airhead, thanks for your interest in the Norge. To anwer your question, "is kapok better than other flotation materials," we will need to take a look at what 'better' could mean in a PFD...
-Kapok jackets conform "better" than foam as they are built from organic plant fibers (inside a bladder) that can fill the nooks and crannies of your torso.
-Kapok comes from the fruit of the cieba Pentandra tree. It is "better" than producing foam because it gives off no harmful emissions from production (except for burning petroleum during transport) unlike PVC foam which is extremely toxic to produce.
-Foam has a shorter lifespan than Kapok because over time plasicizers and pthalates leach out, making it loose its flotation charachteristics. This is not the case with Kapok and it never looses flotation making it "better"
I hope this helps to answer some of your questions reguarding Kapok. Feel free to check out this blog post on kapok for more Q&A Astral Currently » Blog Archive » Organic Kapok: A Discussion with Astral’s Founder Philip Curry
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