Limestone neoprene has a high micro-cell structure. These are independent closed cells (bubbles basically) within the neoprene that are packed together at an extremely high density. Oil-based neoprene has a cell penetration of 60-70%, whereas limestone neoprene has a 94% cell penetration. What this means in simple terms is that limestone neoprene has a lot more air bubbles inside the rubber than other brands (over 30% to be exact), and is way less dense than oil-based neoprene.
Because of this micro-cell structure, limestone neoprene provides several serious distinct advantages to the functionality of wetsuits compared to the traditional oil-based neoprene:
-It is more impermeable
-It is lighter in weight
-It is warmer
-It is more durable
-It is stretchy
How is limestone neoprene made?
The first stage of production is to make the polychloroprene rubber chips. To do this, extracted limestone is fed into a furnace and heated at a temperature around one-tenth of that used for refining petroleum. The source of the heat is from burning used tires and hydroelectric power sourced from several local dams (any waste heat is then reused to power a local eel nursery). From the furnace, components are reacted with other chemicals to make the acetylene gas needed for the polychloroprene rubber chips.
The polychloroprene rubber chips are then melted and mixed together with foaming agents and black carbon pigments, and then baked in an oven to make it expand. Once this sponge block has cured the next process is to slice it up into sheets. This is like slicing a loaf of bread, except it is slit horizontally and to the desired neoprene thickness. Finally, the soft sheets are laminated with high stretch nylon or polyester jersey knit to give them strength.