In the early days of plastics, cost was high and phenolic plastics were brittle. So there were many attempts to add some kind of cheap filler material. Sawdust, agricultural waste, etc. This sort of worked. Not too well. Adding a filler which absorbed water caused the material to bulge when wet. Not too good for auto body panels.
The real frontier in this area is finding uses for agricultural waste - stuff that's a byproduct of growing food. Rice hulls. (Sometimes used to make rice paper.) Corn cobs. Bagasse, the waste from extracting sugar from sugar cane. (Sometimes used to make oriented strand board.)
[1] https://en.wikipedia.org/wiki/Duroplast
There's an interesting passage in this Wikipedia article, regarding its limitations in industrial use:
> Because it can be made in a press similar to shaping steel, it is more suitable for volume car production than fiberglass. However, in comparison to shaping steel, duroplast needs much more time for hardening in the press. This was one of the reasons why it was not possible to scale-up production of Trabant to the volume that was demanded.
(I guess, the same may be true for other organic filler materials, e.g., hemp.)
Edit: While the German edition of Wikipedia doesn't mention the Trabant in the context of duroplast at all, the entry on the Trabant cites a curing time of about 20 hours.
Yeah, sure. If a material like that existed, no amount of anti-marijuana moral outrage would stop the industry from using it.
It is true that in the United States, hemp production was illegal for many years, limiting research and development into its use.
It is also true that in many countries, covering populations much larger than that of the United States, hemp production was never made illegal and continued unabated since prehistory. And it is true that in those countries entire industries, arms of research departments, and government agencies exist to study and promote the use of hemp.
This leads me to assert that there are two possible reasons why we aren't using hempsteel, hempcrete, and hemplastics:
1. It is not the miracle material that people claim it is and that's why hempsteel is not a thing, or
2. Americans are the only people on the entire planet smart enough and capable enough to productize it and the prohibition on its cultivation has stopped development.
It has never been illegal to import finished hemp products into the United States and even prior to the recent relaxations of prohibitions on hemp growing you could buy an endless variety of hemp goods online.
So I'm going to go with 1. I've met many non-americas and they seem no smarter or dumber than we are.
The article states that "big paper" lobbied to ban hemp because it might do... something? why wouldn't big paper switch to hemp if it was better? they farm trees like farmers farm corn they'd just switch to farming hemp instead of trees like farmers switch to more profitable crops.
And any renegade paper manufacturer could have switched to hemp by buying by the container shipload from China and making paper out of it, undercutting (because hemp is, apparently, cheaper and better) the Big-tree big-paper conspirators.
But you can buy hemp paper on Amazon today, right now. Hemp paper sucks. Like, really bad.
>because hemp is, apparently, cheaper and better
Economies of scale might make it more expensive right now, because we're all using cotton. It could be a local maximum.
Also paper production for classical paper has been optimized to great lengths, maybe you'd need similar efforts to get great paper out of hemp. This doesn't mean it's not possible or the material isn't better. Just that you first have to convince everybody to use it. Again this could be a local maximum we're in.
Just look at how much money we're spending on improving batteries for EVs now. We spent 150 years optimizing ICE vehicles. For EVs to get cheaper and better we need a lot of subsidies, from a lot of countries, for a few decades.
Kenaf paper works reasonably well.
Only India and China are more populous than USA and it's illegal in India despite being an import and useful ingredient of Indian medicine system.
I am not claiming hemp to be a miracle material. But covert lobbying, scheming to obliterate the superior alternatives does exist.
