Why can't all plastic be recycled?

Some things I buy, but there is not a recycling # on it. I don't understand. Why is that?

A few years ago I noticed this on a Heinz ketchup bottle. When I checked into it, I was told it was because there were actually two layers of plastic and they were of different composition so it was not recyclable. Sure enough I cut the bottle up and it was two layers of plastic.

Julie Helms wrote:A few years ago I noticed this on a Heinz ketchup bottle. When I checked into it, I was told it was because there were actually two layers of plastic and they were of different composition so it was not recyclable. Sure enough I cut the bottle up and it was two layers of plastic.

Hmm strange!

Actually the recycling of plastic depends totally on its ingredient...
Only PET plastics can be recycled identified by the symbol or number.
Other plastic without number or symbol can't be recycled as they are contaminated by other polymer types mixed within while manufacturing it!

Wow, great knowledge. Seems absurd that they would not find a way to utilize a sole polymer type for each type of material contained. Such as one polymer type for soaps, one for edible liquids, one for cleaning agents etc

May be John, i am not having much idea about those polymers!!

Annah Isenberg wrote:Some things I buy, but there is not a recycling # on it. I don't understand. Why is that?

Not an expert by any means but I did take a plastics course in college and remember there being a difference between thermoplastics and thermoset plastics. I believe thermoplastics can be recycled because they don't undergo chemical changes when they are processed, whereas, thermoset plastics went through a process that changed them chemically. This could explain why some plastics can be melted and reused while others are one and done. Though one would think that a thermoset could be shredded and reused for something. I also remember reading someone in the Mycelium forum posting their experiments with composting plastics with mushrooms, seems like a far more energy efficient solution...


*Edit: Source

http://en.wikipedia.org/wiki/Plastic

BTW I heard Paul Stamet's is working on Oyster mushroom fungi that can break down plastic... wouldn't it be great to compost your plastic?

Because there are asshat chemical company engineers and representatives out there who figured it would be 'innovated' to create something the earth and it's organic process(es) couldn't destroy.
A true problem we have on our hands now. Just to answer your question.

ALL plastics can be recycled, and turned into diesel fuel.

http://www.youtube.com/watch?v=0SDS58y0hDY

Crafty people all over the place are building miniature refractory furnaces in their garage, using the same principles as shown in this video (but on a much smaller scale).

I found this forum posting, which they claim to be able to make diesel fuel for 17 cents per liter using electricity for heat, and maybe cheaper if they can build a liquid fuel heater.
http://www.energeticforum.com/renewable-energy/7040-how-turn-plastic-waste-into-diesel-fuel-cheaply.html

An Amazonian fungus could eat our most durable landfill waste. A group of students from Yale found the fungus during an expedition to Ecuador and learned it breaks down polyurethane.
The fungus called Pestalotiopsis microspora can subsist on a diet of polyurethane alone, and do so in an anaerobic environment, according to the researchers who found it. The Yale team isolated the enzyme that enables this fungus to do its work and noted it could be used for bioremediation.
http://www.popsci.com/science/article/2012-02/rainforest-fungus-eats-plastic-potentially-solving-landfill-problems


Plastic Bags in Landfill Samuel Mann via Flickr

Regards,
Monte Hines

Mark Edward wrote:ALL plastics can be recycled, and turned into diesel fuel.

http://www.youtube.com/watch?v=0SDS58y0hDY

Crafty people all over the place are building miniature refractory furnaces in their garage, using the same principles as shown in this video (but on a much smaller scale).

I found this forum posting, which they claim to be able to make diesel fuel for 17 cents per liter using electricity for heat, and maybe cheaper if they can build a liquid fuel heater.
http://www.energeticforum.com/renewable-energy/7040-how-turn-plastic-waste-into-diesel-fuel-cheaply.html

Holy crap that second link is awesome!!

I just read through about half of the 11 pages of that thread and I am amazed. Near 90-95% conversion rate between plastic and diesel fuel, in small batches on the cheap. Reading through it seems that you can use either thermoplastics or thermoset plastics for conversion, though thermoplastics seem to require an additional step. This seems like great news; plastic that normally "can't" be recycled is the easiest to make fuel from.

After thinking a little more on the subject I remember an analogy that my material science teacher used to describe plastics. He described the hydrocarbon chains, in a thermoplastic, as a plate of spaghetti, the noodles being the long chains able to slip and slide past each other, thus giving plastic it's flexibility. A thermoset would be if you took that plate and squished it really hard with heat and pressure, forcing the chains to bond together creating interesting shapes and reducing the chains ability to slip and slide past each other.

So flexible plastic - probably recyclable, probably a thermoplastic, can be repaired with plastic welder, can be made into fuel with one additional step.

Non-flexible plastic - Might not be recyclable, probably a thermoset (especially if it's resistant to heat), can't be repaired, easiest to make into fuel.

Monte Hines wrote: An Amazonian fungus could eat our most durable landfill waste. A group of students from Yale found the fungus during an expedition to Ecuador and learned it breaks down polyurethane.
The fungus called Pestalotiopsis microspora can subsist on a diet of polyurethane alone, and do so in an anaerobic environment, according to the researchers who found it. The Yale team isolated the enzyme that enables this fungus to do its work and noted it could be used for bioremediation.
http://www.popsci.com/science/article/2012-02/rainforest-fungus-eats-plastic-potentially-solving-landfill-problems


Plastic Bags in Landfill Samuel Mann via Flickr

Regards,
Monte Hines

I heard about this recently, too. How awesome!

was woundering kinda off the subject but how long does it take the average bottle to degrade i was wanting to use a bunch of bottles for siding and shingles i think that 2liter plastic bottles would do this good as soon as i can get a bunch for free