As per the article:
What plastic
polyethylene terephthalate (PET)
How scalable is it
They're working on increasing to industrial scale.
The description of their process sounds fairly exciting, in that it doesn't need a solvent, uses a cheap, non-toxic catalyst and produces PET precursors. If they manage to get it to industrial scale they'll go some way to solving the plastic problem.
It's not just the size, or the sound, but the fact you could comfortably concuss an elephant with it, or stop a bullet and go right back to typing. Those things were built like tanks.