Let’s rehabilitate industrial hemp!

[GuyGadebois]

- mechanical properties: hemp fiber, with equal cross-section, is 3 times less resistant than fiberglass (linen is better, 2 times less resistant); even taking into account the different density, hemp is 2 times less resistant than fiberglass. source CELC. <<< Maybe, but less energy to produce, lighter, biodegradable, not (or less) dangerous for the respiratory tract.

- durability: one of the constant concerns of navigators of this era was not to find their ropes and rotten sails after wintering, the slightest trace of humidity inducing an immediate attack by micro and macroorganisms, in short time (2 or 3 months ); <<< Immediate within 2 or 3 months ... Leave a folded nylon sail in a very humid environment, you will tell me news. I specify that we practice the sail and have an old rigging the fishermen, to fight against this scourge, "tanned" their sails and nets with products that were not necessarily ecological (copper sufates, tars, tannins, etc.); cotton sails (more expensive and reserved for yachting) rotted less, but molded, which is hardly better. It is above all thanks to a much superior durability that synthetic fibers very quickly established themselves in this field. <<< What infrastructure is needed to produce these synthetic fibers, what chemicals, what waste, what biodegradability?

- the "comfort" of natural fibers for clothing remains very relative; this is true for cotton, it is much less true for hemp (which left some bitter memories for young sailors)<<< This is no longer the case today, I have hemp clothes (jeans and shirt) as soft and comfortable as cotton.
There is no point in giving these natural fibers exceptional "little known" qualities, it is doing them a very disservice in the medium term. There are hardly any miracles on earth and the properties of the various fibers have been known, sometimes for a very long time; remember that the most resistant fiber that we know is of natural origin, it is spider silk (it is a protein); maybe we could start knitting ...<<< It's being tested, but the researchers are unable to reproduce this silk for the moment, it seems to me.

I did not speak only of fibers and quote me a single plant so versatile with so many properties: Textiles, paper, biomass, use in the building, composite fiber, bioplastic, medical, oil, proteins, etc ... And above all, knowing the ravages of cotton growing and the poor quality of BT cotton fibers, could we not eventually replace it with hemp which requires much less water, less fertilizer, enormously less pesticides and who as a bonus produces oil with interesting properties and proteins?
https://www.cermav.cnrs.fr/wp-content/u ... hanvre.pdf

[Bardal]

Hemp may have all kinds of useful uses…

But it is useless to adorn it with the magical qualities which it does not have; contrary to what is said in your first post (and in several following), hemp fiber is not more resistant than fiberglass, it is not immune to attack by microorganisms, it is not naturally soft to the touch; and the plant, to grow requires almost as much water as corn, needs fertilizers (nitrogen in particular) like all plants, and has no more biomass production per hectare…

I think it is useless, even harmful, to sanctify a plant (while one demonizes another) to promote it; a little measure and objectivity seem preferable to me, and much more effective. No plant, nor for that matter any material or any technology has all the virtues and is suitable for all uses; the choices are made by studying the best compromises according to the real need and the context.

[GuyGadebois]

Hemp may have all kinds of useful uses…

But it is useless to adorn it with the magical qualities which it does not have; Contrary to what is said in your first post (and in several following), hemp fiber is not more resistant than fiberglass << Where did you see that I wrote this? *, it is not immune to attack by microorganisms << I said it was rot-proof, which is confirmed everywhere https://www.google.com/search?client=fi ... utrescible., it is not naturally soft to the touch << It all depends on the carding; and the plant requires almost as much water to grow as corn << Source? I haven't read anything like that. ** , needs fertilizers (especially nitrogen) like all plants, and has no more biomass production per hectare…<< Source? It is the plant that produces the most fiber per hectare and one of the few that can be used at 100%

I think it is useless, even harmful, to sanctify a plant (while one demonizes another) << Isn't the disappearance of the Aral Sea evil? I still say that cotton is almost useless in these times of paradigm shift. to promote it; a little measure and objectivity seem preferable to me, and much more effective.

I did not miss any objectivity or measure. The demonization of industrial hemp proves how much this plant scared (and continues to do so) the most polluting chemical industries, DuPont in particular and William Hearst (for paper).

* I wrote:
"It can serve as an adjuvant in resin which can advantageously replace fiberglass."
Not that it was more solid. But its lightness makes it a major asset when solidity is not the main concern.
Hemp: 1480 Kg per cubic meter
Fiberglass: 2470 Kg per cubic meter.

** Hemp is drought tolerant thanks to its deep root system with a taproot and fasciculate root. Its water requirements are 20 to 40 mm / t DM.

[GuyGadebois]

https://books.google.fr/books?id=8c453l ... el&f=false