PrawnTech3D Lives Here!

( - responsible plastic)

A Manufacturing Hub

The next step would be to make the Collection Point into a Manufacture / Design Hub. Because what happens to that plastic we send out, is that a larger Hub turns it into useful products again and sells those to defray their costs. The nice thing about the Precious Plastic / One Army licensing is that everything is free to use, and you're welcome to make money with it. You're just not allowed to create a new thing, process, or machine with their technology and then not share it freely. So if you make a design for an injection-molded left handed retromangle for making orange juice back into oranges, you by the terms of the license NOT patent it exclusively and you have to make the design publicly available. But you can sell as many injection-molded left handed retromangles as you want, to cover the costs of your Hub and staffing. 

This is a logical step. The plastic is on its way around the consumption cycle again, it's (hopefully) cheaper than a factory injection-molded left handed retromangle and so you'd save tens of thousands of injection-molded left handed retromangles from being made with new virgin plastic and adding to the existing mountain of plastic, and it would cover the costs of buying, maintaining, and operating the machines. 

But what you'd need:

While all the machines that Precious Plastic and One Army have already designed and made available for free (under their license terms) are things that a reasonable fabrication shop could turn out, it's not easy. There need to be motors, electrics, and so forth. They need to be CE tick certified, but luckily if you build a machine exactly to the specifications, it's many times cheaper than buying such a machine commercially, complies with the CE tick standards, and will usually make products reliably for many years to come. 

In any case we'd need:

A shredder and a washer, no matter what we do. Because Australia's a wide brown land, distances between the various centres and Hubs are a bit much to just cart huge bales of complete plastic trash to the next point. It makes far more sense to turn a cubic metre of plastic trash into about a litre or two of shredded washed plastic for transporting. (Think: 25kg of loose plastics in bales on the tray of a 1/2 ton ute vs 25kg of shredded plastic in a couple of 15litre tubs in the boot of a car.)

Then we'd need:

So whether we sell our product to one of the other Hubs or process it ourselves to value-add, we need the above at a minimum, the collection points, the shredding machine, and hopefully a washing machine.

Additionally, there are only a few ways to make plastic into products:-

  1. You can spread it out on a plate press, heat it, and then press large sheets of new material out of it. These plates can become wall cladding or material for making other products out of. (Chairs, trays, artwork, toilet seats, etc.)
  2. You can extrude it out of a nozzle and make various cross-section extruded products out of it.
  3. You can 3D print it using a bulk feed 3D printer. (Small products only though as large scale 3D printing is problematic.)
  4. You can injection mold it using injection molding presses and dies. 

Of these, No 1. is the easiest in terms of know-how needed, but requires extremely powerful machinery compared to the others. Making things from sheet material is also easy, needing just basic workshop tools. No 2., extrusion into basic shapes and lengths, is a bit harder to get the mechanics of right, but the product, like sheets, is easy to work with, you can work both sheets and extruded beams as you would use wood. 

Injection molding (#4.) is rerlatively easy - once you have injection molds and some basic pressing equipment - and if you have more than one injection mold (aka "die") you can just cycle them through one after another, unmold the cooled items and return the die to the head of the queue to be re-filled, so you could in theory turn out hundreds of items a day, more if you have a die that produces multiple products at a time. It's fast, that's why manufacturers use injection molding. (But they have $200,000 machines where we try to make do with $200)

#3., 3D printing, is good for complex little parts that don't need a huge amoutn of strength, and is slow. A part that is injection-molded in under 4 minutes from end to end takes several hours to print layer by layer. There are some large scale 3D printers out there (one prints electric cargo bike bodies) but they're problematic and there are some quite difficult to solve problems with large printers. 

Additionally, using method #2., you can work your way down to extruding filament of 2.85mm or 1.75mm diameters in some plastics and use these to 3D print using existing machines, and there are some 3D printers that are set up for continuous production and so you can realise reasonable output with a small "printer farm" being fed by a plastic recycling operation. There are only a very few plastics that are usable for 3D printing as the consumer end of the market is currently, and one of them (PET) is difficult to work with on current PPV4 machines although hobbyists have for quite a while been hand-stripping PET bottle plastic and processing them in specialised filament extruding systems that are cobbled together out of 3D printer parts and arcane magic. This does seem to suggest though that if PreshPlast could make a machine that worked in parallel producing 6 or more filaments at a time with the same sort of small scale systems and minimal manual intervention needed, one could make a decent income selling filament to the 3D printing community as PETG (a version of PET with an added ingredient) sells for around $20 - $40 AUD a kilogram, and we could injection mold PP or HDPE spools and sell those plus "unspooled coils" of filament and that is eco friendly.

Additionally, if we made (say) 5mm or 8mm filament out of our base extruder we could perhaps work out a medium-format 3D printing process that could produce larger complex items at speed. And of course we could take a leaf out of the small-format 3D printing technology and set up continual feed print mills that could (for example) turn out cargo bike load compartments and cabinets for electric assist. (This becomes a bit more feasible if you check out my "Beyond just plastic" section.)