Recycle plastics

To recycle plastics..
Find the melting point that breaks them down at a chemical level. But just before it ignites (or melt it in the absence of oxygen) a vacuum maybe? A metal sealed thick metal pipe.

Heat it up with energy.free energy would be the sun. Mirrors that focus a large area onto the metal pipe. Or solar panels that charge batteries that power heating coils.

Then extrude the molten plastic into moulds of useful items. I.e. Bricks, plant pots, wall panels, chairs and table parts..

Could make a whole school out of it.

And now with 3D printing... Gosh.. The possibilities.