December 10, 2020

Principles of filtration

By Jacques Hestres, Joseph Vickers, Antoine Pozniak , Cytiva

Filtration is a science of growing information, distinctive terminology, and proprietary knowledge. These basic concepts have been compiled so that we can establish a common ground with you, our customer, on the basic language of filtration. Over the next few blogs, we will explain some of the fundamental aspects of filtration technology and how they relate to each other and to your application. Then, we will guide you through the logic of selecting a filter media for specific market applications in each market application section. As always, if you have questions about any of these concepts or how they apply to your specific application, please contact us.

Filtration is a process by which particles are removed from a fluid (whether liquid or gas) as it passes through a permeable material. There are various types of filtration including but not limited to conventional dead-end filtration, depth filtration, tangential flow filtration, and ultrafiltration.

Filtration media have many different properties that impact their performance in certain applications. When selecting the best filter media for your application, consider the following important properties:

  • Depth vs. membrane filtration

  • Filter efficiency

  • Hydrophilic vs. hydrophobic

  • Pore size rating

  • Chemical compatibility

  • Flow rate and throughput

  • Extractables

  • Binding

  • Thermal stability

Depth vs. membrane filtration

A depth filter consists of either multiple layers or a single layer of a medium having depth, which captures contaminants within its structure opposed to on the surface.

Advantages:

  • Protects final filters (pre-filter)

  • High throughputs

  • High particulate loading

A membrane filter typically traps contaminants larger than the pore size on the addressed surface of the membrane. Contaminants smaller than the rated pore size may pass through the membrane or may be captured within the membrane by other mechanisms. Membrane filters are typically used for critical applications such as sterilizing and final filtration.

Advantages:

  • Absolute sub-micron pore size ratings possible

  • Bacteria and particle retentive (pore size-dependent)

  • Generally lower extractables

Explore our filtration solutions.

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.