Asymmetric filter membranes provide fast and consistent flow rates in applications such as prefiltration and clarification. These membranes are different from conventional microporous membranes in that the larger pores on the upstream side of the membrane acts as a prefilter, capturing larger sized particulate while maintaining throughput and low pressure drop, whereas the absolute rated downstream side, or exclusion zone, acts as an absolute cut off layer. This is in contrast to traditional microporous grades, which have comparable pore sizes on both the upstream and downstream sides of the membrane. The graded nature of asymmetry results in a sidedness to the membrane, requiring knowledge of the upstream side of the membrane for optimal performance in the application.
Here is a high-level comparison of membranes according to these attributes:
| Asymmetric microporous membrane | Conventional microporous membrane | Nominally rated depth membrane | |
| Absolute rated pore size | YES | YES | NO |
| High flow rates per area | YES | NO | NO |
| High particulate loading capacity | YES | NO | YES |
Author bio
Jacques Hestres, Product Manager for Media — Membrane
Focusing primarily on Medical OEM applications. Throughout his over 25 years, Jacques has held various positions in Customer and Technical Service, Operations Planning, and Product Management. This experience has given him the knowledge of the products, the manufacturing processes used to produce these materials, and an understanding of applications where these are used. Jacques holds a Bachelor of Science Degree in Biology from the University of Puerto Rico.
Joseph Vickers, Portfolio Lead — Membrane and Media
A Global Portfolio Leader, responsible for the membranes and media portfolio. He has previous experience in global marketing and operations, holding an MEng in Chemical Engineering from the University of Surrey.
Antoine Pozniak, Product Manager Media — Membrane
Antoine has held various roles in sales and marketing throughout his four-year career in the medical device industry. Throughout those four years he has worked with key opinion leaders and developed commercial and technical knowledge. Antoine holds an MBA from Rice University and Bachelor of Arts/Sciences in Interdisciplinary Social Sciences from the University of South Florida.