Breathability can be described as the moisture vapour transmission rate (MVTR) and it represents the amount of water vapour that passes through a film or a structure over a certain period of time.
Thanks to the process used to produce resins (autoclave reactor), their melt characteristics (high melt strength, low neck-in, high drawability) make them perfectly adapted for extrusion-coating process.
Thus, coating on solid substrates like fabrics or non wovens can be used to make strong flexible membranes and covers.
High polarity and low cristallization rate induce very good bond between Lotryl and substrate (woven or fabric fibers).
Because the breathability of Lotryl is limited, the MVTR of the membrane can be adjusted by blending in an hydrophilic grade .
Blending functional polyolefins with copolyamides is the solution to provide structures with:
Adjustable breathability
Very good processability even at high speed of extrusion
Light weight & soft touch
Good mechanical strength
Good adhesion to non wovens and fabrics
Unlike microporous films, the monolithic structure of blends coated on fabric offers a barrier to water while exhibiting adjustable MVTR making it a material of choice for applications like construction wrapping (housewrap), sport & medical clothing, roofing,fruits and vegetables.
