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If they can indeed depolymerize thermoset plastics. (Which are hard and brittle, thus useful when in composite with something strong in tension like carbon fiber), it would be an over all good.
This may make it so carbon fiber items could be repaired as the epoxy can be removed and reapplied. Being able to repair goods is much better for the environment than being able to recycle them.
There are two major complication to repair.
First, carbon fiber items are made in a mold. Repair doesn't have access to that mold, so you've got to build your own. You can get a good approximation from casting an adjacent part, or the opposite side - otherwise you have to improvise and sand it to match. Catastrophic failure, like when the bow is broken more than a few degrees, requires an alignment jig to keep the boat straight.
Second, carbon fiber works best when it's a laminate - e.g. a carbon/foam/carbon sandwich. So most designs are tubular or involve a stackup. This is tricky if the inside layer isn't accessible. Or a high-performance inner layer is used, like delicate honeycomb aluminum. Rebuilding something that was custom-made to tight tolerances is difficult.
I'd think that a degradable epoxy would be best for recycling applications; repair has a lot of other challenges.
This may make it so carbon fiber items could be repaired as the epoxy can be removed and reapplied. Being able to repair goods is much better for the environment than being able to recycle them.
how durable would this stuff be? good enough for wind mills?
This story isn't really about carbon fiber... it's about finding a way to recycle thermosetting plastics. Carbon fiber is just the click bait. If they can indeed depolymerize thermoset plastics. (Which are hard and brittle, thus useful when in composite with something strong in tension like carbon fiber), it would be an over all good.
But it enables a lot of the lightweight “green” things people can pat themselves on the back for, which is the majority of the point for many.
Better epoxies would help, but we’re quite a ways off.
I find the Epoxy substitute very interesting - I feel like there could be a lot of uses for an epoxy strong enough to work in Carbon Fiber applications but can be removed with a chemical process at room temperature. Re-enterable potting compound? Fixturing material for machining?
Cured polyester resin as used in fiberglass reinforced plastic is soluble at room temperature using solvents like MEK or Acetone...
FWIU flax and hemp are more sustainable and potential substitutes for carbon fiber, which is industrially hazardous to produce? The branching structure makes e.g. hemp bast fiber ideal for supercapacitor (~battery) anodes. How does this plant-based epoxy affect conductivity and resistivity in various materials in various outdoor conditions with and without a coating? If it's plant-based, is it safe next to plenum cab…
When I can order sheets of hemp fiber pre-preg and a recyclable epoxy I’ll get my company to use it same day.
Here I am holding my breathe, because I’m not sure what you heard but an organic fiber will never be as thin, strong, uniform as curated carbon thread that was produced specially for this purpose.
FWIU flax and hemp are more sustainable and potential substitutes for carbon fiber, which is industrially hazardous to produce? The branching structure makes e.g. hemp bast fiber ideal for supercapacitor (~battery) anodes. How does this plant-based epoxy affect conductivity and resistivity in various materials in various outdoor conditions with and without a coating? If it's plant-based, is it safe next to plenum cab…
Hemp: 150 c
Flax, saline treated: 153 c
Basalt: 1,500 c
Carbon: 3652 c
FWIU flax and hemp are more sustainable and potential substitutes for carbon fiber, which is industrially hazardous to produce? The branching structure makes e.g. hemp bast fiber ideal for supercapacitor (~battery) anodes. How does this plant-based epoxy affect conductivity and resistivity in various materials in various outdoor conditions with and without a coating? If it's plant-based, is it safe next to plenum cab…
> potential substitutes When I can order sheets of hemp fiber pre-preg and a recyclable epoxy I’ll get my company to use it same day. Here I am holding my breathe, because I’m not sure what you heard but an organic fiber will never be as thin, strong, uniform as curated carbon thread that was produced specially for this purpose.
Agreed, already lignin (wood sugar) can be turned directly into carbon fiber through an electrostatic process or a cryogenic process. If somebody wants carbon fiber to be cheaper, they should build equipment and make more.
This may make it so carbon fiber items could be repaired as the epoxy can be removed and reapplied. Being able to repair goods is much better for the environment than being able to recycle them.
I've done carbon fiber boat repair, and removal is pretty easy - lots of cutting and sanding. Applying a patch works pretty well - mechanical bonding to the roughed-up surface is pretty good, and even if the patch uses 2x the material of the original, it doesn't affect overall weight too much. There are two major complication to repair. First, carbon fiber items are made in a mold. Repair doesn't have access to that…
I imagine the repair process would be something like:
1. Place bike/boat in mold/alignment frame.
2. Dissolve core then epoxy.
3. Refill and cure core.
4. Reapply epoxy to carbon fiber.
5. Vacuum bag the bike/boat then cure epoxy.