PolyPure: Woven and Knitted Reinforced Tubular Support

Beside the structural strength, it is important that the textile supporting material is not causing geometrical deformations while spinning the membrane fibers. Indeed, if the textile tubular support is not cylindrical or having defects on its surface, it may cause the final membrane fiber being oval or having irregular thickness along the circumference. Additionally, the support shall not have filament breakages that protrudes from the outer surface that can lead to “pinholes” causing filtration defects along the membrane fiber.

There are many factors that shall be considered while selecting the correct membrane support material. Inner and outer diameter, material structure, whether braided or knitted, support rigidity, type of filaments and other paraments shall be evaluated. PolyPure® offers a variety of diameters and structures that is suitable theoretically to any tubular membrane production. In terms of diameter the minimal size offered goes down to 1.0mm and a maximum diameter up to 10mm.

PolyPure® is a textile support compatible with most of the coating material. It can be widely used for wet spinning processes during the production of membrane fibers. Different mesh densities can be selected according to the dope solution. For lower flux resistance, it is however advisable to have lower mesh densities to allow permeates flowing easily through the tubular support’s wall.

PolyPure® -braid it is manufactured on braiding machines, where multiple yarns are intertwined each other creating the tubular shape. The yarns create a strong structure on which the membrane layer can be applied on, with very low elongation rate.

PolyPure® -knit is a tubular support created on knitting machines, where the yarn turns around the knitted head and generates interconnected spirals. The density is dictated by the pitch of the spiral.