In terms of environmentally friendliness and cost reduction: did somebody already thought about (real) modular construction of the machines?
e.g. powersource: maybe it is possible to use a power transmission unit / line shaft with belts to empower all machines with one motor / powersource (shredder / extruder). In this case its also more easy to use renewable energy like water / wind / human or animal power.
e.g. heating units / controller: if you look at the extrusion and injection machine you ll recognize that they use very similar components. An excellent construction will consider both uses with one unit (as long there´s no need to run both machines at the same time). Moreover a solution for unplugged heating and controlling would be quite interesting.