Biodegradable Fibers As Strong As Steel Made From Wood Cellulose
Zothecula writes "A team of researchers working at Stockholm's KTH Royal Institute of Technology claim to have developed a way to make cellulose fibers stronger than steel on a strength-to-weight basis. In what is touted as a world first, the team from the institute's Wallenberg Wood Science Center claim that the new fiber could be used as a biodegradable replacement for many filament materials made today from imperishable substances such as fiberglass, plastic, and metal. And all this from a substance that requires only water, wood cellulose, and common table salt to create it. The full academic paper is available from Nature Communications."
Stronger than steel is cool and all, but that doesn't necessarily mean "all the same properties of steel". Durability, heat tolerance, reaction to moisture and a host of other things are likely to mean it's not a drop-in replacement for fibreglass/plastic/metal.
Just because you're paranoid doesn't mean there isn't an invisible demon about to eat your face
When was the last time someone made a bridge out of fibreglass?
http://www.scsolutions.com/fib...
http://www.ettechtonics.com/
Peace on earth is within our reach.
... and the wars, I take it, are in the asteroid belt?
Someone flopped a steamer in the gene pool.
Not sure that the use case is very compelling. Usually things made strong, say fiber reinforced plastic, are meant to be durable. Furthermore, if the cellulose fibers don't degrade uniformly, you would end up with very unpredictable failure modes.
"Consensus" in science is _always_ a political construct.
Carbon fibers are five times stronger than steel and about a third the weight, so in a head to head competition, no way.
Still, it could compete with (say) steel if it's easier to work, cheaper, and less polluting.
-WolfWithoutAClause
"Gravity is only a theory, not a fact!""Stronger than steel" or "stronger than x", by either absolute measure or ratio of strength to weight, doesn't mean shit. There are a million factors.
1) What kind of steel? Tensile yield strength (MPa) is all over the place:
ASTM A36 structural steel: 250
API 5L X65: 448
AISI 4130, water quenched 855C (1570F), 480C (900F) temper: 951
Aermet 340: 2160
2800 maraging steel: 2617
Micro-Melt 10 Tough Treated Tool Steel (AISI A11): 5171
Usually when someone says "stronger than steel" they mean stronger than crappy A36 or the like. If you're going to build a fabric-covered fuselage, you use the 4130. If you've got a building or bridge to erect, you use something closer to A36. For a cutting bit, tool steel. It is brittle as hell but harder than any steel you can use structurally; takes and keeps a wicket edge when ground.
2) Do you care about anything besides tensile yield strength? Just say yes. It matters. Such properties as the following:
Elastic modules
Compressive strength
Hardness
Toughness
Elongation
Endurance limit / fatigue properties
Resistance to corrosion and other degradation
Many of these properties play off against each other. Want hard or tough? Pick one. They are inversely related. Want something that is mechanically workable? It better have decent elongation, which limits achievable strength. On the other hand, piano wire doesn't need to be very workable at all. It has fantastic strength.
3) What safety factor will you require? Depends on a number of factors, and one of these factors is material chosen. Balsa needs a much higher safety factor than steel or aluminum alloy. Its mechanical properties are much more variable, and it tends to have imperfections.
These are just some of the factors that make the simplified table you reference horse shit. Bottom line, if you are building a bridge or airplane to highly optimized requirements, suitable steel or aluminum alloy is going to give you a lot less weight for the same safety-factored strength as balsa - completely aside from temperature/humidity limits, flammability, and liability to rot.