Any additives to facilitate plastics recycling ?

Seems it is not simple to melt several kinds of refuse plastics to do something useful with it.

My point is as to transfer the recyclability from the expert industrials more towards the general public that collects the material.  If the public collecting the trash could produce something -like lumber, bricks- by melting/molding themselves instead of selling the material to distant experts doing such, a greater amount of plastics would find immediate uses as would be much sought-after, with an increased incentive to recycle and reuse.

So what additive or process could be used to facilitate raw melting/thermoforming ?   Chemists came up with great plastic materials; should come up now with a great incentive.