Astral Buoyancy, makers of PFDs for kayakers, rafters and sailors, went seeking an environmentally benign alternative to the petrochemical foams, like PVC, commonly used in Personal Flotation Devices. They found the answer, as a guy called Bob once famously wrote, 'blowin' in the wind.'
More precisely they rediscovered Kapok, the wooly floss-like fibre that protects the seed of the Cieba pentandra tree. The fibre, eight times lighter than cotton, assists in the wind propelled propogation of the seed, which is normally only released about five years or so. What Astral also discovered was that this fibre has even more remarkable properties that saw it used for marine lifejackets, as late as the 60's.Five times more buoyant than cork
Cieba seed fibre is said to be five times more buoyancy than cork. It manages this through tiny tubes of cellulose, which have air sealed inside (see image below). This trapped air lends it an insulative quality, that once also saw it used as the filling in sleeping bags. According to some reports it can support up to 30 times its own weight in water, losing only 10% buoyancy over the period of month. Additionally it's non-allergic, non-toxic, rot-resistant and free of odour.
All these attributes impressed Philip Curry founder of Astral, but what also grabbed his attention was the ability of the kapok floss to contour to the wearer's form rather than being a stiff slab of foam. "Kapok is a fill material or stuffing allowing it to better fit the natural bends and curves of the body making for a much more comfortable platform than the PVC designs of years past. Kapok is inherently buoyant and will remain so even when it is wet. To maintain its shape for stuffing kapok fiber into the PFDs we have developed a special bladder that is resistant to cold, solvents, and salt."
No Comparison with PVC
Philip is quoted as saying there is really no comparison between the environmental footprint of PVC foams and kapok. "Basically, the only toxins released from using organic kapok are from gas emissions during transportation." Additionally he notes that they can use 100% of the kapok they order, whereas they used to waste about 20% of the PVC after cutting the foam to shape. So way less material waste, and no PVC headed for landfill. Or worse incineration, where it would generate poisonous toxins.
Astral Buoyancy use organic kapok fill inside the front panels of their Abba (sen above), Norge, Otter, LDB, and Grunion jackets. This goes to show that synthetic manmade materials are often inferior to what Mother Nature can produce. We took an old concept from the 50's and found that it was a better option that what was the norm in the 90's," says Phillip Curry.
::Astral Buoyancy, via web trawling.
Top Kapok fibre photo source: Greenfibres. Other pics from Astral website