would be more fruitfully spent in the melting process. There is currently a rigid plastic shredder available at the State Library in Brisbane, however because my plastic experimentation ventured toward using soft plastics, this type of shredder will be something to use in the future when I am branching out to different plastics. I have been given a contact of a person who open to allowing me access to a soft plastic shredder with a hot plate, I very interested in using this machine to see weather or not the hot plate could be added to my process.
The addition of lining the mould is essential as I have lost a few melts due to not being able to release it. Between 160 and 140 degrees Celcius has been the most successful range for heating the plastic, any higher and I have charred the plastic. The time limit is something I haven't been able to pin point, as each of my melt has been a different amount of plastic and I must add additional plastic throughout the melt. For each melt I have just checmk in avery 20 mins or so and adjust accordingly. For future, I hope to streamline this step by weighing out exact amounts of plastic and note down exact times and temperature so I will have an exact method for melting. I would also like a larger amount of plastic to produce bricks rather than tiles which will rely on sourcing more waste plastic and streamlining the shredding process.
After the I melt process I been sanding back the tiles to finish into a more uniform shape and also to reveal the patterns created. I have tried to make sure that I am collecting any dust or waste produced by sanding and cutting, which can go back in to use producing an interesting speckled texture. I have just begun reworking the tiles and mixing them together to produce different effects and experimenting with different surface finishes and this will be helped with addition of more tools to assist in the reworking of the material.
I have only touched on the texture and pattern ability of the material and wish to take this much further. However, I believe the resolution of this process is showing that this once obsolete waste material can be transformed into aesthetically pleasing forms reminiscent of natural materials.