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<p><span data-sheets-value="{"1":2,"2":"As a result of the manufacturing process, one side of the glass fiber filters is indeed slightly rougher than the other side. This difference does not affect performance and users need not be concerned with filter orientation. The filters will exhibit similar retention and throughput regardless of which surface is facing upstream."}" data-sheets-userformat="{"2":9089,"3":[null,0],"10":0,"11":4,"12":0,"16":8}">As a result of the manufacturing process, one side of the glass fiber filters is indeed slightly rougher than the other side. This difference does not affect performance and users need not be concerned with filter orientation. The filters will exhibit similar retention and throughput regardless of which surface is facing upstream.</span></p>
You can find the current specifications for the Advantec quartz fiber filters at https://www.sterlitech.com/quartz-fiber-filters.html. Click the "Application/Specification" tab near the middle of the page and scroll down as necessary. The QR-100 grade is shown to have a collection efficiency of 99.99% when challenged with 0.3µm dioctyl phthalate (DOP) aerosol particles. Similarly, the QR-200 grade is shown to have collection efficiency of 99.90%. It can be reasoned from these results that either grade has an effective absolute pore size rating of 0.3µm when used to filter air or gases. It should be noted that filtration efficiency, and consequently pore size rating, would be significantly different if used to filter water or liquids.
<p><span data-sheets-value="{"1":2,"2":"To some extent, all glass fiber filters have the potential to shed some fibers.\u00a0 Acrylic resin bonded glass fiber filters typically shed much lower amounts of fibers compared to binderless glass fiber filters.\u00a0 The amounts of shed fibers not only depend on the grades of glass fiber media used but are also influenced by the application conditions.\u00a0 Shed fibers are not typically a concern in applications where the glass fiber filters are used as a prefilters for subsequent membrane filters."}" data-sheets-userformat="{"2":11137,"3":{"1":0},"10":0,"11":4,"12":0,"14":{"1":2,"2":9961472},"16":8}">To some extent, all glass fiber filters have the potential to shed some fibers. Acrylic resin bonded glass fiber filters typically shed much lower amounts of fibers compared to binderless glass fiber filters. The amounts of shed fibers not only depend on the grades of glass fiber media used but are also influenced by the application conditions. Shed fibers are not typically a concern in applications where the glass fiber filters are used as a prefilters for subsequent membrane filters.</span></p>
<p><span data-sheets-value="{"1":2,"2":"Glass Fiber Filters have nominal pore size ratings.\u00a0 These ratings are not necessarily consistent between different manufacturers.\u00a0 Consequently, it is possible for glass fiber filters from different manufacturers to have equivalent retention characteristics while having different nominal pore size ratings."}" data-sheets-userformat="{"2":11137,"3":{"1":0},"10":0,"11":4,"12":0,"14":{"1":2,"2":9961472},"16":8}">Glass Fiber Filters have nominal pore size ratings. These ratings are not necessarily consistent between different manufacturers. Consequently, it is possible for glass fiber filters from different manufacturers to have equivalent retention characteristics while having different nominal pore size ratings.</span></p>
<p><span data-sheets-value="{"1":2,"2":"The smallest available pore size rating for the glass fiber filters is 0.3\u00b5m, as featured by the Advantec Grade GF75 and Sterlitech Grade A glass fiber filters.\u00a0 It is important to note that the glass fiber filters are nominally rated and it should be expected that some amount particles \u22650.3\u00b5m will pass through these filters."}" data-sheets-userformat="{"2":11137,"3":{"1":0},"10":0,"11":4,"12":0,"14":{"1":2,"2":9961472},"16":8}">The smallest available pore size rating for the glass fiber filters is 0.3µm, as featured by the Advantec Grade GF75 and Sterlitech Grade A glass fiber filters. It is important to note that the glass fiber filters are nominally rated and it should be expected that some amount particles ≥0.3µm will pass through these filters.</span></p>
DOP is an abbreviation for dioctyl phthalate, a compound historically used to generate monodisperse aerosol particles for air filter testing and efficiency characterization. DOP aerosols produce particles with a highly uniform size of approximately 0.3 µm, which corresponds to the most penetrating particle size (MPPS) for many air filtration media.
Because of this consistency, DOP aerosol testing has been widely used to evaluate air filter retention and performance, including in standards such as ASTM D2986, Standard Practice for Evaluation of Air Assay Media by the Monodisperse DOP (Dioctyl Phthalate) Smoke Test.
Note: Due to health and safety considerations, DOP has largely been replaced in modern testing by alternative aerosols (such as PAO), but the term “DOP test” is still commonly used in the filtration industry.
The acrylic (PMA) resin binder used in glass fiber filters significantly enhances their wet strength, improving durability during liquid filtration. This resin binder helps hold the glass fibers together, making resin-bonded glass fiber filters easier to handle and more resistant to fiber shedding.
As a result, glass fiber filters with an acrylic (PMA) binder provide more consistent performance and improved integrity in both laboratory and industrial filtration applications. When assessing chemical compatibility and application suitability, it is important to consider the presence of the acrylic (PMA) resin binder.
Glass fiber filters offer excellent thermal stability and can operate at high temperatures, making them suitable for demanding laboratory and industrial applications. They are particularly economical and effective as pre-filters, where they help extend the life of final membrane filters by capturing larger particles and high particulate loads.
Due to their high dirt-holding capacity and fast flow rates, glass fiber filters are commonly used in air and liquid filtration, sample clarification, and analytical applications. Their combination of high-temperature resistance, cost-effectiveness, and reliable pre-filtration performance makes glass fiber filter media a versatile choice across many filtration processes.
