Question 1

I've never heard of PET being recycled into 3D printing filament. Why?

Accepted Answer

PET is different from other types of plastic, like ABS and PLA, which are commonly used in 3D printing. It has much different properties, and degrades rapidly compared to other types of plastic. Each cycle of heat and melting will degrade the PET, eventually making it unusable.
 
The PETBOT uses a new process to turn strands of PET into filament without melting it, meaning that our filament quality will remain high, wheras typical filament extruders will take plastic shreds, melt them, then shape them. This just isn't possible to do with PET.

Question 2

Is it tricky to print with PET?

Accepted Answer

Yeah, of course it can be tricky sometimes. There is no manual for printing with PET, and so it can take time to get it right. We have worked with PETBOT users and 3D printers from around the world to try and get our printing just right. Some settings that work for certain printers won't work with other printers.
 
So, yes, it does take time and practice, but it gets a lot easier once you get the hang of it.
 
That being said, if you don't know a whole bunch about 3D printing, it will be hard to make proper adjustments, so we do not recommend using the filament if you are a beginner or novice printer.

Question 3

How good is the filament quality?

Accepted Answer

It's good.
 
It is definitely not commercial-grade filament, but it is comparable. With a little help from our new friends from the University of Saskatchewan, we have determined that our filament that the average tolerance/deviation of our filament diameter is 0.016mm, which is even lower than most store-bought filaments.
 
Our filament diameter isn't perfect, though. It is about 1.711mm, when it should be more like 1.75mm. This isn't a problem for printing, though, you just have to make a couple adjustments to the flowrate and speed, and you'll be good to go!
 
The printed product is also comparable to store-bought filament. The tensile strength of our products were just a shade off of products printed with professionally-made filament.
 
[Weins, T., Ph.D., P.Eng. Tensile Testing of Recycled PET Filament (pp. 1–5). University of Saskatchewan.] - Special thanks to Dr. Weins for all the data and information!

Question 4

Why can't you just drop them off at SARCAN, or some other company that responsibly recycles plastic?"

Accepted Answer

We do love SARCAN; we've got nothing against companies that recycle responsibly. However, in order for plastic bottles to be commerically recycled, they need to travel hundreds or even thousands of kilometers. PET bottles are usually sent to factories that turn them into pellets, who then ship them off to manufacturers who will use those pellets. It's a long, energy-consuming process.
 
So, why not simplify community recycling, by turning them into new products, right here in our community? Almost all our filament will go straight to our schools, to fuel programs that will inspire and educate youth; the next generation of scientists, plastic recyclers, and more.

Question 5

How much does this cost? How long is the process?

Accepted Answer

Our bottles are collected from community members and garbage cleanups. We pay nothing to get these bottles.
 
You could get your bottle deposit refunded for $0.25, yes, but our method of recycling will get you a lot more money worth of filament.
 
Each 2L bottle will yield about 30g of filament, so it takes about 30-35 bottles to get a kilogram of filament. 35 bottles, would get you an $8.75 refund at SARCAN, or it could get you a kilo of filament. On average a kilo a filament will cost you about $25. So, the "cost" of our filament is less than 35% of commerically made filament.
 
The process takes about 17 minutes from start to finish. Cleaning the bottle is simple with the right cleaning supplies, and so it usually takes 2 of those 17 minutes. Nearly all of the processing time is hands-off, meaning that we just have to let the machine do what it does, most of the time!

Question 6

Why not just help reduce the amount of plastic being used?

Accepted Answer

We absolutely are trying to reduce plastic use. We personally stay away from them, and try encourage others to do the same. This is why we are trying to shift away from bottle donations from commuinity members, and gear more towards collecting them through community cleanups.
 
This way, we will only be reducing the amount of littered plastic, instead of encouraging the use of plastic bottles by community members.
 
It all starts with you. We vote and decide with our money. If we try our best to reduce our footprint, we can make a difference.

Question 7

What happens to the printed products once you're done with them?

Accepted Answer

We are really trying to find a way to reuse our PET as much as possible. However, PET degrades extremely quickly. So it can only be used a certain amount of times before it becomes unusable.
 
Most of your PET is turned into polyester for use in clothing, etc. From there, it can't really be given another life, unfortunately.
 
The same goes with our products. They can't easily be recycled, due to the nature of PET, and it really does suck! Our filament produces high quality products and prints that can be used for decades.
 
It's also better to recycle our waste into new things that would normally be made of brand new plastic.

Frequently asked questions