With state-of-the-art production equipments and experienced multidisciplinary staff, Etanchal has developed a manufacturing process that is extremely well codified and which reveals acknowledged know-how by all professional fields.

The assembly line, called "universal", is totally automated and includes high-speed blenders with a high sheering rate. The latter are quite efficient for dispersing plastomers and elastomers into bitumen, thus ensuring rapid and appropriate formulation of the compounds of bitumen binders.

Indeed, distilled bitumen heated to a temperature of 190°C is mixed at very high speed to a blend of thermoplastic modifiers (APP) or elastomeric ones (SBS) which are chosen to make single-layer membranes applied by blowtorch without coating.

This process results in producing:

• thin sheets which are cooled with a significant hydraulic cylinders battery ; 
• single-layer membranes which are cooled on a three-stage "bain-marie". 

Various sorts of strong and flexible frames such as fibreglass and/or non woven polyester can then be impregnated and loaded on both sides of the modified bitumen to form a reinforced membrane of 2 to 6 mm.

Finally, a very thin polyethylene foil is stuck on the inner side of the membrane to be flared by a blowtorch whereas the outer side is covered with fine sand and coloured slate granules or self-protected by a corrugated aluminium strip.