bardal wrote:- 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