Depth vs Membrane Filter
Updated: Oct 20, 2020
If you're in an industry which requires liquid filtration, you've probable heard of both Depth and Membrane filters. But what's the difference between them?
A Depth filter uses "depth" to trap and hold particles within the filter media. It consists of using filter media with either multiple layers, or a single layer with random structures that have smaller pore sizes towards the core, as shown in the diagram of a Melt Blown Depth Filter below.
Depth filters pose the added advantage that they are able to attain a high quantity of particles without compromising the separation efficiency. This means it has a high "dirt" or particle holding capacity. In fact, it becomes more efficient in blocking dirt as more particles are trapped within, reducing the pore size even further.
The tortuous path is suitable for capturing wide range of particle sizes and gelatinous contaminant. They typically have a nominal retention rating. Examples of a depth filters are the Melt Blown and String Wound Filters.
Membrane filters are also know as Surface filters as they trap contaminants larger than the pore size on the surface of the membrane. It functions like a sieve to separate large particles while allowing smaller particles to pass through. Unlike the depth filter, membrane filters have a uniform structure.
Membrane filters have a low dirt holding capacity and a higher choke rate. They usually have absolute retention rating and are typically used for the precise removal of contaminants including vent filters, bacterial filters, as well as end-stage wine filters and beer filters. They are also used in critical applications such as sterilizing. See our range of Depth Filters and Membrane Filters here. Not sure which product can match your current needs? Drop us an email with the product specifications and we will get back to you with the recommended product(s).