What is limestone neoprene?
It might sound strange, however, it’s common practice these days for your high-end wetsuit to be made out of limestone rock. What is limestone neoprene, and how is this possible? The world is full of supprises, and yes we can turn rock into wetsuits. But it’s not that simple.
Let’s rewind to the 1930s when synthetic foamed rubber was invented and was called neoprene. At that time, wetsuits didn’t exist yet, especially not to be used for surfing. The first wetsuits were developed for army divers, so they could stay in cold water for longer. Neoprene is an elastomer with the chemical name polychloroprene. Polychloroprene is produced through a chemical process by binding strings of a clear liquid called chloroprene together. The original oldskool chloroprene wetsuits are made with petroleum-based chemicals, which are harmful to the environment. Consequently, neoprene has been reinvented over the years to our benefit.
Limestone neoprene wetsuits
What is limestone neoprene? And how is it different from oldskool petroleum-based CR chloroprene? In the 1960s, a new way of making neoprene was invented. The main neoprene compound remains chloroprene. However, instead of using dirty petroleum-based ingredients it now uses calcium carbonate from limestone. This ingredient is used to form chloroprene rubber chips. Thereafter, they are melted down in an oven and go through a chemical process. The melted substance is infused with air bubbles and baked into a block of neoprene foam. This block is then sliced into neoprene sheets. At this stage, the neoprene thickness is determined. It can vary between 0.5mm, all the way up to 7mm when used for surfing wetsuits.
Limestone neoprene characteristics
The quality of neoprene is determined by a few factors. Firstly, the elongation percentage. This measures the amount of flexibility in the neoprene. The higher the number, the more stretch the neoprene has. Therefore, the better it is. Secondly, the softness and weight are measured by calculating the density. the heavier the foam, the harder, this also affects the stretch. Softer and lighter foam is considered more high-end when used in surfing wetsuits. Thirdly the ozone and UV resistance. High resistance to ozone and UV rays results in more durable neoprene. This also means it is less easy to crack or get brittle. All these characteristics of limestone neoprene are more advanced than its predecessor petroleum-based neoprene. On top of that, it’s way less harmful to the environment. This makes limestone neoprene when used in the right grade, one of the most flexible and warm neoprene types out there.
The invention of limestone neoprene made a big impact on wetsuit manufacturing. It transformed the high-end wetsuit industry to become more durable and environmentally friendly. Some companies have different names for their more environmentally friendly neoprene. You might have heard of Japanese Yamamoto neoprene which is used in some wetsuit. Other versions of limestone neoprene are Bioprene and Geoprene wetsuits. Yulex is another alternative neoprene made out of natural rubber which unfortunately has limited availability. SRFACE has chosen to manufacture with limestone neoprene, which has the lowest carbon footprint in modern wetsuit production. It is processed from raw material to finished product by its manufacturing partner. The use of limestone neoprene is an effort to make wetsuits as green as possible.
Double lined neoprene
After limestone neoprene foam is sliced into sheets of the right thickness it’s laminated with a stretchy fabric layer. Lining can be applied on both sides of the wetsuit. As a result, making your wetsuit more durable. On top of that, it protects it against outside influences like UV and ozone. Outside lining also offers protection from fingernails cutting through the neoprene. The inside of your wetsuit is lined with flexible and soft lining. Therefore feels comfortable to wear on the skin. The main body panels of most high-end wetsuits are lined with a quick-dry plush lining. Resulting in an insulating layer between the body and the cold water. This quick-dry plush fabric helps the material to dry faster too, so you can be ready for your next session in no time. Double lined neoprene is the neoprene which has fabric lining laminated onto both sides of the neoprene foam.
Single lined neoprene
In contrast to double lined neoprene, there is single lined neoprene. A raw neoprene foam sheet’s surface can be melted on one side with a metal embossing tool. This creates a skin coating to the foam. Single lined neoprene types are also known as mesh, smoothskin or glideskin. Single lined neoprene panels are mainly used on the outside of chest and back panels only. Specifically on cold water surfing wetsuits. High-end winter wetsuits often use a single-lined neoprene chest and back panel such as smoothskin. The smooth outside doesn’t absorb water and helps the water run down the surface immediately. Therefore, protecting your body from windchill, so you can stay in the water longer. Wetsuits that are completely made out of single lined neoprene do exist, but are not commonly used for surfing. However, you might find full single lined wetsuits to be used for open water swimming or triathlon.
Over the past few years, limestone neoprene has become the standard for most high-end wetsuits. However, this doesn’t mean old school petroleum neoprene is gone. It is still used by some brands in mid and entry-level wetsuits. If you can, stay away from petroleum-based neoprene and only use limestone neoprene wetsuits from brands like SRFACE. Our wetsuits are made with the highest grade materials and technologies. This includes the most flexible limestone neoprene foam. The double lined wetsuit panels feature the most flexible (360° limitless stretch) outside lining available. Chest and back panels are made with a smoothskin single lined neoprene outside to avoid windchill. The body panels are lined with a comfortable and heat-retaining quick-dry plush insulating inside lining. The seams are glued and blind stitched with heat-welded neoprene tape on the inside. The outside seams are liquid rubber sealed too. The best wetsuit quality is now affordable.
Read more about SRFACE wetsuit materials here.