Geoprene – Neoprene Made Out Of Limestone

A few years back some of the companies have started to use another kind of “neoprene” in their wetsuits. It was discovered and developed by a Japan neoprene manufacturer Yamamoto and it is basically not made out of oil as normal neoprene but out of limestone. So they have called it GEOprene.

There has been quite some talk about this new geoprene but not a lot of wetsuit companies had adapted it and started using it in their wetsuits. As fas as I know geoprene is only used by Matuse, Patagonia and West wetsuits. Some of them make wetsuits completely 100% out of geoprene and some use a combination of both materials. The reason why the new material hasn’t become more popular is probably the higher price. And also the fact that people mostly like things the way they are. Remember Clark Foam? All the “new” surfboard manufacturing technologies were available long long time ago, long before Clark Foam closed down. But it took a kick in the behind like the Clark Foam shutdown to force the shapers to look for other materials and technologies.

Anyway – what’s the deal with geoprene?

Why would you want to use it instead of regular oil based neoprene in the first place?

1. It’s more impermeable

Limestone Geoprene is 98% water impermeable and petroleum-based neoprene is 65% water impermeable. This is a huge difference.

2. Absorbs much less water

Geoprene suits don’t absorb as much water as normal wetsuits. Actually they hardly absorb any. You notice this when you come out of the water your your wet geoprene wetsuit is much lighter than a normal wetsuit would be. So you are sitting in the water with much drier neoprene on you and that also means geoprene wetsuits dry quicker.

Why Is Geoprene Better?

The main difference is the independent closed microcell structure of geoprene. What? As you can read in our wetsuit guide – neoprene is full of small bubbles (microcells) filled with air or even better Nitrogen gas. These are the basic insulation units of neoprene. Now in standard suits lots of these bubble cells are connected with one another and if some of them broke, if their wall is broken, the insulation of the neoprene is reduced.

But in geoprene every cell is perfectly independent. Every cell for herself. If for instance your the material gets scratched – new closed cells will be exposed to the water and will still keep it out and still have the same insulation capabilities.

The results of this difference are the two before mentioned benefits of geoprene – it’s more impermeable and is absorbs much less water. Also – all geoprene bubbles are filled with Nitrogen gas which is even better insulator than air. Practical consequence of this is a warmer, lighter and just as flexible wetsuit. Because of these properties geoprene’s technology allows you to wear a thinner wetsuit than you normally would and still be warm.

Matuse is one of the companies that use geoprene in their wetsuits.

Geoprene Flexibility

As found on Matuse website: “Geoprene’s maximum elongation is 480-530%. The human skin’s greatest elongation—found in the armpit—is only 60-70%. Even better, Geoprene never gets stretch marks.”

Oil vs. Limestone And The Nature Friendly Argument

Geoprene has been also touted to be a more green and eco friendly version of the material. But as it is today often the case, thing are not that simple. Ecological impact of a certain product is not only the product itself, but also the long process in which this product was made. All the raw materials, all the transport, all the energy that goes into production etc… Like for instance – solar panels are green technology right? They just soak up the sun and give electricity. But the production process of making them is as dirty and messy as it can be. Or electric cars and their batteries, same story.

So thing are not that simple. A few facts:

– geoprene is derived from limestone, limestone reserves on Earth will last approximately 3,000 years

– neoprene is made out of oil, opinions on how big are Earth oil reserves change all the time but no one thinks that oil will last even remotely close to 3,000 years. So reducing our oil dependency is good.

– limestone also has to be mined, transported, crushed and then fed into a furnace and heated to extremely high temperatures (over 3600o F) which is about twice as much heat as is regular neoprene production. This means lots of energy is needed for its production.

– oil spill vs. limestone spill, no comparison here

– also, the chemical polymers that are the result of the neoprene/geoprene manufacturing process are Chloroprenes. They are chemically the same no matter if they are derived from either petroleum or limestone. The differences in the end material come from different manufacturing processes.

As far as I can see three things speak in favor of geoprene:

– reduces our oil dependency

– if it is warmer less of it can be used in a wetsuit (thinner wet for same warmth) which means less of it ends back in nature when our wetsuit goes to waste

– better durability, if geoprene wetsuits last longer then less of them end in our landfills and again less impact on the environment.

Limestone?

Yep, that’s limestone.

But Is Geoprene More Durable?

According to Matuse it is. Geoprene has “Spherical Carbon Black” application in addition to the “Regular Carbon Black”. This disperses all force loads: stretch, elongation, pressure and compression. Geoprene also has a “FE Polymer” which prevents self-curing and reduces aging (i.e. hardening) that affects inferior foam rubber compounds.

This is a lot of technology talk for a wetsuit but data like this and a surf shop owner that smoothly presented it to me convinced me to get a Matuse Tumo 5/3 front zip wetsuit. And the next article will be a short first hand review of the “new” geoprene and Matuse wetsuits.

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