[aerohead]

I was given a tour at a local thermoplastics company decades ago.
Electric ovens heated pre-treated ABS which was attached to a framework.
When the plastic began to yield,it was rapidly moved over a vacuum table which held hollow,perforated wood tooling.
The frame was quick-clamped and full vacuum applied immediately until the ABS was fully seated on the tooling.
The frame was then de-clamped and lifted off the tooling,then ABS separated from it's frame,and sent to a router station where it was trimmed to final form.
The expense was in the oven,and tooling which was fabricated by a master tool-maker off site.
I did locate a manufacturer in the Dallas area who was willing to rent his facility for off-hours production.
Only limited -volume production would justify the costs.