Lotryl®, Providing Competitive Solutions for Breathable Membranes

June 2020

The building industry always explores competitive and cost-effective solutions to protect constructions from moisture and prevent deterioration, health hazards and premature aging. Such concerns can easily explain why Housewrap and Roofing Underlayment has gained notoriety and interest in the last decades. Indeed, this membrane technologies prevent water infiltration in buildings (walls and roofs) while allowing vapour moisture to escape from the inside to the outside.

Several range of breathable membranes are currently available on the market. Among the different solutions, monolithic membranes made of polar copolymers coated onto fabrics gather many advantages: Adjustable moisture vapour transmission rate (MVTR) by tuning the polymeric composition and the coating thickness, long shelf life and sustainability, excellent liquid and odour barrier, high tear resistance, etc…

That is why SK Functional Polymer has designed a full range of LOTRYL® copolymer resins to answer the Housewrap and Roofing Underlayment market needs regarding breathable performances, suitable mechanical properties and cost-efficiency. Breathable LOTRYL® copolymer resins can be extruded into thin films by extrusion coating or extrusion blown process. Their excellent melt strength allows a good productivity contributing to the cost-efficiency of the end products.

Regarding breathable properties, pure LOTRYL® 28MA07 exhibits an MVTR of 106 g/m2.24h (ASTM E96 Method A (23 °C, 50% HR)) when extruded in a 15 µm film. That is why high acrylate content LOTRYL® 28MA07 and LOTRYL® 29MA03 have proved their effectiveness in the construction membranes where none of copolyesters and copolyamides were able to reach required breathable performances